Adams, W.M., 1974, First strong-motion instrumentation in Hawaii: with results from the earthquake of April 26, 1973: Bulletin of the Seismological Society of America, v. 64, no. 6, p. 1909-1918. 



 On April 26, 1973, an earthquake with magnitude of 61/4 occurred at a depth of 40 km below Honomu (north of Hilo). Serendipitously, in the preceding February, one SMA-1 accelerograph and one Wilmot seismoscope were installed near Waikiki on the island of Oahu. Also, one SMA-1 accelerograph and three Wilmot seismoscopes were installed on the island of Hawaii. The records from these instruments provided the first strong-motion data for the State of Hawaii. The motion was dominantly horizontal. This finding explains the extensive damage to the Hilo area, reported to be about 6 million dollars.



Agassiz, A., 1889, The coral reefs of the Hawaiian Islands: Harvard College Museum of Comparative Zoology Bulletin, v. 17, no. 3, p. 121-170. 



 Agassiz gives a thorough review of previous ideas of coral reef formation in the Pacific, beginning with observations by Chamisso on Kotzubue's voyage of 1821 (Kotzubue, 1821, v. 3, p. 331). Few of the early references, including Chamisso, mention Hawaii but provide background information for evaluating the formation of reefs in the Hawaiian islands. Agassiz' purpose in providing background is to demonstrate alternatives to Darwin's (1842) theory of subsidence. Beginning on p. 144, Agassiz describes his own observations on the Hawaiian Islands while summarizing the work of others. He notes the different kinds of coral rock, i.e., compact reef rock, "pudding-stone" (volcanic beach pebbles cemented by calcium carbonate), and coral sands. He gives data for wells that have penetrated coral and describes charred wood recovered from one well as evidence of material washed down from shore and not necessarily as evidence for subsidence. He then describes alternation of coral and lava in the drill holes as indicating " . . . the gradual extension seaward of the shore line as fast as lava detritus was washed down or flowed over from successive eruptions, while the growth of the layers of coral indicates the period of rest during which the coral beds were deposited, each in its own turn being overwhelmed by a layer of lava or laval detritus, until we reach the existing condition of things." He concludes that, from the evidence of coral deposition, "there appears to be no evidence that there has been any considerable elevation of the Hawaiian islands, twenty to twenty-five feet being probably the extreme; while the presence of cinder cones with their base close to the present sea level would indicate also that there had been no special subsidence." He continues "there have yet been no sunken reefs discovered in any of the channels between the islands . . .". [Agassiz, as others, were hampered by lack of bathymetric data which later (e.g., Moore, 1970) revealed the existence of submerged reef terraces as definite evidence of subsidence. Agassiz also appears not to have recognized the possibility of changes in sea level as an alternative to uplift to explain the emergent reef deposits.]

 Agassiz does, however, recognize subsidence of the coastline at Kalapana and Kaimu on the island of Hawaii, illustrated by a photograph entitled "the sunken coral sand beach at Kaimu." [This plate depicts the effects of the 1868 earthquake and accompanying land subsidence and tsunami. the foreground shows drowned palm trees, broken off near the water's surface. On the beach, the lower trunks of palm trees stand at a 45-degree angle to the horizontal, indicating that the local tsunami arrived from the east (opposite to the direction toward the earthquake epicenter but similar to present surf patterns), whereas the upper parts of the palms are vertical, perhaps recording growth between 1868 and the date of the photograph (unknown, but earlier than 1889). The raised coral reef described by Brigham (1868) was mostly lost in the subsidence accompanying the earthquake. It is possible that destruction of the reef contributed enough coral detritus to temporarily convert what had been a black sand beach (from 18th century eruptions from Kilauea's east rift zone entering the ocean to the east) into a beach white enough to be designated a coral sand beach.]

 Agassiz describes coral formations on islands other than Oahu, including a patch of elevated coral on the edge of the sunken plain of Kalapana. [This is no longer visible; whether its disapearance is due to erosion or further subsidence is not clear]. On Maui, he interprets the occurrence of coral sands 500-800 above sea level on West Maui volcano as follows: "The existence of coral sandstone on the east slope of West Maui at a considerable height, over extensive tracts, does not indicate any elevation, but is due merely to the aeolian deposits which have found their way to certain favorably situated places under the action of the prevailing trade winds. Nowhere in the district I have examined on Maui have I succeeded in finding any trace of corals beyond the height to which fragments might be carried by the action of the waves or wind and tides of unusually severe storms. The bedding of the sandstones at considerable heights was evidently entirely due, as has been shown by Dana, to the successive deposits of sand cemented together by interrupted rain fall, forming the delicate crusts which separate the various thin layers of coral sandstone which have accumulated at certain points." He similarly interprets the elevated deposits of 200 feet on one side of Diamond Head and near Wailuku, Maui.



Alexander, W.D., and Graton, L.C., 1871, On the earthquake at Oahu, Hawaiian Islands on February 18, 1871: American Journal of Science, 3rd ser., v. 1, p. 469-471. 



 Alexander describes an earthquake on Feb. 18, 1871, as the strongest ever experienced on Oahu, being as strong on Oahu as on Hawaii, and felt most seriously at Lahaina, Maui. The shock lasted about a minute, with the motion "chiefly vertical with a rocking movement northeast and southwest." The earthquake was accompanied by a flash of light. At Lahaina damage was severe, the ground cracked open in many places, and the direction of vibration was south to north. The shock was less severe on the east side of west Maui but quite severe on Molokai and was felt on the south side of Kauai. On the west and north coasts of Hawaii, the shock knocked down stone walls with the impetus coming from the west. He guesses that the shock was centered leeward of the island chain at a great depth. [Wyss and Koyanagi (1992) locate the epicenter on the island of Maui and assign it a depth of less than 15 km.]



Alexander, W.D., 1886, Map of the island of Hawaii, Hawaiian Islands (preliminary ed.): Honolulu, Hawaii Government Survey, scale 1:240,000. [Map by W.A. Wall; Primary triangulation by W.D. Alexander, C.J. Lyons, and J.S. Emerson; Kau and Puna surveys not completed] 



 This map, in shaded relief, is the only map of the Island of Hawaii published in the 19th century. The map's importance lies in the identification of the fractures produced on Kilauea by the 1868 earthquake. [The fractures follow Kilauea's southwest rift zone, then turn seaward along the onshore trace of a submarine structure identified by bathymetric surveys conducted in the 1990s.] Lava flows on the southeast side of the island are mismapped.



Alexander, W.D., 1891, A brief history of the Hawaiian people: New York, American Book Co., 347 p. [Pages 14-15, 131, 151, 222-223, 231-232, 287, 292-294, 305-306 contain references to the active volcanoes. Reprinted in 1899] 



 A general description of the Hawaiian Islands and brief accounts of the 1790 eruption of Kilauea; the 1801 eruption of Hualalai; the tsunamis of 1819, 1837, 1841, 1868, and 1877; the Kilauea eruption of 1840; and the Mauna Loa eruptions of 1855, 1859, 1868, 1880, and 1887. The paper includes an excellent drawing from a photograph of Kilauea Crater in 1885 and a brief description of the Kilauea earthquake swarm of 1886.



Algermissen, S.T., 1986, Seismicity and design zonation in Hawaii, in, EERI Regional Seminar on Earthquake Fundamentals, Honolulu, HI, Oct. 16-17, 1986, Outline of lecture: [s.l.], s.n.], 33 p. 



 Introduction

Hawaii has a known history (since 1834) of moderate seismic activity with a number of shocks causing damage in the intensity VII-VIII range. The seismicity appears to be related to the well known volcanic activity of the islands in a complex and as yet not completely understood way. The purpose of this presentation is to present a discussion of the seismicity and suggest techniques for the definition of seismic hazard. An outline of the presentation follows together with illustrations and selected references.

Seismicity

Characteristics of earthquakes

 Spatial distribution

 Depths

 Focal mechanism of a large earthquake

 Maximum magnitudes

Description of the seismic hazard

 Observed Modified Mercalli Intensity (MMI)

 Strong ground motion

 Probabilistic hazard analysis

An example of a probabilistic hazard assessment

 Concept of probabilistic hazard assessment

Probabilistic hazard Analysis for Hawaii Sesimic source zones

 Magnitude distribution of earthquakes

 Maximum and minimum magnitudes

 Atenuation

 Probabilistic acceleration map

Discussion

 The acceleration map

 Seismicity

 Attenuation

References



Anderson, R., 1870, History of the Sandwich Islands mission: Boston, Congregational Publishing Society, 408 p. 



 Anderson briefly refers (p. 307-309) to the events of 1868, quoting from Titus Coan. He also recounts (p. 187-190) Queen Kapiolani's defiance of Pele in 1825



Ando, M., 1976, A source model of the M = 7.2 Kalapana earthquake of November 29, 1975 [abs.]: Eos, Transactions, American Geophysical Union, v. 57, no. 12, p. 954. [AGU fall meeting, San Francisco, CA, Dec. 6-10, 1976, Program and abstracts] 



 Seismic wave, tsunami, and crustal deformation data were used to study the Kalapana earthquake. The source process can be divided into three stages: 1) During the first 2O seconds, a small event occurred close to the largest foreshock. The fault plane is taken with a dip direction of N15OE and dip of 10, the hanging wall side down to the south. The seismic moment is about one-tenth of the next stage. 2) Thirty to 40 seconds after the onset, a large rupture started west of the epicenter. The 100-sec seismic moment is 1.2 x 1027 dyne cm. The radiation pattern is quite similar to that expected from the body wave first motions. Thus, the two events may lie on the same fault plane. However, the fault area required to generate the surface waves was larger than the aftershock area (5 x 40 km2). 3) A large slow slip must have occurred beneath the ocean at the time of earthquake though the exact onset time is unclear. Subsidence on the coast and uplift offshore derived from tide gage records show that normal faulting took place to the south of aftershock area. A 10 m dislocation and 3O x 40 km2 fault plane area are required to explain these data if this slow slip occurred on the same plane. This earthquake might have been accompanied by injection of a huge volume of magma accumulated beneath Kilauea since the last large earthquake of 1868.



Ando, M., 1979, The Hawaii earthquake of November 29, 1975: low dip angle faulting due to forceful injection of magma: Journal of Geophysical Research, v. 84, no. B13, p. 7616-7626. 



 The mechanism of the Hawaii earthquake of November 29, 1975 (Ms = 7.1), which took place on the south flank of Kilauea Volcano, is discussed on the basis of a comprehensive set of body wave and surface wave data, the aftershock distribution, and tsunami and crustal deformation data. The aftershock distribution defines a gently dipping plane at about 10-km depth beneath the south flank of Kilauea. This suggests that the shallowly dipping P wave nodal plane fits the fault of the Hawaii earthquake better than the nodal plane that has a nearly vertical dip angle. The fault length is fixed well by the aftershock distribution, which is also consistent with the tsunami and crustal deformation data. The fault width which is obtained from tsunami and crustal deformation data is, however, significantly greater than that obtained from the aftershock distribution. This discrepancy implies that about half of the main shock fault plane was not associated with aftershock activity. The source parameters are strike N70E; dip angle 20SSE; fault length 40 km; seismic moment 1.8 x 1027 dyne-cm; fault width 20-30 km; fault movement is pure normal dip slip of 3.7-5.5 m, and stress drop is 43-93 bars. Results of geodetic surveys throughout the twentieth century and a history of volcanic activity on Kilauea imply that a north-south compression due to magma injected into rift zones may have steadily increased on the south flank of Kilauea since the 1868 earthquake, an event comparable to the 1975 shock. This compressional stress was possibly released by the 1975 Hawaii earthquake. The long-term eruptive activity of Kilauea may be affected by large earthquakes like the 1868 and 1975 events and may also have a similar 100-yr recurrence interval.



Ando, M., 1979, Large earthquakes and a cycle of eruptions at Kilauea Volcano, Hawaii [abs.], in Decker, R.W., Drake, C., Eaton, G., and Helsley, C., ed(s)., Hawaii Symposium on Intraplate Volcanism and Submarine Volcanism, Hilo, HI, July 16-22, 1979, Abstract volume: Hawaii National Park, HI, U.S. Geological Survey, Hawaiian Volcano Observatory, p. 155. 



 On November 29, 1975, an earthquake (MS=7.1) occurred on the south flank of Kilauea volcano, resembling the 1868 event in its pattern of tsunami heights, crustal deformation and seismic intensity. A study of the mechanism based on a comprehensive data set of body and surface waves, aftershock distribution, tsunami and crustal deformation produced a well-defined source model as a normal fault with a gentle dip angle. The fault parameters are: dip angle, 20 down to SSE; fault strike, N70E; focal depth, 10 km; fault area, 20 x 40 km2; normal fault component of displacement, 6 m. This earthquake was characterized by a southward movement of the south flank along a nearly horizontal plane, consistent with the movement anticipated from the accumulation of preseismic strain on the south flank. The nature and timing of magma intrusion and seismic events suggest a model of the south flank in which the fault plane of 1975 plays an important role as a horizontal bottom sliding plane. Magma is intruded forcefully into the rift zones and pushes the flank southward while the fault plane is locked against shear displacement (Fig la). When the stress exceeds a threshold, the lock is released and a sudden slip occurs on the fault plane to cause a large earthquake (Fig lb). By means of this earthquake the strain accumulation cycle is completed on the south flank. The same intrusive process starts again at a later time with the location of the south flank several meters south of its previous position. Thus, the south flank intermittently moves southward (Fig lc) at an interval of about 100 years associated with a large earthquake. The long quiescence of eruptions after the 1868 and an unusual postseismic deflation at the summit of Kilauea immediately after the 1975 earthquake suggest that confining pressure in the magma reservoir does not control the rate of magma supply from the mantle. If it did, the low confining pressure in the reservoir would have allowed magma to flow freely from the mantle to the reservoir and fill the voids left by large earthquakes, so that eruptions would have begun. Perhaps the rate of magma supply is related to the mantle processes, but independent of movements in the crust. This rate seems steady as inferred by the steady rate of crustal deformation due to magma injection on the south flank over the last 70 years. Assuming the steady rate of magma supply, we can anticipate that Kilauea will be generally quiescent for 20 to 30 years for large eruptions.



Andrews, C., 1907, Experiences at flow by one of Waiohinu party: Honolulu Evening Bulletin, 01/31, p. 3. 



 Waiohinu, Kau, Hawaii, Jan. 16

Description of the eruption from Mauna Loa's southwest rift zone.

 . . .

 "Last Friday morning, the 11th inst., shocks of a rotary motion were felt at almost regular intervals. The day before, several thumps were likewise felt. These shocks, on account of their rotary motion and frequency, caused us evil forebodings. They were the harbinger of trouble. The sequel will show that our prognostications were correct. Were these shocks caused by Madam Pele's fiery train rushing through the bowels of the earth, in a subterranean passage, from her impossible pavilion at Kilauea, to her winter resort at Mokuaweoweo? At any rate, the quakes ceased, all but one more vicious thump which apparently forced an opening through the lower wall of Mokuaweoweo.



Anonymous, 1840, [no title]: The Polynesian, v. 1, no. 15, 09/19, p. 59. [Extract from a letter dated Hilo, Aug. 26, 1840] 



 The correspondent describes the spot where lava [from the 1840 eruption] first broke out. "It is about six miles from Kilauea [crater]. After running two miles above ground, it again disappears, and flows in a subterranean channel at a great depth below the surface; its course being marked by seams and deep fissures in the earth's surface, and by the emission of smoke and gasses. About twenty miles from the sea it breaks out again, in a terrific sea of fire, and rolls on above the surface to the ocean. The whole length of the stream may be thirty-five miles; more than one third of which is under ground."

 He closes by describing Kilauea crater. Everything is new compared to before the eruption. the caldron is one great sea of fire, much as it was described in the week before the eruption.



Anonymous, 1841, [no title]: The Polynesian, v. 1, no. 36, 02/13, p. 143. 



 A description Dr. Judd's escape from active lava, on a specimen-collecting trip to Halemaumau lava lake.



Anonymous, 1841, More earthquakes: The Polynesian, v. 1, no. 42, 03/27, p. 167. 



 On the 11th inst. two earthquakes were felt at Kailua, Hawaii--the first shock occurred 15 minutes before 10 o'clock, P.M. The second about half an hour later. Rev. Mr. Thurston states that they were the strongest that he has ever felt there. At Kealakekua much rock was thrown down from the pali. When these occurred, an unusual light was observed in the direction of the volcano.



Anonymous, 1841, Earthquakes at Hilo, Hawaii: The Polynesian, v. 1, no. 49, 05/15, p. 195. 



 Last month several shocks were experienced at Hilo--one of which was the most severe that has happened for a long time. It occurred about midnight--and shook the houses violently, shattered the plastering, threw down stone walls, created quite an excitement among the crockery and all brittle ware, splashed about the milk in the milk-pans, and many like vagaries and eccentricities, to the alarm of the inhabitants. As an instance of the severity of the shock, it fairly waked all the native population; a circumstance heretofore unknown in the annals of earthquakes at Hilo. Had the houses been constructed of less yielding materials, they would have experienced much injury.



Anonymous, 1841, Another earthquake, and knocking at our barn doors: The Polynesian, v. 1, no. 50, 05/22, p. ? 



 On Monday night last, between 12 and 1 o'clock [May 18 A.M.], a shock was experienced here of sufficient violence to shake a house and awake its inmates.



Anonymous, 1852, [no title]: The Polynesian, v. 8, no. 44, 03/13, p. 2. 



 Further accounts of the eruption, as it broke out on the side of Mauna Loa, from several correspondents, including Fidelia Coan. No date or time of the initial outbreak is given. Most information concerns progress of the lava down the mountainside.



Anonymous, 1852, The late eruption: The Polynesian, v. 8, no. 45, 03/20, p. 2. 



 An account from a resident in Hilo of the breakout of eruption in Mokuaweoweo on Feb. 18 and on the side of the mountain on Feb. 20. Fountains at the summit were estimated to be 300-500 ft high. The last entry date is March 2nd. Hilo is covered in Pele's hair; the length of one strand was measured at 26 inches. [signature obscured]



Anonymous, 1852, The late eruption: The Polynesian, v. 8, no. 46, 03/27, p. 3. 



 Activity in the crater has greatly abated and lava has ceased to flow, after reaching within seven miles of Hilo.



Anonymous, 1855, [no title]: The Polynesian, v. 12, no. 63, 08/25, p. 2. 



 The eruption began on the evening of August 11 in Mokuaweoweo and was on the northeast rift by Aug. 14. "On the 15th August, at near 12 noon, another eruption was witnessed on the plain about equi-distant from Mauna Loa and Mauna Kea, and at a point where one was never before known." [This is most likely a breakout from the channel of the earlier eruption.]



Anonymous, 1857, The earthquake on Hawaii: Pacific Commercial Advertiser, 08/13, p. 2. 



 Our letters by the Liholiho came to hand too late for insertion in our last issue. The shock it seems, was one of the most severe that has been felt there for years. We will make an inquiry or two which some of our Hilo friends can answer perhaps. Are there any special changes observed to follow these severe shocks, in the crater of Kilauea, or do new eruptions take place after very severe earthquakes? In regard to the shock on the 30th of July, Mr. Wm. F. Conway writes: "A few minutes past one o'clock this morning, the people of Hilo and of the surrounding districts were suddenly aroused from their usually quiet slumber by a very heavy quake of the earth which lasted for several seconds and was felt more severely than any we have had on this side of the island for a number of years past: during my residence on the island of nearly five years, I have not experienced its equal. No damage however was done though it created a little fright to those who had not previously experienced the effects of a heavy shock. The undulation of the earth was from west to east. You can tell our neighbors on the other islands not to feel alarmed for their safety; for we say here, as schoolboys say when skating on the ice, 'all's right so long as she cracks.'"



Anonymous, 1858, Earthquake at East Maui: Pacific Commercial Advertiser, 08/05, p. 2. 



 On Sunday, July 25th, quite a smart shock of an earthquake was experienced in the districts of Hana and Koolau, East Maui. Dishes clattered, and furniture sensibly vibrated. It was not noticed in other parts of Maui, nor at Kohala. Is Haleakala getting uneasy?



Anonymous, 1859, Earthquake: Pacific Commercial Advertiser, 11/24, p. 2. 



 A severe shock of an earthquake occurred on Monday morning last, at 25 minutes past two o'clock, A.M., which lasted but a few seconds. It was felt by several persons, who were aroused by it. A gentleman who was awake at the time, says that the sensation felt was very similar to a person taking hold of another by the shoulders and shaking him suddenly. His native cook was aroused by it, and rushed into the house to inquire the cause. It is very seldom that an earthquake occurs on this island. We would like to have our correspondents at Hilo inform us, if any shock occurred there about that time.



Anonymous, 1859, The earthquake at Waimea: Pacific Commercial Advertiser, 12/15, p. 2. [Communication dated Waimea, Hawaii, Dec. 4, 1859] 



 Noticing in your issue of Nov. 24 an account of the earthquake, and its being felt on the island of Oahu, perhaps you would like to know if Waimea is still above water. The shock was felt here about three o'clock on the morning of Monday, the 1st of November, and lasted about 10 seconds. It was preceded by a heavy rumbling sound, like distant thunder, which lasted about the same length of time. Nor was that all: about a half an hour after we felt another, not quite so severe, but it made the tree tops tremble. As there was no wind, we could hear the leaves shake over the house. The bed on which I slept shook like a man with the fever and ague. It made some of the natives commence saying their prayers, and the truth is, Mr. Editor, I felt something like it myself.



Anonymous, 1860, From Hilo: Pacific Commercial Advertiser, 06/14, p. 2. 



 "A correspondent writes under the date of June 7: 'On the 1st of June, at 3 o'clock A.M., we had a quite severe shock of an earthquake. It awoke persons out of a sound sleep, and lasted about two minutes.'"



Anonymous, 1861, Getting shaky: Pacific Commercial Advertiser, 06/13, p. 2. 



 From Hawaii, we hear that three earthquakes have recently occurred on that island, showing that Madam Pele is getting up steam again, and will probably erupt herself shortly. The old dame manages to become uneasy and make a display of fireworks about every three or four years; and as it is now two and half years since the last eruption broke out, we should not be surprised to hear of another soon. . . . .



Anonymous, 1861, Earthquake: The Polynesian, 12/07, [no page]. 



 On Thursday forenoon, at 10 minutes to 12 o'clock the good people of Honolulu were not a little startled by two distinct shocks of an earthquake. The first shock was apparently perpendicular with a tremendous crash, with a perfectly sensible, though perhaps not visible lifting up and down of buildings and houses. This was followed by a heavy rumbling sound, as of the rolling of large casks of old iron over a pavement, and a horizontal, wavy motion proceeding from east to west. Window panes glassware and crockery shook as if the town had been bombarded, and in several places the plaster fell from the ceilings of houses. People rushed from their buildings into the street and - we presume, thanked God that no damage was done. Although shocks of earthquake are a common occurrence in Hawaii, yet for very many years none has been felt on Oahu at all comparable to the present in strength and duration.

 

Anonymous, 1861, Severe earthquake: Pacific Commercial Advertiser, 12/12, p. 2. 



 A heavy earthquake occurred on Thursday last, at 11 minutes before 12 M. Two distinct shocks were felt, and so severe were they, that everybody experienced them, whether walking, standing or sitting. In several instances it threw persons quite from their balance; and more probably experienced sensations of astonishment or fright. Nearly every house was shaken, in some cases so strongly as to cause the inmates to leave the building. At Punahou College, the plaster of the ceiling was shaken down, and the pupils ran out of doors. The same scene, so far as the stampede was concerned, occurred at the courthouse, where a suit was in progress in Chambers. The quake was accompanied by a noise resembling that of a dray driven over the roof, or the rolling of casks over head. The shock was felt at Lahaina, and was so severe, that ink was spilled out of an inkstand on a table. We cannot learn that it was noticed at Hilo or anywhere on Hawaii.

 It is very seldom that earthquakes have been felt on this island, though they are of frequent occurrence on Hawaii. The cause is probably that Oahu is more remote from the seat of activity of the volcanic fires beneath us. Twice, however, during the last twenty years, this island has been visited by tidal waves, which are probably attributable to volcanic eruptions--once about the year 1842 at Honolulu, and again about the year 1851 at Waialua.



Anonymous, 1861, [no title]: Pacific Commercial Advertiser, 12/12, [no page]. 



 [quotations from Cox, 1986]

The time of the first shock was given as 11 minutes before noon. 

 Nearly everyone in Honolulu "whether walking, standing or sitting" was reported to have felt the earthquake and "in several instances it threw persons quite from their balance. "Punahou College" was cited as a place where ceiling plaster was shaken down; and the exodus from buildings was attributed to students at Punahou and the occupants of the courthouse (downtown).

 The shock was felt at Lahaina, and so severe that the ink was shaken out of inkstand on a table. We cannot learn that it was noticed at Hilo or any where on Hawaii.



Anonymous, 1861, Another earthquake: Pacific Commercial Advertiser, 12/26, p. 2. 



 On Sunday evening last, at about 21 minutes past seven o'clock, another severe shock was felt all over this island (Oahu). It consisted of ten or twelve very regular vibrations from East to West, and was felt equally plain by those sitting or walking. It was accompanied by a noise more distant than that which accompanied the shock of the 12th. some persons felt an electric sensation in the knees, In the harbor the effect of the quake was most noticeable. Some persons standing at the harbor-master's office, observed the fishes suddenly flying on the surface toward the sea, while the water disturbed by the fish, appeared like a sheet of phosphorous. The schooners lying by the wharves were also set to rocking. These earthquakes are something new to Honolulu, and the query suggested by our Maui correspondent below is not inappropriate--"Are we going under?"



Anonymous, 1861, [no title]: Pacific Commercial Advertiser, 12/26, [no page]. 



 ANOTHER EARTHQUAKE-On Sunday evening last, at about 21 minutes past seven o'clock, another severe shock was felt all over this island (Oahu). It consisted of ten or twelve regular vibrations from east to west, and was felt equally plainly by those sitting or walking. It was accompanied by a noise more distant than that which accompanied the shock of the 12th [sic]. Some persons felt an electric sensation in the knees.- In the harbor the effect of the quake was most noticeable. Some persons standing at the harbormaster's office, observed the fishes flying on the surface toward the sea, while the water disturbed by the fish, appeared like a sheet of phosphorus. The schooners lying by the wharves were also set to rocking. These earthquakes are something new to Honolulu, and the query suggested by our Maui correspondent below us not inappropriate-"Are we going under."

STILL ANOTHER EARTHQUAKE-the correspondent on Maui (at Ulupalakua), gives the time of the earthquake as "twenty minutes before 5 o'clock; it was said to have awakened "all hands" and it was described as if more intense than the "shake of the previous Thursday."



Anonymous, 1861, Earthquake: The Polynesian, 12/28, [no page]. 



 [Quotes from Cox, 1986]

The time of this second earthquake [Dec. 15] in Honolulu was given as "about 8:00 o'clock," the direction of its motion there was reported as "apparently the same as that on the previous occasion (December 12) [sic], from east to west," and the water in Honolulu Harbor was described as having "bubled [sic] up and down, like in a state of boiling."

 Earthquakes were reported in the newspapers as observed on Oahu, Maui, or both, on Thursday. 5 December; on Thursday, 12 December; and at two significantly different times on Sunday, 15 December. It is, however, very doubtful that any earthquake was felt on Oahu with significant intensity on 12 December, although one may have been observed on Maui on that date. If three quakes had been observed on Maui, it is somewhat unlikely that the Ulupalakua correspondent to the Advertiser would have mentioned the second but failed to mention the first (which had been felt at least at Lahaina) in his or her report on the third. If three quakes had been observed on Oahu, it is much more unlikely that either newspaper would have mentioned the second but failed to have mentioned the first (which had clearly had a high intensity on Oahu) in its report on the third. Furthermore, the Polynesian issue of 14 December made no mention of a quake occurring two days earlier.

 

Anonymous, 1862, [no title]: Pacific Commercial Advertiser, 01/02, p. 2. 



 The earthquake was felt on Hawaii on Sunday night [12/29-30/1861], but the heaviest shocks were noticed on the following morning, which were unusually severe, even for that island, where they are of frequent occurrence.



Anonymous, 1862, From Kona: Pacific Commercial Advertiser, 01/30, p. 2. 



 . . . . There have been several severe shocks of earthquake felt on the Kona side of Hawaii during the past month, auguring more than usual activity in the volcano. . . .



Anonymous, 1862, Notes of the week; the "shakes" on the increase: Pacific Commercial Advertiser, 02/06, p. 2. 



 Almost every letter we receive from Maui and Hawaii, makes reference to frequent earthquakes, some much heavier than others. On the morning of the 29th January (one letter says the 29th another the 30th,) a few minutes after 5 o'clock, a very severe shock was felt--so heavy as to wake up all who were asleep, and set doors, windows, lamps, crockery, &c., into an unusual nervous state. One correspondent, writing from Maui, says:

 " . . . . , the supply of earthquakes is fully up to demand. A fine sample was offered at 5 A.M. this morning, and there was a lively time among the spectators for about 20 seconds, which was met with a corresponding briskness among the lamps and crockery. . . . 

 . . . Another correspondent writing from Makawao, (Jan. 30,) says:

 "At 5 o'clock this morning, we were pretty thoroughly shaken up by an earthquake. I had risen and was striking a light, so that I fully realized the movement. . . .



Anonymous, 1863, [no title]: Pacific Commercial Advertiser, 12/03, p. 2. 



 An unusually severe shock of occurred at Hilo, about 4 o'clock on the morning of the 26th--the heaviest that has been experienced there for many years.



Anonymous, 1865, Earthquake: Pacific Commercial Advertiser, 03/04, p. 2. 



 On Friday morning, March 3rd, about fifteen minutes before one o'clock, a very severe shock of an earthquake was felt, many being waked out of a sound sleep by it. It appears to have been accompanied by a noise like that of persons tramping heavily over the floor. The frame dwelling we occupy was shaken very sensibly. It continued an unusually long period, and the motion was heaving up and down, rather than sideways as it generally is. No fear of any serious accident from earthquakes on this island need ever be entertained; and their occurrence only indicates increased activity in the volcanic fires under Hawaii. It is possible a new eruption may take place there soon. We should request our readers on Hawaii to advise us of anything of the kind occurring there, with dates and full particulars.



Anonymous, 1865, [no title]: Pacific Commercial Advertiser, 03/11, p. 2. 



 The earthquake noticed in our last issue, was felt on Maui, more distinctly than on this island. Many of the people were waked up by it. On Hawaii it was very severe. Mr. Paris writes, under the date of March 8--"On Thursday night, the 2nd inst. about half past 12 o'clock, we had the hardest shake of earthquake I have experienced in 25 years. The plastering of our house is much damaged, and a great deal of stone wall in this region damaged."

![where was Mr. Paris?-call mission library]



Anonymous, 1868, Earthquake: Hawaiian Gazette, v. 4, no. 38, 10/07, p. 3. 



 On Thursday last, there was a smart shock of earthquake at Kawaihae, Hawaii, that started everybody out of their houses. At Hilo, on the 22nd ult., the atmosphere was loaded with smoke, and frequent slight shocks of earthquakes were felt. . . .



Anonymous, 1868, Earthquakes and eruptions on Hawaii: The Friend, May, p. 33. 



 A brief account of the earthquakes and the Mauna Loa southwest rift eruption.

 

Anonymous, 1868, Direction of the earthquakes: The Friend, May, p. 36. 



 "Mr. Rexford Hitchcock, of Hilo, informs us that [during the earthquake of April 2, 1868] stone walls running due north and south were not so much thrown down and demolished as walls running in the opposite direction. After the great shock on the 2d of April, curtains and other things suspended in the dwellings at Hilo were left swinging north and south. 

 Culmination, April 2d--Although the number of shocks have exceeded two thousand, yet all accounts agree on the point that the severest was experienced April 2d, six minutes before four o'clock, P.M. This was the moment when the 'mud flow' issued forth, when the whole Islands shook and trembled, when the clocks stopped in Honolulu, when the tidal wave swept over the southeast shore of Hawaii, when Capt. Ludlow, off Hamakua, Hawaii, saw the precipices tumble into the sea, when the most damage was done at Hilo, Kau, and other places on Hawaii."

 The author quotes Brigham, to the effect that earthquake precursors to eruption were previously unknown. The earthquakes took place in 1868 only because the lava could not find a vent higher on the slope.

 

Anonymous, 1868, The mud flow: The Friend, May, p. 37. 



 The author quotes F.S. Lyman's letter [see F.S. Lyman, 1868a-b] on the earthquakes and the mudflow triggered by the April 2 shock.

 

Anonymous, 1868, Earthquake: Pacific Commercial Advertiser, 04/18, p. 2. 



 Earthquakes were still felt at Hilo and Kohala on April 14.



Anonymous, 1868, Earthquakes and the volcano: Pacific Commercial Advertiser, 04/11, p. 3. 



 A collection of reports regarding the earthquakes and volcanic activity in April. Kilauea caldera was reported very active, the lava level was dropping fast, and smoke had issued from the line of craters on Kilauea's east rift zone. [This is the only indication that an intrusion may have accompanied the 1868 collapse.] Smoke from Mauna Loa was first sighted on March 27. The article concludes with a list of earthquakes felt from March 28-31, compiled by C.G. Williamson. [See Anonymous, 1868e.]



Anonymous, 1868, New eruption of the volcano and Postscript: later from the volcano!: Pacific Commercial Advertiser, 04/04, p. 3. 



 Notice of the summit eruption of Mauna Loa, March 27, and the beginning of the earthquake swarm.



Anonymous, 1868, The eruption: Hawaiian Gazette, 04/29, p. 2. 



 A brief account of the 1868 Mauna Loa lava flow and littoral cone, and the April 2, 1868 landslide. The correspondent mentions that the eruption had ended but that earthquakes were still being felt. Kilauea Crater had sunk 500 ft and no lava was visible.



Anonymous, 1868, [On the eruption and earthquakes of 1868]: Hawaiian Gazette, 04/15, p. 2. [Excerpted in American Journal of Science, 1868, 2nd ser., v. 46, p. 122-123] 



 An account of the great earthquakes of 1868, and the activity of Mauna Loa and Kilauea, including a description of the effects of the accompanying tsunamis at Hilo and along the southern shore.



Anonymous, 1868, The volcano active: Hawaiian Gazette, 04/08. 



 This article contains an account of the summit eruption of Mauna Loa, first seen at 5:45 am on Mar. 27, and the ensuing earthquake swarm. Effects of the April 2, 1868, earthquake are described as they affected Kau, Kohala, Maui, and Oahu. The article includes a list of earthquake times from March 28-31. [See also Williamson, 1868a-b.]

The following sections describe effects at places other than Kau:

Earthquakes at Kohala

 A strong shock was felt at Kawaihae at 4 pm on April 2 lasting 30 seconds, accompanied by a deep rumbling noise and landslides on the Kohala slopes. Tsunami at Kawaihae marked by 13 cycles of ebb and flow, leaving the reef exposed and returning beyond high water mark.

 Several shocks, not severe. were experienced on a ship offshore of Hamakua; landslides into the sea were observed.

Earthquake on Maui

 At Lahaina an earthquake felt at 4 pm April 2, lasting 90 seconds, accompanied by a low rumbling sound, and shaking the house and everything in it. About 5 o'clock the sea receded, the space between reef and beach left dry in many places. The sea ebbed and flowed thirteen times, the time between each flow being between seven and eight minutes.

 shocks and similar tidal disturbances were observed on Lanai at the same hour.

 Two earthquakes felt at Lahaina on the early morning of April 4, 12:19, lasting 30 sec, and 12:37 am, lasting a bit longer. they were both more violent than the one on Thursday, the latter more particularly so, and were both atended with the same rumbling sound and my house was violently shaken; no tidal effects were seen to follow these quakes.

On Oahu

 At 4 pm on April 2 a first, very light, shock occurred, noticed only by those inside of stone buildings. The movement was lateral and quick and was not noticed by the majority of the townspeople. The sea was observed to recede, but the disturbance was not great.

 The same shocks were noticed at Kaneohe. Probably three shocks on the night of April 3-4 extended all over this island.



Anonymous, 1868, The late earthquakes: Pacific Commercial Advertiser, 05/02, p. 3. 



 A discussion of the earthquake of April 2, 1868, the mudflow, and the tsunami. The earthquake waves were estimated to travel from Hilo to Kona at 12 mi/hr. [This is far too slow.] The summit activity on Mauna Loa was reported to have built a cone several hundred feet high [exaggerated]. The fire was returning to Kilauea as of May 1.



Anonymous, 1869, From Hilo: Hawaiian Gazette, v. 5, no. 64, 02/24, p. 3. 



 Somehow the rumor has got current about town, and was near being snapped up by our reporter, that there was an eruption of Kilauea, quite formidable in its character, and that some more heavy shocks of earthquakes had been felt in Hilo. We are able to state, on the reliable testimony of Capt. Babcock, arrived thence on Monday last, that although Kilauea was bubbling and boiling enough to be interesting, there was no eruption, and that although there had been a couple of slight earth tremors at Hilo, there was nothing that approached the dignity of an earthquake.



Anonymous, 1869, The coast-line of Hawaii: The Friend, Sept., p. 77. 



 A brief note, quoting from the Pacific Commercial Advertiser, regarding the subsidence of the shoreline associated with the 1868 earthquake.

 

Anonymous, 1871, Earthquake: Pacific Commercial Advertiser, 02/25, p. 3. 



 " . . . the 4th day of February 1871, and the 10th day of February, 1871, are days ever to be remembered in Lahaina. The first was the occasion of a free fight, before mentioned, and the other was the great earthquake, at 10 o'clock 15 minutes P.M. on Sunday. It came as near from the S.E. as you could have made it. We heard the noise like distant thunder, long before we received the shock, and when it did come, it came good. There is not an adobe or adobe and stone, or a stone house but what is cracked, and some scattered so bad that it is dangerous to live in them. The old mission church is damaged, the walls are all cracked. Also the fine stone building of Col. Spalding is damaged. Then as you come along the main road, that is cracked open for many feet. Then along the Court House, which is damaged, and will need repairing . . . Since Sunday night, we have had repeated shocks, but light.



Anonymous, 1871, The earthquake: The Friend, March, p. 21. 



 "At ten minutes past ten o'clock Sabbath evening, February 19, many of the people in Honolulu and elsewhere on the islands experienced a new sensation. There was no doubt about the reality of the agitation of the earth. Hitherto, however, severe the shocks may have been on the island of Hawaii, this island has escaped. This time, from all accounts, the islands of Oahu and Maui have been more seriously affected than Hawaii. The vibrations continued not over thirty seconds on this island [Oahu], but elsewhere report says they lasted three minutes. Several houses and public buildings were more or less cracked, and in some places crockery and glassware were thrown down and broken. There is a report of an eruption on the summit of Mauna Loa, but the old crater of Kilauea, report says, remains in status quo."

 

Anonymous, 1871, An earthquake: Pacific Commercial Advertiser, 09/30, p. 3. 



 Notice of an earthquake on Sept. 18, 1871, the largest since April 2, 1868.



Anonymous, 1872, Rev. Mr. Coan's "Kilauea" criticized: Pacific Commercial Advertiser, 01/27, p. 3. 



 The author questions the dimensions of Halemaumau lava lake, the steepness of slope and the height of its shield during August 1871, and the distance from Kilauea to Mauna Loa, as set forth by Titus Coan (1871).



Anonymous, 1875, Earthquake, storm and volcano: Pacific Commercial Advertiser, 01/23, p. 3. 



 A series of short communications reporting increased activity at Kilauea in December 1874, a new eruption at Mokuaweoweo on January 10, 1875, and a strong earthquake felt at Hilo on December 29, 1874.

Hilo, Jan. 3d, 1875-- . . . Old residents say that with two exceptions--in 1855 and in 1868 . . . there has been nothing like the recent one [earthquake] A continuous shake of two or three minutes, like the earthquake of Dec. 29, must have torn everything to pieces.

Kailua, Hawaii, January 12, 1875--The summit crater of Mokuaweoweo . . . broke out active again on [just before sunrise] last Sunday morning, the 10th instant. . . . At Kau a sharp shock of earthquake immediately preceded the outbreak.



Anonymous, 1877, From the crater of Kilauea: Pacific Commercial Advertiser, 05/12, p. 3. 



 . . . the old South Lake of Kilauea, which for many years has been the principal vent of that volcano . . . has become extinct . . . On Friday the 4th inst., several severe shocks of earthquake were felt at the volcano house (and also at Hilo at the same time) and shortly thereafter a brillian eruption burst out in the S.E. corner of the great pit, and worked its way up into the extinct crater of "old Kilauea [Keanakakoi] ." Subsequently the eruption subsided here but broke out again on Monday the 7th in the bottom of the pit [Kilauea crater floor], right on the path from the volcano house to the South Lake. . . . [This is the only published account of eruption in Keanakakoi Crater. See also Bevens, 1988.]



Anonymous, 1877, The volcano: Pacific Commercial Advertiser, 03/03, p. 2. 



 A brief account of the eruption in Kealakekua Bay, first seen by natives at about 8 a.m. on February 24. Light porous lava was constantly rising to the surface in lumps in a state of fusion, and sinking again to the bottom as soon as the gases had escaped. Activity at Mauna Loa summit on February 14 lasted less than one day. A severe shock of earthquake had been felt on the night of the 23d [Feb.], and that quite a crack in the old lava deposit had been traced from Keei point (opposite the submarine flow) several miles inland in the direction of Mauna Loa..



Anonymous, 1881, The earthquake: Hawaiian Gazette, 10/05, p. 3. 



 A smart shock of earthquake roused a number of people out of their beds [on Oahu] a few minutes before five on Friday morning [Sept. 30] last. The exact time is difficult to settle, as the clocks in this city [Honolulu] have a way of keeping the most extraordinary time. Reports vary from seven minutes to 5 to two minutes to 5; the latter was our observation, and agreed with the clock in the Government buildings. There were three shocks in all; one a severe one, lasting about 30 seconds, followed by two short and light ones. Beyond stopping a few clocks, and slightly cracking the walls of one building, no damage was done. The shock in Honolulu was not nearly so severe as the one of Feb. 19, 1871. Considerable anxiety was felt, till news was received from Hawaii; the shock appears to have been very severe there, and we may hear of great damage in Hilo and Kau. We give below the letters which we have received from our various correspondents in all parts of the group. These go to show that the effects of the shock were felt almost simultaneously all over the islands.

Kauai, Kapaa, Oct. 1, 1881--The earthquake was felt all over the Island of Kauai, shortly beofore 5 o'clock on friday morning, the 30th ult. There were three distinct shocks all within the space of a minute or two; the first two shocks were quite severe for this island--and the last was an almost imperceptible tremor.

 . . .

Maui--Maui was visited by an Earthquake on Friday morning--between 4 and 5 o'clock. The first shock lasted perhaps fifteen or twenty seconds and was quite severe. After an interval of a few minutes, another slight shaking was experienced, but not as heavy as the first. It is the general opinion of those who have resided in Wailuku for many years, that there has bbeen nothing like it on this island since '68. Some declare that there was another slight shock on Friday evening, but if so it was so exceedingly slight as to be noticeable only by a few.

 From Lahaina conmes the following:

 The dwellers on the "hill," and doubtless those also in Lahaina were awakened at 5 0'clock, Friday morning, by a fair sized earthquake, which heralded its advent by terrible rumblings. the rumblings resembled those of rapidly driven lorries filled with sheets of corrugated iron, coming from a distance, and passing within a rod of the sleeper. The rumblings preceded the earthquakes some twenty seconds, and in the midst of the loudest din the quake occurred. A second quake immediately apoceeded [sic] the first, attended by like rumblings, almost deafening.

 The rumblings appeared to approach from the south-east and died away to the north-west. No damages occurred to property.

Hawaii, Waimea, Sept. 30, 1881--At eight minutes before 5 this morning, the earth quaked terrifically, and our houses rocked to and fro most fearfully. There were three shocks of earthquake in quick succession. . . . Stone walls were thrown down more or less all over Waimea. Nothing like it since the Kau earthquake of '68. Much more stone-wall was thrown down in Waimea by these than by those earthquakes. What other damages have been done, I have not yet heard.

Hamakua--At about 5 o'clock this morning of the last day of September, a series of of earthquake shocks occurred. the first one was even heavier than than that which happened in 1868 . . . For a while, there was a stampede among the natives around us. A great many left their beds in a hurry. Our house is a substantial wooden structure, but it cracked and creaked as if the whole fabric would come to pieces.

 There are three houses in the Kohala district so badly shaken as to be untenable. The cisterns at Kohala plantation, have been cracked, and the water has leaked out, probably the same thing will have happened at Ookala.



Anonymous, 1881, The earthquake on Hawaii: Pacific Commercial Advertiser, 10/08, p. 3. 



 At Kailua--About 5 o'clock this morning (Friday, Sept. 30th.) we had a severe shock of earthquake. a second shock was felt about three minutes after the first; and a third one about 1/4 past 5 a.m. The shocks did some damage to my crockery on the shelves; threw down some stone wall fences, cracked Kapakui's stone building, the church buildings and several others. It rocked structures pretty roughly. It frightened some people very much . . .

 The shock was severely felt throughout Hawaii. In Kona, and along the coast, through the Waimea and Hamakua districts, we have accounts of stone walls being cracked, and of considerable damage to crockery, and other fragile articles. Several large water cisterns on plantations have been cracked, and their contents discharged.



Anonymous, 1881, The earthquake: Pacific Commercial Advertiser, 10/01, p. 2. 



 Yesterday morning the 30th ult., at 4:53 a.m., the early wakers of this town [Honolulu] were startled by a very sensible undulation of the earth from east to west. There was a decided roll and heave of the earth that made some parties feel slightly nauseated. there followed a jar and rattle, as though a great train of cars was moving past, which caused the ground to rumble and the crockery and window-sashes to clatter. This shock lasted about thirty seconds; and in about five minutes afterwards was followed by another very light roll and tremble of the earth.

 This earthquake, though quite marked and unmistakeable, is spoken of by the most of the observers as not being equal in force and effect to the shock felt on Sunday night, 10.6 p.m., 19th, February 1871; or the one of the 8th of April, 1868--in this city. We have not heard of any damge to buildings in the city. There was a little dispute about the exact time of the commencement of the first shock--varying from 5 to 6 minutes in time--our neighbor Dr. Hoffmann contending that it was exactly seven minutes to 5; and on entering our office we discovered our pendulum clock, which had been set correctly the day before, had stopped at exactly seven minutes to 5, thus confirming the doctor's time. We may expect to hear of a lively shake up on Hawaii. Our late news from the chief island stated that there were indications of unusual activity in the crater of Kilauea.



Anonymous, 1887, [no title], in Island Notes: Pacific Commercial Advertiser, 01/31, p. 3. [replace in main bib!] 



 Hilo, Hawaii, January 28th

 Hilo was shaken up lively on Sunday evening, 23rd instant, seven earthquakes occurring at 11:15, 11:30, 11:45, 11:50, two were slight. The most noticeable was the second one, and it shook things down all over town. Most of the people, both native and foreign, were up after the first shock in expectation that more would follow. They were ready for the second one, which seemed as though the houses would be shaken down and everything in them that was loose. Clocks stopped, and some people were afraid to sleep in their own houses, and went to sleep at houses of friends. The shocks were very severe to nervous people. The only licensed liquor saloon lost over $100 in broken liquor bottles. . . . .The other side of this island has suffered some. At Kapapala Ranch the water tanks broke, a building was moved eight inches, stone fences were thrown down. The shakes were much more severe than at Hilo; in fact, they usually are. . . .



Anonymous, 1887, Volcano trip: Pacific Commercial Advertiser, 01/31, p. 2. [replace in main bib!] 



 [subheads: A week's excursion by the S.S. Kinau; Visit to the crater of Kilauea; Grand display of the great lava flow; Incidents of the excursion, etc.]

An account of an excursion beginning January 24, 1887, on the steamer Kinau. Kilauea was moderately active, the lessened activity attributed to the eruption of Mauna Loa. On January 28, the second eruptive vent was seen above and to the right of the main vent feeding flows to the ocean.



Anonymous, 1887, [On the 1887 eruption of Mauna Loa]: The Whaleman's Shipping List, Mar. 1, p. 1. 



 An eruption began January 16, 1887, at Mauna Loa's summit, was quiet for 2 days, and broke out on the southwest rift zone on January 18. The eruption was accompanied by an earthquake swarm; 383 shocks were felt in 36 hrs. Lava reached the ocean in two days, destroying plantations, houses, etc., but no lives were lost as the natives and foreigners received timely warnings and abandoned their places ahead of the flow.

 

Anonymous, 1887, [On the earthquake swarm of 1887]: Hawaiian Gazette, 02/01, p. 1. [Letter no. 04] 



 Subheads over letters from correspondents, signed and unsigned:

Mauna Loa!; Hawaii's great volcano; twenty miles of liquid fire in motion!; Madam Pele on the rampage!; continuous earthquake shocks!; description of the flow!; notes and incidents



Pahala, January 23, 1887--A vivid description of the the earthquake swarm and early stages of eruption at Mauna Loa. She notes eruption a little way down from the summit on Sunday night, January 16 at 9 p.m. The light vanished at 11:30 p.m , as suddenly as it appeared, and we had six terrific earthquake shocks between thatn and morning, not counting the trembling and occasional jerk, which were constant. We felt better by daylight though the trembling kept on and the big shocks seemed as though they meant to take the house down. . . . then came a shock that was worse than what we had experienced already. By night there was still no smoke or fire, and still the awful shocks and we were all wondering and we were all wondering where the force would spend itself. 

 Monday night [Jan. 17] was literally a night of terror, and we felt as though we couldn't live through any more, the heavy shocks were nearly as continuous as the trembling had been for four hours, there was no pause longer than five minutes or often only three between the shocks, and sometimes three succeeded each other like ocean waves.and again on January 18. . . . .

 At 11:30 a.m., Tuesday [Jan. 18], the smoke burst out again immediately after two very heavy shocks, just where it did at first quite a way down on the western slope. . . . Later, smoke came from the '81 opening [See annotation to Anonymous, 18871.]. The trembling was not so constant and the shocks less heavy after this, then the flow broke out very near the old '68 outbreak . . . . 

 . . . .

 We have only two or three heavy shocks a day now though frequent tremblings, and last evening [Jan. 21] a very long shock that swayed the house back and forth making us sick and dizzy.

 . . . .



Anonymous, 1887, [On the earthquake swarm of 1887]: Pacific Commercial Advertiser, 01/31, p. 3. 



 A report from Hilo of earthquakes on January 23 and of a view of the Mauna Loa eruption.



Anonymous, 1887, [On the earthquake swarm and eruption of 1887]: Hawaiian Gazette, 02/01, p. 8. [Letter no. 07] 



 Subheads over letters from correspondents, signed and unsigned:

The latest from Kau!; great damage to property!; continued earthquakes



 . . . The lava is still pouring into the sea and another flow has started down the mountain, bursting forth somewhat higher up than that of January 18th.

 The earthquakes has been continuous in the Kau district, and have done great damage, while severe shocks have been felt in every part of the island.

 On Sunday January 24th, the earthquakes were very severe in Kau, every house at Kahuku was moved some inches from its foundation and the contents smashed. The mail carrier reported at Hilo that eight buildings had been burned in Kahuku during Sunday night in consequence of the lamps having been overthrown by the vibrations. The walls throughout the Kau district have been leveled to the ground. The crockery in every house has ceased to exist, one correspondent reports only seven plates left and his stove in pieces, others tell the same tale. . . . Fortunately no loss of life is reported.

 Kilauea is reported by the Rev. Baker to be in the same state that it has been for some time past.

 Seven shocks of earthquake were felt in Kohala on the 23rd but, beyond giving the people a fright, no damage was done.

 At Laupahoehoe, nine shocks were felt the same night, a little after eleven. Two of these were quite severe. There have been light shocks ever since.

Pahala, Jan. 24th, 1887--We had two very heavy severe shocks of earthquake about 11:00 last night that did us considerable damage. Nearly all the work done in setting out new boilers was damaged, so that it will have to be done over again. The large iron tank at the mill was thrown down and a number of pipes broken about the mill.

 The Moaula and the new reservoir were badly damaged. The Whitney reservoir very little. Nearly all the houses on the slopes are off their underpinning. Last night was one of terror.

Hilo, Jan. 27, 1887--Hilo had a decided shaking up on Sunday night, January 23rd [sic-should be Saturday night]. The first shake was a rouser, at 11:18 o'clock p.m., followed five minutes later by another more terrible than the first. these were followed by numerous minor shakes, and half an hour later by a third heavy shock, but not as heavy as the two previous ones, which seemed determined to tear doors and windows off the houses. Many a frightened person ran out of doors, and some left their houses to spend the night with their neighbors. In fact it was the heaviest jolt at Hilo since 1868. Many articles, such as vases and ornaments and dishes, were thrown down in the various houses and broken. In one store in Hilo over $30 worth of lamps and chimneys were thrown down and destroyed by the earthquakes of Sunday night.

 The chimney of the kitchen at the Onomea Sugar Company Manager's house was thrown down, and slight damage is reported all about Hilo.

 The oscillations were from east to north-northwest.

[the rest of the article talks about weather conditions]



Anonymous, 1887, [On the Mauna Loa eruption and earthquake swarm of 1887]: Hawaiian Gazette, 02/01, p. 1. [Letter no. 01] 



 Subheads over letters from correspondents, signed and unsigned:

Mauna Loa!; Hawaii's great volcano; twenty miles of liquid fire in motion!; Madam Pele on the rampage!; continuous earthquake shocks!; description of the flow!; notes and incidents



Lava first shot up on Sunday night, January 18th [sic--other accounts give this date as January 16th, consistent with the statement below regarding lava not being seen on the 17th], three or four miles below the summit of Mauna Loa near Pohakuohanalei. Earthquakes were continuous for over 36 hours. Mr Jones counted 383 well-defined shocks and created a standard by which he could judge the force of the shocks. The reason for nothing having been seen during Monday the 17th, was that the lava had found an underground channel through which it surged along until reaching the steep slope about 10 miles west of Mr. Jones Ranch, when it burst once more into view.

[Followed by Jones, 1887]



Anonymous, 1887, [On the earthquake swarm and eruption of 1887]: Hawaiian Gazette, 02/01, p. 8. [Letter no. 06] 



 Subheads over letters from correspondents, signed and unsigned:

Mauna Loa!; Hawaii's great volcano; twenty miles of liquid fire in motion!; Madam Pele on the rampage!; continuous earthquake shocks!; description of the flow!; notes and incidents



Hilea, Jan. 23, 1887-- . . . up to 7 o'clock Tuesday night [Jan. 18] we had 508 earthquakes, then we gave up counting. On Tuesday 4 p.m., smoke was seen on the slopes of Mauna Loa, and fire at 7 p.m.. She briefly describes the lava streams in Kahuku and damage done on January 23-24.



Anonymous, 1891, Collapse of Kilauea: The Friend, Apr., p. 28. 



 Brief mention of the earthquake swarm from March 5 to 8 accompanying collapse of Kilauea and draining of Dana lake.

 

Anonymous, 1895, Madam Pele stirring; Showers of much needed rain; taro shipped to Maui: Pacific Commercial Advertiser, 05/29, p. 3. 



 Kau (Hawaii), May 25.--On Friday night the 17th inst. Madam Pele gave a vicious kick about 9 o'clock. It was felt at the Volcano House and throughout the district. It is reported that fire has appeared in the crater, and at time small stones are thrown over forty feet into the air. (This occurs at the bottom of the lake). There is plenty of smoke and it will not be a surprise if Madam Pele will entertain us once more.

 . . . .



Anonymous, 1895, Slight earthquake at Kau: Pacific Commercial Advertiser, 07/12, p. 2. 



 Kau (Hawaii), July 7.--On Wednesday, June 26th, about 3 p.m., a slight earthquake shock was felt.

 . . . .



Anonymous, 1895, Earthquake at Kau; Plantations cleaning up--anxiety about spread of cholera: Pacific Commercial Advertiser, 08/31, p. 6. 



 Kau (Hawaii), August 28.-- . . . .

 A shock of earthquake was felt throughout the district about 11:30 Tuesday night.

 . . . .



Anonymous, 1895, The earth in a tremble; one of the most violent shocks ever felt on the island; clocks stopped and smashed-damage to residences-reports from outer districts-strong at Waikiki: Pacific Commercial Advertiser, 12/09, p. 1. 



 There were two distinct shocks of earthquake at 11:04 last night, each about ten seconds duration. The first was quite light, the second being much stronger and perhaps the most severe ever felt on the island. Down town the shocks were heavy, but not quite as hard at Waikiki and along King street. The clock at Lucas' mill was stopped, and in the Interisland dock office a clock was thrown to the floor and smashed. At Fred Whitney's residence, King street, the contents of the house were strewn in all directions.

. . . .

 Telephone messages from Waialua and other places beyond the pali reported the earthquakes equally as strong as in Honolulu.



Anonymous, 1895, [no title], in Local Brevities: Pacific Commercial Advertiser, 12/10, p. 7. [A letter to the editor] 



 Two shocks of earthquake were felt Monday morning at about 3:12 o'clock. The first lasted but a few seconds; the second being quite severe and of some fifteen seconds duration.



Anonymous, 1895, Kilauea active again; Small flow seen in one corner of the pit; Severe shakes on Hawaii; Bottom of the crater falls in and fire disappears: Pacific Commercial Advertiser, 12/14, p. 1. 



 Kau (Hawaii), Dec. 11.-- . . . Last Sunday night [Dec. 8] at 11 o'clock, . . . a severe earthquake [occurred], followed by another, and one more shake 3 a.m. (Monday). From reports the earthquakes were felt throughout the island, and more severe within a radius of thirty miles from the volcano [Kilauea]. At the volcano it was very light. . . .fire appeared in the crater Sunday night . . .

 Fire disappears

 Later--Dec. 12--4 a.m. . . . the bottom of the crater had fallen in again and the fire disappeared.



Anonymous, 1895, Hilo gets a shaking: Pacific Commercial Advertiser, 12/18, p. 1. 



 Hilo (Hawaii), Dec. 15-- . . . .

 A heavy earthquake shock was felt here shortly after eleven o'clock Sunday night--the first for months. It was followed by a lighter shock two hours later. [Other reports have the second shock at four hours later]

 The earthquakes that shook up Honolulu were also felt here [Kohala] at the same hours. The one at 11 o'clock began with a preliminary shock that wakened most of those who were asleep. After an interval of a second or two it was followed by a strong tremor that continued with decreasing force for probably thirty seconds. Some reckon it at a full minute. The undulation proceeded from mauka to the sea. The waves were longer, and the shock less violent than is usual with such a considerable earthquake. At 3 o'clock there was a second prolonged tremor, less violent than the former; but characterized by the same long graceful undulations . . . On the Kona side the shocks are reported as being much more violent. Altogether it was the greatest shake up Kohala has had for years.



Anonymous, 1896, The volcano eruption: Pacific Commercial Advertiser, 04/23, p. 4. 



 A report that the crater of Mokuaweoweo has broken out again. No details are given and no earthquakes are mentioned, although there is reference made to the earthquake swarm of 1887.



Anonymous, 1896, [no title], in Local Brevities: Pacific Commercial Advertiser, 04/28, p. 7. 



 Several residents [Honolulu] felt a slight shock of earthquake Saturday night about town.



Anonymous, 1896, Condition unchanged; Mokuaweoweo's crater sending out fire: Pacific Commercial Advertiser, 04/29, p. 6. 



 [subheads: Parties visiting the summit; No returns yet--several shocks of earthquake felt--probability of an overflow--weather in vicinity of outbreak clear and cold]

 Kau (Hawaii), April 27, 1896.--Brief mention of the eruption at Mauna Loa's summit that has been going on for nearly a week.

 Following is an extract of a letter received from Kapapala Ranch by the W.G. Hall yesterday:

 "We had five or six shakes about 1:30 Tuesday morning, April 21st. None of these were very severe, but the reflection was seen down at Pahala about 4 o'clock or earlier, so that the fire must have started soon after the cessation of the earthquakes. . . . .

 . . . .

 "The latest news from Hawaii is to the effect that there have been no earthquakes on the island since Tuesday morning, April 21st, the time of beginning of the outbreak."



Anonymous, 1896, Earthquake shocks; first one felt 4:48 Sunday morning and lasted three seconds: Pacific Commercial Advertiser, 09/14, p. 1. 



 There were two shocks of earthquake early Sunday morning which shook people up considerably and banished sleep from the minds of many. Prof. A.B. Lyons kindly furnished the Advertiser with the following description of the shocks:

 "The first shock was at 4:48 a.m. and lasted perhaps three seconds, appearing to go off in a northeasterly direction.

 "The sound died away gradually, lasting 15 or 20 seconds after the shock. 

 "Then after an interval of 10 seconds there came a second shock about equal in severity to the first but of shorter duration, apparently a reflection of the earthquake wave.

 "It was impossible to tell from what direction the second shock came and it ended quite abruptly." [One quake or two?]



Anonymous, 1896, This was no "night mare"; Hilo treated to good sized earthquake; Earth was rent asunder: Pacific Commercial Advertiser, 09/16, p. 1. 



 [subheads: Severest shock since 1868--bells rang, bottles and dishes tumble from shelves--valuable statuary ruined in J.A. Scott's house--drug company suffers loss]

 News received from the volcano is to the effect that the severest shock since 1868 was felt there at one minute before 5 a.m. Sunday. As near as can be ascertained the shock came from NE. to SW., light in the beginning and growing stronger during the 10 seconds it lasted.

 Dishes were thrown from the shelves in private houses and bottle from shelves and tables in the business section, the heaviest loss being that of the Hilo Drug Co. on Front street. . . Her hundreds of bottles of patent medicines and valuable drugs were thrown to the floor, and smashed, One small show case was broken by heavy articles falling upon it. Where the large drug jars were not thrown down they were turned half around on the shelves leaving the labels next to the wall.

 At John Scott's house, Wainaku, the loss was considerable; several pieces of valuable statuary and bric-a-brac . . . were thrown from their places and smashed to pieces.

 In L. Turner's general store, and Theo. H. Davies branch, in the building next to the drug store, goods were upset generally, but no serious damage resulted. C.E. Richardson suffered a small loss through broken bottles of liquids. . . . Much type in the Tribune office was "pied." Including the damage to effects in private houses, the entire loss will amount to, perhaps, a thousand in the immediate vicinity of Hilo.

 As an evidence of the shock a crack beginning at the sea and running north for half a mile [can be seen]. In some places, too, the stone wall around the Catholic Mission was thrown to the ground and one tree uprooted.

. . . .

 Col. Peter Lee [manager of the Volcano House] says that from all accounts the shock at the crater was not as severe as the one felt in Hilo. Some of his children sleeping in the adjacent cottage did not feel the disturbance at all. Col. Lee considered the shock a good one, equal in every respect to the Kau quakes, but as he is hardened to such things, he may not be a competent judge.

 Artist Howard Hitchcock, who had just returned from a tour of Puna, where he had been making sketches, was rudely awakened by the shock. He suffered no inconvenience beyond a surprise in running up against the wall in getting out of the wrong side of bed.

 [R.T. Perkins reports from Olaa] "I was awakened the moment the shock began; my lamp was in danger of falling from the dresser, so I got up and placed it on the floor and sat down alongside of it, merely to experience the thing in its fullest force . . .

. . . 

 Eben Low of Kohala says the shock was severe there and caused much consternation among his fat cattle. there was no damage from the shock anywhere in the vicinity of his home.

 Maui was in harmony with Hawaii and Oahu in the sensation. Passengers from there state that it was the most severe shock experienced in many years.

 Telephone messages received in Hilo from all stations in Hawaii were to the effect that the shock was severely felt at every point but there was no disturbance of the sea on any part of the island. . . .

 [A drawing of Hilo Bay and village, made from a photograph, has the following caption: The cross shows where the rent in the earth began and extended in almost a straight line for a half mile across town, widening as it got further away from the sea.]



Anonymous, 1896, Hilo gets a shaking up; most violent shock of earthquake in several years; much damage is the result; Hilo Drug Company heavy losers-general smash-up about town-interruption of the volcano, land slides: Hawaii Herald, 09/17, p. 3. 



 The most violent shock of earthquake since the 80s prevailed throughout the Island of Hawaii early last Sunday, striking terror to the hearts of inhabitants and causing much damage to property. It differed from previous quakes in that only one shock was felt--there being a generally lighter and secondary interruption following the first--and being strong from the beginning.

 At precisely one minute to 5 a.m., a slight vibration was felt, which increased a few seconds later to a heavy wave and continuing for fully thirty seconds. People were awakened to see their houses rocking like reeds in the wind, and to hear the smash of crockery, glassware, vases, bric-a-brac, statuary. Clocks were thrown around promiscuously, table overturned, mirrors broken, and sundry other damage done.

[report of damage details in Hilo similar to PCA, Sept. 16]

 Along the Hamakua coast the shock was equally strong as felt here. Cooking ovens in Pepeekeo were cracked, the water dam at Laupahoehoe parted, and in the different gulches tons of rock and earth were loosened, almost blocking the road in several places.

 At the Volcano the quake was not so violent, several guests there failing to be awakened by it. The lava bed leading to the crater opened in places sufficiently large to admit small buildings, and emitted volumes of sulfurous smoke, giving indication of outbreaks at different points.

 In Kau and Kona there was but little notice taken of the shock, it being much milder there than elsewhere.

 News from Honolulu yesterday by the Hall says Oahu was considerably shaken up, but no damage resulted. Two shocks were felt, each about ten seconds duration.



Anonymous, 1896, Mokuaweoweo's fierce fires: Pacific Commercial Advertiser, 04/27, p. 3. 



 A brief notice from Maui, relating the appearance of fire and smoke at Mauna Loa's summit. "During the 20th [April, 1896] a slight shock of earthquake was experienced at Ulapalakua."



Anonymous, 1897, Earth tremors; Three shocks on the Island of Kahoolawe: Pacific Commercial Advertiser, 12/06, p. 8. 



 Maui, December 4.--During Friday, the 3d, three unusually heavy earthquakes waves were felt on the Island of Kahoolawe. Inasmuch as the Island of Hawaii is hidden in smoke, it is thought that these shocks were caused by extraordinary activity in Kilauea. No earth tremors were felt on Maui.

 . . . .



Anonymous, 1898, [no title], in Local Brevities: Pacific Commercial Advertiser, 08/20, p. 7. 



 A slight earthquake shock was felt in the city [Honolulu] at 6:50 yesterday morning. A noticeable tremor was felt at the weather observatory at Punahou.



Anonymous, 1898, A Kau tremblor; Strong shock--runaway Japanese, Rev. J. Kauhane: Pacific Commercial Advertiser, 08/22, p. 3. 



 Punaluu, Kau, Aug. 13.--On August 5, at 6:30 a.m., there was a very heavy earthquake shock in this district--the strongest felt here in some time. It shook dishes, etc., up in great shape.

 . . . .



Anonymous, 1898, [no title], in Local Brevities: Pacific Commercial Advertiser, 12/10, p. 9. 



 The S.S. Mauna Loa, arrived yesterday from Hawaii, reports a heavy shock of earthquake in Kau last Sunday.



Anonymous, 1899, [no title], in Local Brevities: Pacific Commercial Advertiser, 01/09, p. 9. 



 An earthquake shock was felt at Hilo at 4 o'clock last Wednesday morning.



Anonymous, 1899, [no title], in Local Brevities: Pacific Commercial Advertiser, 08/28, p. 11. 



 Rather heavy earthquake shocks were experienced in Olaa and Hilo on Thursday night.



Anonymous, 1899, Sharp earthquake shock: Pacific Commercial Advertiser, 11/20, p. 11. 



 Last Saturday evening at 8:20 the most severe earthquake shock was felt in Hilo since the eruption on Mauna Loa. Though no damage was done the residents were reminded that they still lived on the verge of immediate destruction and said, "There's a shock."



Anonymous, 1899, [no title], in The news boiled down: Pacific Commercial Advertiser, 12/11, p. 13. 



 An earthquake shock in the vicinity of the Volcano overturned a stone wall and started the smoke booming in Kilauea.



Anonymous, 1899, Lava flows stop: Pacific Commercial Advertiser, 07/29, p. 3. [Also published in Hawaiian Gazette, Aug. 1, p. 2] 



 Subheads:

Pele has allowed her fires to go out; Hawaii shaken by earthquakes which have done no damage--Kilauea still quiescent



The eruption ended at Mauna Loa on July 23, 1899. "During the day the whole island of Hawaii was shaken with earthquakes of various degrees. None were very heavy and no damage was done. . . .

 Writing from Punaluu, the Acverrtiser's special correspondent says: 

 On Monday [July 25] about lunchtime Hawaii had a heavy earthquake. It was most severe at Hilo and vicinity and very light here."



Anonymous, 1900, [no title], in Meteorological record for month of December: Pacific Commercial Advertiser, 01/17, p. ? [!did not find on Dec. 7; meteorological record on Jan. 18 reports no earthquakes in December 1899.] 



 There was a slight earthquake at Waimea, Hawaii on Dec. 5.



Anonymous, 1900, [no title], in Local items: Hilo Tribune, 03/03, p. 5. 



 A slight earthquake on Monday morning [Feb. 27] about two o'clock, was noted by those whom troubled conscience or indigestion caused to sleep ill.



Anonymous, 1900, [no title], in Local items: Hilo Tribune, 06/02, p. 5. 



 A light shock of earthquake was experienced in Hilo on Tuesday morning [May. 29].



Anonymous, 1900, [no title], in Local items: Hilo Tribune, 07/14, p. 5. 



 A rather heavy shock of earthquake at about nine o'clock on Tuesday evening aroused a transient interest in the doings of Pele which have of late been conspicuously absent.



Anonymous, 1900, [no title], in Local items: Hilo Tribune, 10/13, p. 5. [Reprinted verbatim in Pacific Commercial Advertiser of Oct. 15] 



 A rather heavy shock of earthquake was felt by many residents of Hilo on last Wednesday evening between eleven and twelve o'clock. The pitching and rocking of the earth brought some alarm to those who roost above the ground floor.



Anonymous, 1900, Did Pele turn over; Hawaii felt the earthquake: Pacific Commercial Advertiser, 10/15, p. 6. [Reprinted verbatim from Hilo Tribune of Oct. 13] 



 A rather heavy shock of earthquake was felt by many residents of Hilo on last Wednesday evening between eleven and twelve o'clock. The pitching and rocking of the earth brought some alarm to those who roost above the ground floor.



Anonymous, 1901, Earthquake reported: Pacific Commercial Advertiser, 01/18, p. 5. 



 Prof. Curtis J. Lyons, the Territorial Meteorologist, reports a slight earthquake as having been reported about 2 o'clock Wednesday morning [on Oahu]. Owing to the lateness of the hour, there were probably very few people awake at the time and this, together with the slight nature of the shock, probably accounts for se few people having commented about it. The seismograph at Oahu College was not in position, therefore there is no scientific record of the earthquake.



Anonymous, 1901, [no title], in Local Brevities: Pacific Commercial Advertiser, 01/23, p. 11. 



 The report of a slight earthquake shock at a quarter past two o'clock last Wednesday morning, has been corroborated by a report of a shock felt at Waimea at the same hour.



Anonymous, 1901, News from the Big Island: Pacific Commercial Advertiser, 03/25, p. 11. 



 Hilo, March 22--A slight shock of earthquake was felt [in Hilo] at 7:15 yesterday [Mar. 21] morning.



Anonymous, 1901, Lahaina notes: Pacific Commercial Advertiser, 04/09, p. 8. 



 Lahaina [Maui], April 4--Was it a diminutive earthquake? About 10 o'clock Tuesday night [Apr. 2] several persons thought they perceived a slight tremor in their houses, accompanied with singular noises. The strange phenomenon lasted for only a few moments.



Anonymous, 1901, Earthquake at Kau: Pacific Commercial Advertiser, 06/12, p. 7. 



 Waiohinu, Kau, June 8--A sharp earthquake occurred [in Kau] at 3:50 p.m. June [date obscured; probably June 6, although the Lyman time for this date is 6 p.m.].



Anonymous, 1901, A submarine volcano here: Pacific Commercial Advertiser, 07/03, p. 1. 



 What is, to all appearances, a submarine volcano, has appeared at Kealakekua Bay, Hawaii. Professor Lyons, the Government meteorologist, has just received some specimens of black pumice stone from Mr. Leslie of Napoopoo, which his informant says is floating all over the Bay of Kealakekua. The pumice is of a shiny, jet black and covers the surface of the water for miles in every direction. The theory is that there has been a submarine outbreak in the vicinity, and that pumice has been ejected by seismic action.

 [reference to 1877 eruption]

 The pumice stone will be placed in the windows of Wall, Nicholls Co. where it may be seen.



Anonymous, 1901, Seismograph at work: Pacific Commercial Advertiser, 07/19, p. 5. 



 The seismograph recently set up at Punahou under the particular care of President Smith of Oahu College, for the purpose of registering subterranean disturbances, is, it is said, behaving badly. The machine is arranged so that violent agitation of the air will cause a needle to register correspondingly jagged lines on a film, and while the apparatus has shown itself faithful to its purpose several times, yet it repeatedly goes beyond its duty, and is now registering, with great precision, the violence of certain jars and shocks that are due not to earthquakes but to the heavy blasting in Manoa valley.



Anonymous, 1901, Earthquake Friday night; two distinct waves felt throughout the island of Hawaii: Hilo Tribune, 11/22, p. 5. [Reprinted verbatim in Pacific Commercial Advertiser of Nov. 25] 



 A vigorous earthquake was felt on this island Friday night [Nov. 15] at 10 o'clock. The shock came in two distinct waves, probably ten seconds apart. The second was the more violent of the two and made the windows rattle in many Hilo homes. At the Volcano Hotel the quaking was felt and the opinion of the manager was that the seismic wave started from the nether regions of Mauna Loa.



Anonymous, 1901, Heavy earthquake at Hilo: Pacific Commercial Advertiser, 11/25, p. 11. [Reprinted verbatim from Hilo Tribune of Nov. 22] 



 Hilo, Nov. 22.--A vigorous earthquake was felt on this island Friday night [Nov. 15] at 10 o'clock. The shock came in two distinct waves, probably ten seconds apart. The second was the more violent of the two and made the windows rattle in many Hilo homes. At the Volcano Hotel the quaking was felt and the opinion of the manager was that the seismic wave started from the nether regions of Mauna Loa.



Anonymous, 1902, [no title], in Local Brevities: Pacific Commercial Advertiser, 06/02, p. 7. 



 The Kinau brought news yesterday of slight earthquake shocks in the Hamakua district. Kilauea is still smoking, but not in an unusual manner.



Anonymous, 1902, [no title], in Local items: Hilo Tribune, 08/15, p. 5. 



 A slight earthquake was felt in Hilo last Friday afternoon [Aug. 8] at 2:25 p.m.



Anonymous, 1902, News notes: Pacific Commercial Advertiser, 08/18, p. ? [Reprinted in Hilo Tribune of Aug. 15.] 



 A slight earthquake was felt in Hilo last Friday afternoon [Aug. 8] at 2:25 p.m.



Anonymous, 1902, [no title]: Pacific Commercial Advertiser, 09/08, p. 9. 



 A map and cross-section of Halemaumau crater on August 29, 1902 drawn by E.D. Baldwin. Data for the surrounding area of Kilauea crater are attributed to F.G. Dodge Plans, in Records 1891-1898, p. 40 and 111. The crater as drawn is about 1500 feet across and 600 feet deep.



Anonymous, 1902, Hot rocks at Puna: Hilo Tribune, 10/17, p. 5. 



 Hilo railroad workmen engaged in obtaining road bed material from the great volcanic cinder pile at Puna were astonished and frightened last Monday morning to see puffs of steam and dust issue about them from the volcanic material upon which they were working. The first puff startled the workmen. The second sent them down the hill. When it was seen that the premonitory symptoms of a Martinique upheaval were not followed up, they resumed their labors but not without fears and misgivings.

 Reports are to the effect that steam is visible every morning. It seems to issue from a volcanic crack along which the rocks are too hot to bear the hand. Answers to a few inquiries indicate that the phenomenon is one altogether new in Puna.



Anonymous, 1902, [no title], in Local items: Hilo Tribune, 10/17, p. 5. 



 The people of Hilo were awakened about 4 o'clock Thursday [Oct. 16] by a slight earthquake shock.



Anonymous, 1902, [no title], in Miscellaneous: Pacific Commercial Advertiser, 10/20, p. 2. 



 Quite a heavy shock of earthquake was felt in the Makawao region [Maui] early Wednesday morning, the 15th.



Anonymous, 1902, Halemaumau's lava pit is rapidly filling up with lava while geysers of fire dot the great lake: Pacific Commercial Advertiser, 11/17, p. 1. 



 A description of the return of lava to Halemaumau beginning Tuesday, Nov. 11. A cross-section shows an asymmetrical conical crater 1500 feet in diameter and about 1000 feet deep.



Anonymous, 1902, Another earthquake: Pacific Commercial Advertiser, 11/17, p. ? 



 One of the heaviest earthquake shocks in recent years was experienced by the people of Honokaa shortly after 7 o'clock Tuesday night. Disturbances were reported at the same time by people in Waimea. The shock was noticed in Hilo and Olaa.



Anonymous, 1903, Early morning earthquake: Pacific Commercial Advertiser, 01/04, p. ? 



 Prof. Lyons, the Territorial meteorologist, report that at 7:29:30 yesterday morning a slight but distinct earthquake was felt in Punahou and also in Honolulu. A number of early risers also noticed that a tremblor was on.



Anonymous, 1903, New years day on Maui: Pacific Commercial Advertiser, 01/05, p. 8. 



 Maui, Jan. 3-- . . . .

 The earthquake

This morning (the 3rd) at 7:20 a.m., East Maui experienced two quite heavy shocks. The second vibration, was heavier than the first, making houses creak and windows rattle. There was an interval of a second or two between them.



Anonymous, 1903, Kilauea plugged; No connection with the Mauna Loa smoke columns: The Weekly Hilo Tribune, 08/07, p. 5. 



 A piece of the Puna side wall of Halemaumau crater, 500 feet long and 6-8 feet thick, fell in on August 1st. [Probably triggered by an earthquake at 11:50 a.m. (see Pacific Commercial Advertiser, Sept. 15, 1903).]



Anonymous, 1903, Has Mauna Loa broken out again?: Hawaiian Star, 09/04, p. 1. 



 A report [later proved false] of fire on Mauna Loa as seen from a ship approaching Oahu from Kauai.



Anonymous, 1903, Others see volcano fire: Hawaiian Star, 09/07, p. 3. 



 Further reports [later proved false] of fire on Mauna Loa as seen from the summit of Haleakala.



Anonymous, 1903, Mokuaweoweo now belching steam: Hawaii Herald, 10/08, p. 1. 



 [subheads: Largest volume ever witnessed by old residents; Great activity shown; Distance prevents many visitors from going to scene--smoke and steam visible from Volcano House]

 The article chronicles the eruption in Mokuaweoweo that began on the evening of Oct. 6, 1903. No mention is made of earthquakes.



Anonymous, 1903, Great glow of lava flow grand show: Pacific Commercial Advertiser, 10/10, p. 1. [Repeated in Hawaiian Gazette of Oct. 18, 1903] 



 [subheads: Miss Paris writes about bright spots of fire seen from Kona; Joseph Emerson's theory sustained--Mr. Bidgood tells of beauty and glory of the scene]

 A communication from Anna M. Paris, Kealakekua, Kona, dated Oct. 7, 1903: . . . "It has all been so quietly done. No earthquakes as yet. If the flow should stop suddenly we may expect them. . . .; communication from St. Claire Bidgood at Volcano House, 12:30 a.m. Oct. 7, 1903: . . .[the eruption] started at 12:45 this p.m. [Oct. 6] without any warning--no earthquakes or reports . . . .



Anonymous, 1903, Great activity at Mokuaweoweo: Hawaii Herald, 10/15, p. 1. 



 [subheads: Bright firelight continues visible from Hilo; With parties for crater; Outbreak was seen from vessel at sea--officers say flow was noticed--crowds watch fire]

 Most of the article chronicles the eruption in Mokuaweoweo that began on the evening of Oct. 6, 1903. Apparently the buildup and beginning of eruption were without felt events. The following entry is the only mention of earthquakes associated with the eruption.

 "Two days after the outbreak [Oct. 8] Kau experienced a short but heavy shock of earthquake, not noticed on the windward side of the island."



Anonymous, 1903, Volcanic tantrums; Mauna Loa crater dark since Tuesday night: The Weekly Hilo Tribune, 12/11, p. 1. 



 "Tuesday night [Dec. 8] . . . unusual brilliancy at the crest of Mauna Loa. But at about 10 p.m. the fire died away. . . . Wednesday night the peak was dark again. From all appearances the curtain has dropped at Mauna Loa.



Anonymous, 1904, [no title]: The Weekly Hilo Tribune, 02/19, p. 5. [Reprinted in Pacific Commercial Advertiser of Feb. 22 and Hawaiian Star of Feb. 20] 



 A vigorous earthquake visited Hilo Thursday [Feb. 18] forenoon between 10 and 11 o'clock.



Anonymous, 1904, News in a nutshell: Hawaiian Star, 02/20, p. 8. [Reprinted from Hilo Tribune of Feb. 19] 



 A vigorous earthquake visited Hilo Thursday forenoon [Feb. 18] between 10 and 11 o'clock.



Anonymous, 1904, [no title]: Pacific Commercial Advertiser, 02/22, p. 6. [Reprinted from Hilo Tribune of Feb. 19] 



 A vigorous earthquake visited Hilo Thursday [Feb. 18] forenoon between 10 and 11 o'clock.



Anonymous, 1904, Hiloites get busy: Hawaiian Gazette, 04/05, p. 2, 6. [Repeated from Hawaii Herald of ?] 



 Earthquake in Kohala

 A severe earthquake was felt in Kohala on the afternoon of the 29th inst. It lasted ten minutes and according to the report received from Manager Tulloch of the telephone company seemed to move in a northwesterly direction from the Kohala club to Mahukona. As yet no fatalities have been listed but we are sure there will be quite a list before the finish--Herald



Anonymous, 1904, Earthquake: Hawaii Herald, 04/07, p. 5. [Reprinted in Pacific Commercial Advertiser of April 11, 1904] 



 Quite a severe shock was felt here Monday morning [Apr. 4] at 7:30. No damage done.



Anonymous, 1904, Hilo earthquake: Pacific Commercial Advertiser, 04/11, p. 6. 



 Quite a severe shock was felt here Monday morning at 7:30. No damage done. The wise phrenologist is circulating the report that it had some connection with Madam Pele's head and this fact seems to be supported by word from the Volcano that there was an outbreak Monday night.



Anonymous, 1904, A whale story by Simerson: Pacific Commercial Advertiser, 05/07, p. 7. 



 On Friday, April 29 at 10:30 o'clock [am assumed] a most severe earthquake shock was felt at Keauhou and Punaluu. The shock lasted about eight seconds and was apparently from north to south.



Anonymous, 1904, Earthquake was heavy on the other islands: Pacific Commercial Advertiser, 06/05, p. 1. 



 Lahaina, June 4--A heavy earthquake lasting thirty seconds shook all Maui at 12:30 p.m. today. Light furniture and bric-a-brac were damaged everywhere.

 Severe on Molokai

Kamalo, Molokai, June 4--A severe earthquake shook Molokai at 12:30 today. Enormous rocks were detached from the mountain above here and rolled down the valley with a fearful noise. No serious damage was done.

 Hawaii heard from

 Manager Cross asked the operators of the Inter-Island Telegraph Co. on Hawaii to send particulars of the earthquake there. In reply it was stated that light shocks had occurred at Hilo and Honokaa. As they stopped at that, the inference was that the shock was less severe on the Big island than the others. Either that, or it takes a very great temblor to jar the island that monopolizes all the volcanoes.

 Temblor shook up Honolulu

An earthquake lasting 20-27 seconds took place yesterday in Honolulu at 12:29:24 and lasted until 12:29:55. The shock, or series of shocks, were distinctly felt in all parts of the city.

 In the business section the shocks were quite appreciable. The quake came with a sudden jolt which caused buildings to tremble. The shock was accompanied by rumbling. A few seconds and the shock was repeated, gradually wearing off into nothingness, to be repeated with less severity at intervals until it finally died out.

 In the grill room of the Young Hotel, the first shock came with what seemed to be a swaying of the building and a heavy rumbling. Diners stopped eating, the Chinese waiters came to dead halts and all talk was hushed. The contents of water coroffes [sic] heaved in miniature billows. When the occupants of the room finally divined the cause, watches were shipped out from pockets and the time taken. It seemed an interminable wait until the last shock had died away.

 At the same time looking from the windows of the grill room, just a perceptible swaying of the black smokestack of the Rapid Transit power house was apparent.

 In Waikiki, Kaimuki, Manoa and Nuuanu valleys the earthquake was quite apparent.

 In Manoa dishes were shaken from shelves and fell to the floor with a crash.

 Territorial Meteorologist Lydecker reports on the earthquake as follows: "My time for the earthquake was 12:27:25 p.m. and it lasted 23 seconds. There were two shocks, very close together, so close it seemed almost one. There was a slight lull between the two, the second one being heavier than the first. The first had a direction from south to north, and the second had a rotary motion, which caused sickness in the stomach for many. It shook the windows of houses in Punahou."



Anonymous, 1904, [no title]: The Weekly Hilo Tribune, 06/10, p. 5. [Also cited in the Pacific Commercial Advertiser of June 5 and 13 and July 14] 



 The slight earthquake shock experienced by Hiloites last Saturday noon was more vigorously felt on Molokai and Maui, where dishes and bric-a-brac suffered from the earth tremor.



Anonymous, 1904, [no title]: Maui News, 06/11, p. 3. 



 A sharp jar of earthquake was felt in Wailuku last Saturday [June 4], but no damage was done. The jar was general throughout the island and did some minor damage.



Anonymous, 1904, The earthquake: Pacific Commercial Advertiser, 06/13, p. 6. [Also cited in the Pacific Commercial Advertiser of June 5 and July 14 and the Hilo Tribune of June 10.] 



 The earthquake of last Saturday was the severest one experienced on Maui in several years. There were two or three shocks, the last being much the heaviest. In Paia and other parts of Makawao district china rattled, pictures swung to and fro, and walls of houses creaked and cracked ominously. At Kahului store much crockeryware was broken and bottles of salad oil smashed, the liquid running over shelves and floor. The vibration was the chief subject of conversation during the afternoon of the 4th.



Anonymous, 1904, [no title]: The Weekly Hilo Tribune, 07/01, p. 5. 



 A pretty vigorous earthquake shock was felt [in Hilo] Tuesday night [June 28] at 10 o'clock.



Anonymous, 1904, News in a nutshell: Hawaiian Star, 07/02, p. 8. 



 Hilo had a vigorous earthquake last Tuesday night [Jun. 28].



Anonymous, 1904, [no title]: The Weekly Hilo Tribune, 07/15, p. 6. 



 There was an earthquake shock on Monday morning [July 11] about 11:00 o'clock, which was felt throughout the city [Hilo] but with more severity in Puueo. Tuesday morning [July 12] about 10 o'clock there was another shock [felt in Hilo].



Anonymous, 1904, Heavy quakes felt in Kau: Pacific Commercial Advertiser, 07/20, p. 7. 



 The steamer Mauna Loa which got in early yesterday morning brings reports of heavy earthquake shocks in the Kau district. The shocks were very frequent and some were of considerable duration. No damage was reported. . . .



Anonymous, 1904, Signs of activity: Hawaii Herald, 07/21, p. 1. 



 Volcano House, July 19--The heavy earthquake shock last Sunday [Jul. 17, 1904] caused a disturbance in the crater here that has kept up ever since. The walls began caving in immediately after the quake and lava has been falling since Sunday. The cones and cracks from which the sulphur fumes have escaped since last January are entirely covered by debris and the floor of the crater is entirely free from smoke. . . .



Anonymous, 1904, Violent earthquake; shock felt throughout district. Volcano changes shape: The Weekly Hilo Tribune, 07/22, p. 2. 



 Last Sunday at 2:00 P.M. quite a seismic visitation came to Hilo and vicinity, waking the good inhabitants from their afternoon siestas, and tumbling pictures and bric-a-brac about in a heedless manner. The quaking was slow and steady, vibrating about 33 seconds, with a period in the middle of about 5 seconds of real genuine jolting. Houses and trees could be seen swaying to and fro, and considerable damage was done to crockery, glass, etc. The shake was felt at the Volcano House, which was rather unusual as most earthquakes that strike Hilo are merely felt at the Volcano. Evidently the shock caused several cracks in the wall of the crater for during the night there were cave-ins on the east and south sides of the pit. Walls heretofore of an angle of 50 or 60 are now perpendicular. The lava flow and cones are covered with about 50 or 60 feet of debris. The hot cracks are much hotter, and the crater itself is perfectly clear, no steam or sulphur fumes escaping at all. If this lack of smoke continues there is apt to be an explosion and outbreak shortly, according to kamaainas who profess to know.



Anonymous, 1904, Kilauea caves in: Pacific Commercial Advertiser, 07/24, p. 10. 



 According to reports brought up to Hilo by the steamer Kinau an earthquake shock last Sunday caused the walls of the inner crater of Kilauea to cave in. The shock occurred at 2 p.m., the vibrations lasting for some 33 seconds with about five seconds of hard quake in the middle. The quake was felt at the Volcano house, an unusual thing. As no smoke is proceeding from the choked crater those who profess to know predict an outbreak of the pent up forces soon.



Anonymous, 1904, [no title], in Locals: Maui News, 10/15, p. 2. 



 At 15 minutes to 4 o'clock yesterday morning [Oct. 14] Central Maui was shaken by a sharp shock of earthquake, no damage resulting.



Anonymous, 1904, Earthquake shock: Pacific Commercial Advertiser, 10/15, p. 3. 



 Honolulu and its suburbs received a rather sharp and prolonged jar at 3:45 yesterday morning. There were two distinct temblors with a short interval between. On the Koolau side of the island the shock, according to reports, was heavier than in town. No damage is reported. Lahaina, Maui, felt a heavy quake at the same hour as Honolulu but without damage.



Anonymous, 1904, [no title]: Pacific Commercial Advertiser, 10/17, p. 3. [date or newspaper wrong-couldn't find in advertiser; column to left "Confidence"; column to right "J. above, picture of file drawers below"] 



 At 3:40 a.m. yesterday morning [10/14] East Maui people were awakened from slumber by the violent shaking of their beds, and their apartments and dwellings as well. The earthquake continued for several seconds. There were two shocks, one of longer duration than the other, Aside from the rocking, rattling and shaking there is little to make mention of.



Anonymous, 1904, [no title]: The Weekly Hilo Tribune, 10/18, p. 5. 



 Distinct shocks of earthquake were felt by Hilo residents at 10:30 Wednesday night [Oct. 12], 9 a.m. Thursday [Oct. 13] and Friday morning [Oct. 14] at 3:40. It is reported that the smoke has cleared from Kilauea crater.



Anonymous, 1904, [no title], in Condensed local items: The Weekly Hilo Tribune, 11/15, p. 5. [The same event [with times of 8 and 8:15 p.m.] is reported in the Lyman diary (Wyss and others 1992) and the Pacific Commercial Advertiser of Dec. 19] 



 A distinct earthquake shock was felt Sunday night [Nov. 13] about 8:40 o'clock.



Anonymous, 1905, Hawaii visited by earthquake: Pacific Commercial Advertiser, 03/27, p. 1. 



 Hawaii experienced an earthquake on Friday evening [March 24] at about 8:30 o'clock. Purser Story of the steamer Noeau, in yesterday from Honokaa, reports the phenomenon.



Anonymous, 1905, [no title], in Weekly crop bulletin for the week ending March 25, 1905: Hawaiian Gazette, 03/28, p. 4. [Repeated from Pacific Commercial ] 



 The eruption of Kilauea, Hawaii continues.

[no mention of earthquakes]

Advertiser of Mar. 28, p. 6



Anonymous, 1905, [no title], in Weekly crop bulletin for the week ending March 25, 1905: Pacific Commercial , 03/28, p. 6. [Repeated in Hawaiian Gazette of Mar. 28, p. 4] 



 Advertiser

The eruption of Kilauea, Hawaii continues.

[no mention of earthquakes]



Anonymous, 1905, Heavy earthquake: Hawaii Herald, 05/04, p. 5. 



 There was a rather heavy temblor in this district at 3:20 p.m. yesterday, the motion coming from all points of the compass at the same time. Dishes rattled on pantry shelves and bottles in the saloons jarred each other . . . The quake was light for the first two seconds and increased in violence until the motion ceased 10 seconds later. This is considered the heaviest shake Hilo has had in nine years. No damage is reported from the country.

 From the Volcano it is learned that the shock was quite distinct there, but . . . no material change was noted in the appearance of the [Halemaumau] lake. . . .

 At 4:10 there was another shock as severe, if not more so, than was the first. The clapper in the foreign church bell was dashed twice against the bell. There was considerable excitement among members of the Japanese colony and on Furneaux street, . . . [where] the women ran out of the houses in fear. At St. Joseph's convent there was an overturning of bottles and dishes, in some instances breaking them. In the saloons [with exposed glassware] no damage was sustained.

 The third and weakest shock occurred at 6:35 p.m. This one did not amount to much and was not noticed in some parts of town.



Anonymous, 1905, Heavy earthquake on Hawaii: Hawaiian Star, 05/06, p. 3. 



 Hilo, May 4.--There was a rather heavy temblor in this district at 3:20 p.m. yesterday [May 3], the motion coming from all points of the compass at the same time. Dishes rattled on the pantry shelves and bottles in the saloons jarred each other worse than a Carter veto of the license bill. The quake was light for the first two seconds and increased in violence until the motion ceased ten seconds later. This is considered the heaviest shake Hilo has had in nine years. No damage is reported from the country

 From the Volcano it is learned that the shock was quite distinct there, but as well as could be ascertained at the hour of going to press no material change was observed in the appearance of the lake. No one had returned from the pit, however since the shake occurred.

 At 4:10 there was another shock as severe, if not more so, than the first. The clapper of the Foreign Church bell was dashed twice against the bell, there was considerable excitement among members of the Japanese colony and on Furneaux Street, where many Japanese reside, the women ran out of the houses in fear. At Saint Joseph's Convent there was an overturning of bottles and dishes, in some instances breaking them. In the saloons, where, it is said, there is much glassware exposed, no damage was sustained.

 The third and weakest shock occurred at 6:36 p.m.. This one did not amount to much and was not noticed in some parts of town



Anonymous, 1905, Pit filling up: Hawaiian Star, 05/08, p. 8. [Communication from Demosthenes Lycurgus] 



 Easter cone more active than ever. Cone spouting several hundred feet. Fresh lava covers floor of crater. Now visible from Volcano House all night. If lava continues as at present, will not be long before pit will overflow.



Anonymous, 1905, The earthquakes; most violent shocks felt in recent years: The Weekly Hilo Tribune, 05/09, p. 5. [Repeated from Hilo Tribune of May 9, 1905] 



 . . . . The seismic disturbances that commenced Wednesday afternoon of last week [May 3] and lasted through the night and early morn, are the hardest shakes given Hilo since the early eighties. While no crack opened through the town as in 1896, yet the vibrations seemed more violent. The first shock at 3:18 and the second at 4:10 in the afternoon caused considerable damage to furniture, bric-a-brac and china, and while there were shakes and jolts during the night at 6:34, 10:38, 10:55, 11:10, 1:00 [am May 4] and at intervals during the wee hours of the morn, yet there was no great damage done, except to nerves and delicate stomachs. The Hilo Drug Store, which suffered so considerable in 1896, escaped damage on this occasion. The frequency of the shocks and at such short intervals seemed to portend something ominous, and it was this feeling that aroused the inhabitants more than the damage to personal belongings. The shocks were felt at the Volcano house, causing the breaking up of the sulphur banks. No apparent difference has been noted in Madam Pele's continuous performance so there was no apparent connection between the Volcano and the subterranean rush of gas, lava and steam, which sent the molecules of the earth tumbling over each other in the violent seismic waves of last Wednesday. On Friday evening [May 5] Hilo received another visitation on a small scale. There were two shocks at about 5 p.m., another at 6:30, one at 7:15 and another at 8:20. On Sunday evening [May 7] at 7:20 p.m. another shock aroused the memory of man, "Lest he forget! Lest he forget!"



Anonymous, 1905, Hilo has the shakes; heavy earthquake jolts: Pacific Commercial Advertiser, 05/12, p. 1. [Repeated from Hilo Tribune of May 9, 1905] 



 Hilo. May 10--The seismic disturbances that commenced Wednesday afternoon of last week [May 3] and lasted through the night and early morn, are the hardest shakes given Hilo since the early eighties. While no crack opened through the town as in 1896, yet the vibrations seemed more violent. The first shock at 3:18 and the second at 4:10 in the afternoon caused considerable damage to furniture, bric-a-brac and china, and while there were shakes and jolts during the night at 6:34, 10:38, 10:55, 11:10, 1:00 [am May 4] and at intervals during the wee hours of the morn, yet there was no great damage done, except to nerves and delicate stomachs. The Hilo Drug Store, which suffered so considerable in 1896, escaped damage on this occasion. The frequency of the shocks and at such short intervals seemed to portend something ominous, and it was this feeling that aroused the inhabitants more than the damage to personal belongings. The shocks were felt at the Volcano house, causing the breaking up of the sulphur banks. No apparent difference has been noted in Madam Pele's continuous performance so there was no apparent connection between the Volcano and the subterranean rush of gas, lava and steam, which sent the molecules of the earth tumbling over each other in the violent seismic waves of last Wednesday. On Friday evening [May 5] Hilo received another visitation on a small scale. There were two shocks at about 5 p.m., another at 6:30, one at 7:15 and another at 8:20. On Sunday evening [May 7] at 7:20 p.m. another shock aroused the memory of man, "Lest he forget! Lest he forget!"



Anonymous, 1905, [no title], in Local Brevities: Pacific Commercial Advertiser, 07/30, p. 12. [date or newspaper wrong-couldn't find in advertiser; Sunday Advertiser-Local Brevities section] 



 "There were two slight earthquake shocks about dinner time last evening" [probably refers to same event as next report]

 "Parties who came over from the windward side of Oahu last night reported that a distinct shock of earthquake was felt at Waihole on Friday night" [July 28].



Anonymous, 1905, [no title], in Local Brevities: Pacific Commercial Advertiser, 10/25, p. 9. [Not reported in Weekly Crop Bulletin for week ending Oct. 21, 1905 (Pacific Commercial Advertiser, 10/24/05, p. 6)] 



 There was a sharp earthquake shock on Hawaii late last week.



Anonymous, 1906, Kona felt the shock; Stirred up Mahukona: Hawaii Herald, 04/26, p. 1. 



 Honokaa, April 25, (Special)--A severe shock of earthquake was felt here shortly before 2 o'clock this morning. It was followed by two others which were less severe. The first shock lasted about half a minute. At Kawaihae stone walls were shaken down and the cistern at Kaiser's was wrecked.

 Mahukona, April 25, (Special)--Earthquake shocks were felt here at an early hour this morning. They were followed by a succession of heavy rollers from the sea. No damage was done.



Anonymous, 1906, Temblors shake Hilo; three mild earthquake shocks woke city up early Wednesday morning: Hawaii Herald, 04/26, p. 2. [Repeated in Hawaiian Star and Hawaii Evening Bulletin of Apr. 28] 



 Three distinct shocks of earthquake were felt in Hilo during the early hours of Wednesday. . . . As it was, the temblors yesterday did no damage. In the absence of an official record it may be stated that the first shock came a minute or so before 2 a.m. It was preceded by a slight rumbling sound and to the casual observer seemed to be a movement from the mountains to the sea. While its movement was distinct it is not known that it did any more harm than merely robbing a few Hilonians of their beauty sleep.

 The second shock was very light. It came a few minutes after the first and was succeeded by another so light that many people did not feel it at all. By telephone it was learned that Kau experienced the temblors at the same time but suffered no damage.



Anonymous, 1906, Earthquake on Hawaii; three distinct shocks felt there last Wednesday at about 2 o'clock in morning: Hawaiian Star, 04/28, p. 8. [Except for Mahukona dateline, repeated from Hawaii Herald of Apr. 26] 



 Hilo, April 26--Three distinct shocks of earthquake were felt in Hilo during the early hours of Wednesday. . . . As it was, the temblors yesterday did no damage. In the absence of an official record it may be stated that the first shock came a minute or so before 2 a.m. It was preceded by a slight rumbling sound and to the casual observer seemed to be a movement from the mountains to the sea. While its movement was distinct it is not known that it did any more harm than merely robbing a few Hilonians of their beauty sleep.

 The second shock was very light. It came a few minutes after the first and was succeeded by another so light that many people did not feel it at all. By telephone it was learned that Kau experienced the temblors at the same time but suffered no damage.

Honokaa, April 26--A severe shock of earthquake was felt here shortly before 2 o'clock this morning. It was followed by two others which were less severe. The first shock lasted about half a minute. At Kawaihae stone walls were shaken down and the cistern at Kaiser's was wrecked.

Mahukona, April 26--Earthquake shocks were felt here at an early hour this morning. They were followed by a series of heavy rollers from the sea. No damage was done.



Anonymous, 1906, Hilo felt quakes on Wednesday morning: Hawaii Evening Bulletin, 04/28, p. 2. [Repeated from Hawaii Herald of Apr. 26] 



 Hilo, April 26.--Three distinct shocks of earthquake were felt in Hilo during the early hours of Wednesday [Apr. 25]. . . . As it was, the temblors yesterday did no damage. In the absence of an official record it may be stated that the first shock came a minute or so before 2 a.m. It was preceded by a slight rumbling sound and to the casual observer seemed to be a movement from the mountains to the sea. While its movement was distinct it is not known that it did any more harm than merely robbing a few Hilonians of their beauty sleep.

 The second shock was very light. It came a few minutes after the first and was succeeded by another so light that many people did not feel it at all. By telephone it was learned that Kau experienced the temblors at the same time but suffered no damage.



Anonymous, 1906, [no title], in Weather bulletin for the week ending April 28, 1906: Pacific Commercial Advertiser, 05/01, p. 5. [Repeated in Hawaiian Gazette, p. 8] 



 Pepeekeo--We experienced quite a heavy earthquake shock at 2:00 a.m., followed by two slight ones at intervals of 10 minutes

 Hakalau--A heavy earthquake shock was felt here at 1:57 a.m. of the 25th, and a lighter one at 10:55 p.m. of the 26th

 Kau--A heavy earthquake shock, with direction north to south, occurred on the 25th at 2 a.m.



Anonymous, 1906, Slight earthquake: The Weekly Hilo Tribune, 05/01, p. 2. 



 A slight earthquake shock aroused some of the sleeping residents of the island at 2 a.m. Wednesday [April 25]. The whole island was affected in about the same degree--as was reported from the Volcano House, Waimea and Mahukona. . . .



Anonymous, 1906, Island pumice stone met, in News of the waterfront: Pacific Commercial Advertiser, 05/26, p. 7. 



 For nearly 200 miles large pieces of floating pumice stone were passed by the bark St. Katherine, which arrived at this port last Friday from the Hawaiian Islands. They were seen on April 20, about 400 miles from the Island of Oahu. Captain Saunders is under the impression that the pumice stone was from a subterranean volcano which was in action at the time of the earthquake here. [possibly the large earthquake of 4/25/1906] It was undoubtedly of recent occurrence, as the pumice stone was massed together. On many of the large pieces deep se crabs were seen clinging. Captain Saunders brought several samples of the pumice stone and will present them to the Academy of Sciences.



Anonymous, 1906, Pumice stone is found, in News of the waterfront: Pacific Commercial Advertiser, 05/30, p. 2. 



 Captains Schlemmer and Welsbarth bring news from the shores of the French Frigate Shoals, Laysan Island and other islands to the westward are covered with pumice stone. . . . The captains are of the opinion that this pumice stone came from near Formosa and was thrown upon the sea from some volcanic disturbance there. It is not thought that the pumice has anything to do with the San Francisco earthquake. The pumice at French Frigate Shoals is about the size of walnuts. At Laysan it was much larger. That at Laysan had been cast up on the beach on March 23, a month previous to the San Francisco quake. . . .



Anonymous, 1906, A quake at Hilo; a sharp temblor there night before last: Pacific Commercial Advertiser, 08/21, p. 1. 



 There was a sharp earthquake here [Hilo] at 9 o'clock last evening.



Anonymous, 1906, Hilo has a light quake: Pacific Commercial Advertiser, 09/01, p. 1. 



 There was a light earthquake here [Hilo] at 6:30 a.m.



Anonymous, 1906, Earthquake at Hilo followed by appearance of scalded fish: Pacific Commercial Advertiser, 09/04, p. 1. 



 An earthquake occurred here at 6:40 a.m. Shortly afterwards hundreds of dead fish were strung along the beach. The fish were apparently scalded by a submarine eruption off Keaukaha.



Anonymous, 1906, A fish phenomenon: The Weekly Hilo Tribune, 09/04, p. 5. 



 An unusual occurrence is reported by Fish and Food Inspector J.M. Hering. Since last Tuesday large numbers of dead fish have drifted ashore along the coast on both sides of Hilo Bay. . . .

 . . . the water was unusually warm, and this, in connection with the appearance of the fish, leads Mr. Hering to believe that the killing of them may have been due to submarine volcanic action, connected with the slight earthquake shock felt the Sunday evening previous [Aug. 31] at Hilo. Such a killing of fish occurred only once before, in the [18]70's, during an eruption of Mauna Loa.



Anonymous, 1906, Scalded fish drift up at Hilo; fish drift ashore dead at Hilo for the first time since the seventies: Hawaiian Star, 09/05, p. 1. 



 After describing the fish kill, the article concludes as follows: . . ."leads Mr. Hering to believe that the killing of them may have been due to submarine volcanic action, connected with the slight earthquake shock felt the Sunday evening previous at Hilo. such a killing of fish occurred only once before in the '70s during an eruption of Mauna Loa."--Hilo Tribune



Anonymous, 1906, A severe earthquake; Hilo got another shock early yesterday morning: Pacific Commercial Advertiser, 09/05, p. 1. 



 A severe earthquake was felt here [Hilo] at 3:15 this morning. It was not felt at the Volcano House and was felt lightly at Mountain View.



Anonymous, 1906, Deep water fish came up scalded: Pacific Commercial Advertiser, 09/06, p. 7. 



 An account, taken from the Hilo Tribune, of the fish kill thought to be connected with the earthquake felt in Hilo on Aug. 31, possibly indicating submarine eruption.



Anonymous, 1906, [no title], in Local Brevities: Pacific Commercial Advertiser, 09/10, p. 6. [Quoted from the Hawaii Herald of 9/4/1906] 



 A sharp earthquake shock awakened most Hilonians at 3:15 a.m. Tuesday. Beyond disturbing slumbers, the temblor did no damage.



Anonymous, 1907, Volcano measured; report that crater moved was incorrect: Hawaii Herald, 01/10, p. 2. [Repeated in Hilo Tribune, Oct. 15, 1903] 



 A survey of Halemaumau by E.D. Baldwin showed the depth to be 597-602 feet and width of 1300 feet. The locus of activity was found to be in exactly the same place as it was in 1893.



Anonymous, 1907, Volcanic action appears to be confined to Kau; Authentic statement regarding outbreak: Honolulu Evening Bulletin, 01/11, p. 1. 



 Hilo, Hawaii, Jan. 11--The crater on Mauna Loa broke out in eruption about midnight on Wednesday night; the illumination therefrom continued very brilliant until 4 o'clock in the morning, at which time it disappeared entirely.

 Fisherman who were in their boats off the Kona coast at the time reported that they saw a lava flow beginning at about the same place where the flow which occurred in 1887 commenced. However, it continued only a short distance until morning.

 The mountain has been clear aside from what appears to be a cloud of smoke. On the Kona side there is no indication of fire.

 "At Kapapala there were numerous earthquakes yesterday, but none of them were very severe. One shock took place at 1:30 o'clock and another at 9:30 o'clock yesterday evening, which was felt all over the island.

 This morning it was reported from Waiohinu, in the Kau district, that there had been five shocks felt there between the hours of 10 and 11 o'clock.

 At Pahala the shaking of the earth is almost continuous.

 There is still a little fire in the crater of Kilauea, but it appears to be in no way affected by the outbreak on Mauna Loa.

 The continuous earthquakes on the Kau side of the island are an indication of further activity.



Anonymous, 1907, Much interest is manifested in the Mauna Loa outbreak: Hawaiian Star, 01/11, p. 1. 



 Mokuaweoweo burst out last night, about eleven-thirty . . . . . . . Over thirty slight earthquakes have occurred here (Hilo) since midnight. . . .



Anonymous, 1907, Mokuaweoweo resumes her activity; fountains of fire play in the summit crater of Mauna Loa--Heavens lighted by subterranean glow: Hawaiian Gazette, 01/11, p. 1, 8. [Repeated in Pacific commercial advertiser of Jan. 11, 1904] 



 Accounts of the eruption in Mokuaweoweo. Start times are given variously as 11:30 p.m. and midnight. One correspondent says that "Over 30 slight earthquakes have occurred here (Hilo) since midnight." The article continues, stating that "There were no earthquake shocks just prior to the outbreaks of 1899 and 1903."



Anonymous, 1907, Fountains of fire play in the summit crater of Mauna Loa--heavens lighted by subterranean glow: Pacific Commercial Advertiser, 01/11, p. 1, 2. 



 [Two different sources report that Mokuaweoweo came into eruption at 11:30 or around midnight on Jan. 9]

 . . . [A Hilo correspondent reports that] over thirty slight earthquakes have occurred here (Hilo) since midnight [Jan. 9-10].

 There were no earthquake shocks just prior to the outbreaks of 1899 and 1903. [The remainder of the article recalls those two eruptions].



Anonymous, 1907, Fire continues in both craters; slight earthquakes in Hilo district yesterday morning, glow seen in Kohala: Hawaiian Star, 01/12, p. 10. 



 . . . Purser Beckley [of the S.S. Kinau] reports a few slight earthquakes of the earth in the Hilo district yesterday morning.

 . . . No earthquakes were felt in that [Kohala] district . . .



Anonymous, 1907, How the outbreak looked at Hilo: Hawaiian Star, 01/12, p. 1. 



 Nearly all Hilo was awakened on Wednesday night by the outbreak at the summit of Mauna Loa. It was first seen at about midnight. . . .

 . . . There have been many earthquake shocks on the other side, especially at Kapapala and one was felt in Hilo at 1:30 p.m. on Thursday [Jan. 10]. Another slight one was felt at 9 in the evening.



Anonymous, 1907, Lava still flows from Volcano in Kau district: Honolulu Evening Bulletin, 01/12, p. 1. 



 A report from a passenger on the Kinau covers continuing eruption from Mauna Loa's southwest rift zone, concludes with the statement:

 "There were a number of earthquakes in Kau, but very few in Kona."



Anonymous, 1907, Three forked stream of lava is flowing to the sea: Honolulu Evening Bulletin, 01/14, p. 1. 



 The article described continuing eruption from Mauna Loa's southwest rift zone, including information that the flow was advancing at the rate of about seven miles per hour.



Anonymous, 1907, Mauna Loa is in activity: Hilo Tribune, 01/15, p. 1. 



 [Subheads: Wonderful fiery spectacle witnessed from Hilo last Thursday morning; Flow crosses over Kahuku to the ocean; The government road covered and telephone system destroyed--second outbreak from the summit headed for the Kona side of the Island]

A report on the Mauna Loa eruption of 1907. There is a brief mention of seismic activity, as follows:

 Though not a solitary shock of earthquake was felt during the display in Hilo, it was learned that shocks were continuous at Montserrat's [Kapapala] Ranch, some thirty or forty being counted. During the day [Jan. 10], however, two temblors were felt in Hilo and a number of slight ones on the Puueo side of the Wailuku river. . . .



Anonymous, 1907, Kona reports new outbreak: Pacific Commercial Advertiser, 01/15, p. 1, 7. 



 Most of the article chronicles the flow from Mauna Loa's southwest rift zone.

 "The flow, which was accompanied by frequent severe earthquakes, started at 7:30 a.m. on January 16 and the eruption ceased on January 31."



Anonymous, 1907, Mauna Loa sends lava to the ocean: Hawaii Herald, 01/17, p. 1. 



 A report on the Mauna Loa eruption of 1907. A brief mention of seismic activity is made, as follows:

 The outbreak was utterly without warning, as far as is known. It was accompanied by a large number of earthquakes, on the other side of the island [from Hilo], and two or three in Hilo, though few people felt the Hilo ones. Those on the other side were severe and continuous enough to cause residents to pack their glassware and discuss moving, but no damage was done by the shakes.



Anonymous, 1907, [no title]: Pacific Commercial Advertiser, 01/18, p. 1, 3. 



 Over 50 shocks have been felt at Pahala on Jan. 8 and 9, one quite heavy on the afternoon of Jan. 8, with swaying bushes and trees. [The Lyman diary (Wyss and others, 1992), does not mention either the heavy earthquake on Jan. 9 or the swarm of thirty earthquakes on the morning of Jan. 9, said to be felt in Hilo (see Pacific Commercial Advertiser, Jan. 11, 1907.]



Anonymous, 1907, New cones forming close to the coast in Manuka district; New outbreaks reported at Kahuku--fresh flow crosses government road--two hundred earthquake shocks: Hawaiian Gazette, 01/18, p. 1, 8. 



 An account of the ongoing eruption from Mauna Loa's southwest rift zone.

 Repeated earthquake shocks (p. 8)

 Slight earthquake shocks continue to be felt throughout the island of Hawaii. Postmaster T.C. Wills, of Pahala . . . reports that two hundred distinct shocks have been felt [at Pahala] since the outbreak of Mauna Loa.

 Another resident of Pahala writes:

 . . . .

 "Thursday and Friday [Jan. 10-11] we felt at least fifty shocks or more of earthquake, the greater number being slight . . .

 "Thursday afternoon we had quite a heavy shock, plainly observing the trees and bushes swaying back and forth."

 The next section notes that Kilauea is exceptionally active.



Anonymous, 1907, Spectacle of lava from the sea; Captain Simerson of S.S. Mauna Loa tells of what he saw yesterday: Hawaiian Star, 01/18, p. 1, 5. 



 Much of the article is about the Mauna Loa southwest rift eruption, ending with the following two paragraphs:

 Earthquakes of a slight nature, generally, are being felt all over the island: In Pahala two hundred shocks have been felt since the outbreak. Various places report all the way from eight to sixty ordinary shocks since the outbreak of the lava. We did not feel any of the earthquakes aboard ship. They were not severe enough.

 Purser Charles Jones of the S.S. Mauna Loa reports that at Punaluu last Tuesday [Jan. 15], 53 distinct earthquake shocks were felt. At Kailua the telephone operator at central informed the purser that sulphur fumes were very noticeable.



Anonymous, 1907, Weekly Weather Bulletin for the week ending Jan. 19, 1907: Hawaiian Star, 01/22, p. 7. [Abridged from the Pacific Commercial Advertiser of the same date] 



 Earthquake shocks were felt during the week at a number of stations in the western and southern portions of Hawaii. The observer at Kau (Waiohinu) reports that there were many earthquake shocks felt on the 10th and 11th, and a light one on the 16th. Also, that an eruption occurred on the south side of Mauna Loa on the 11th, and that three streams of lava, all from one source, were flowing toward the sea in south, southwest and west directions. Very little of the glow from the eruption was seen at Kealakekua (Davis), Hawaii.



Anonymous, 1907, [no title], in Local Brevities: Pacific Commercial Advertiser, 04/04, p. 9. [Not listed in Honolulu Bulletin (Hazard, 1911); No Crop Bulletin published for this week] 



 Various credible citizens [Honolulu] say they felt an earthquake moving west to east and lasting three to seven seconds at 12:43 o'clock Tuesday morning [Apr. 2].



Anonymous, 1907, [no title], in Local Brevities: Pacific Commercial Advertiser, 04/26, p. 9. [Not listed in Honolulu Bulletin (Hazard, 1911)] 



 A slight shock of earthquake is reported to have been felt at Lihue, Kauai, between 12 and 1 o'clock Thursday morning [Apr. 25].



Anonymous, 1907, Quakes on Hawaii; two shocks felt on Tuesday morning--lasted for 40 seconds or longer: Hawaiian Star, 06/14, p. 1. 



 Two severe earthquake shocks were felt on the Island of Hawaii on Tuesday last [Jun. 11], early in the morning.

 Purser of the S.S. Mauna Loa, which arrived early today from Hawaii and Maui ports, states that he was standing ashore at Honuapo, with many others, when a violent tremor was felt, the shake continuing steadily for about 40 seconds.

 Those aboard the Mauna Loa . . . did not feel the shake . . . Everybody on the wharf felt the shock and several declared that it was the heaviest they had felt on Hawaii.

 At 4 o'clock, 26 minutes later, another and almost as heavy shake was experienced, lasting longer.

 It was learned later that the shocks had been felt in Hilo, Kona and Waiohinu.

 . . .



Anonymous, 1907, Big Island shaken last Tuesday by earthquake shock; Recent lava flows emitting steam: Honolulu Evening Bulletin, 06/14, p. 1. 



 Two heavy earthquake shocks occurred on the Kau coast last Tuesday morning . . . .

 The first shock was experienced at 3:43 a.m., and the last about fifteen minutes later. Purser of the Mauna Loa . . says they were tremendous. the trend of the temblor seemed seaward and the whole vessel shook and rolled as if in a heavy storm. . . .

 "We were lying off Honuapo, loading sugar," said this morning, when the shock occurred. It caused the steamer to tremble from stem to stern, so the shock must have been felt with considerable force on shore. The shocks seemed to be strongest in Kau, but they were also felt in the Kona district, even as far as the Maguire ranch at Heuhu. They were also felt in a small degree at Hilo, but the force seems to have diminished the further places were from Kau. I do not think that any damage was done, at least none was reported to us.



Anonymous, 1907, Steamer reports shocks: Pacific Commercial Advertiser, 06/15, p. 9. 



 Earthquake shocks on the Island of Hawaii last Tuesday morning were reported by officers of the Steamer Mauna Loa upon her arrival here early yesterday morning. Purser states that at 3:43 o'clock a most severe shock was felt, and another longer though less violent tremor was felt at 4 o'clock sharp. The Mauna Loa was in Honuapo at the time . . . and, with a number of others was ashore near the landing. Those aboard the steamer did not feel the disturbance, but all ashore agreed that they felt a shake more violent than any they had experienced on Hawaii. The first shake lasted about forty seconds. It was learned that seismic phenomena had been felt elsewhere on the island, in Hilo, Kona and Waiohinu.



Anonymous, 1907, [no title], in Local Brevities: Pacific Commercial Advertiser, 06/15, p. 9. 



 Two heavy shocks of earthquakes are reported as having occurred last Tuesday morning [Jun. 11] at 3:43 and fifteen minutes later on Hawaii.



Anonymous, 1907, Slight earthquake shook the city: Pacific Commercial Advertiser, 07/06, p. 1. [Not listed in Honolulu Bulletin (Hazard, 1911)] 



 A slight earthquake shock was felt in all parts of the city [Honolulu] last night at five minutes to twelve. The shock lasted but a few seconds but was quite distinct.



Anonymous, 1907, Locals: Maui News, 07/13, p. 5. [Not listed in Honolulu Bulletin (Hazard, 1911)] 



 A distinct earthquake was felt on Maui and throughout the group last Friday night [Jul. 5] at 11:45. The shock lasted some seconds, but did no damage.



Anonymous, 1907, Hawaii shaken by sharp 'quake: Honolulu Evening Bulletin, 09/06, p. 1. 



 Hilo, Hawaii, Sept. 6.--A sharp earthquake shock was felt here at eight minutes of seven last evening. the quake was felt all over the Island of Hawaii and was especially hard in Kohala, at Papaikou and Kau. A slight second shock was felt thirty seconds later.

 Hilo buildings creaked and swayed in a long movement and the foundations trembled. Liquid in full bottles was upset. The general opinion is that this shock is the worst since 1882. Communication with the Volcano is interrupted.



Anonymous, 1907, Beckley tells of recent earthquake at Hilo: Honolulu Evening Bulletin, 09/07, p. 2. 



 . . . heavy shocks of earthquakes were felt in Hilo at about 7 o'clock on Wednesday night. the wharf was badly shaken up, but fortunately was not damaged. . . .



Anonymous, 1907, Shock slight at the volcano; Hilo rocked by quake but Kilauea shows only slight interest in event: Pacific Commercial Advertiser, 09/08, p. 1. 



 Hilo, September 7 (received 5:15 p.m.)--The Volcano wire was interrupted after the earthquake shock [on Sept. 5]. Communication was restored this afternoon.

 There was but a slight shock of earthquake at the Volcano Thursday [Sept. 5]. . . .



Anonymous, 1907, [no title], in Condensed local news: Hilo Tribune, 09/10, p. 5. 



 A sharp earthquake shock was felt in Hilo on Thursday evening [Sept. 5] shortly before seven o'clock. No damage was reported.



Anonymous, 1907, Hilo stirred by earthquake; sharp shock made houses tremble; after dinner coffee spilled from cups: Hawaii Herald, 09/12, p. 6. [Text, omitting last paragraph, repeated in Pacific Commercial Advertiser of September 13, 1907] 



 Some made a rush for their babies. Others made a rush for their doors. This was when the earthquake shook up Hilo at 6:42 o'clock on Friday [Thursday] evening last.

 . . . 

 It was a lively little shock, while it lasted, only a few seconds, lively enough to let everybody in Hilo know that something unusual had happened. It was a long, steady motion that swayed houses perceptibly, made timbers creak and foundations strain. But it was soon over and pictures settled back against the wall, tea and coffee stopped from spilling over into the saucers, liquids in full bottles that had been dripping over returned to their normal steadiness. Only in Kennedy's jewelry store, on Front street, is it known that a few pieces of cut glass moved from their place, and a couple of articles of silverware fell on their sides. Yet in the Hilo Drug Store, close by, nothing moved at all, so far as could be seen.

 First reports by telephone came from Laupahoehoe, then Kau was heard from. . . . Next morning Hakalau reported a lively terrestrial movement, while Kohala seemed to have excelled in shakes. E. Faxon Bishop came in from Papaikou and said it was as bad as he wanted. Waimea felt it. In fact the tremor showed no discrimination but let its presence be felt all over the Big Island.

 One man in Hilo, who has been living on Hawaii for nearly thirty years, said:

 "It was the worst shake I have felt since '82."

 Other old timers would not go back as far as that, but they shook their heads and acknowledged that "it was a bad shake all right, the worst we have had for many years."

 There was no communication with the Volcano House till Saturday afternoon when it was learned that only one light shock had been felt there. At Shipman's ranch, however, there were three distinct shocks, one at 6:52 p.m., a lighter one 20 minutes later, and a third during the night which was sharp enough to awaken the entire household. The first of the three was the most severe felt for many years; pictures moved, a few bottles upset in a workroom, and as a matter of safety a rush was made for the lamps.



Anonymous, 1907, Shake was sharp but not prolonged: Pacific Commercial Advertiser, 09/13, p. 6. [Repeated from Hawaii Herald of September 12, 1907] 



 Hilo, September 9--Some made a rush for their babies. Others made a rush for their doors. This was when the earthquake shook up Hilo at 6:42 o'clock on Friday [Thursday] evening last [Sept. 5].

 . . . 

 It was a lively little shock, while it lasted, only a few seconds, lively enough to let everybody in Hilo know that something unusual had happened. It was a long, steady motion that swayed houses perceptibly, made timbers creak and foundations strain. But it was soon over and pictures settled back against the wall, tea and coffee stopped from spilling over into the saucers, liquids in full bottles that had been dripping over returned to their normal steadiness. Only in Kennedy's jewelry store, on Front street, is it known that a few pieces of cut glass moved from their place, and a couple of articles of silverware fell on their sides. Yet in the Hilo Drug Store, close by, nothing moved at all, so far as could be seen.

 First reports by telephone came from Laupahoehoe, then Kau was heard from. . . . Next morning Hakalau reported a lively terrestrial movement, while Kohala seemed to have excelled in shakes. E. Faxon Bishop came in from Papaikou and said it was as bad as he wanted. Waimea felt it. In fact the tremor showed no discrimination but let its presence be felt all over the Big Island.

 One man in Hilo, who has been living on Hawaii for nearly thirty years, said:

 "It was the worst shake I have felt since '82."

 Other old timers would not go back as far as that, but they shook their heads and acknowledged that "it was a bad shake all right, the worst we have had for many years."



Anonymous, 1907, Directors of Kukuihaele meet: Pacific Commercial Advertiser, 10/08, p. 2. 



 About three weeks ago [Sept. 20?] an earthquake at Kukuihaele split the land on which the largest warehouse is built, a large crack running under the building and causing part of it to settle from eight to nine inches.



Anonymous, 1907, An earthquake last evening; a disturbance about nine o'clock lasting for several seconds: Pacific Commercial Advertiser, 12/20, p. 1. 



 Yesterday evening, at about five minutes to nine, an earthquake occurred, which was felt all over the city [Honolulu]. There were two shocks, which followed each other within a few seconds, the entire disturbance occupying a period of about fifteen seconds.

 It is some four or five years since an earthquake of similar intensity has been felt in this city, although slight shocks have been reported now and then. The fact that the crater at Kilauea, on the island of Hawaii, has been active for the first time in seven months, is interesting in connection with the shocks last night.

 The quake was felt also in the outskirts of the city. In Nuuanu valley, Palolo and in Kalihi, as well as at Waikiki, the residents at once reported it to the Advertiser over the telephone. Owing to the fact that the Wireless Telegraph Company is closed in the evening, it is impossible to find whether the quake was caused by any volcanic disturbance which was noticeable on the island of Hawaii.

 R.H. Trent, living in Nuuanu Valley, reported a long shock in that section. In Palolo the quake was reported by W.F. Foster, who stated that it was severe and lasted for twenty seconds. On Pacific Heights, Gilbert J. Walter felt two shocks, slightly separated from each other and both severe.

 W.I. Soper states that at his home on Wyllie street he felt the quake in two shocks and that the direction seemed to be from southeast to northwest. Judge Kingsbury, living on Thurston avenue, says that his house was well shaken up. At the fire station the switchboard was affected by the force of the movement.

 From Waikiki, Colonel McFarlane reported. He said: "The shock apparently reached the beach from the direction of Punchbowl. I believe that there must have been a shock on the island of Hawaii as the shocks on this island generally follow seismic disturbances there."



Anonymous, 1907, Earthquake visits Maui and Oahu; Two distinct earthquakes were felt on Maui and Oahu--no damage done: Maui News, 12/21, p. 1. 



 Honolulu, December 20--Two distinct earthquake shocks were felt here last night about nine o'clock



Anonymous, 1907, [no title], in Personal and General [datelined Lahaina, Maui, Dec. 20]: Pacific Commercial Advertiser, 12/23, p. 2. 



 There was a sharp earthquake vibration in this town [Lahaina] on Thursday, December 19, at 9 p.m.



Anonymous, 1907, Madam Pele restless; Earthquake of long duration was felt Thursday night: Hilo Tribune, 12/24, p. 5. 



 A long sustained shock of earthquake was felt in Hilo and, in fact, all over the island of Hawaii on Thursday evening at ten minutes to nine. Though it was by no means severe the unusual length of time that the vibration continued was sufficient to alarm many people. There came the usual premonitory rumble, a slight jelly-like shivering and then a very pronounced lateral shaking. This subsided to the former shivery motion and again there was a more severe shock. Various estimates are made as to the total duration but it is agreed that it lasted anywhere from fifteen to twenty five seconds. No damage of any kind was done. Reports from different parts of the island indicate that the temblor was generally felt. In Honokaa and all through Kohala the earth trembled. The volcano, which has recently been active, continued in activity . . . .



Anonymous, 1907, [no title], in Local Brevities: Pacific Commercial Advertiser, 12/24, p. 13. 



 There were two distinct shocks of earthquake felt on Molokai last Thursday night, corresponding to the hour at which tremors have been reported on Hawaii, Maui and Oahu. It seemed to be a perpendicular vibration rather than a lateral motion, as if the earth's disturbance was directly underfoot.



Anonymous, 1907, Earthquake on Hawaii: Hawaii Herald, 12/26, p. 5. 



 A long shock of earthquake was felt in Hilo Thursday evening [Dec. 19] about 8:50 o'clock. While not very sharp, it was vigorous enough to shake bottles on shelves, but was mainly notable for its duration. It corresponded with the time of a Honolulu tremor which was severe. Honokaa reports feeling the shock which was very sharp about the middle period of its illustration. Laupahoehoe reported a very hard shock there at 8:54 p.m., but no damage done.



Anonymous, 1907, New cones forming close to the coast in Manuka district: Pacific Commercial Advertiser, 01/18, p. 1, 3. [Reports from various persons; also in Hawaiian Gazette, Jan. 18, p. 1, 8] 



 Eruption began in Mokuaweoweo on January 9 and died quickly. An earthquake swarm began on January 10. By January 12, 200 earthquakes had been felt, and a second eruption had begun above Kahuku. Kilauea was also active.



Anonymous, 1908, [no title]: Hilo Tribune, 01/19, p. 1. 



 Three slight earthquakes were felt at Hilo last week, almost coincidentally with the tidal phenomena on the Kona and Kohala coasts.



Anonymous, 1908, Volcanic activity is noticed in Hilo: Hawaii Herald, 07/23, p. 1. [Reprinted in Volcano House Register (Bevens, 1988)] 



 . . . . shortly after nine o'clock on Tuesday morning [Jul. 21, 1908] , a slight shock of earthquake was felt [in Hilo], its direction seemingly being from east to west.



Anonymous, 1908, Collapse of molten lake; magnificent sights seen at crater--lava rises again: Pacific Commercial Advertiser, 09/09, p. 1, 5. 



 On Friday afternoon last [Sept. 4] an earthquake shock of unusual force was felt in Hilo and that evening the boiling lava in Halemaumau began to pour out in a fiery whirlpool through the bottom of the firepit. On Saturday afternoon another shock came to [Hilo] and that night it was reported from the Volcano House that the volcano was again active and the molten lake was rising. Whatever the connection there may have been between the two shocks and the subsidence and breaking out again of the volcano can only be authoritatively addressed by scientists, but the two affairs were very generally commented on by Hiloites yesterday.

 [The remainder of the article describes the collapse and recovery of Halemaumau lava lake. The timing of earthquake and collapse quoted above disagrees with that reported in the Hawaii Herald of Sept. 10. That article makes clear the collapse and draining began in the afternoon and the earthquake occurred after much of the lake was drained.]



Anonymous, 1908, Freaks of Halemaumau and shocks of earthquake: Hawaii Herald, 09/10, p. 1, 5. 



 In connection no doubt with the subterrestrial disturbance that has taken place in the Kilauea region, several earthquakes have been noticed in Hilo. The first of these occurred about noon on Wednesday, September 2. The next was on Friday evening [Sept. 4] at 6:15 o'clock. This was followed by a third one, twenty-four hours later at 6:15 o'clock. On Sunday morning [Sept. 6], at 8:30 o'clock, a lighter quake was felt. That of Saturday evening was the most severe. Its motion apparently was from east to west . . .

[The beginning and remainder of this article has personal descriptions of the sinking lava lake. The lake began sinking on Friday afternoon, Sept. 4, prior to the earthquake on the evening of Sept. 4. By Saturday morning the lake was empty, five or six hundred feet down from where it was Friday morning, with nothing but smoke to be seen. On the morning of Monday, September 7, the bottom of Halemaumau again dropped at eight o'clock]



Anonymous, 1908, Collapse of molten lake: Hawaiian Gazette, 09/11, p. 2. [Repeated from Pacific Commercial Advertiser of Sept. 9, 1908] 



 Hilo, Hawaii, September 7.--On Friday afternoon last [Sept. 4] an earthquake of unusual force was felt in Hilo and that evening the boiling lava in Halemaumau began to pour out in a fiery whirlpool through the bottom of the firepit. On Saturday afternoon another shock came to the Big Island metropolis and that night it was reported from the Volcano House that the volcano was again active and the molten lake was rising. Whatever connection there may have been between the two shocks and the subsidence and breaking out again of the volcano can only be spoken of authoritatively by scientists, but the two affairs were very generally commented upon by Hiloites yesterday.



Anonymous, 1908, Hilo had shake last night; Hilo shocked seven seconds: Honolulu Evening Bulletin, 09/21, p. 1. 



 Hilo, Hawaii, Sept. 21.--The heaviest earthquake that has visited this town in years and experienced Sunday evening at ten minutes past eight. The shock was heavy and lasted seven seconds.

 No serious damage was done although all the stores and residences suffered some loss from broken glass ware that was shaken off the shelves.

 The shock had no apparent connection with the Volcano, which has undergone no special change, though still very active.



Anonymous, 1908, Severe earthquake shocks and more volcanic action: Hawaiian Gazette, 09/22, p. 1. [Repeated in Hawaiian Gazette of Sept. 22, 1908] 



 Hilo, September 21.--The heaviest earthquake felt on the island of Hawaii since 1868 occurred at 8:15 Sunday night [9/20/1908]. All parts of the Island were shaken. While no serious damage was done, much crockery and bric-a-brac were broken. The volcano became exceedingly active, the lakes rising and filling the pit from ten to fifty feet every few hours, accompanied by falling banks. There were many fire fountains. An artesian well of molten lava twenty-five feet in diameter gushed to a considerable height continually pouring a cataract down the east bank of the pit.

 Other particulars: Prof. Alexander stated yesterday that he distinctly felt an earthquake shake Sunday evening at eight minutes past eight o'clock. It was from mauka to makai and quite distinct. In fact, it was of such long duration and the movement so pronounced that he put out his hand to hold a lamp which was on a table. News of the same series of shocks at Hilo was received yesterday in the following wireless telegram from Hilo:

 A very sharp earthquake shock took place here at eight o'clock last night.

 Much glass and liquor in bottles resting on shelves were destroyed by being thrown to the floor. Windows were broken in many places and plaster was cracked in the Inter-Island office.

 The shock was severest in Puueo.

 An hour before the shake the lava in the volcano dropped a hundred feet. Then, immediately before the shake, it rose to almost the level of the top of the pit.

 The shock was violent in Hilo and also in Puna. Sam Johnson was shaken from his bed.



Anonymous, 1908, Hilo has big shake; a roar and a rattle--the volcano joins in the fun--Neptune takes a hand--big fright, damage slight--worst quake for over twenty years: Hilo Tribune, 09/22, p. 1. 



 . . .

 . . . For the brief space of half a minute, the town of Hilo rocked and rattled to its foundations, and then the sensation was over . . .

 . . . Some old residents say there has been nothing like it for thirty years past, but others aver that the shake of 1887 was quite equal to that of Sunday night. . . .

 . . . without the slightest warning, there came a mighty subterranean roar, and to the music of this sound the churches, stores and dwellings swayed and rattled and shook. . . .

 . . .

 Visits of inspection and inquiry around town disclosed the fact that very little damage had resulted from the earthquake. The only building showing perceptible injury was an old unoccupied store . . . The high false front of this structure came down with a crash and partly wrecked the veranda and front of the building. As seen yesterday, the sight was a confused mass of old timber and electric wire.

 [Detailed damage reports follow, mainly falling plaster, broken bottles, etc. in various businesses]

 The damage done in private dwellings may amount to a considerable sum in the aggregate, but in no individual case was it great. Many clocks stopped short, so that there was no difficulty in fixing the time of the shock at a few minutes after 8 p.m. In one home the clock refused to stop, despite the fact that the pendulum was lifted from its attachment by the shock and thrown down.

 Along the water front some alarm was felt, from the fact that immediately after the shock a considerable tidal wave was impelled ashore. This did not rise more than four feet over the usual mark, but some shore residents were so frightened that they came into town for the night.

 [at the volcano] about six in the evening the lava in the crater of Kilauea suddenly dropped down about 100 feet and the fountains began to play with great vigor. . . Then the crater began to fill very rapidly to within 50 to 100 feet of the rim. . . 

 The earthquake shock was very severe at Volcano House. It is described as the heaviest shock ever experienced at that altitude.

 From inquiries at a number of places, it is evident that the shock was felt all over the island. At Waimea, Punaluu and Holualoa, as well as at other points, the shake was alarming, but in no case was any damage done. At the Mahogany Company's mill in Puna, there was a severe shock, and a lighted lantern was thrown down with great violence, but no damage whatever was done to the mill buildings or machinery.



Anonymous, 1908, Houses down and slight earth cracks caused by Sunday evening's quake: Hawaii Herald, 09/24, p. 1, 5. [Reprinted verbatim in the Pacific Commercial Advertiser of Sept. 28, 1908, and the Hawaiian Gazette of Sept. 29, 1908, p. 3] 



 "The most severe shock of earthquake felt in Hilo since 1868," is how L.A. Thurston described the shake-up that this city received a few minutes after 8 o'clock on Sunday evening last. Others claimed it was not so bad as the tremors of 1886 or 1888. Anyhow, it was lively enough to make everybody sit up and take notice. Both Mr. Thurston and Mr. Julian Monsarrat agreed that it was a Mauna Loa shake, and as Mr. Monsarrat lives on the slopes of the big mountain he ought to be credited with some knowledge about them.

 The most serious damage was done near Kalapana, in Puna, where three houses occupied by Hawaiians were leveled to the ground. Slight cracks in the earth have been made in Hilo, near the bridge, and on the road leading to the Shipman residence on Reed's Islands. There was a tidal wave about three feet high. A few buildings suffered from cracked plaster, there was loss in grocery and liquor houses, and more of it in private dwellings.

 Shocks were felt slightly on Monday, and at least six distinct ones during Monday night; others until Tuesday evening, so that the earth has been trembly for forty-eight hours.

 When the crash came, for it did come with a crash, there was a general desire for fresh air . . . As usual, the shake was felt most severely in Puueo, but there was considerable damage done in the business section of the town. An unusual feature consisted of in cracks, small ones, appearing in the road to the Shipman home across the bridge, and on the made ground from the house at Reed's Island to the government road. Both Mr. Shipman and Mr. Thurston told the Herald that these cracks were visible longitudinally and transversely, and were about wide enough to admit the insertion of a knife.

 Slight tidal wave: A second, and lighter, shock followed a few minutes after the first one. Others were reported at 9 p.m., 11 p.m., near midnight, and at 3 a.m. A tidal wave about three feet high accompanied the shake, being noticed where the Wailuku River discharges itself at Puueo, at Waiakea, and at Reed's Bay. On board the Claudine, lying alongside the Hilo railroad wharf, the shock was distinct, and the little vessel trembled from stem to stern. The motion of the shake was from northwest to southeast, and like a succession of waves. At the Volcano House it was not felt as nearly as severely as at first reported, and the fire did not reach the top of the pit. It was very active, however, sometimes dropping a hundred feet, again rising.

 Chimneys move and break: In Hilo there were many curious freaks played in the movement of furniture, glassware, pictures and other household adornments and necessaries. Water spilled from many tanks in bathrooms. No buildings were thrown down here, but many owners and occupants thought they would be, so got out from under. At the Board of Health office it will cost about $25 to replace the glassware needed by Inspector Bowman, who also lost half the chimney of his rodental crematory. At the hospital Dr. Hayes report the brick chimney cracked across and the upper portion turned halfway around on the lower base. The high school suffered no damage. At Ferndale station, on the Hilo railroad, the water tank came to the ground.

 Downtown section: Serrao building, at the corner of Shipman and Bridge street, is cracked slightly on both frontages. The bottle pickles, sauces, jams and other things fell in a mass in the Serrao and Turner groceries, . . . Glassware and bottles in Serrao's, Demosthenes' and other places went from bar to floor, the liquor stocks in pantries and wholesale houses also blending with the broken glass. There was much cleaning up to be done, except at the Peacock wholesale house, where Austin has his goods wired in and consequently lost only one bottle of sake. But the Peacock's block was not so fortunate, the four corners on the Bridge street side of the Hilo Bank windows are chipped off, though nothing touched them. There is a crack in the plaster of the bank several feet long and several inches wide, which also show in the Count Attorney's office on the other side of the wall. In the sitting room upstairs and in the hall there was, here and there, a light sprinkling of plaster on the floor, and the big water cooler went off its base. At Holmes' store it was the crockery that suffered most. Soap fell to the floor in barbershops, a window in the Inter-Island office was smashed, two windows in the Herald office were broken and one press was moved five inches out of plumb. The top of the little shoe shop next door was about three inches out of place, overhanging on the sidewalk, and it has since been moved back into position. The Hilo drug store lost a couple of bottles, everything there being wired, and there was no damage at Kennedy's jewelry store, not even a piece of cut glass cracked.

 It was near Kalapana that three houses, occupied by Hawaiians, fell to the ground. At the Hawaiian Mahogany Camp, Superintendent Sam Johnson was thrown from his bed. He immediately rushed to the mill, where he found all the lamps upset and extinguished, but no damage done. At Waimea, Charlie Hall landed on the floor after retiring early. At the plantation the mill machinery is being carefully examined, and from all parts of the island the reports come of more or less severity in the shake and of more or less damage. The private houses seem to have suffered the most, and the loss from broken furniture and glassware must mount up to many thousands of dollars in all parts of the island.



Anonymous, 1908, 'Quake returns: Honolulu Evening Bulletin, 09/24, p. 5. [Repeated in Hilo Tribune of Sept. 29] 



 Charles K. Notley received a letter from his son William, who is at Paauilo, Hawaii. Under the date of September 21 he writes, "We had quite an earthquake shock up here on Sunday evening. It shook pretty lively; the strongest we have had on this Island. It shook the water out of the tanks; I thought we were going to lose all of our water.

 From Kalae, Molokai, comes the following: On Sunday evening 20th inst. a very gentle rocking of the earth was felt here. First an instantaneous movement, a pause and then a gentle and continuous rocking. The movement gave the sensation of being directly underneath.



Anonymous, 1908, Telegraphic news: Maui News, 09/26, p. 4. 



 Hilo, September 21--The heaviest earthquake since 1868 occurred at 8:15 Sunday night [Sept. 20] and was felt throughout the island. Much crockery and bric-a-brac was broken. No serious damage was done. Sam Johnson was shaken out of his bed at the camp. The volcano is exceedingly active. The lava lake is rising every few hours and filling the pit from ten to fifty feet each time. The active spells are accompanied by falling banks and many fountains. An artesian well of molten lava 20 feet in diameter is continually poring a fountain of lava down the eastern bank of the pit.



Anonymous, 1908, Details of the earthquake as gathered by the Hawaii Herald staff: Pacific Commercial Advertiser, 09/28, p. 5. [Abstract text copied verbatim from Hawaii Herald of September 24, 1908; repeated in Hawaiian Gazette of Sept. 29] 



 "The most severe shock of earthquake felt in Hilo since 1868," is how L.A. Thurston described the shake-up that this city received a few minutes after 8 o'clock on Sunday evening last. Others claimed it was not so bad as the tremors of 1886 or 1888. Anyhow, it was lively enough to make everybody sit up and take notice. Both Mr. Thurston and Mr. Julian Monsarrat agreed that it was a Mauna Loa shake, and as Mr. Monsarrat lives on the slopes of the big mountain he ought to be credited with some knowledge about them.

 The most serious damage was done near Kalapana, in Puna, where three houses occupied by Hawaiians were leveled to the ground. Slight cracks in the earth have been made in Hilo, near the bridge, and on the road leading to the Shipman residence on Reed's Islands. There was a tidal wave about three feet high. A few buildings suffered from cracked plaster, there was loss in grocery and liquor houses, and more of it in private dwellings.

 Shocks were felt slightly on Monday, and at least six distinct ones during Monday night; others until Tuesday evening, so that the earth has been trembly for forty-eight hours.

 When the crash came, for it did come with a crash, there was a general desire for fresh air . . . As usual, the shake was felt most severely in Puueo, but there was considerable damage done in the business section of the town. An unusual feature consisted of in cracks, small ones, appearing in the road to the Shipman home across the bridge, and on the made ground from the house at Reed's Island to the government road. Both Mr. Shipman and Mr. Thurston told the Herald that these cracks were visible longitudinally and transversely, and were about wide enough to admit the insertion of a knife.

 Slight tidal wave: A second, and lighter, shock followed a few minutes after the first one. Others were reported at 9 p.m., 11 p.m., near midnight, and at 3 a.m. A tidal wave about three feet high accompanied the shake, being noticed where the Wailuku River discharges itself at Puueo, at Waiakea, and at Reed's Bay. On board the Claudine, lying alongside the Hilo railroad wharf, the shock was distinct, and the little vessel trembled from stem to stern. The motion of the shake was from northwest to southeast, and like a succession of waves. At the Volcano House it was not felt as nearly as severely as at first reported, and the fire did not reach the top of the pit. It was very active, however, sometimes dropping a hundred feet, again rising.

 Chimneys move and break: In Hilo there were many curious freaks played in the movement of furniture, glassware, pictures and other household adornments and necessaries. Water spilled from many tanks in bathrooms. No buildings were thrown down here, but many owners and occupants thought they would be, so got out from under. At the Board of Health office it will cost about $25 to replace the glassware needed by Inspector Bowman, who also lost half the chimney of his rodental crematory. At the hospital Dr. Hayes report the brick chimney cracked across and the upper portion turned halfway around on the lower base. The high school suffered no damage. At Ferndale station, on the Hilo railroad, the water tank came to the ground.

 Downtown section: Serrao building, at the corner of Shipman and Bridge street, is cracked slightly on both frontages. The bottle pickles, sauces, jams and other things fell in a mass in the Serrao and Turner groceries, . . . Glassware and bottles in Serrao's, Demosthenes' and other places went from bar to floor, the liquor stocks in pantries and wholesale houses also blending with the broken glass. There was much cleaning up to be done, except at the Peacock wholesale house, where Austin has his goods wired in and consequently lost only one bottle of sake. But the Peacock's block was not so fortunate, the four corners on the Bridge street side of the Hilo Bank windows are chipped off, though nothing touched them. There is a crack in the plaster of the bank several feet long and several inches wide, which also show in the Count Attorney's office on the other side of the wall. In the sitting room upstairs and in the hall there was, here and there, a light sprinkling of plaster on the floor, and the big water cooler went off its base. At Holmes' store it was the crockery that suffered most. Soap fell to the floor in barbershops, a window in the Inter-Island office was smashed, two windows in the Herald office were broken and one press was moved five inches out of plumb. The top of the little shoe shop next door was about three inches out of place, overhanging on the sidewalk, and it has since been moved back into position. The Hilo drug store lost a couple of bottles, everything there being wired, and there was no damage at Kennedy's jewelry store, not even a piece of cut glass cracked.

 It was near Kalapana that three houses, occupied by Hawaiians, fell to the ground. At the Hawaiian Mahogany Camp, Superintendent Sam Johnson was thrown from his bed. He immediately rushed to the mill, where he found all the lamps upset and extinguished, but no damage done. At Waimea, Charlie Hall landed on the floor after retiring early. At the plantation the mill machinery is being carefully examined, and from all parts of the island the reports come of more or less severity in the shake and of more or less damage. The private houses seem to have suffered the most, and the loss from broken furniture and glassware must mount up to many thousands of dollars in all parts of the island.



Anonymous, 1908, How Hawaii was shaken: Hawaiian Gazette, 09/29, p. 3. [Abstract text copied verbatim from Hawaii Herald of September 24, 1908; repeated from Pacific Commercial Advertiser of Sept. 28] 



 "The most severe shock of earthquake felt in Hilo since 1868," is how L.A. Thurston described the shake-up that this city received a few minutes after 8 o'clock on Sunday evening last. Others claimed it was not so bad as the tremors of 1886 or 1888. Anyhow, it was lively enough to make everybody sit up and take notice. Both Mr. Thurston and Mr. Julian Monsarrat agreed that it was a Mauna Loa shake, and as Mr. Monsarrat lives on the slopes of the big mountain he ought to be credited with some knowledge about them.

 The most serious damage was done near Kalapana, in Puna, where three houses occupied by Hawaiians were leveled to the ground. Slight cracks in the earth have been made in Hilo, near the bridge, and on the road leading to the Shipman residence on Reed's Islands. There was a tidal wave about three feet high. A few buildings suffered from cracked plaster, there was loss in grocery and liquor houses, and more of it in private dwellings.

 Shocks were felt slightly on Monday, and at least six distinct ones during Monday night; others until Tuesday evening, so that the earth has been trembly for forty-eight hours.

 When the crash came, for it did come with a crash, there was a general desire for fresh air . . . As usual, the shake was felt most severely in Puueo, but there was considerable damage done in the business section of the town. An unusual feature consisted of in cracks, small ones, appearing in the road to the Shipman home across the bridge, and on the made ground from the house at Reed's Island to the government road. Both Mr. Shipman and Mr. Thurston told the Herald that these cracks were visible longitudinally and transversely, and were about wide enough to admit the insertion of a knife.

 Slight tidal wave: A second, and lighter, shock followed a few minutes after the first one. Others were reported at 9 p.m., 11 p.m., near midnight, and at 3 a.m. A tidal wave about three feet high accompanied the shake, being noticed where the Wailuku River discharges itself at Puueo, at Waiakea, and at Reed's Bay. On board the Claudine, lying alongside the Hilo railroad wharf, the shock was distinct, and the little vessel trembled from stem to stern. The motion of the shake was from northwest to southeast, and like a succession of waves. At the Volcano House it was not felt as nearly as severely as at first reported, and the fire did not reach the top of the pit. It was very active, however, sometimes dropping a hundred feet, again rising.

 Chimneys move and break: In Hilo there were many curious freaks played in the movement of furniture, glassware, pictures and other household adornments and necessaries. Water spilled from many tanks in bathrooms. No buildings were thrown down here, but many owners and occupants thought they would be, so got out from under. At the Board of Health office it will cost about $25 to replace the glassware needed by Inspector Bowman, who also lost half the chimney of his rodental crematory. At the hospital Dr. Hayes report the brick chimney cracked across and the upper portion turned halfway around on the lower base. The high school suffered no damage. At Ferndale station, on the Hilo railroad, the water tank came to the ground.

 Downtown section: Serrao building, at the corner of Shipman and Bridge street, is cracked slightly on both frontages. The bottle pickles, sauces, jams and other things fell in a mass in the Serrao and Turner groceries, . . . Glassware and bottles in Serrao's, Demosthenes' and other places went from bar to floor, the liquor stocks in pantries and wholesale houses also blending with the broken glass. There was much cleaning up to be done, except at the Peacock wholesale house, where Austin has his goods wired in and consequently lost only one bottle of sake. But the Peacock's block was not so fortunate, the four corners on the Bridge street side of the Hilo Bank windows are chipped off, though nothing touched them. There is a crack in the plaster of the bank several feet long and several inches wide, which also show in the Count Attorney's office on the other side of the wall. In the sitting room upstairs and in the hall there was, here and there, a light sprinkling of plaster on the floor, and the big water cooler went off its base. At Holmes' store it was the crockery that suffered most. Soap fell to the floor in barbershops, a window in the Inter-Island office was smashed, two windows in the Herald office were broken and one press was moved five inches out of plumb. The top of the little shoe shop next door was about three inches out of place, overhanging on the sidewalk, and it has since been moved back into position. The Hilo drug store lost a couple of bottles, everything there being wired, and there was no damage at Kennedy's jewelry store, not even a piece of cut glass cracked.

 It was near Kalapana that three houses, occupied by Hawaiians, fell to the ground. At the Hawaiian Mahogany Camp, Superintendent Sam Johnson was thrown from his bed. He immediately rushed to the mill, where he found all the lamps upset and extinguished, but no damage done. At Waimea, Charlie Hall landed on the floor after retiring early. At the plantation the mill machinery is being carefully examined, and from all parts of the island the reports come of more or less severity in the shake and of more or less damage. The private houses seem to have suffered the most, and the loss from broken furniture and glassware must mount up to many thousands of dollars in all parts of the island.



Anonymous, 1908, Notes on earthquake: Hilo Tribune, 09/29, p. 5. [Repeated from Honolulu Evening Bulletin of Sept. 24] 



 Honolulu, Sept. 24--Charles K. Notley received a letter from his son William, who is at Paauilo, Hawaii. Under date of September 21 he writes, "We had quite an earthquake shock up here on Sunday evening. It shook pretty lively; the strongest we ever had on this island. It shook water out of the tanks . . . .

 From Kalae, Molokai, comes the following: On Sunday evening, 20th inst., a very gentle rocking of the earth was felt here. First an instantaneous movement, a pause and then a gentle and continued rocking. The movement gave the sensation of being directly underneath.



Anonymous, 1908, Shakes and tremors: Hawaii Herald, 10/01, p. 1. [Repeated in the Pacific Commercial Advertiser of Oct. 4] 



 Slight shocks of earthquake have been noted nearly every day within the past week, three on Friday [Sept. 25], two on Saturday [Sept. 26], one early Monday morning [Sept. 28] and one at 3 o'clock on Tuesday morning [Sept. 29]. That of Saturday, at 8:04 p.m., was short but particularly sharp. The original shake of Sunday, Sept. 20, appears to have been more severe in Puna than elsewhere, the Herald receiving reports of fallen walls and a large earth crack. At 5:16 yesterday morning there was a short but very sharp quake that caused tremors among the nervous and some unusually early rising. It also extended the cracks in the plaster at the Hilo Bank.



Anonymous, 1908, Puna rent by earthquake; severer than that of 1868, so say many of the natives: Pacific Commercial Advertiser, 10/04, p. 1. [Reprinted in the Hilo Tribune of Oct. 13, 1908] 



 "The earthquake of two weeks ago," said L.A. Thurston, who has just returned from Hawaii, " was most interesting in its manifestations and in the evidences left of its force. At first I was inclined to think it had its origin on Mauna Loa, partly because Mauna Loa is the source of most of the severe earthquakes on Hawaii. But I feel now that Kilauea was the source of this one.

 "There is a line of fissures and cones extending, at first, southeasterly from Kilauea, and then northeasterly, along the line of the flow of 1840, and everywhere along this line there is evidence of the destructiveness of the earthquake. At one place the deepest crater in the Islands exists. It is, or was, about 1500 ft deep [Makaopuhi crater]. Great masses of rock and earth have been shaken into this crater, piling up debris at the bottom.

 "In other places there has been similar destruction. At one place along the old Puna trail a new wall was being built. It was three or four feet thick and four or five feet high, and contained many stones weighing two or three hundred pounds. This wall was thrown down and the stone in many places hurled eight or nine feet. Practically every stone wall in Puna was thrown down. . . .

 "The earthquake was much more severe in the part of Puna between Kilauea and Kapoho, which is near the 1840 flow, than it was there on to Hilo. A number of old natives who have lived there all their lives say it was the severest earthquake they have ever experienced, much severer than that of 1868.

 There have been slight earthquakes every day since then. In Hilo these are very slight tremors, but they are felt practically every day."

 "Kilauea is much more active than she has been for months, Her present activity is of a kind entirely new to her--unknown before. I refer to the rising and falling of the molten lava in the pit. Of course, the regular phenomena of Kilauea is that the lava gradually rises until it finds outlet somewhere lower down, as it did in the flow of 1840, and then it is quiescent till it begins to rise again in the same way. But now it rises and falls daily and sometimes more frequently. The rapidity of the rise and fall and the immense amount of material that pours in and pours out of the pit is marvelous beyond computation. 

 [The remainder of the article offers more detail of the activity, including drops and rises of 10 to 50 feet, and artesian flow from one side of Halemaumau to the other]



Anonymous, 1908, Items of interest from Hawaii: Pacific Commercial Advertiser, 10/05, p. 8. [The last paragraph repeats the Hawaii Herald of Oct. 1] 



 The earthquake caused some trouble in the work on the new Masonic building, the shake tilting the uprights so that the cross beams were found too small to fit between them. Later, there was a tilt the other way and the cross pieces were too large to fit. . . .

 When the Hilo High School was being built, there was more or less discussion as to the probability of its being immune from earthquake. Not a crack has appeared since the severe earthquake of last week and the plaster is perfectly sound. In the laboratory, more or less full of glass, where a row of glass bottles, vessels and other containers stood on the edge of a high shelf and closet, not one piece of glassware fell to the floor, nor was one moved from its place. . . . 

 Slight shocks of earthquake have been noted nearly every day within the past week, three on Friday [Sept. 25], two on Saturday [Sept. 26], one early on Monday morning [Sept. 28] and one at 3 o'clock on Tuesday morning [Sept. 29]. That of Saturday, at 8:04 p.m., was short, but particularly sharp. The original quake of Sunday, Sept. 20, appears to have been more severe in Puna than elsewhere, the Herald receiving reports of fallen walls and one large earth crack. At 5:16 yesterday morning there was a short but very sharp quake that caused tremors among the nervous and some unusually early rising. It also extended the cracks in the plaster at the Hilo bank.



Anonymous, 1908, Earthquake pranks; country split open and houses overturned--A. Gartley tells of what he saw: Hilo Tribune, 10/06, p. 6. 



 Honolulu, Sept. 30--In the Advertiser, A. Gartley writes as follows of his observations of the effects of the recent big shake:

 Gerritt P. Wider and I just came through Puna from the Volcano on horseback, and saw many evidences of the earthquake which were of interest.

 We left the Volcano on Keauhou trail, passing the line of small craters Panau, Panau-iki, Kapaahu, Kalapana, Pahoa, Kapoho and to Hilo. At the crater of Makaopuhi tons of material have been shaken down from the vertical banks into the mauka pit below. Some smoke was issuing from the bottom of the mauka pali and quite large deposits of sulphur have formed.

 The shake must have been very heavy in Puna. At Kapaahu a crack about a foot wide opened for about 500 feet, extending mauka from the sea.

 At Kalapana the old '68 crack, which opened when the Puna coast sunk, opened about twelve inches more, and about a quarter mile back of this crack toward Kau a new crack has opened, extending from pali to pali and several hundred feet long. Some say there was a small crack before one or two inches wide, but it is now twelve to eighteen inches wide.

 At Kahena it is reported that a strip of the pali (about 100 feet high) along the coast, some 50 feet wide and half a mile long, split off and dropped into the sea, and a new crack has opened parallel with the front of the pali 50 feet back and over two miles long.

 The schoolhouse at Kauaea was either overturned or badly set off its foundation.

 Three houses and many water tanks were overturned in Kalapana and nearly every stone wall was thrown down. On the trail from Kalapana to Kahena the walls on the mauka side of the road suffered, those on the makai side being left intact.

 Between Kalapana and Pahoa the aa lava from old flows was thrown into the road and blocked it some hours.

 L.L. McCandless was speaking in Kalapana school when the quake came, and the crowd disappeared like magic. He could not induce them to return.



Anonymous, 1908, Schools hit by earthquake: Pacific Commercial Advertiser, 10/06, p. 8. 



 . . .

 Inspector Charles King of Hawaii reported that at Kamaea, in Puna, the schoolhouse was moved two feet by the earthquake and tipped over, the main building going over one way and the lanai another. At other places in Puna water tanks at schoolhouses were knocked over by the earthquake.



Anonymous, 1908, Link and the earthquake; just calling on Hawaiians to "Wake up" when it came: Pacific Commercial Advertiser, 10/11, p. 2. 



 [An account of the earthquake as felt at Kalapana during a meeting in the Kalapana schoolhouse]

 . . . It was a terrific quake, and I thought certain the building was going to fall over. It rocked violently. . . .

 [at the house where I was staying] a lamp, which had been left lighted on a table, had been tipped over so that the oil had leaked out on the tablecloth. . . The lamp was one of the kind made to set in a hanging frame, and it had tipped over so that the chimney touched the table. . . .

 There were several slight earthquakes that same night and the next day. The next morning, . . . I was leaning against a stone wall. While I was in this attitude an earthquake occurred which shook my feet back and forth, sideways as I stood.

 Stone walls were thrown down in all that part of Puna. Water tanks were overturned, and in a way a good deal of damage was done.



Anonymous, 1908, A Kilauea quake; L.A. Thurston's theory of the late big shake--Puna suffered most--eccentric volcanic activity: Hilo Tribune, 10/13, p. 6. [Identical text to the article in the October 4 issue of the Pacific Commercial Advertiser] 



 "The earthquake of two weeks ago," said L.A. Thurston, who has just returned from Hawaii, " was most interesting in its manifestations and in the evidences left of its force. At first I was inclined to think it had its origin on Mauna Loa, partly because Mauna Loa is the source of most of the severe earthquakes on Hawaii. But I feel now that Kilauea was the source of this one.

 "There is a line of fissures and cones extending, at first, southeasterly from Kilauea, and then northeasterly, along the line of the flow of 1840, and everywhere along this line there is evidence of the destructiveness of the earthquake. At one place the deepest crater in the Islands exists. It is, or was, about 1500 ft deep [Makaopuhi crater]. Great masses of rock and earth have been shaken into this crater, piling up debris at the bottom.

 "In other places there has been similar destruction. At one place along the old Puna trail a new wall was being built. It was three or four feet thick and four or five feet high, and contained many stones weighing two or three hundred pounds. This wall was thrown down and the stone in many places hurled eight or nine feet. Practically every stone wall in Puna was thrown down. . . .

 "The earthquake was much more severe in the part of Puna between Kilauea and Kapoho, which is near the 1840 flow, than it was there on to Hilo. A number of old natives who have lived there all their lives say it was the severest earthquake they have ever experienced, much severer than that of 1868.

 There have been slight earthquakes every day since then. In Hilo these are very slight tremors, but they are felt practically every day."

 "Kilauea is much more active than she has been for months, Her present activity is of a kind entirely new to her--unknown before. I refer to the rising and falling of the molten lava in the pit. Of course, the regular phenomena of Kilauea is that the lava gradually rises until it finds outlet somewhere lower down, as it did in the flow of 1840, and then it is quiescent till it begins to rise again in the same way. But now it rises and falls daily and sometimes more frequently. The rapidity of the rise and fall and the immense amount of material that pours in and pours out of the pit is marvelous beyond computation. 

 [The remainder of the article offers more detail of the activity, including drops and rises of 10 to 50 feet, and artesian flow from one side of Halemaumau to the other]



Anonymous, 1908, Earthquakes, storms and steamer burned: Hawaii Herald, 10/22, p. 1. 



 At 9:55 o'clock Tuesday morning [Oct. 20] there was an earthquake shock in Hilo, short but distinct. At 6:20 yesterday morning [Oct. 21] there were two shocks [in Hilo].



Anonymous, 1908, Italy's earthquake felt on Hawaii: Hawaii Herald, 12/31, p. 1. 



 It was between 1 and 1:30 p.m. on Monday [Dec. 28], the same day that the disastrous earthquake occurred in Italy, that Mrs. F.M. Swanzy and Mrs. Mary Gunn arrived at Julian Montserrat's Kapapala ranch, and Mrs. Gunn had just asked if they now had any of their old time earthquakes, when a smart tremor shook the house. A second shock was felt in the evening, though not so severe as the first one. It may be that scientists can trace some connection between the shakes in Italy and Hawaii, if so their ideas would be interesting.



Anonymous, 1908, Earthquake shocks: Hawaiian Annual for 1909, p. 172. 



 A strong earthquake at 8:15 p.m. on September 20, 1908, was most severe in Hilo and in Puna.

 

Anonymous, 1909, What Omori said about local quakes: Pacific Commercial Advertiser, 01/02, p. 2. 



 August 11, 1906.--Professor F. Omori, a leading scientist of Japan, and recognized as among the world's leading authorities on seismic questions, on passing through Honolulu en route to Japan from California, where he had been sent by the Japanese government to investigate the earthquake in San Francisco on April 19, 1906, made the following statement to the Advertiser:

 "I would say there is a very slight possibility of there ever being a an earthquake of any magnitude in the Hawaiian Islands.

 "It is noticeable that in the immediate neighborhood of large volcanoes, such as here, there are no violent earthquake shocks. Naples, for instance, is free of them. And it is therefore quite safe to say that these islands will never be visited by such a shock as has been had in California.

 The article concludes with a statement that California will be immune from serious shocks for at least thirty years.



Anonymous, 1909, [no title], in Local Brevities: Pacific Commercial Advertiser, 01/02, p. 7. [For times see Hawaii Herald of December 31, 1908] 



 Passengers from Hawaii on the Mauna Kea yesterday report that the Big Island experienced an earthquake shock on Monday last [Dec. 28, 1908], on the day when the Sicilian disaster occurred.



Anonymous, 1909, [no title], in Local Brevities: Pacific Commercial Advertiser, 01/05, p. 7. 



 A story is published to the effect that Hilo felt a severe earthquake shock yesterday [Jan. 4], shortly after noon. The shock is said to have been sharp and decisive.



Anonymous, 1909, [no title], in Local Brevities: Pacific Commercial Advertiser, 01/13, p. 7. 



 A light earthquake was felt at Hilo last Sunday night [Jan. 10] , and two more have been felt since then.



Anonymous, 1909, Weekly weather bulletin for the week ended January 23, 1909: Pacific Commercial Advertiser, 01/26, p. ? 



 A slight earthquake shock was felt at Kapoho, Hawaii, at 6:45 p.m. of the 20th



Anonymous, 1909, Shake on Hawaii: Honolulu Evening Bulletin, 03/13, p. 2. 



 Hilo, Hawaii, March 13.--A sharp earthquake shock was felt here and through Kona and Kau at 3:30 o'clock this morning.



Anonymous, 1909, [no title], in Local Brevities: Pacific Commercial Advertiser, 03/14, p. 5. 



 A sharp earthquake shock was felt in Hilo and throughout Kona early yesterday morning.



Anonymous, 1909, [no title]: Pacific Commercial Advertiser, 03/23, p. 5. 



 An earthquake shock, which was severe in parts of the island, was felt generally over Hawaii about 3:20 a.m. of the 13th.



Anonymous, 1909, Local Brevities: Pacific Commercial Advertiser, 06/14, p. ? 



 A sharp earthquake jolt was felt in Hilo on Tuesday morning [June 8], a few minutes after seven o'clock. There was only one shock and it was short, but it left no doubt as to its existence or that its direction was from north to south



Anonymous, 1909, At the mouth of Hell: Hawaii Herald, 07/22, p. 2. 



 Prof. Daly, of Massachusetts, who accompanied Prof. Jaggar to the Volcano to study the requirements for the establishment of an observatory at Kilauea, has stood at the mouth of Hell, and he was not alone, with him being his sister-in-law, Miss Haskell, and Rev. J. Lidgate [sic]. The three were lowered over the brink of the precipice, surrounding Halemaumau, by ropes down a depth of 190 feet from the top. Professor Daly took measurements and found that the active fire was a distance of 235 feet from the top. His party, therefore, was within 45 feet of the active boiling lava, standing on a ledge of black lava that surrounds the fiery furnace. While there, Mr. Daly, with scientific instruments, tested the heat of the mouth of Hell.

 Exactly how long they remained there is not known, but the length of their visit to the inferno was somewhat shortened by the fumes of sulphur which compelled them to ascend to the brink of the pit earlier than they had intended. The descent was made on July 5, 1909, but Mr. Daly does not advise others to go and do likewise.



Anonymous, 1909, Hitchcock finds two new craters near Kilauea: Pacific Commercial Advertiser, 12/29, p. 1. 



 Two new live craters of almost the same dimensions as Halemaumau, the living, boiling fire-pit of Kilauea, were discovered two weeks ago by Professor Hitchcock, the eminent geologist and volcanologist, and Rev. W.D. Westerveldt. The craters are about six miles from the Volcano House and about two miles from Halemaumau, the location of the craters being between Kilauea and Keauhou.

 The craters are in a region which has practically never been explored and is unsurveyed, a waste which apparently has no more value or interest than much of the surrounding lava cropped surface. A convict, who has been at work, with a large gang of territorial prisoners, on the new road which leads down from the Volcano House around the eastern edge of Kilauea, led Professor Hitchcock's party into the new land. After leaving the road the explorers went into a rough country and finally came to the craters. Each crater is reported by professor Hitchcock to be full of steam, but no lava is visible.

[The distance from Volcano House and description of the terrain fits what are now called "Cone Craters," on Kilauea's southwest rift zone east of Puu Koae.--the distance from Halemaumau is too short and the direction is considerably east of a line connecting Kilauea's summit and Keauhou landing on Kilauea's south coast. A subsequent article in the Pacific Commercial Advertiser of Nov. 13, 1910 makes it appear that the two craters were on Kilauea's east rift zone, including Puhimau and perhaps Hiiaka.]



Anonymous, 1910, Observatory of our own; Hawaii should be independent of Massachusetts Institute of Technology; the study of the volcano; educators object to having it under the Boston Institution's control: Pacific Commercial Advertiser, 02/20, p. ? [!cannot find] 



 A declaration that Hawaii should assume control of Professor Jaggar's proposed volcano observatory for Kilauea. An alternative to control by M.I.T. would be the assumption of responsibility by the College of Hawaii [predecessor to the University of Hawaii at Manoa}.



Anonymous, 1910, Kilauea oldest volcano in the world; Prof. Jaggar announces it as the Earth's first, with Fuji of Japan the latest: Pacific Commercial Advertiser, 02/20, p. ? [!cannot find] 



 Addressing the 665th meeting of the Society of Arts, in Boston, Jaggar lectures, not only holding that Kilauea is the world's oldest volcano, but that the world's volcanoes can be grouped by age and chemical composition, the oldest being most fluid (basic in composition) and the youngest most sticky (acidic in composition). He also holds from experiments conducted in his laboratory that the temperature of basic and acidic eruptions is about the same. [Ed. note: A very strange lecture, completely at odds with modern volcanological knowledge.]



Anonymous, 1910, Earthquake's severe shock: Hawaii Herald, 04/21, p. 1. 



 A very sharp earthquake shock took place Tuesday morning [Apr. 19] at about 3:50, causing those were awake to jump around and those who were asleep to get up suddenly. The shock, while severe, was of such short duration that very little damage was done, other than the breaking of a little crockery where it had been left close to the edge of a shelf. An interesting feature of the shock was the fact that immediately after it took place the Kilauea crater flamed up suddenly, lighting the sky in that direction with great brilliancy. Though the weather was very cloudy it could be seen plainly. the glare only lasted for about five minutes then dying down.



Anonymous, 1910, Decapitate the Garden Island; Kauai is eighty feet lower than it was some months ago, but does not miss the loss; the Federal topographers find island has held head too high: Pacific Commercial Advertiser, 10/20, p. 1, 4. 



 A new topographic survey of Kauai, under the direction of Birdseye, shows the summit to be 5170 feet, 80 feet lower than shown on earlier maps. All maps will be revised to reflect the results of the new survey.



Anonymous, 1910, New craters smoking up: Pacific Commercial Advertiser, 11/13, p. 1. 



 Hilo, November 9--Some time ago it was reported that prisoners working on the new volcano road had found two new craters, being attracted thereto by the steam rising from the pits. This became more noticeable and Henry Cockett, in charge of the prisoners, has a trail built there. The craters are within seven or eight miles of the Volcano house and can be easily reached on horseback. It is claimed that they are the most attractive craters in the vicinity of Kilauea. One of them pours forth an abundance of steam incessantly. In shape it is perfectly round, while the inside walls are absolutely precipitous, and its depth is unfathomable. Handsome forest growth surround it to its very brink.

 Mrs. James Dougherty has given the crater the name of Puhimau. which means "always retiring." [Puhimau is not steaming since at least 1964. If these are the craters described by Hitchcock in the Pacific Commercial Advertiser of Dec. 29, 1909 (Anonymous, 1909), his description seems at odds with this one.]



Anonymous, 1911, Quake is felt in Honolulu: Honolulu Evening Bulletin, 07/14, p. 1. 



 Wailuku, July 14.--Two heavy earthquake shocks were felt here at 11:30 today, each of about ten seconds duration.

 A slight but distinct earthquake shock at 11:37 o'clock this morning was felt in various parts of the city [Honolulu]. For twenty seconds the temblor rocked the earth, the motion being gentle by easily felt, and then subsided as quickly as it began.

 The shock was recorded by the U.S. weather Bureau instruments, the time being given as 11:30 o'clock. At the Capitol the shock was quite noticeable, but nowhere was it severe enough to cause any fear or uneasiness.



Anonymous, 1911, Honolulu has an earthquake: Hawaiian Star, 07/14, p. 1, 8. 



 Honolulu had the very unusual experience of an earthquake shock this morning shortly after half-past eleven. It was not a shock to do any damage, or to be noticed except by people sitting or lying down, but nevertheless it was a shock of severity beyond recent precedent, and was very distinctly felt by many people. No damage was done.

 The shock was distinctly felt in the Capitol, where it manifested itself in two distinct movements. the first was a series of vertical shocks-five or six in number-which were believed at first to be the results of heavy blasting in the harbor, as when a series of charges are detonated in succession. with possibly a brief interval in between, the second motion began, and this was described by those who felt it as a wave motion, or a backward and forward motion from sea towards the mountains. During the second shock a book toppled from the shelf in the Secretary's office, and windows and blinds rattled as though shaken by a strong wind. According to clocks in the Capitol, the shake occurred at 11:39, and lasted perhaps half a minute.

 Felt on Tantalus

 W.R. Castle, from his residence on Tantalus, described the shock as occurring at 11:34 am and lasting half a minute. The motion was up and down and slightly rotary.

 The quake seemed to increase in severity and ended with a severe shock.

 The Castle house is built on a ridge consisting mostly of black sand, and therefore more susceptible to a shock than would be a location down town.

 The shock was distinctly felt in the McCandless building and in the U.S. engineer's office people were rocked backward and forward in their chairs.

 Residents of Alewa Heights felt the shock, or rather the two shocks, for so the quake is described by dwellers in the neighborhood.

 The Kaimuki people had their share of the shock, and a lady living near Sixth Avenue states that the earth shook with the motion of a boat at sea, making her head so dizzy that she had to lie down for a spell.

 On the Waterfront

 Along the water front the shock could be distinctly felt. In the office of Collector Stackable, the building could be felt moving as though it were being shaken by heavy gusts of wind. The door of the office rattled so that inspector Stackable thought that someone was knocking for admittance, and he shouted "come." but of course there was no answer. The shock seemed to be a gentle one, although of quite a long duration, but the big clock that is situated in his office was not thrown enough out of its course to stop the pendulum.

[The remainder of the article is written in a less serious manner, detailing the reactions of a number of persons in different places in Honolulu. Common observations are that furniture moved, a sound of rumbling or a blast was heard, and hanging fixtures swung. A few persons ran out into the streets in panic.]



Anonymous, 1911, Maui people feel 'quakes: Honolulu Evening Bulletin, 07/14, p. 1. 



 Wailuku, Maui, July 14.--There were two quite severe earthquake shocks felt on Maui at about 11:30 o'clock this morning, its direction being from east to west. The first shock was quite heavy and lasted about ten seconds. The second shock followed in quick succession and lasted for about the same duration of time, and perhaps longer, but those in the new Wailuku courthouse and the County Building at the time did not care to wait until the second shock had died out, for the solid building of reinforced concrete seemed to shake from its very foundation and appeared to sway to and fro. The occupants ran outside post haste and from the outside watched for further demonstrations, but luckily the buildings stood the test as well as other buildings of similar character in Wailuku. The new church of the Good Shepherd stood the test nobly, as also did the new Wailuku Union Church under course of construction.

 Many of those in wooden frame buildings even flew outside in almost double quick time. It is many years now since Maui was visited by such severe earthquake shocks.



Anonymous, 1911, Marvelous whirlpool of fiery lava forms at Halemaumau--gorgeous sight for the scientists: Pacific Commercial Advertiser, 07/15, p. 1. 



 Hilo, July 14.--The tremendous activity in the pit of Halemaumau of the last few days has brought about a startling phenomenon, something which has never been seen before in the history of the volcano. Yesterday the molten lava took the semblance of a whirlpool until the revolving center of the disturbance was sucked down, leaving a hole into the depths. Into this, from both sides, the lava is pouring in two Niagaras of living fire, with a roar that is heard miles distant from the pits. The hole is almost in the center of Halemaumau, directly under the arch junction of the two floating islands.

 Prof. F.A. Perret the volcanologist, has a theory that the maelstrom is caused by the lighter subfluids being forced down by the heavier surface lavas, forming the viscous crust, the result being that two levels have been formed in the pit.

 . . . .

 The scientists have finished their task of stretching the wire cable across the fire pit, the cable being twelve hundred feet from post to post. The first instrument to test the temperatures of the lava will be lowered probably early next week. The work of erecting a cottage-observatory on the brim of the fire pit is well under way.

 Earthquake is experienced

 All Hawaii visited by earthquakes yesterday and reports are coming in of special activity at Kilauea.

 The Advertiser received a wireless last evening from Hilo to the effect that the volcano was much more active than usual.

 Honolulu felt the quake just before noon, its duration being 20 seconds. It was felt throughout the city, but nowhere was it severe. 

 From Wailuku, the Bulletin received a wireless that two severe shocks were felt there at eleven-thirty o'clock, the same time that the shock was registered here.

 The shock in Honolulu was felt distinctly at the capitol, and out in the Punahou district it was apparently more severe than downtown.



Anonymous, 1911, To measure volcano heat; Professor Perret has strung cables and station is completed; "Waterfall" has disappeared: Hawaii Herald, 07/20, p. 1. 



 The earthquake of Friday morning [July 14], which was felt on all the islands of the group and was quite severe in Honolulu, was not noticeable at Halemaumau, according to Professor Frank A. Perret, the volcano expert who is stationed there.

 The rest of the article describes the current action in Halemaumau and Perret's preparations to measure its temperature.



Anonymous, 1911, Shock felt at crater; Professor Perret tells of rapid drop in surface of molten lava after earthquake on Tuesday: Hawaii Herald, 07/27, p. 1. 



 An earthquake which took place at the Kilauea volcano Tuesday morning at 10:32 and which was observed by Frank A. Perret, was the cause of considerable commotion in Halemaumau. The shock was quite noticeable at the station which has recently been erected and was immediately followed by a rapid drop in the surface of the molten lava. Mr. Perret noted a fall of twelve feet in a short space of time. The shock lasted for three-fourths of a second.

 The rest of the article confirms unusual activity at Halemaumau as manifested by a strong glow seen by passengers on the inter-island steamer "Mauna Kea".



Anonymous, 1911, Temperature of live lava recorded: Hawaiian Gazette, 08/01, p. 1. 



 The temperature of Halemaumau was recorded at 1010 C, on the third attempt after losing two thermocouples. [The temperature is probably low by at least 100--a platinum thermocouple was used, shown by later lava lake studies to take in iron on contact with molten lava, thus causing a low temperature reading.]



Anonymous, 1911, Pele on a rampage: Hawaii Herald, 12/28, p. 1. 



 The fire pit of Halemaumau is exhibiting unusual wonders. Seldom has the Kilauea volcano been more active. . . . A few days ago the molten lava was within 65 feet of the rim. On Tuesday afternoon [Dec. 26] three earthquakes rattled the crockery in the Volcano House and the lava lake sank 20 feet. Immediately afterwards the floor of fire started to rise again, and rose 50 feet in less than a day. Now it is within 35 feet of the observation hut of Prof. Perret . . .



Anonymous, 1912, Preparing for the lava flow; topographers to be sent into the volcanic region to map out the hollows: Pacific Commercial Advertiser, 02/03, p. 1. 



 A report of the first topographic survey of the island of Hawaii and the implications for better predicting where lava flows from the next Mauna Loa eruption will go. The article also discusses the value of new topographic data for the drive to create a "Kilauea" National Park.



Anonymous, 1912, Earthquake felt yesterday in Hilo: Hawaii Herald, 04/11, p. 1. [Repeated in the Hawaiian Star of Apr. 13.] 



 The earth shivered perceptibly at exactly four o'clock yesterday afternoon.

 Hundreds of people noticed the quiver of the crust of nature.

 Those located in their homes and offices mentioned the phenomenon more especially; the folks on the streets not paying any particular attention to the occurrence. 

 . . . , but yesterday afternoon's shiver was particularly perceptible.

 The motion was from west to east for about seventeen seconds, with an interval of five seconds and then another shake enduring for about twenty seconds. After that there was an interval of probably half a minute with a following of three slighter trembles of about 10 seconds each with brief intervals of 2 or 3 seconds.

 In this connection it may be stated that Kilauea is very active, not more active than in the last three or four weeks, but active in a way somewhat different from the recent activity. The liquid lava seems to be changing its manner of eruptive expression and seeking new avenues of escape. The scientists' prophecy of an imminent eruption of Mokuaweoweo appears about to be fulfilled. [This didn't come about until 1914.]



Anonymous, 1912, Quakes at Hilo, crater erratic: Hawaiian Star, 04/13, p. 8. [Quoted from the Hawaii Herald of Apr. 11.] 



 The earth shivered perceptibly at exactly four o'clock yesterday afternoon.

 Hundreds of people noticed the quiver of the crust of nature.

 Those located in their homes and offices mentioned the phenomenon more especially; the folks on the streets not paying any particular attention to the occurrence. 

 . . . , but yesterday afternoon's shiver was particularly perceptible.

 The motion was from west to east for about seventeen seconds, with an interval of five seconds and then another shake enduring for about twenty seconds. After that there was an interval of probably half a minute with a following of three slighter trembles of about 10 seconds each with brief intervals of 2 or 3 seconds.

 In this connection it may be stated that Kilauea is very active, not more active than in the last three or four weeks, but active in a way somewhat different from the recent activity. The liquid lava seems to be changing its manner of eruptive expression and seeking new avenues of escape. The scientists' prophecy of an imminent eruption of Mokuaweoweo appears about to be fulfilled.



Anonymous, 1912, Hilo's heaviest quake since this island's last lava flow: Hawaii Herald, 04/18, p. 1. [Not listed in Honolulu Station Bulletin (Hazard, 1913)] 



 Hilo shuddered yesterday afternoon.

 She shook!

 At 5:08 p.m. Hilo trembled with the heaviest quake since 1899, which olden shake was accompanied by a lava flow.

 On Waianuenue street a number of business men ran out of their stores, into the streets, fearing the buildings were about to fall.

 The quiver did not last more than about five seconds, but it was severe while it lasted.

 A peculiar incident in connection with this shock is the way animals behaved. The roosters back of Demosthenes' Hotel [Hilo Hotel] crowed lustily. The hens ran in circles. Several persons who felt the temblor were affected with a feeling of sickness at the stomach.

 Strange to say nobody in the Hackfield building felt the tremor.

 A member of the topographic survey was taking a bath when he felt the shock. He thought a safe had been let loose of its fastenings and was running amuck. He cannot explain why he thought that, but that is what he thought.

 Two men in a printing office were conversing. Of a sudden the machines and the type shelves quivered and the men looked at each other imagining that somebody had discharged a load of dynamite in the vicinity without producing a sound, if such a thing were possible..

 In Leo Toma's cigar store the proprietor thought at first that something had fallen on the roof. Captain Duval, in his office on Waianuenue street, declared it was the heaviest quake he had ever felt..

 A gentleman in an automobile in the act of coming out of the Volcano stables, thought there was something wrong with the machine. His excitement was explained later when he heard about there having been an earthquake.

 Telephone communication with various parts of the island brought forth the information that the shiver of the earth's crust was felt in many sections.

 Some people declare they felt a long succession of quivers after the first violent shock. The observation of the writer was that after the big shake at 5:08 o'clock, there was a very slight fading-away series of tremors, but that may have been imagination borne of the nervous effect of the first violent shock.

 The opinion has been expressed that the motion was north-southerly, and the probabilities are that it was about that direction.



Anonymous, 1912, Quake defaces scenery: Hawaiian Star, 05/06, p. 1. [Repeated in the Hawaii Herald of May 16.] 



 It appears that the shock reported at Hilo on Sunday week [Apr. 28?] was severely felt on the Kau coast as well.

 The quake was distinctly felt aboard the steamer Kilauea, lying at Honuapo, and from that vessel was witnessed the rare sight of a portion of the land scenery being precipitated onto the sea by the quake, as if it had been blown out by a heavy blast of dynamite.

 "I was talking with the mate at the time," Purser Logan of the Kilauea said last night, "when we felt the deck trembling under our feet, while at the same time a deep rumbling sound could be heard.

 "What's that?, I asked the mate and he replied that it was likely the fireman starting the boilers. But just then we happened to look toward the shore, where we saw a mass of debris rumbling from the bluff into the sea, making a cloud of dust. The ragged crest of the bluff that overlooks the ocean had been shaken down by the quake."



Anonymous, 1912, Quake tumbles bluff: Hawaii Herald, 05/16, p. 6. [Quoted from the Hawaiian Star of May 6. Not listed in Honolulu Station Bulletin (Hazard, 1913)] 



 It appears that the shock reported at Hilo on Sunday week [Apr. 28?] was severely felt on the Kau coast as well.

 The quake was distinctly felt aboard the steamer Kilauea, lying at Honuapo, and from that vessel was witnessed the rare sight of a portion of the land scenery being precipitated onto the sea by the quake, as if it had been blown out by a heavy blast of dynamite.

 "I was talking with the mate at the time," Purser Logan of the Kilauea said last night, "when we felt the deck trembling under our feet, while at the same time a deep rumbling sound could be heard.

 "What's that?, I asked the mate and he replied that it was likely the fireman starting the boilers. But just then we happened to look toward the shore, where we saw a mass of debris rumbling from the bluff into the sea, making a cloud of dust. The ragged crest of the bluff that overlooks the ocean had been shaken down by the quake."



Anonymous, 1912, Hawaii shakes in quakes; volcano belching smoke: Pacific Commercial Advertiser, 05/24, p. 1. 



 Hilo, May 23--An earthquake shock was felt here and in all the adjacent towns and villages which, while it worked no apparent damage, was the heaviest the locality has experienced for many years and created little panics in a number of places. A report comes from Pukoo that Mokuaweoweo is belching smoke, and during the brief but pronounced tremor a rumbling sound was heard in many parts of Hilo and Kau.

 The effect of the earthquake on ponds and streams was pronounced and it is said to have caused miniature tidal waves on the small bodies of water. Livestock and the residents of the districts where the shock was felt were equally terrorized by the quake and here was a veritable epidemic of runaway horses and cattle.

 The quake, which is undoubtedly intimately connected with the recent activities of Kilauea, has been preceded by numerous slight tremors, excessive heat and other omens. . . .



Anonymous, 1912, Earthquake did but little harm on the Big Island: Pacific Commercial Advertiser, 05/27, p. 5. [Text repeated in The Hilo Tribune of May 28.] 



 Hilo, May 23--A severe shock of earthquake was felt in Hilo at eleven o'clock Wednesday night. The tremor seemed to travel from west to east and, while it lasted, the rumbling was most uncanny. The shake lasted some seven seconds and, in town, many people were much alarmed. Very little damage was said to have been done by the quake, and the articles broken were confined to bottles and glasses, that were left standing too near the edge of tables and shelves.

 There was little or no warning before the quake struck Hilo. The first indication was a faint rumbling that could be heard a long way off. It seemed something like a shower of rain on tin roofs, and only old-time residents knew what was coming.

 As the rumbling noise approached, mules and horses confined in stables, began to bray and neigh. Roosters also started to crow and there was a noticeable noise all around. The first tremors were very faint, but the main shake soon came along. Then there was a straining and groaning of wooden houses, and everything swayed back and forth.

 The hard part of the shake did not last long, however, and things soon resumed their normal quiet Hilo way. The rumbling of the quake could be heard going away in the distance, and that finished the shake.

 Many newcomers, who are not used to small earthquakes, were very scared and a great desire for company was expressed by several persons who, while declaring that they were not frightened, seemed anxious not to be left alone for the rest of the night.



Anonymous, 1912, Pele preparing play from summit crater: Hawaii Herald, 05/30, p. 1. [Not listed in Honolulu Station Bulletin (Hazard, 1913)] 



 . . . .

 The energetic trembler of Wednesday night last [May 22] was, without doubt, . . . the heaviest since that memorable shake of a few years ago [Sept. 20, 1908] when considerable damage was done to household effects and to some buildings.

 At precisely 11 o'clock at night last Wednesday's quake came. It was preceded by a queer roaring sound, as of a great wind starting from a far distance and gathering speed as it rushed onward. Perhaps this endured, or seemed to endure, as near as the ear could detect, for four or five seconds; and then came a pregnant lull, like the space between the beginning and the ending of a giant sneeze. It was this lull, to one who was in a position to feel full force of the shivering earth crust and who had felt these things before, that was the most uncomfortable period of the phenomenon.

 Then came the tremble, nor was it any baby spasm. The force was huge but brief. It could be imagined that damage would be accomplished by the same force if sustained. Mercifully it was brief and not repeated. Not more than ten seconds it lasted, the quaking; possibly eight seconds would cover the period. One does not pull out ones watch and hold the second-ticker on earthquakes.

 Those who had borne in mind the prophecies of the scientists, who have been studying this island's volcanoes, were reminded that such quakes were necessarily preliminary to the promised outbreak of Mokuaweoweo; that such an outbreak is scheduled and is about due. Sure enough, next morning was reported smoke from Mauna Loa's crater, Dr. Schute of Puu Oo ranch being the first to sight the column of smoke.

 There will likely be other quakes before Mokuaweoweo gets into the full swing of a real exhibition of pyrotechnics. . . .

 Two gentlemen were comfortably ensconced at a round table on the veranda of Demosthenes Hotel [Hilo Hotel], Waianuenue street, when the shock came. One was a Hiloite, the other a stranger to Hawaii. "What's that?" suddenly inquired the stranger, gripping the arms of his chair. "Why," replied his friend, strangely enough looking behind him (northward), "It sounds like--." He hesitated, trying to say what it sounded like. Then the pause between the roar and the shakes, and as the first quiver came, the stranger bolted from the veranda. A horse on the street, fifty yards away, gave an odd scream and madly tugged a hack up hill, his driver, awakened by the rattling of iron roofs, gathered in the lines as he went. A late diner rushed from the restaurant, a plate of sandwiches in one hand and a bottle of beer in the other, and in the midst of the quake, sat down at the veranda table, saying: "This is no time to be alone." A tall two-by-two brick chimney, apart from the house vibrated sickeningly.

 In the Elk's club, over The Tribune office, a Hilo man was entertaining the Italian Saxophone quartet which had for the first time in Hilo showed at the Gaiety theater that night. They knew something of old-world earthquakes, but had never experienced the Hawaiian brand. They were out of their chairs in an instant and scrambling for the doorway. The Hilo man ordered them back. They were frightened enough to obey any commanding voice.

 A man walking home in Waiakea, about a mile from the Hilo post office, suddenly felt his knees weaken. He felt quakes before. He saw the waters of a large pond, usually placid, jump up and break into waves with a strange slapping and slopping sound, breaking on the banks as if a giant hand had altered the pond's entire contents.

 A game of cards was proceeding it a certain house when one frame wall rattled as if it was separate from the rest of the building; then the whole structure wobbled, rocking chairs rocked vigorously and crockery and ornaments gave out a weird clattering noise. The players, speechless, waited for a repetition of the quivers, though there was but the one series. Pictures in many houses were disarranged on the walls and everywhere sleepers were awakened, jumping out of bed and hastily gathering clothes.

 Telephone intelligence from many sections of the island was forthcoming the day following. The quake had been generally felt. It was at first thought that some damage might have been done in Kau, for it is that district that the quakes are usually felt most severely. But descriptions of the incident, from that part of the island, revealed the fact that Hilo felt the seismic disturbance quite as heavily as did Kau. No damage anywhere outside of fright has been recorded.

 Some people are talking of an increase in the activity in Kilauea crater, but are apparently not familiar with what the volcanologists have been teaching of late, for when the quakes begin to be numerous and strong in Hawaii, it is to Mokuaweoweo that the Big Islanders must look for action. The quake of last Wednesday night must have been simultaneous with the Mauna Loa crater activity, for the morning revealed a broad ribbon of smoke from Mokuaweoweo and that crater is still smoking generously. There have been many very moderate vibrations of the earth's crust in the last week, not severe enough to occasion serious remark. The opinion, however, is that Mokuaweoweo is preparing for a big exhibition.



Anonymous, 1912, Jaggar on the way to Hawaii; Recent shakes in Hawaii-hurry him-expects predicted outbreak soon: Pacific Commercial Advertiser, 06/07, p. 1, 4. [Repeated in Hawaiian Gazette of the same date] 



 The article summarizes Jaggar's plans for the new observatory.



Anonymous, 1912, Jaggar on the way to Hawaii; Recent shakes in Hawaii-hurry him-expects predicted outbreak soon: Hawaiian gazette, 06/07, p. 1, 8. [Repeated in Pacific Commercial advertiser of the same date] 



 The article summarizes Jaggar's plans for the new observatory.



Anonymous, 1912, Earthquake felt on all islands: Pacific Commercial Advertiser, 10/15, p. 9. 



 Wailuku, October 14--A severe earthquake was felt throughout Maui yesterday morning, the shock coming at half past five o'clock.

 A wireless to the Star-Bulletin yesterday states that the shock was felt throughout the island of Hawaii and that increased activity of the volcano is reported. The shock, as reported in the Sunday Advertiser, was felt throughout this city [Honolulu], being especially strong in the Kaimuki district.

 Full particulars of the records made by the seismograph at the Technology Station [HVO] will be received in the regular weekly report to the Advertiser from Professor Jaggar, and, in all probability, the connection between the earthquake and the increased activity at Kilauea--if there be any connection--will be explained.



Anonymous, 1912, Locals: Maui News, 10/19, p. 5. 



 The earthquake on Sunday last [Oct. 13] was felt throughout the group. It was most severe on Maui.



Anonymous, 1912, Many shocks at the volcano; instruments record series of minor quakes through all of last week: Pacific Commercial Advertiser, 10/21, p. 2. 



 A swarm of earthquakes were recorded during the past eight days [beginning Oct. 14] by the seismographic instruments at the Technology Station, Kilauea . . . None of the shocks were at all strong, the one most noticeable being recorded on the morning of Sunday the thirteenth, which same shock was felt in Honolulu and throughout the group.

 . . . .

Shook the Territory [This information duplicates that given in Jaggar, 1947, p. 44]

 Early in the morning of the 13th of October and earthquake was distinctly felt at the Volcano House by several persons, including the writer [H.O. Wood]. The motion communicated to the second story of the hotel was gentle and relatively slow, yet sufficiently strong to waken light sleepers. This was a multiple shock, eight distinct maxima being counted by L.A. Thurston at the Volcano House. It is doubtful if this could be due to a peculiar response in the swaying of the structure. Owing to an unaccountable stopping of the driving clock of the major tromometer, this shock was not registered properly, and the time of its occurrence or its duration were not measurable. The maximum amount of its motion indicates that it was a shock of only moderate strength. Approximately its time of occurrence was about quarter to six in the morning. It has been reported that this shock was felt lightly in Honolulu and distinctly in Hilo. Whence the writer concludes, since the area of sensible motion was fairly large and the motion nowhere strong on land, that this was a submarine shock of fairly deep origin and relatively slight energy. The geographical position of the origin cannot be estimated.

 Throughout the forenoon of October 13 the pendulum of the major tromometer swung irregularly with long period indicating relatively rapid and irregular movements of tilting at the edge of the Kilauea sink at this time. These movements were superimposed upon the normal diurnal tilting.

[The article concludes with reports of more quakes, duplicating information in ESPHVO for that week]



Anonymous, 1912, Seismological notes: Bulletin of the Seismological Society of America, v. 2, no. 2, p. 144-145. 



 "EARTHQUAKES AT HONOLULU, 1909-10.In the Report of the United States Coast and Geodetic Survey's Magnetic Observatory, near Honolulu, prepared by Mr. Daniel L. Hazard, there is given in addition to the magnetograph records a short note on the behavior of the Milne seismograph belonging to the Seismological Committee of the British Association. This was transferred from Oahu College to the Magnetic Observatory in April, 1903. The pendulum points north, recording east-west motion. The pendulum period is between 19 and 20 seconds, and the sensitiveness or amount of tilt corresponding to a displacement of 1 millimeter at the end of the pendulum has been determined at various times. A table of the earthquakes recorded during 1909 and 1910 is given, covering in all 259 disturbances. The phases are given in Greenwich mean time, counting from midnight. Nearly all of the disturbances recorded were tremors of short duration and small amplitude. In many cases a mere swelling of the line without well-defined phases has been tabulated as the beginning of the principal portion." The remainder of this short note lists earthquakes by number, not by date and time. One earthquake (no. 588) is described as being felt generally on the island of Hawaii.



Anonymous, 1913, Earthquake at Hilo worst in many years: Honolulu Star-Bulletin, 05/20, p. 7. [Nearly identical text in The Hawaii Herald of May 23, 1913] 



 Hilo, May 19--Old residents claim that the earthquake at about 8 o'clock Sunday night [May 18] was one of the sharpest ever experienced here, although of very short duration. The quake interval was for about half a minute, coming with a most decided shock from sea to mountain, followed by two others which seemed to be from Puna toward the Hamakua coast.

 So roughly did it jar frame buildings that there was considerable evidence of fright, especially among strangers who rushed into the middle of the streets. But by the time most of the people were in the streets the quake was over. It is claimed that of recent years there has only been one other so severe and that was five years ago when large articles were shaken from shelves of buildings. The quake was not felt at Volcano House. [This last statement is refuted by the report from HVO.]



Anonymous, 1913, Sharp earthquake Sunday evening: Hawaii Herald, 05/23, p. 1. [Nearly identical text in The Honolulu Star-Bulletin of May 20, 1913] 



 Some old residents claim that the earthquake at about 8 o'clock last Sunday night was one of the sharpest ever experienced here, although of such short duration that it had no opportunity to cause any damage. The quake interval was for about half a minute, coming with a most decided shock from sea to mountain, and just as severely two quickly followed which seemed to be from Puna toward the Hamakua coast.

 So roughly did it jar frame buildings that there was considerable evidence of fright of people in Hilo, especially among strangers who rushed to the middle of the streets. But by the time most of the people were in the streets the quake was over. It is claimed that of recent years there has only been one other so severe and that was five years ago [Sept. 20, 1908] when large articles were shaken from shelves of buildings. The last quake was not felt at the Volcano House. [This last statement is refuted by the report from HVO.]



Anonymous, 1913, [no title]: Pacific Commercial Advertiser, 09/10, p. 6. 



 A very sharp and short earthquake shock was felt in Hilo Monday morning just before noon.



Anonymous, 1913, Volcano gets ready to give brilliant show: Honolulu Star-Bulletin, 10/25, p. 1. 



 Hilo, Hawaii, Oct. 25.--An earthquake shock, felt for eighteen or twenty seconds last night, alarmed Hilo residents slightly. Two small cracks were caused in the Masonic building. signs of activity are reported at the crater of Kilauea.



Anonymous, 1913, Earthquake lasting twenty seconds is reported from Hilo: Pacific Commercial Advertiser, 10/29, p. 2. 



 Returning passengers from Hilo yesterday by the steamer Mauna Kea brought particulars of a rather severe earthquake which was felt in the southern metropolis Saturday morning at one o'clock. Oldtimers claim the quake was by far the most severe experienced there since 1880 when Mokuaweoweo erupted and the lava flow reached within half a mile or the rear gates of the city.

 Saturday morning's earthquake is said by some to have lasted fully twenty eight seconds. Editor Santos of O Luso, who returned yesterday from Hilo, states it duration was fully twenty seconds and that for a considerable time after the actual quake there was a pronounced oscillation of the land.

 Two easily visible cracks appeared on the walls of the Masonic building, which is a concrete structure reinforced by steel. A large plate glass in one of the show windows of the Peacock building, a big two-story brick structure, was cracked from top to bottom. Curiously, no damage was done in many of the stores. In the country most of the old-fashioned stone bread ovens were demolished.



Anonymous, 1913, Instruments broken by quake; Professor Jaggar, from Kilauea, tells of Earth tremors that awakened Hilo--people of other islands asked to send in reports whether or not they felt the shocks: Pacific Commercial Advertiser, 11/03, p. 9. 



 Much of this article describes what happened at Kilauea, particularly in the Whitney Laboratory of Seismology, during October. Descriptions of the October 25 earthquake duplicate what is published in the weekly and monthly HVO Bulletins (Bevens and others, v. 2, p. 62, 64). 

 Under the subtitle of "Want people to aid," Jaggar makes the following plea:



Anonymous, 1913, Professor Jaggar wants data; man who watches Kilauea seeks information regarding earthquake: Maui News, 11/08, p. 5. 



 Professor Jaggar is interested in obtaining from the public as much information as possible about the earthquake of October 25, 1913. "We want to get an idea of the distribution of earthquake intensity," said Professor Jaggar. "What we learn from this will be valuable for us when later on we distribute simple observation instruments at various points on the island."

 . . . . Professor Jaggar asks that those interested will cut out the list of questions, paste it on a piece of paper and write out the answers in the space opposite each question. Here are the questions and the directions.

Earthquake of October 25, 1913; Information Blank.

What is your name, occupation, and P.O. address ?

Did you feel the earthquake October 25, 1913, about 1 a.m.?

How many shocks did you feel?

At what locality were you? Describe place as exactly as possible.

Were you indoors or outdoors, and if indoors, on what floor of house?

Were you walking, riding, standing, sitting or lying down?

At what time did the shock or shocks occur, as nearly as you know?

How long, in your judgment, did the shock or shocks last?

 At your locality.

(1) Was the earthquake felt by few or many persons ?

(2) Did doors and windows rattle, or buildings creak?

(3) Did hanging objects, like pictures swing ?

(4) Did plaster crack?

(5) Was furniture moved about?

(6) Did bottles, vases, etc., fall?

(7) Did church bells ring?

(8) Were people generally awakened?

(9) Were pendulum clocks stopped?

(10) If so, in what direction did the pendulum swing? (answer north-south, east-west, etc.)

(11) Were many people frightened?

(12) Were many people made dizzy or sick?

(13) Did trees, doors, etc., swing slowly, or did they quiver?

(14) Was water in tanks observed?

to swing slowly, or splash quickly ?

(15) Did chimneys fall?

(16) Did brick masonry crack?

(17) Did window glass break?

(18) If so, what directions did most of the broken windows face?

(19) Did concrete masonry crack?

(20) Were any buildings destroyed?

(21) Was there any damage to wooden buildings?

(22) Were there any landslips, cracks in the earth or new springs formed?

(23) What noise did you hear, if any, before, during or after the earthquake?

(24) Was there general evidence that objects shook or fell in one direction or one line of direction, as north-south, east-west, etc.?

(25) Were animals or fowls restless, noisy or unusually quiet before the earthquake?

(26) Were there any other noteworthy happenings?

(27) Persons of scientific training who receive this are invited to write here a complete brief description of phenomena observed.



Anonymous, 1913, Signs of the quake: Pacific Commercial Advertiser, 11/09, p. 2. 



 New slides about Kilauea, generated by the earthquake of October 26 [sic], 1913, have been discovered near the base of Waldron's ledge, where a single large block has fallen out near the trail, and from the low cliff west of the foot of the trail leading from the Volcano House to the crater. This last place is a broad fresh notch, marking the scar of a landslip of considerable magnitude, as shown by the talus heaps beneath. Very respectfully, 

 T.A. Jaggar Jr.,

 Director



Anonymous, 1914, Heavy downpour covers islands; Earthquake accompanies storm that is reported to have been general: Pacific Commercial Advertiser, 03/30, p. 1. [Repeated in Hawaiian Gazette of Mar. 31, 1914, p. 2] 



 Most of the article describes a regional storm.

 "An unusual accompaniment of the storm was an earthquake shock which jarred houses and startled the occupants but did no damage. Reports of the temblor came to the Advertiser from G.W.R. King and W. Hole of Kaimuki and W.R. Castle of Tantalus road, Punahou, and in varying degrees of severity it was felt in all parts of the city."



Anonymous, 1914, Severe quake felt: Maui News, 04/04, p. 1. 



 On Sunday night last [Mar. 29] at seven minutes past eight o'clock a severe shock of earthquake was felt in Wailuku. The tremor appeared to come from the north and traveled toward the south. It lasted for about six seconds. Two shakes were felt at an interval of a second or two.

 The earthquake was the most severe felt on Maui for a long time, and there were many conjectures as to where the trouble originated. Some people thought that either Kilauea or Mauna Loa had broken out afresh. However dispatches from Washington show that the seismograph recorded a severe shock there.

 It is now surmised that there has been a big eruption in some isolated place and that, later on, news will come of the outbreak. People in Hawaii do not feel nervous as they knew Kilauea is a safety valve.



Anonymous, 1914, Kilauea's fires brilliant sight: Hawaii Herald, 04/17, p. 1. 



 A description of the lava lake in Halemaumau occupies the first several paragraphs, succeeded by the following:

 A slight earthquake shock was felt by a number of persons in Hilo shortly before 2 o'clock last Tuesday morning [Apr. 15]. The say it was only one brief tremor, noticeable in their homes but having no material effect and causing no damage.



Anonymous, 1914, Earthquakes: Hilo Tribune, 05/05, p. 2. 



 Hilo had a mild earthquake shock last Wednesday afternoon [Apr. 29]. It was of long duration, but not strong enough to be felt except by people seated or lying down. On the following Saturday [May 2] Honolulu was shaken, as shown by the following in the Sunday Advertiser [May 3, 1914]:

 Two earthquake shocks a few seconds apart were recorded in all parts of the city and environs last night at 6:43 o'clock. The first shock was light, very much like the vibration from a heavy blast. The second shake a few seconds later, was short and quick also but heavier than the first. Telephone reports to the Advertiser revealed that the earth tremor was distinctly felt in all parts of the city as well as the adjoining country districts. So far as is known no damage was done.



Anonymous, 1914, [no title], in Brevities: Hawaii Herald, 06/05, p. 5. [Nearly identical text in The Honolulu Star-Bulletin of May 20, 1913] 



 Hilo experienced another mild earthquake last Monday morning [June 1] about 6:20 o'clock. There were two distinct tremblors, the first being the heavier and quite noticeable but the second, several minutes later was so faint that only a few observed it. They caused no damage or excitement.



Anonymous, 1914, Sixteen quakes at the volcano; Scientific observers testing theory of moon's influence on seismic phenomena here--the lava rising, in Brevities: Hilo Tribune, 07/14, p. 6. 



 Technology station, July 9, 1914-- . . . .

 During the week ending July 8 sixteen local earthquakes were registered. All but two of these occurred within a period of forty-eight hours on July 5, 6 and 7, eleven of them between 2:44 p.m. July 5 and 1:41 a.m. July 6. . . .



Anonymous, 1914, [no title], in Brevities: Hawaii Herald, 07/24, p. 5. [Nearly identical text in The Honolulu Star-Bulletin of May 20, 1913] 



 An earthquake that was felt from Hilo to the volcano was experienced Monday morning [July 20] about 4 o'clock. It was sharp, coming in three distinct tremblors and continuing several seconds. An unusually fine display of rising lava was reported from the crater the previous evening. The shock caused no damage.



Anonymous, 1914, Earthquakes are felt around Hilo: Hawaii Herald, 10/02, p. 1. 



 Two rather severe earthquake shocks were felt in Hilo last Sunday [Sept. 27] and the first, in the morning time, lasted for about fifteen seconds. The shake traveled from north to south and began at 10:14 a.m. The second tremor was felt at 1:17 p.m. and was not quite as pronounced as the first one.

 Reports from outlying districts are to the effect that the earthquakes were felt both in the morning and the afternoon. The direction of the shakes in some places seems to have been from east to west.

 The increased activity of the volcano is thought to have something to do with the recent tremors of the earth.



Anonymous, 1914, More earthquakes felt in Hilo: Hawaii Herald, 11/20, p. 1. 



 Earthquakes are becoming frequent, and the laymen wonder if Mauna Loa is due for an eruption soon, or whether Kilauea is going to play up more than usual. Besides the shakes felt at Paauilo and Laupahoehoe last week, there have been quakes experienced in Hilo lately.

 On Friday evening last [Nov. 13] at 7:50 o'clock there was a shake that lasted about 15 seconds. It was distinctly felt at Puueo where pictures hanging from walls swung to and fro. The shake alarmed some malihines but did no damage at all.

 On Sunday afternoon before one o'clock in the afternoon, there was a more severe shake [than the one on the 13th] which seemed to travel from south to north. The tremor lasted about ten seconds, rattled windows and threw pictures out of plumb again.



Anonymous, 1915, Hilo is shaken by earthquake; damage slight: Honolulu Star-Bulletin, 03/29, p. 8. [Repeated in Maui News of Apr. 4, 1915] 



 Hilo, March 29.--Hilo was shaken by a severe earthquake at 8:30 Sunday morning [Mar. 28]. The tremor was felt all over the Island and was palpable to all, houses shaking, dishes being hurled off tables and shelves, and windows rattling. Slight damage was done to many houses. Nobody was injured.



Anonymous, 1915, Very severe earthquake; a shake-up that was heavier on this side of the island than the other: Hilo Tribune, 03/30, p. 1. 



 An earthquake here was the severest felt here for a number of years, occurred at about half past eight on Sunday morning [Mar. 28]. Many a house was quickly emptied of its inhabitants by a rush for the streets. The shock was of such long duration that those who started quickly could get out-of-doors before it was over. Though some old-timers declare it the severest they ever felt here, many think they recall harder shocks, and the damage this time was practically nothing, while a shock of seven or eight years ago did great damage in drug stores and among household glassware.

 At the Volcano House the shock was not as heavy as in Hilo, judging by the reports of those who felt it. But it was too heavy for the instruments at the Observatory to record it,--the "needle went off the tape" and the record is soon lost after the shake began.

 Professor Wood stated at the Observatory yesterday that the shock was lighter at the Volcano, than the one of a year ago last October. "It appears from reports I have received to have been more severe in Hilo than on the Pahala side," he said. "It was the second shock we have had since the Observatory started, that was too severe for our instruments to complete a record of it."

 In a few Hilo homes vases were toppled over, and in the drug stores some bottles fell. The shock was remarkable for its duration as well as for the severity reached at its climax.



Anonymous, 1915, Hilo has a shock, in On the other islands: Maui News, 04/03, p. 5. [Repeated from HSB, Mar. 29. 1915] 



 The town of Hilo was shaken by a severe earthquake at 8:30 Sunday morning [Mar. 28]. The tremor was felt all over the Island and was palpable to all, houses shaking, dishes being hurled off tables and shelves, and windows rattling. slight damage was done to many houses. Nobody was injured.



Anonymous, 1915, [no title], in Brevities: Hawaii Herald, 05/28, p. 6. [Also noted in the Hilo Tribune of Jun. 1] 



 There was a slight shock of earthquake felt in Hilo at five o'clock on Wednesday morning [May 26]. Another quiver of the earth's crust was experienced at about half past seven o'clock on this same morning.



Anonymous, 1915, [no title], in Brevities: Hilo Tribune, 06/01, p. 6. [Also noted in the Hawaii Herald of May 28] 



 There was a slight earthquake felt in Hilo at five o'clock on Wednesday morning [May 26]. Another shock was experienced at about half-past seven o'clock on the same morning.



Anonymous, 1915, [no title], in Brevities: Hawaii Herald, 08/20, p. 6. 



 There was a sharp shock of earthquake at five-fifteen last Sunday morning [Aug. 15]. It was felt more in Puueo than in other parts of the town.



Anonymous, 1915, Dewey crater showed signs of activity: Hawaii Herald, 09/24, p. 1. 



 The beginning of the article reports smoke from Dewey crater and speculates on the possibility of a new eruption in Mokuaweoweo. The article concludes as follows:

 . . . A series of earthquakes had been felt on Monday [Sept. 20] along the Hamakua coast and, more specially, at Kukaiau Ranch, where five temblors were felt within three hours. In Hilo small shakes had been felt on Sunday [Sept. 19] and Monday . . . .



Anonymous, 1915, Broke the record for earthquakes: Hilo Tribune, 09/28, p. 1. 



 L.A. Thurston, who returned from the Volcano yesterday morning, reports a continuance of the rapid sinking of the lava in Halemaumau and a record-breaking series of small earthquakes registered by the instruments at the observatory. "Up to yesterday morning a days record of 87 shocks was shown by the instruments," said Thurston, "and this is not counting 137 tremors not heavy enough to be recorded as shocks. This is the largest number ever recorded since the observatory was started. Professor Jaggar is inclined to think the earth's shaking is due to adjustments down below resulting from the downward flow of lava in the crater."



Anonymous, 1915, Dewey steams: Hawaii Herald, 10/01, p. 1. 



 The first two paragraphs discuss smoke see at Dewey crater, speculating on the possibility of a new eruption in Mokuaweoweo.

 There have been several rather severe earthquake shocks during the past week and one on Sunday last [Sept. 25] was rather strenuous. It was felt at Honokaa and Kukuihaele more than at places near Hilo. Other quakes have been felt along the [Hamakua?] coast and in fact all over the island.



Anonymous, 1916, Quake tears down old stone house: Hilo Tribune, 02/29, p. 1. 



 H.O. Wood, volcano observer, has been informed that an earth temblor strong enough to destroy a stone house on the trail from the volcano to Mauna Kea occurred on February 15. Extracts from the weekly volcano report telling of the quake are given below:

 An earthquake has been reported to the writer, strong enough to throw down a rude stone house situated on the trail leading from Kilauea to Mauna Kea at a point not far from the course of the Mauna Loa rift belt. This occurred in late evening of February 15. There is no report that this shock was felt except by ranchmen who happened to be in camp along the trail. This is of interest as a shock almost surely emanating from the northeast segment of the Mauna Loa rift system. The anticipation of eruption on this flank adds to its interest.

 A light earthquake was felt at the Volcano House in the early morning hours, at about 4 o'clock, on February 23.

 There were, of course, no seismic records of these or other shocks. 

[HVO seismographs were out from a storm that occurred around January 13, 1916. Seismic registration did not begin again until March 26.]



Anonymous, 1916, [no title], in Brevities: Hawaii Herald, 04/07, p. 5. 



 There was a rather severe shock of earthquake felt on Sunday night [Apr. 3] and it appeared to be worse in the Puueo district than anywhere else.



Anonymous, 1916, [no title]: Hilo Tribune, 04/10, p. 2. 



 Several communications datelined Volcano House quote T.A. Jaggar as announcing [erroneously] the beginning of an eruption on Mauna Loa, following a series of earthquakes widely felt throughout the district.



Anonymous, 1916, Mokuaweoweo crater breaks out in grand display: Honolulu Star-Bulletin, 05/19, p. 1. 



 [subheads: Mauna Loa's lofty crater erupts steam, smoke, 20,000 feet; lava flow reported]

 An account of the May 1916 eruption on Mauna Loa's upper southwest rift zone. Eruption began in Mokuaweoweo on Friday [May 19] at 7 a.m. [Star-Bulletin Hilo correspondent] or 7:15 a.m. [Inter-Island steam Navigation company's Hilo correspondent]. There is no mention of earthquakes. 

 Later reports indicate the eruption was at 11,000 feet on Mauna Loa's southwest rift zone, accompanied by earthquakes.



Anonymous, 1916, Majestic volcano of Mauna Loa in eruption and reports say lava flows after outbreak: Pacific Commercial Advertiser, 05/20, p. 7, 9. 



 [subheads: Dense volumes of 'smoke' are shot into air; One crater of 'fiery island' supposed to be Mokuaweoweo. Again 'blows off'; caldron of Kilauea fills simultaneously; Indications are that lava flows, if such there be, is on Kahuku side]

 An account of the May 1916 eruption, beginning high on Mauna Loa's southwest rift zone at 7 or 8 a.m. [reported times vary] May 19 and lava was reported flowing toward Kona.

 Kilauea very active

 A brief mention of activity in Halemaumau lava lake

 No earthquakes reported

 Usually earthquakes precede an outbreak of Mokuaweoweo, but none of the many wireless messages received here yesterday report temblors of any kind. Preceding and accompanying one of Mauna Loa's great eruptions, that of 1887, almost four hundred earthquakes were felt at Pahala, Kau, fissures being afterwards noted in many parts of the district. The plantation water system was entirely disrupted, the pipes being forced apart at the joints, in many places.

 . . . .



Anonymous, 1916, Mauna Loa is quieting down from all signs: Pacific Commercial Advertiser, 05/21, p. 9, 12. 



 [subheads: Professor Jaggar, from Volcano house, reports no new evidence of outbreak; Kau had series of quakes yesterday; Fire pit of Kilauea presenting a most spectacular sight for tourists]

 Hilo, Hawaii, May 20.--An account of the ending of the first stage of the May 1916 eruption, high on Mauna Loa's southwest rift zone, and possibly in Mokuaweoweo as well.

 Kau has earthquakes

 At Pahala, Kau, six earthquakes were felt between one and three o'clock this afternoon [May 19]. They were of short duration and no damage was done.

 It was learned today that on Thursday night [May 18] a short but severe, earthquake was felt at Waimea, South Kohala.

 The remainder of the article describes activity in Halemaumau lava lake.



Anonymous, 1916, Mauna Loa erupts; big lava flow moving mile an hour toward Kau: Honolulu Star-Bulletin, 05/22, p. 1. 



 [subheads: Mauna Loa's lofty crater erupts steam, smoke, 20,000 feet; lava flow reported]

 An account of the May 1916 eruption on Mauna Loa's lower southwest rift zone. Eruption began at 7000 feet on May 21 at 11 p.m. There is no mention of earthquakes.



Anonymous, 1916, Triple fiery streams of molten lava are flowing to the sea down Mauna Loa; eruption gaining strength as it devastates district of Kau and threatens homesteads and towns: Hilo Tribune, 05/23, p. 1. 



 An account of the May 1916 eruption on Mauna Loa's southwest rift zone. Eruption began about 11:15 Sunday night [May 21]. An earlier gas eruption began near the 11,000 foot level on Friday [May 20] at 7:15 a.m. At that time six distinct earthquakes, following each other at an interval of a few minutes, shook the district of Pahala, Kau.



Anonymous, 1916, See streams of lava flow from Mauna Loa in eruption: Pacific Commercial Advertiser, 05/23, p. 7, 9. 



 [subheads: Bertelmann ranch is destroyed and cattle in danger; Three streams of molten rock pour out of fissures and down mountainside; Courses are along tracks of old flows; Country of Kau district south of Volcano being devastated by fiery rivers]

 An account of the ongoing eruption from Mauna Loa's southwest rift zone and the damage caused to ranches. The original outbreak on May 19 lasted five hours. A paragraph on p. 9 states: "Almost continuous slight earthquakes [May 21] have convinced Professor Jaggar that a second outbreak of Mauna Loa is momentarily possible."

 The new eruption broke out at 11:30 p.m. on May 21 at 7,000 feet altitude.



Anonymous, 1916, Lava burst from Mauna Loa: Pacific Commercial Advertiser, 05/25, p. 9, 12. 



 [subheads: Clouds of vapor accompany flow of fiery liquid; Molten rock makes way down slope toward Papa and crashes through forest; Terrific outbreak at night brilliant; Streams on south side apparently have halted, although heat is intense]

 An account of the ongoing eruption from Mauna Loa's southwest rift zone. 

 Outbreak long expected

 Jaggar is quoted as saying "We have been long expecting this outbreak and realized at once that this was the great main flow of lava. It follows the course of the outbreak in the crater of Mokuaweoweo of December 1914. That outbreak was the premonitory symptom of the main eruption which we now have. . . .

 Six distinct earthquakes

 Jaggar repeats information regarding the six earthquakes felt in Pahala, identifying them as an expected precursor of eruption.



Anonymous, 1916, Many 'quakes on Big Island, Wood reports: Honolulu Star-Bulletin, 06/05, p. 1. 



 Hilo, Hawaii, June 5.--Many earthquakes are being recorded at the Volcano Observatory. H.O. Wood, Prof. Jaggar's associate observer, describes them as "a flock."

 Kilauea's crater is very active now.

 Smoke has been seen coming from Mokuaweoweo at the top of Mauna Loa.



Anonymous, 1916, Volcano lake's fall giving grand display; rise expected soon, Prof. Jaggar predicts: Honolulu Star-Bulletin, 06/06, p. 1. 



 Hilo, Hawaii, June 6.--This is declared to be the most spectacular day in the history of the volcano of Kilauea since 1894.

 Late yesterday the "bottom fell out of Kilauea" as enthralled spectators expressed it and the lava sank 300 feet in four hours.

 The earthquakes are continuing, the sides of the crater crushing down to the bottom of the pit, falling in great masses into the seething sea below the rim. . . .



Anonymous, 1916, Kilauea's lake of molten lava drops many feet: Hawaii Herald, 06/09, p. 8. 



 Kilauea, not to be outdone by Mauna Loa's craters, gave a splendid exhibition on Monday and Tuesday last [June 5-6] when the "bottom" fell out of the crater and the sides went tumbling down to a spot 675 feet below, where the remains of the lava still seethed and boiled with "Old Faithful" doing his best to liven things up.

 The beginning of the fall of the lava was on Sunday night [June 4], but it was on Monday that some lucky spectators sat for hours and watched the huge shelves and ledges of lava break off and thunder down to the bottom of the pit. It took about four hours for all the lava to fall from the three hundred foot mark. As the lava ran out, the benches or shelves of rock higher up broke off and tumbled down below. The sight was an awe-inspiring one and those who saw it will never forget it. As the depth of the funnel-like pit became more and more, the confined lava in many a cave began to run and fall like a beautiful cascade of fire into the pit. The noise of the falling rocks and the splashing of the molten streams of lava could be heard for a long distance.

 Earthquakes accompanied the phenomenon and the seismograph at the Volcano Observatory registered hundreds of shocks. Professor Wood describes the shakes as being a regular "flock" of earthquakes.

 The pit of Kilauea is a wonderfully changed sight now-a-days and is well worth a visit. The huge vent has assumed the aspect of a funnel which is wide at the top and narrow at the bottom.

 That there is a direct connection between the craters of Mauna Loa and those of Kilauea seems certain, and the supposition is that as Mauna Loa relieved herself of accumulated lava through the many flows of a couple of weeks ago, Kilauea's supply is being drawn upon and is going to fill a vacuum created by the expulsion of Mauna Loa's mass of molten rock.



Anonymous, 1916, Earth's tremors stir up things: Hawaii Herald, 06/16, p. 8. 



 When the earth began to shake last Monday morning [Jun. 12] at about six forty-five o'clock, there were some badly scared people in the Puueo district. The tremors of the earth were not as severe as those experienced a little over a year ago [Mar. 28, 1915], but all the same, they made people and animals sit up and take notice.

 The quake seemed to come from the south and travel in the direction of the north and the shake was sufficient to scare malihinis. It also scared the life out of a certain fox terrier pup belonging to a Puueo man. The animal was terrified by the shaking and ran howling from the front of the house to the kitchen. Not finding the cook there, the dog gave up all hope and simply sat on its haunches and waved both its legs in the air in hopeless fashion.

 When the quake attained its full strength pictures swung from the walls and crockery rattled in the pantries of the Puueo households. The sensation was not a nice one for ten or fifteen seconds and citizens wondered what was doing at the volcano.



Anonymous, 1916, [no title], in Brevities: Hawaii Herald, 07/14, p. 5. 



 There was a severe shock of earthquake at 9:55 p.m. on Tuesday evening last [Jul. 11] and the quakes lasted for almost a minute. In the Puueo district the tremors were felt more than in other suburbs.



Anonymous, 1917, Hilo is rattled by big earthquake; was severest experienced in several years: Pacific Commercial Advertiser, 08/01, p. 2. 



 An earthquake shook Hilo until the buildings quivered and people ran into the streets, Saturday evening [Jul. 28] shortly after eight o'clock, according to reports reaching here yesterday. The quake began with a long tremble gradually augmenting in force until the windows literally rattled. It was the severest earthquake the city has felt in years, and was more or less generally felt over the island. 

 A second quake followed six hours later and again buildings shook and people ran into the streets. No damage is reported except near Laupahoehoe, where a huge stone rolled from its place into the road between the railroad and station and tore up the road for a few feet.



Anonymous, 1917, [no title], in Brevities: Hawaii Herald, 08/03, p. 5. 



 There was a rather severe shock of earthquake experienced in Hilo on Saturday evening last [Jul. 28] at half past eight o'clock.



Anonymous, 1917, Lava column at Kilauea rises slightly during week; Most conspicuous object in the pit is great central crag mass which has slowly risen during summer to 76 feet above lake: Hilo Daily Tribune, 09/25, p. 5. 



 Most of the article documents changes in the level of Halemaumau lava lake.

 "The seismographs of the Whitney Laboratory for the week ending at 10 a.m. Sept. 21, 1917, registered two local earthquakes which occurred two minutes apart in the very early morning of Sept. 15 and were generally felt in Kau and Hilo."



Anonymous, 1918, Pele, furious, flows into crater: Daily Post-Herald, 02/23, p. 1, 6. 



 [subheads: Two streams of fiery lava are reported to be pouring out of pit and covering roadway; four feet of lava now fills space where the automobiles have been parking; sudden rise early this morning; actual overflows began about five o'clock today after lava had trembled on brim of crater for several days.]

 An account of the first overflow of Halemaumau since the pit became continuously active in early 1907.



Anonymous, 1918, Lava wells over rim of pit onto floor of crater: Hilo Daily Tribune, 02/24, p. 1, 5. 



 [subheads]: Automobile parking corral filled level and fiery floods threaten to blot out crater road as far as bottom of gravel banks; lake now higher than ever before in history; earthquake felt in Hilo yesterday may mean apex of climax, but Jaggar believes overflow has not yet satisfied pressure.

 The article describes the rise and overflow of lava from Halemaumau onto the crater floor. This is the first time that the lava lake has overflowed since Halemaumau became continuously active again near the end of 1907. The third paragraph reads as follows:

 At 12:55 p.m. yesterday a sharp earthquake shock was felt in Hilo, indicating, perhaps, said Professor Jaggar, the apex of the crisis.



Anonymous, 1918, Many flows spread from Halemaumau into crater: Pacific Commercial Advertiser, 02/24, p. 1. 



 [subheads: Auto road into crater threatened by latest reported flow, which broke over fire pit lip at six o'clock last night--phenomena of 1894 being repeated--tourists see marvelous sights]

 An account of the first overflow of Halemaumau since the pit became continuously active in early 1907.

 "There was a slight earthquake at the volcano, perceptible at Hilo, last night."



Anonymous, 1918, Volcano again overflows into road covering piece of land: Daily Post-Herald, 02/25, p. 1, 6. 



 A continuing account of the first overflow of Halemaumau since the pit became continuously active in early 1907.



Anonymous, 1918, Quake shakes observatory: Daily Post-Herald, 02/26, p. 1. 



 [subheads: spectacular display feature of busiest night Goddess has had for many years; Professor Jaggar issues warning to visitors the crater to keep off new lava flows as they are dangerous; fresh overflows into southern basin; publicity expert L.W. de Vis Norton compliments police department upon efficient manner in which they have handled the crowds at Volcano]

 Late crater news

 A heavy local earthquake shook the Volcano observatory this morning shortly before 10 o'clock, throwing the needles off the rollers and upsetting the instruments.

 Professor Jaggar issued a warning to the visitors to the Pit against walking on the new lava flows. the type of lava, he says, is thin and exceedingly brittle, making it very dangerous to venture upon it unless one is thoroughly familiar with the conditions

 The lake overflowed from the southeast basin this morning.

 A broad stream of lava is reported to be flowing out of an old cone under the west bench.

 Beginning at 9:45 this morning and lasting for several seconds a severe earthquake shook the entire vicinity of the Volcano Observatory, throwing the needles of the seismographs off the rollers and in some instances upsetting instruments.

 As a rule these shocks when the lava lake is high are indicative of a coming subsidence of the level, but this morning Professor Jaggar declared that other indications lead him to believe that the lake will not fall for some time to come, and may indeed raise considerable more.

 The article continues with description of the overflow.



Anonymous, 1918, New flow blots out another 400 feet of highway: Hilo Daily Tribune, 02/26, p. 1, 2, 6. 



 [subheads: Lava lake maintains it unprecedented level and brims over from its basin four more times since Saturday night's spill; Fearful pressure from beneath visible to all; Most suggestive aspect of Pit now is evidence of powerful upthrust held back by weight of main floor of Kilauea crater]

 The article describes the continuing rise and overflow of lava from Halemaumau onto the crater floor.



Anonymous, 1918, Two-thirds of volcano trail buried in lava; Hilo experiences sharp earthquake--Halemaumau displays intense activity: Pacific Commercial Advertiser, 02/26, p. 1. 



 [subheads: Auto road into crater threatened by latest reported flow, which broke over fire pit lip at six o'clock last night--phenomena of 1894 being repeated--tourists see marvelous sights]

 An account of the first overflow of Halemaumau since the pit became continuously active in early 1907.

 "At 9:25 tonight [Feb. 25] there was a sharp earthquake." [date/time disagrees with ESPHVO-2/26 9:42 am]



Anonymous, 1918, Crater crags 90 feet above lake; two more short flows and sharp earthquake but upthrust of whole area is most significant sight: Hilo Daily Tribune, 02/27, p. 1. 



 The article describes the continuing rise and overflow of lava from Halemaumau onto the crater floor. The following quoted passages concern the process of magma rise.

 "But the most noteworthy symptom . . . was the extraordinary elevation of benches, crags and the floor of Kilauea itself. The highest crag of all had been lifted to a level where the topmost pinnacle was fully ninety feet above the pit rim.

 "A sharp local earthquake yesterday, so abrupt that it jarred the needle of the seismograph off the record chart, testified to a new adjustment of the rising column of stiff magma below the level of the lake.

 "Professor Jaggar is inclined to think that grinding friction between the magma and the walls that contain it may account for the earthquakes of much greater amplitude, during periods of rising, as well as do subterranean collapses in periods of depression. Just before the 1916 eruption of Mauna Loa, there was a whole flock of minor quakes registered at the Volcano Observatory, as the Mauna Loa column slowly forced its way to the surface."



Anonymous, 1918, Kilauea overflows into old crater; many changes are made by Pele: Hawaii Herald, 03/01, p. 2. 



 The article describes the first overflow of Halemaumau [Feb. 23, 1918] since lava disappeared at the end of 1894. Lava continued to overflow on Feb. 28 and Mar. 1.

 "Beginning at 9:42 a.m. Tuesday [Feb. 26] and lasting for several seconds a severe earthquake shook the entire vicinity of the Volcano Observatory, throwing the needles of the seismographs off the rollers and in some instances upsetting instruments."



Anonymous, 1918, Former Kilauea scientist invents cannon detector: Hilo Daily Tribune, 04/02, p. 1. 



 Washington, April 1--H.O. Wood, formerly associated with Professor T.A. Jaggar, Jr., at the Kilauea Observatory, Hawaii, and now employed here by the Bureau of Standards, is engaged in perfecting an instrument whereby the tremors of the earth occasioned by the discharge of heavy guns can be used to determine the approximate distance and general direction from the point of observation. In his work he is using data gathered while he was seismologist at Kilauea.

 [This work led to the development of the Wood-Anderson seismograph, which, in the 1930's, became the standard instrument used to calibrate earthquake magnitudes.]



Anonymous, 1918, Great lava lake of Halemaumau drops 150 feet: Hilo Daily Tribune, 04/02, p. 1. 



 [subheads]: Swiftly and gently mighty core of volcano subsides, till summits of crags no longer are visible from the site of the [Volcano House] hotel; floor of crater looks like abandoned quarry; opening of crevasses and undercutting of walls present precarious aspect, with promise of tremendous avalanches to come.

 The article describes the rapid draining of Halemaumau lava lake beginning March 26, 1918. Earthquakes accompanying the collapse are mentioned in the Hilo Daily Tribune of April 9.



Anonymous, 1918, Lava lake stops falling, period of rising begins: Hilo Daily Tribune, 04/09, p. 1-2. 



 [subheads]: Halemaumau core subsides till pit resumes its old aspect of craggy hills and bubbly expanses of fiery lakes of lava; plunger of well sinks 260 feet in nine days; retrogression so gentle, yet swift, that spires and pinnacles of molten lake maintain balance while being carried down.

 The article describes the rapid draining of Halemaumau lava lake beginning March 26, 1918, and ending April 4. The lake moved down as a coherent mass, carrying crags and islands intact. 

 "Numerous localized small earthquakes accompanied the movement of subsidence, increasing in vehemence as it increased and ceasing completely when recovery began. During the maximum these jars were quite perceptible at the edge of the pit."



Anonymous, 1918, Quake shakes Hilo; sharp vibration also felt in other parts of island: Hilo Daily Tribune, 05/22, p. 1. 



 A sharp shock of earthquake was felt in Hilo at 3:31 yesterday afternoon. The quake was felt in many different parts of this island and from Kau, Kona, the Hamakua, Puna and north Hilo came reports of the shock being registered. The motion of swaying objects in Hilo showed the movement to have been on a north-south line

 Judge Quinn's court was sitting at the time of the earthquake and for three seconds or so the whole federal building shook violently. the temblor was felt all over Hilo and while no damage that can be noticed was done the buildings of the town shook a great deal.

 [The next paragraph describes damage done during the earthquake of Sept. 20, 1908]

 The shock yesterday was felt slightly at the Volcano, but Professor Jaggar who visited the crater shortly afterward, noticed nothing unusual in the behavior of Halemaumau.



Anonymous, 1918, Profound quake sways Big Island; Kau and Kona roads full of loose stones; plates shaken from shelves in Naalehu; probably of distant origin: Hilo Daily Tribune, 06/15, p. 1. 



 A strong earth movement, probably of distant origin, was distinctly felt In Hilo yesterday, at the Volcano House and in the Kona and Kau districts.

 The sensible duration of the movement In Hilo was about fifteen seconds beginning at 11:18 a.m. It could hardly be described as a shock. Rather did It seem a deep, slow, gentle swaying.

 Between Waiohinu and Kailua, Secretary Lane's party found the road filled with loose boulders that had rolled down hillsides and had been shaken free from dry stone walls.

 At the Crater there were several small slides of rock into the pit, but the movement to the ordinary person, going about his business, appears not to have been so noticeable as It was In Hilo and elsewhere. At Naalehu, for Instance, crockery standing on the shelves of the Aki store was thrown to the floor.

 As soon as Professor Jaggar felt the movement he ran to the seismograph. The pens had been jarred off the paper by the force of the first slip, and one of them was broken, The Professor readjusted the instrument and then stood there watching It write.

 "It was a curious performance," he said later, "to see the Instrument go on writing long after all sensible movement had disappeared. It gave one something the sensation of watching a Ouija board.

 "The first movement lasted 1 minute and 40 seconds, and, after I put the pens back on the chart, they kept writing for 40 minutes more. That is a record, I believe, for this observatory.

 "I haven't studied the charts very carefully as yet, but from the length of the movement and the deep, gentle character of the swaying, I should say that we probably were on the, outer edge of a big quake, possibly at a considerable distance. Unfortunately the pens jumped the start just at the phase that might have told us the approximate distance. However, I may learn more from closer study later. 

 "You know when the San Francisco earthquake reached Nevada It was felt there as, a deep gentle undulation. This movement had the same quality. That is why I think It was not of local origin."

 Swimmers at Coconut Island yesterday noticed that the water was muddy, and there was a jumbled, lumpy sea running, unlike the usual measured swell.



Anonymous, 1918, Secretary F.K. Lane enjoys volcano and quake: Hawaii Herald, 06/21, p. 6. 



 . . . The earthquake which was felt in Hilo shortly after 11 o'clock yesterday morning, rocked the West Side like a boat at sea . . .

 It played havoc with the road in the vicinity of Manu-ka . . . The roadbed was disrupted, rocks were thrown into it, and crevices were opened. The condition was so bad that Secretary Lane's party attempting to pass that way later on was halted for some time while the road was being cleared . . .

 . . . .

 A tank of water which stood near where the road was torn up, was upset. Also, at Keokea a saloon had all the liquor bottles shaken off the shelves. . . .



Anonymous, 1918, Pele's moods; lava lake slowly subsides, with no sign of rising as equinox of next week draws near: Hilo Daily Tribune, 09/17, p. 4. 



 The article speaks mostly of the levels of Halemaumau lava lake during the week ending Sept. 13, 1918.

 "In the Whitney laboratory of Seismology the week has been a notable one in that three pronounced seismic movements have tested the new instruments satisfactorily. [The first, at 7 a.m., was a teleseism]. "About eight hours later a pronounced earthquake wave [T-phase of the teleseism] raised the waters of Hilo Bay some four feet and was observed in the Wailuku River . . . .

 "The next morning, Sept. 6 [sic; 8] about 7:40 a.m., a local earthquake felt generally in the southern part of the island was admirably registered on the rebuilt drum of the Bosch-Omori instruments, showing for the first time in routine registration at this station every detail of the timing and amplitude of the first preliminary tremor of a local earthquake.

 The seismograph was adjusted on Sept. 13 so that the smoked paper under the writing boult moved at the slow rate of only 3.5 centimeters in twenty four hours. . . . [Continues with description of the tilt motions of the Bosch-Omori].



Anonymous, 1918, Hilo rattled by earthquake, but the damage is slight: Daily Post-Herald, 11/02, p. 1. 



 At 11:33 last night there was one of the sharpest earthquakes felt in Hilo for a long time. The shake lasted for at least half a minute and while it was in progress people jumped from their beds and made their way to the tops of the stairways and out onto lanais, dressed in costumes that might be all right in Samoa for street wear but not in Hilo.

 The shake was a very severe one, yet there was not much damage done anywhere. In the Puueo district, where earthquakes are always felt more than on the city side of the Wailuku river, there were showers of crockery at some homes. Pictures swung out of line on the walls, clocks stopped, dogs barked and chickens began to wake up thinking they heard the morning rattle of dishes in the houses.

 The clock in the Post-Herald office stopped on the dot of 11:33 and other timepieces in the city did the same.

 Out along the North Hilo coast and in the Hamakua district the shock was a very sharp one. At Honokaa there was a real lively time. The mules in the plantation stables hee-hawed their heads off and horses squealed with fright.

 At Waimea . . . the quake woke everybody up . . .

 At the Hawaii Drug company it was reported that some slight damage was done to the stock

through the earthquake. Some bottles were shaken off the shelves but not broken.

 One lady, when the quake came to Puueo, made a leap for the window and only for the intervention of her husband would have suffered a serious fall.

 . . . it was a stiff shake at Honuapo, but no damage was done. . . .

 L.A. Aungst of Holualoa said the quake was felt good and stiff over in Kona, but that no damage has been reported so far.

 The guards at Kuhio wharf report a severe shock and, judging from all reports, it was felt heavier there than elsewhere. They report that there were three shocks in all, lasting over half a minute. The structure being on made ground no doubt made for the severity of the shake there.



Anonymous, 1918, Quake splits open Kilauea lava floor: Pacific Commercial Advertiser, 11/03, p. 1. 



 [subheads]: Fire fountains active hundred feet and more back from Halemaumau edge--lava flows running toward and into pit; whole Big island gets severe shock; culmination of three days steady rising of crag islands and tilting up of center of Kilauea floor--no damage reported

 Hilo, November 3--The island of Hawaii shook Friday night from Hilo to Kohala, an earthquake of unusual sharpness occurring at eleven-thirty o'clock, attracting the attention of all and alarming some in the districts of Hilo, Kona, Kau, Hamakua and Kohala.

 Simultaneously the lava floor of Kilauea, which has been gradually tilting, was heaved upwards and on Saturday morning it was seen that the floor had been torn with wide cracks over a wide area.

 New lava outlets; Through these new orifices, lava was being expelled in great quantities, particularly at points near the site of the old rest house, a hundred feet back from the edge of the fire pit of Halemaumau and near the old stone house corral, where tourists used to leave their mounts during their visits to Pele's fiery shrine. . . .

 The seismic disturbance and the unusual activities at Kilauea are the culmination of three days steady rising of the inner crag islands in the fire pit with a pronounced back tilt of the whole floor of the crater from the fire lake in the center.

 The earthquake was a severe shake for this island, but no damage is reported greater than the shaking down of stone walls throughout many miles and the temporary blocking of some of the highways by the boulders rolled onto the roads.

 Most severe in years; Manager Monsaratt of the Kapapala Ranch reported that the quake of Friday night was the most severe shock for his section of the island since 1887, twenty-four? distinct tremors being counted. A half-mile long stone fence on the ranch was shaken down and water pipes were broken,

 At Mahukona doors were rattled as the houses twisted and the howling of frightened cows added to the midnight confusion of the shake. In may instances people leaped from their beds and dashed into the open, fearful lest the building might crash down upon them.

 Chairs in houses at Kawaihae slid across the floors of rooms.

 The damage was very small, consisting mainly of broken crockery and glassware at various points.



Anonymous, 1918, Worst quake since '87 says Julian Monsaraat: Hilo Daily Tribune, 11/03, p. 1, 8. 



 [subheads]: Water tank dished, stone wall tumbled, pipes broken and houses out of plumb at Kapapala; sleepers rush from beds at Mahukona. Twenty-six separate tremors felt in Kau; entire island shaken to core by disturbance originating at Kilauea, but damage done confined to breakage of glassware and crockery

 Originating in a volcanic disturbance which Professor Jaggar says lay directly under the mound of Halemaumau in Kilauea crater, Friday night's earthquake traveled straight through the vast bulk of Mauna Loa and Mauna Kea to the outermost margins of the Kohala coast, shaking the entire Island to Its very core.

 Reports of fright and astonishment flowed into Hilo from the different districts of the island all yesterday. Apparently the quake was felt in greatest force In Kau, where 26 shocks were counted, water pipes were broken and a stone wall shaken down.

Doors Slam, Dogs Howl.

 At Mahukona, doors slammed and the houses rocked so violently that sleepers jumped from their beds and I ran out into the night, while the dogs howled dismally, as the earth swayed under their paws. At Kawaihae chairs slid across the floor and standing objects were toppled over.

 As in Hilo, the shock began at Kawaihae with a gentle swaying movement and ended with a sudden grinding wrench, accompanied by heavy subterranean noises. A strong gale sprang up Immediately after and was still blowing great guns last night.

 At Waimea, Senator Desha was sufficiently roused to jump outdoors in his night clothes. Others in the same house slept through the whole disturbance.

Tenement Dwellers Affrighted

 The general impression in Hilo was that the final spasm was more severe than any shock felt here for several years past.

 Along the Hamakua coast no damage whatever was done, and in Hilo little beyond the breaking of small amounts of crockery. In some of the Japanese tenements, the effect of the main shock was intensely felt, and the inhabitants were greatly alarmed. In one case, where there were several children, and where the crockery was broken, the children broke into cries, which the frightened mothers found it hard to quell.

 At the Waiakea house lots, the water tanks swayed and the water swished against the sides of the tanks but practically no damage was done. All around town the same reports were made, that no harm was done, but that fear followed the tremors.

 Considerable damage was done in Kau, according to a statement made by Julian Monsarrat, manager of the Kapapala ranch, where the shocks numbered 26. There were four very severe shocks, followed by six of a lighter degree, and then came sixteen more which might be classed as light, with an additional number not of sufficient force to warrant noting.

 The worst effects of the four severe shocks were the smashing of all the water pipes in the vicinity of the ranch manager's house, the demolition of the water tank and the casting down of approximately half a mile of stone wall. This much could be seen by Mr. Monsarrat yesterday, but there may be more damage on the outside which has not yet been ascertained.

Houses Out of Plumb.

 When the heavy shocks were felt in the house, everything that was stored loosely crashed to the ground, raising a vast amount of noise. The building itself stood the effect of the earthquake well, but several other structures In the vicinity settled on their foundations slightly, causing them to sag somewhat, but not sufficient to render them dangerous.

 Tables, chairs, beds, and other pieces of furniture were moved in most of the houses. In fact, a piano in the manager's dwelling was shifted between six and eight inches, while some of the beds and tables moved about one foot.

Worst Shock Since 1887.

 "This is the worst series of earthquakes I have experienced since 1887," said Mr. Monsarrat yesterday. "'Then they were much more severe, but this one beats anything meantime. It looks to me as though there will be an outbreak at the Volcano, if there has not already been one. We cannot see from here. as the mountain is very much overcast I would not be surprised to see these shocks repeated, unless there Is an outbreak at the crater.

 "It will cost something to repair the damaged wall here, but aside from that there is not much serious damage. Owing to the smashing of the water pipes, we are without water just now."

 With the exception of the report from Kapapala ranch, little damage seems to have been done in Kau. From Waiohinu, it is reported that no damage was done, and similar reports come from Naalehu, Pahala and Meila. A strong wind is blowing at Waiohinu, in fact, almost a gale has raged for the past few days.

Clocks Stopped at Kealakekua.

 South Kona reports a hard shock, but no damage at Kealakekua or Napoopoo; nothing more than the stopping of a clock at the latter place. The intensity of the shock alarmed people, but nothing further.

 At Kailua, M.M. Springer states that the earthquake lasted about thirty seconds strong but of an easy rocking motion. It was felt all over the North Kona district, and at Honokohau rocked water tanks sufficiently to spill the water.

 People at Honokaa were frightened, but the tremor soon ceased and as it began very slightly and then only Increased a little, the fear soon died down.



Anonymous, 1918, Temblors felt on Oahu: Honolulu Star-Bulletin, 11/04, p. 3. 



 The Island of Hawaii was shaken by not less than 26 seismic waves between 11 and 12 o'clock Friday [Nov. 1] night, one of the heavier vibrations being felt at Waikiki and at other points along the shore of this island, Renewed activity in Halemaumau cauldron, observed Saturday morning, suggested that as the center of the disturbance, although the vibrations appear to have been heavier on the west side of the mountains around Kapapala ranch and toward the Konas and Kau. Julian Montserrat, manager of the Kapapala ranch, reports that the shocks were the heaviest felt there since 1887. There was no property damage so far as is known.

 Earthquake shocks on the west half of Hawaii of those of the intensity of Friday night may indicate activity in Mokuaweoweo, near the top of Mauna Loa, although not necessarily so. Shocks have come from Kilauea many times before when there were no manifestations whatever in the region of the mountain top, but any disturbance in Mokuaweoweo is responded to at once in similar activity in Halemaumau.



Anonymous, 1918, Earth shakes Maui folk out of dreams: Maui News, 11/08, p. 1. 



 [subheads]: Sharp seismic disturbance felt all over Territory last Friday--Most severe on Hawaii--Kilauea opens new outlets for lava.

 Many persons on Maui were shaken from their slumbers about 11:30 o'clock last Friday night [Nov. 1] by a real, goodness-to-gracious earthquake. the tremblor was one of the sharpest that has been felt on Maui for years, making dishes in the pantry rattle and pictures on the wall shake ominously. No danger however, has been reported and the disturbance did not last long.

 The quake, which probably originated in connection with volcanic disturbances on the Island of Hawaii, was more severe there than here, being reported to have been one of the heaviest in 20 years. Roads were blocked by rocks shaken from the hills and a lot of stone fences in Kau and Kona were tumbled down, but otherwise there was little loss of property reported.

 The most interesting feature of the shock is in connection with the behavior of the lava pit in Kilauea volcano. The pit has been very full, and the earthquake apparently opened a number of large cracks in the floor of the main crater through which lava is flowing into parts of the big crater that have seen no live lava for many years. The old stone rest house is reported overwhelmed as well as the stone shelter for horses not far distant.

 On Oahu no less than 26 waves of earthquake were recorded.



Anonymous, 1918, Mme. Pele has sinking spell; crags and lake sink fifty feet in twelve hours; one small quake: Hilo Daily Tribune, 11/15, p. 1. 



 The article describes the draining of Halemaumau lava lake, similar to the subsidence of the preceding April.

 "One slight earthquake, not reported yesterday in Hilo, was felt at the volcano early in the morning."



Anonymous, 1919, Earthquake on Monday: Maui News, 01/31, p. 1. 



 A very brief but sharp earthquake shock was felt on Maui on Monday afternoon [Jan. 27] at 5 o'clock by many persons in different parts of the island.

 According to the Honolulu papers the shock was felt also on Oahu. Professor Romberg, of the College of Hawaii, is quoted as of the opinion that the shake was local on Oahu, within a radius of perhaps not over 20 miles.



Anonymous, 1919, Earthquake hits Maui: Pacific Commercial Advertiser, 02/02, second section, p. 1. 



 A very brief but sharp earthquake shock was felt on Maui on Monday afternoon [Jan. 27] at 5 o'clock by many persons in different parts of the island, says the Maui news last Friday [Jan. 31].

 According to the Honolulu papers the shock was felt also on Oahu. Professor Romberg, of the College of Hawaii, is quoted as of the opinion that the shake was local on Oahu, within a radius of perhaps not over 20 miles.



Anonymous, 1919, Pele had quieter moods last week; reaction from recent high gas pressure causes sinking spell: Hilo Daily Tribune, 02/05, p. 3. 



 The article speaks mostly of the levels of Halemaumau lava lake during the last week of January, 1919.

 " . . .the seismographs have registered a near shock on the afternoon of January 29 [sic-Jan.. 27], which was felt in Honolulu. . . ."



Anonymous, 1919, New crater trail again covered by overflow of lava: Hilo Daily Tribune, 02/26, p. 1. 



 [subheads: Outpouring of two streams from southeast heap followed by sharp earthquake felt throughout Island]

 The article describes the overflows that began the 9-month-long overflow onto the Kilauea caldera floor.

 "At 9:35 last night a sharp, grinding, abrupt earthquake was felt in Hilo, at the Volcano House, in the Puna district generally, and even in the Kohalas. Kawaihae noted that it was strongly felt at the wireless station."

 Reason for the earthquake

 "Like the last earthquake felt throughout the Island, the present disturbance came during a period of high pressure relieved by an overflow, and probably is to be accounted for in the same manner--a slump in the column of semi-solid lava caused by release of support when the imprisoned liquid found a vent and gushed out onto the floor of Kilauea."



Anonymous, 1919, Two-thirds of volcano trail buried in lava; Hilo experiences sharp earthquake--Halemaumau displays intense activity: Pacific Commercial advertiser, 02/26, p. 1. [Repeated in Maui News of Feb. 28, 1919] 



 Hilo, February 25--Two streams of lava began overflowing from the crater of Halemaumau at 5 o'clock tonight. The flows are on the southeast side and already have buried two-thirds of the newly-constructed trail. At 8 o'clock tonight the flows were still in progress.

 At 9:25 tonight there was a sharp earthquake.



Anonymous, 1919, Treacherous lava crusts trap feet of crater hikes: Hilo Daily Tribune, 02/27, p. 1. 



 [subheads: Jaggar says brittle blisters of latest flow where it covered trail should be broken in by County; Three trig stations out of four useless; Tuesday night's earthquake explained as product of upward thrust of main lava column, not backslip]

 The article describes the overflows that began the 9-month-long overflow onto the Kilauea caldera floor.

 Upward pressure caused quake

 " . . . Nor was the local quake, as recorded by the instruments, similar to that of last fall, which also occurred during a period of rising.

 "That shock [earthquake of Sept. 8, 1918, felt over the southern half of the island] came from a slip or slump of the Earth's crust, after the interior pressure had been relieved by the flow and the semi-solid column of lava sank abruptly to lower levels." Tuesday night's quake appeared to be the product of upward pressure, which still continues."



Anonymous, 1919, Pele feels very lively, in On the other islands: Maui News, 02/28, p. 5. [Repeated from Pacific Commercial Advertiser of Feb. 26, 1919] 



 Hilo, February 25--Two streams of lava began overflowing from the crater of Halemaumau at 5 o'clock tonight. The flows are on the southeast side and already have buried two-thirds of the newly-constructed trail. At 8 o'clock tonight the flows were still in progress. At 9:25 tonight there was a sharp earthquake.



Anonymous, 1919, Explores summit Halemaumau dome; Prof. Jaggar gives graphic description of view into heart of volcano: Hilo Daily Tribune, 06/10, p. 7. 



 The article describes a minor subsidence in Halemaumau accompanying the 9-month-long overflow onto the Kilauea caldera floor.

 Local earthquakes

 "The seismographs of the Whitney Laboratory for the week ending June 6 have registered local quakes-May 31 1:49 a.m. and 5:16 p.m.; a very pronounced shock of large amplitude at 4:14 p.m. June 2, not felt here, but felt strongly in the district of Kau to the south; slight shocks 1:38 a.m. June 4, 10:15 p.m. June 5, and 4:50 p.m. June 6."



Anonymous, 1919, Torrents of lava downward rush: Hilo Daily Tribune, 06/17, p. 5. 



 [subheads: Prof. Jaggar gives graphic description of Volcano activities for week past; Molten falls all aglow; Notwithstanding a continual emptying of lakes they do not lower]

 The article documents continuing subsidence of the Halemaumau lava column associated with the ongoing eruption on the floor of Kilauea caldera. Earthquakes reported are all slight.



Anonymous, 1919, Volcano sinking walls and lakes: Hilo Daily Tribune, 07/09, p. 4. 



 [subheads: Prof. Jaggar gives graphic description of subsidence, lava; floors falling; Lava fountains active; Famous Postal river of fire slowly drying up as substance pours into depths]

 The article documents continuing subsidence of the Halemaumau lava column associated with the ongoing eruption on the floor of Kilauea caldera. Earthquakes reported are all slight.



Anonymous, 1919, Islands are shaken up by earthquake: Honolulu Star-Bulletin, 09/15, p. 1. 



 Hilo, Hawaii, Sept. 15.--A severe earthquake was felt here Sunday afternoon [Sept. 14] at 5:22 o'clock. Slight damage was reported by the drug stores, where many bottles were broken. At the same time a large cliff at Kilauea volcano fell into the crater.

 According to Professor Arnold Romberg of the College of Hawaii a severe shock was registered in Honolulu at exactly the same time by the seismograph at the college. The shock was so severe, he said that he believed that many people must have felt it in the city.



Anonymous, 1919, Big Island has regular old style Pele shakeup: Daily Post-Herald, 09/15, p. 1. 



 At Hilo and the surrounding districts right up to the Volcano in one direction and Waimea in the other, received a great shakeup yesterday afternoon at 5:22 o'clock when an earthquake that lasted for about 6 seconds was experienced. The first rumbling of the earthquake was heard a second or two before the actual shake. then came a minor quiver which was followed by a much stronger one which eventually died down to about the strength of the first one.

 At the Waiakea homestead tract the earthquake worried many of the farmers, whose houses are not yet complete. Other householders were also frightened that their tanks would be thrown down from their high perches, but nothing like that happened.

 In Hilo the quake was felt distinctly and some damage was done through bottles of drugs being thrown from the shelves in the Hilo and Hawaii Drug Stores. A plate glass window in the first named store was also broken. In all, the Hawaii Drug company lost about $200 worth of drugs and glassware and the Hilo Drug company, including the window, about $150.

 In the local board of health office two jars . . . broke . . .

 Visitors to the crater of Halemaumau yesterday afternoon say that at 5:21 there was a strong quake felt and a huge cliff of lava fell with a great splash into the pit. . . .

 At the Volcano House the quake was severe and guests state that the whole building swung to and fro.

 The Hilo police courthouse was moved back and forth for quite a time and the groaning of the ancient timber in the structure was heard a good distance away.

 . . . .



Anonymous, 1919, Earthquake does great damage at Kau plantations; Mills damaged, flumes broken and reservoirs cracked by the worst temblor in years: Honolulu Star-Bulletin, 09/16, p. 1. 



 The most severe earthquake in the history of the plantations of that district visited Kau, Hawaii, at 5:56 o'clock Sunday evening, damaging mills, breaking flume lines, cracking reservoirs and wrecking stone fences.

 A letter sent before a full damage assessment had been made reported that reservoirs mauka were cracked by the shock, which is described as a "twister." Upper flumes were dislocated and broken and the dwellings of four of the skilled employees were twisted from their underpinnings. some of the pipes in the mill were twisted and broken . . . 

 No reports yet from Kapapala Ranch or Hutchinson Sugar.

 The shock was felt over most of the island of Hawaii, but was probably heaviest in Kau.



Anonymous, 1919, Whole island is shaken by quake; Expected: Jaggar: Hilo Daily Tribune, 09/16, p. 1. 



 Subheads: Approach of Equinox Should Bring Temblor Volcanologist Says as He Departed for Visit to Honolulu.

 Effect on fire pit to be seen shortly

 Seismograph Unable to Record Entire Shock; Minor Damage in City; Kohala Stone Walls Fall.

 Sunday evening's earthquake was to be expected at the approach of the equinox., said Professor T.A. Jaggar Jr., yesterday. It Is always at that time that the Volcano shows extra activity, and tremblings of the earth , follow, the vagaries of Madame Pele.

 No change was visible in Kilauea crater Sunday evening as, result of the quake, but Professor Jaggar says evidence of' the temblor probably will be apparent In the fire pit within a day or two. . . . .

Came at 5:22

 The earthquake came at 5:22 Sunday afternoon at the Volcano. The seismographic Instruments at the observatory recorded It up to the peak and then flew the track, so that it was impossible to obtain a complete record. The action of the instruments shows the severity of the shock, which Professor Jaggar said was harder than the one of last November, which startled so many Hilo inhabitants and did damage all around the Island.

 Early diners in restaurants, pedestrians on the streets stay-at-homes, and travelers all felt the quake Sunday. At the Hawaii Bakery a number of gobs were enjoying a meal when the shake began. Nearly all of them began a rush for the door .but returned to their seats before actually forsaking their food In favor of the middle of the avenue.

Benches Swaying

 People sitting In parks felt the benches sway under them, and some of. the high lumber piles along Kamehameha Avenue fell with a crash. Bottles went down from the shelves In the drug stores, and a plate glass window was broken In the Hilo Drug Co. Clocks stopped all over the city, doors opened and shut In uncanny fashion, and dishes fell from cupboards and broke in a number of homes. No water tanks were wrecked at Waiakea, though many of the homesteaders were afraid of such a mishap. The quake was felt all over the Island, from Kohala on the north to Puna on the south. At Puna the shock was not sharp, but strong and of long duration, and the movement seemed to have a corkscrew twist at intervals. Faint shocks could be felt a minute and a half after the first quake. 

 A number of stone walls fell in Kohala, which suffered the same sort of damage from the November earthquake. Minor damage was done in all districts of the Island but no serious mishaps occurred, according to reports obtained yesterday.



Anonymous, 1919, ?: Pacific Commercial Advertiser, 09/18, p. ? 



 [an] extremely heavy earthquake shock felt throughout the island of Hawaii, Maui and Honolulu; ground motion continued for one hour, slow swaying like teleseism; 22 hours of aftershocks in Hilo; probably deep-seated



Anonymous, 1919, New volcano at Kaumana began riot: Hawaii Herald, 09/19, p. 1. 



 The article describes the panic engendered by the earthquake of Sept. 14.



Anonymous, 1919, Light earthquake shocks felt here: Hilo Daily Tribune, 09/19, p. 3. 



 [subheads: Second temblor in week wakes people at 3:40 yesterday morning; Heavy quake at Puu Oo; Naalehu and Waimea report no disturbance; rouses Peter at Volcano House]

 Three shocks of earthquake, two of them comparatively light, were felt throughout Hilo at 3:40 a.m. yesterday, but no damage was done in the city. A great many persons were awakened from their morning slumbers by the severity of the third shock, but it was not as strong as that experienced on Sunday last {Sept. 14, 1919].

 In one home . . . two little girls were frightened by the shaking of the house and burst into screams. . . .

 Although the shocks were severely felt in Hilo, reports from Naalehu and Waimea yesterday stated that no quake was felt in those places. If there was a shock it was too light to waken anyone from sleep.

 Other places felt shock

 A long but not heavy shock was felt at Puu Oo, but no damage was done . . . The quake was not severe at Kapapala, and no damage was done there, but some stone walls ere said to have shaken down in Pahala.

 At the Volcano House the shock awakened Peter from sleep . . . Peter said that this shock was only the fifth which had been ever severe enough to be felt since he went to the Volcano House.

 Sunday's quake at Kau

 Letters to Honolulu from James Campsie, manager of the Hawaiian Agricultural Company, at Kau, stated that the quake of last Sunday [Sept. 14, 1919] twisted and broke pipes in the mill, broke upper flumes, and twisted some buildings from their underpinnings, as reported in the Star-Bulletin.



Anonymous, 1919, Mauna Loa flow subsides; glare vanishes; activity continues for 24 hours, then stops, says wireless from Big Island observers: Pacific Commercial Advertiser, 09/28, second section, p. 1. 



 An account of the beginning of the 1919 Mauna Loa southwest rift eruption. A report from Kawaihae places the beginning at 6:30 p.m. on Friday [Sept. 26].

 "The extremely heavy earthquake shock felt throughout the island of Hawaii and even on Maui and here in Honolulu, was undoubtedly the warning sign of an approaching equinoctial crisis, according to L.W. de Vis Norton of the Hawaiian volcano Research Association. The shock took place at 5:20 p.m. on Sunday the 14th of September and the actual movement of the ground continued for more than an hour afterward in slow period swayings resembling a teleseism, while the swarm of felt aftershocks, continuing with gradually decreasing intensity at Hilo for some 22 hours after the primary shock, proved that the origin was deep-seated. Another shock took place on September 18, and the appearance of these earthquakes with maximum effect between Kilauea and Mauna Loa pointed very strongly to a crisis at the equinox a few days later."

 The remainder of the article speculates on the relation between Kilauea and Mauna Loa. de Vis Norton opines that the 1919 Mauna Loa eruption is a continuation of the aborted 1916 eruption and that, following the end of Mauna Loa activity, Kilauea will subside from the high level sustained since 1918.



Anonymous, 1919, Flame-red lava spouting 250 feet in air found at source of flow; hundreds along coast of Kona are menaced by tidal wave: Hilo Daily Tribune, 10/03, p. 1, 5. [A separate article entitled "Big eruption on Mauna Loa traced to 8,000 foot elevation" gives details of the eruption from Mauna Loa's southwest rift zone.] 



 [subheads]: Carlsmith family hurled into sea by rush of water; scores of others in peril in submarine disturbance extending from Kailua to Hoopuloa; revolt by Neptune cause, say Hawaiians; fifteen-foot backwash leaves bed of ocean bare and thousands of fish are seen flopping around

 From Hoopuloa--where the family of C.S. Carlsmith had a narrow escape from death--to Kailua the Kona coast was swept by a tidal wave early yesterday [Oct. 2].

 In the backrush of water which followed the waves were from 4 to 15 feet in height according to the various distances from Alika, where the lava from Mauna Loa is cascading into the sea.

 At Hoopuloa, where four members of the Carlsmith family were caught and nearly perished, the waves were fully 15 feet in height. At Keauhou, where the lanai of Thom White's beach house was washed by the waves their height was about 8 feet. when the back rush of waves swept the beach at Kaiolua, nearer the northern end of the Kona coast, their height was not more than 4 feet. . . .

 The disturbance of the sea is attributed to the Mauna Loa eruption, either because the pouring of water into the water at Alika, not far from Hoopuloa, or to the opening of a crack at sea, because of volcanic action, into which the water was sucked.

[The remainder of the article gives detailed accounts of the waves at different points]



Anonymous, 1919, Tidal wave on Hawaii plays queer pranks; tank carried out to sea and returned intact: Pacific Commercial Advertiser, 10/06, p. 1. 



 [subheads: Hilo attorney Carlsmith and his wife narrowly escape death--Madame Pele also displays peculiar vagaries]

 An account of a tidal wave at Hoopuloa, associated with the 1919 eruption of Mauna Loa



Anonymous, 1919, Kilauea getting ready for more fireworks, report; Jaggar reports activity is due; lava flow down Kona side is great spectacle: Pacific Commercial Advertiser, 10/16, p. 1. 



 A brief account of the continuing flow into the sea from the eruption from Mauna Loa's southwest rift zone.

 "There was a recurrence of small earthquakes or tremblors measured at the United States observatory yesterday."



Anonymous, 1919, Fear, admiration run close race in Hilo when Mauna Loa's glare lights up heavens over Island: Hilo Daily Tribune, 10/16, p. 1, 6. 



 [subheads: Professor Jaggar in explanation--says fume cloud over Kilauea flattened out at proper elevation to serve as refracting mirror, thus throwing almost full glare of the flow in Kona in view of residents of this city--no danger here, he says; Kona phone manager reports creeping flow burning all in path; Kau rancher tells of seeing sight from lanai of home 20 miles away--view similar to that on night Alika stream broke away on dash to sea--volcanologist tells of visit to source and why he thinks lava cannot climb ridge and come down this side]

 A description of the ongoing eruption from Mauna Loa's southwest rift zone includes the following section covering the associated seismic activity.

 Swarms of small quakes

 One notable feature is that during the past 48 hours there has been a swarm of small earthquakes, which were recorded at the observatory. This may signify the beginning of the end. It may be the settling of the Mauna Loa center, which I [Jaggar] would be inclined to credit, if there should be any sinking shown by the lava in Kilauea. But as Kilauea is active and high, it may be that these shocks indicate more activity on the part of Mauna Loa. In view of this I am in doubt as to whether it is a gentle shaking down to the finish or getting ready for more outbursts."



Anonymous, 1919, Sharp earthquake shock felt on Maui: Honolulu Star-Bulletin, 11/26, p. 1. 



 Wailuku, Nov. 26--A sharp earthquake was felt here last night at three minutes after 10 and lasting several seconds. It started as a heavy jar, rattling the doors and windows. No damage is reported.

 Whether or not the shock was felt in Honolulu is not known, because the instrument for registering earthquakes at the college of Hawaii has been out of order, according to Professor Arnold Romberg.



Anonymous, 1919, Volcano crater drops 400 feet; Hilo is shaken: Honolulu Star-Bulletin, 11/26, p. 1. 



 Hilo, Nov. 28--The crater of Halemaumau collapsed this morning at 2 o'clock and sank 400 feet making the pit much larger than formerly. Crags fell continuously. There were ten earthquakes.



Anonymous, 1919, Maui gets jarred by sharp earthquake: Maui News, 11/28, p. 1. 



 Perhaps the sharpest earthquake shock on Maui in many years was that which occurred about 10 o'clock last Tuesday night [Nov. 25].

 It came as a heavy jolt or jar which set doors and windows to rattling, and the vibration continued in diminishing strength for several seconds. Persons in the upper floors of frame buildings felt the quake especially, many being awakened by the trembling of the buildings and the noise of loose objects in the rooms.

 Those who were awake describe the shock as comparable to the concussion of a heavy explosion, with the resulting vibration as things settled back to normal.



Anonymous, 1919, Bottom drops out of volcano pit, lowering lava 500 feet; subsidence occurs early this morning following series of sharp earthquake shocks, Prof. Jaggar announces; heavy gas pressure released by fissures: Daily Post-Herald, 11/28, p. 1. 



 Unusual activity of both lakes at Kilauea last night, followed by a number of quite severe earthquake shocks, some of which were felt at Waiakea, preceded a sudden drop of the lava to a point about 500 feet below the crater's rim at 2 o'clock this morning. . . .

 The rest of the article describes the subsidence.



Anonymous, 1919, Sharp earthquakes in early morning arouse Volcano residents and herald disappearance of fire pit: Hilo Daily Tribune, 11/29, p. 1, 6. 



 Sharp local earthquakes, strongly and almost continuously felt at the Volcano House and at Twenty-nine Miles preceded and accompanied the collapse yesterday of Halemaumau. A. T. Short, of the Crater Hotel, counted 32 distinct shocks. "Jim," the. Japanese bookkeeper at the Volcano House, said he got no sleep after half past one, so rapidly did one tremor follow another.

 H.B. Mariner, who was spending the night in his cottage at Twenty-nine Miles, was wakened by a severe shock at 1:25 a.m. "At first I thought it was the wind swaying the house," he said, "but getting wider awake and finding the house swaying continuously, I knew it was an earthquake. The swaying continued until 3 o'clock, when I went to sleep again. I was surprised on my return to Hilo to learn the shocks had not been felt here."

 Several persons [in Hilo?] reported to the Tribune last night that they believed they had felt light tremors early yesterday morning.

 Professor Jaggar, in his cottage adjoining the observatory, was roused between 1:30 and 2 o'clock. By the time he could get to a vantage point nearby, the domelike mass marking the summit of the Halemaumau column could be seen in the glow of the surrounding fire lakes, slowly sinking. While he still gazed, it disappeared below the rim of the pit. The entire subsidence had taken not more than half an hour, and by the time he could dress, drive down into the crater and walk to the pit, the lakes, domes, crags separating walls between the lakes, and pressure ridges enclosing them, were down 400 feet.

 . . . .

 . . . In the final paragraph, Jaggar is quoted as saying: "It is now a pit 1200 feet across at its greatest diameter and roughly a mile in circumference, with a depth of about 500 feet. . . ."



Anonymous, 1919, Crater bottom falls 400 feet on Big Island; Jaggar watches Halemaumau pit subside--quakes shake isle for two hours: Pacific Commercial Advertiser, 11/29, p. 1. 



 Hilo, November 29--(Special to the Advertiser)--Beginning at 2 o'clock yesterday morning, Halemaumau crater sank 400 feet within an hour, leaving an elliptical pit approximately a mile in circumference. The walls are perpendicular and for the most part follow the former contour of the crater.

 A sharp earthquake roused Professor Jaggar, government volcanologist, who, leaping to his window, was able to see the crags and central cone still silhouetted in the glow from the sinking lakes. Before the government expert could reach the pit, however, the domes, crags, pressure ridges and all other familiar landmarks noiselessly vanished.

 The new walls of the crater glowed red after the sinking, while tunnels and pockets spirited lava into the depths. A continuous succession of sharp local quakes kept the guests of Volcano House and other residents of the neighborhood awake for two hours. There was no disturbance at Hilo.



Anonymous, 1919, Jaggar pleads for maps to forestall menace of flows: Hilo Daily Tribune, 12/02, p. 1, 6. 



 [subheads: U.S. Geological Survey willing to spend dollar for dollar with Territory on improvement, he says; Present records are held to be inadequate; Ad club members hear talk on how property may be protected from lava; Extension of present record would aid in forestalling menace, claim]

 A plea from Jaggar for more topographic mapping, particularly on the Big Island where lava flows present a danger. Residents need the maps to know exactly what of their property was destroyed after a lava flow moves through the land.



Anonymous, 1919, Seismological notes: Bulletin of the Seismological Society of America, v. 9, no. 4, p. 141. 



 Kilauea, Hawaii, November 25,1919.The Associated Press announces a collapse in the crater of Kilauea accompanied by earthquake jars. The lava is said to have fallen four hundred feet.



Anonymous, 1920, Hilo rocked by quake; residents somewhat shaken by disturbance: Hilo Daily Tribune, 03/14, p. 1. 



 A slight earthquake shock was felt in Hilo at 11 o'clock last night, of sufficient force to shake desks and chairs in the Tribune office and send the occupants hurrying to the doors. It was also felt in the resident districts of the city. Neither the observatory or the hotels at the Volcano could be reached by telephone. A Japanese who answered the phone at Nineteen Miles Olaa said the shock was not felt there.



Anonymous, 1920, Hard earthquake wakes sleepers--no damage done: Maui News, 05/21, p. 4. 



 Hundreds of persons on Maui were awakened from their sleep between 2 and 2:30 o'clock last Saturday morning [May 15] by one of the sharpest earthquake shocks felt on Maui in years. The tremblor lasted for several seconds and caused some alarm among the more nervous individuals. No damage has been reported.

 The shake was felt in Honolulu where as reported in the Honolulu papers it appeared to be two distinct shocks. If it was also felt on the Big Island, as seems likely from its violence, no mention was made of it in the Hilo papers--perhaps for the reason that they are used to earth shocks over there, and also for the reason that Hilo people, like those of San Francisco, are somewhat sensitive on the subject.



Anonymous, 1920, Earthquake and eclipse early today: Daily Post-Herald, 10/27, p. 1. [Reprinted verbatim in Hawaii Herald of Oct. 29] 



 The first two paragraphs discuss an eclipse of the sun.

 Following the eclipse, and occurring at 5:35 a.m. there was a pronounced earthquake shock, three distinct rocking motions being observable, followed by a somewhat lengthy shivering. Houses tipped back and forth and sleepers were awakened. The tremor was felt in all districts of Hilo.



Anonymous, 1920, Earthquake and eclipse early today: Hawaii Herald, 10/29, p. 8. [Text verbatim from Daily Post Herald of Oct. 27] 



 The first two paragraphs discuss an eclipse of the sun.

 Following the eclipse, and occurring at 5:35 a.m. there was a pronounced earthquake shock, three distinct rocking motions being observable, followed by a somewhat lengthy shivering. Houses tipped back and forth and sleepers were awakened. The tremor was felt in all districts of Hilo.



Anonymous, 1922, Earthquake shock furnishes thrill; Japanese workmen worried; Puueo housemaid fails to grasp elusive clothes pole: Daily Post-Herald, 02/21, p. 1. 



 The earthquake that shook Hilo this morning found many citizens in an uncomfortable position.

 One resident reports that he was just descending the stairs when the tremor came, and he descended more rapidly than gracefully.

 One of the housemaids in Puueo district was putting out the morning washing, when suddenly the clothes pole began to sway back and forth wildly. The girl grasped frantically for the wandering pole, but it continued to evade her until the quake had subsided. She picked herself up from the ground.

 A Japanese workman on the new Pacific Bakery was probably the most frightened victim of the quake. He was working on the tower being erected to pour in the concrete, when the tremor caused the tower to shake like a 'Frisco shimmy dancer, the worker greatly frightened hung on with his arms and legs entwined in the rigging until the shock was over.



Anonymous, 1922, Severe quake is brief thriller for tourists: Hilo Daily Tribune, 03/14, p. 5. 



 On Sunday afternoon [Mar. 12] an earthquake shock, slightly more severe than that of a month ago [Feb. 21], shook Hilo for possibly 30 seconds. Aside from some crashes of china on plate rails no damage was done. Houses quivered slightly and some of the buildings in the business zone did a bit of a "shimmy dance," but that was all.



Anonymous, 1922, Great fall in volcano pit at Kilauea: Daily Post-Herald, 05/27, p. 1. 



 [subheads: Lava down to 600 feet below level of rim; tremendous slides into vortex; All danger signs go down with falling rim; Great cauliflower clouds color the air above the tremendous seething mass]

 The lava pit at the Volcano went down with a great rush early this morning and is continuing to fall with tremendous perturbation. . . . Earthquakes are frequent in all the region. . . .



Anonymous, 1922, Kilauea erupts near sea: Daily Post-Herald, 05/29, p. 1. 



 [subheads: Makaopuhi extinct crater breaks out near Kalapana; following days of tremblors felt frequently in Hilo; old crevice becomes alive; tremendous activities in Kilauea; Dr. Jaggar makes report]

 Following nine days of almost continuous tremblors the long dead crater Makaopuhi halfway between Kilauea and the sea broke out with a stream of lava which lighted up the whole vicinity so it was easy to see from Hilo.

 . . .

 Dr. Jaggar said the outbreak was heralded by the numbers of earthquakes which have been felt for a fortnight. He was out all day yesterday in the desert of Kau looking for possible outbreaks to explain the sudden drop in Kilauea lava. He says there are many cracks about Makaopuhi which may become active anytime. He advises people to be prepared along the shore at Kalapana for earthquake shocks. A close watch will be kept daily on the cracks about Makaopuhi where it has not been active before since 1840.

 The rest of the article describes the outbreak at Makaopuhi.



Anonymous, 1922, Flow of lava from Kilauea may reach ocean: Honolulu Star-Bulletin, 05/29, p. 1. 



 [subheads: Volcano sinks, breaking out in new place; Fire pit falls almost 1000 feet and lava now flows in old Makaopuhi crater; spectacular collapse at Halemaumau is greatest known in last 36 years]

Hilo, May 29.--The Volcano of Kilauea broke out at 9 o'clock last night at a new point half way between Kilauea and Kalapana. The main lava pit is now down an additional 700 feet.

 The lava broke through the dead Makaopuhi crater, on the upper side in a fissure, two feet wide, much higher than the bed of the crater itself which slopes off toward the sea. The lower rim, it is believed, will soon overflow. should the flow continue it would make a river of lava from the crater to the sea five miles distant. In that event, Kalapana, in the Puna district, would be in danger. The preceding descriptions appears to apply to Napau, not Makaopuhi, crater.

 . . . .

 Previous to the outbreak there were daily earthquakes every half hour for several days.

 The article continues with more description of the eruption in Makaopuhi and the collapse at Halemaumau, claiming it as the biggest since 1886.



Anonymous, 1922, Still another old crater fills with lava; great sight; roar of cascading molten rock is heard far away--fiery stream recalls the famous Alika flow: Honolulu Advertiser, 05/30, p. 1. 



 A description of the eruption in Napau crater, beginning about 9:30 p.m. on Sunday May 28, and the accompanying subsidence of Halemaumau.



Anonymous, 1922, Volcanic activity in Puna district increasing: Honolulu Star-Bulletin, 05/30, p. 1, 3. 



 [subheads: Kilauea lava draining into old craters; Molten rock is now pouring into two ancient pits and others are smoking; Jaggar does not believe underground flow will 'bleed' Kilauea to death]

 The article describes the continuing eruption in Panau [sic-Napau] crater. Jaggar believes the [eruption] "was caused by a series of earthquakes of daily occurrence throughout two weeks preceding last Sunday, causing a rupture of the underground tube that feeds Halemaumau, permitting the lava flowing from a higher level to find a new exit in a place of least resistance."

 The article continues with further accounts of the eruption. As part of Jaggar's official report, the following statement is made:

 "The spectacular sinking reported last week continued at about the same rate until May 25. Swarms of earthquakes were registered by instruments, many of them felt at the Volcano, and finally some of these were reported from Hilo, Honomu and Waiohinu."



Anonymous, 1922, Ancient craters awaken to life and stage spectacular pyrotechnic displays; streams of molten lava burst through Halemaumau pit and sweep seaward down the slopes to Makaopuhi and Napau; great excitement occasioned here; hundreds rush to view thrilling sight: Hilo Daily Tribune, 05/30, p. 1. 



 An account of the eruption at Makaopuhi crater, beginning about 6 p.m. on May 28, and the subsidence of lava in Halemaumau, accompanied by earthquakes.



Anonymous, 1922, Old craters in Puna now lakes of lava; may sweep to ocean: Honolulu Advertiser, 05/30, p. 1, 10. 



 [subheads: Makaopuhi is aflame with fiery flood running over the brim; Hilo sees glow of fire in sky; heavy bookings made on inter-island boats as news spreads]

 An account of the eruption on Kilauea's east rift zone that began about 9 p.m. Sunday May 28, 1922, and the accompanying subsidence of Halemaumau lava lake.



Anonymous, 1922, Lava flow is expected to go to coast; activity of volcano seemed much lessened last night; remarkable changes in crater reported; holiday rush to watch Pele's "tantrums": Hilo Daily Tribune, 05/31, p. 1, 6. 



 An account of the eruption at Makaopuhi crater, beginning about 6 p.m. on May 28, and the subsidence of lava in Halemaumau.



Anonymous, 1922, Kilauea left dead by new lava outflow: Honolulu Star-Bulletin, 05/31, p. 1. 



 [subheads: Jaggar says outbreak at ancient pit may change whole volcanic situation; Famous Halemaumau firepit, drained of lava, is smoking hole in earth]

 The article describes the aftermath of the great draining of Halemaumau lava lake. The article closes by noting that "All earthquakes, which presaged the outbreak, have now ceased."



Anonymous, 1922, Halemaumau reported as practically dead: Maui News, 06/02, p. 1. 



 Honolulu, June 1--The article describes Halemaumau as "dead," and the east rift eruption over, concluding with a statement that "all earthquakes, which presaged the outbreak, have now ceased."



Anonymous, 1922, New outbreak said to show on Mauna Loa: Daily Post-Herald, 06/20, p. 1. 



 A false report of an eruption on Mauna Loa.[See Hilo Daily Tribune of May 29.]



Anonymous, 1922, Mystery shrouds reported eruption far up Mauna Loa: Hilo Daily Tribune, 06/21, p. 1. 



 A false report of an eruption on Mauna Loa.[See Hilo Daily Tribune of May 29.]



Anonymous, 1922, Mauna Loa erupts on Hilo side; sight of glare and smoke reported from various points indicating acitivity in region of Dewey crater at 11,000 feet: Honolulu Advertiser, 06/21, p. 1, 7. 



 A false report of an eruption on Mauna Loa.[See Hilo Daily Tribune of May 29.]



Anonymous, 1922, Unusual activity is reported on top of Mauna Loa: Hilo Daily Tribune, 06/27, p. ? 



 A false report of an eruption on Mauna Loa. [See Hilo Daily Tribune of May 29.]



Anonymous, 1922, Story of eruption on Mauna Loa is a false alarm; Explorers who make trip to summit to report on crater find smoke and steam, however; soldiers deceived: Hilo Daily Tribune, 06/29, p. 1. 



 Observers who went up to Mokuaweoweo saw smoke and steam issuing from vents on the crater's floor, but concluded that the earlier reports of eruption seen from below were an optical illusion.



Anonymous, 1922, Earthquake shock is felt in town: Hilo Daily Tribune, 07/25, p. 1. 



 There was a sharp shock of earthquake yesterday afternoon at exactly 5 o'clock, and it was more especially noticeable in the heart of the city [Hilo], although no damage was done.

 Nothing unusual was noticed at the Volcano House or in its vicinity at the time mentioned. . . .

 At first, when the earthquake was felt in Hilo, it was thought that there might have been some huge avalanche at Halemaumau, and that a severe earthquake would be reported from there later on. But messages from the Volcano House last night said that there had been no shock felt and that there was no sign of any special activity at Halemaumau.



Anonymous, 1922, Yesterday's 'quake a record breaker: Hilo Daily Tribune, 11/21, p. 1. 



 Many kamaainas of the Big Island state that the earthquake which rocked Hilo and vicinity at 3:25 o'clock yesterday [sic-this, to agree with other papers] morning was the most pronounced one they have ever experienced.

 It seemed to come as an echo of or a protest to the false report which had been broadcast over the world the day before that Hilo had been destroyed by an earthquake.

 Yesterday morning's quake, like all the others in the Big Island's history, was of only a few seconds duration and except for the breaking of a few mirrors and dishes no damage resulted. It was felt in all parts of the city and in the vicinity of the Volcano House.

 While the quake yesterday morning was of considerable violence, some of Hilo's citizens contend that the shock which came about four years ago was of much longer duration.



Anonymous, 1922, Real quake backs up rumor of one yesterday; Earth has waves like the ocean at 3:27 a.m.; two distinct shocks; felt at volcano: Daily Post-Herald, 11/21, p. 1. [Repeated in Hawaii Herald of Nov. 23] 



 . . . .Throughout Hilo it [an earthquake] was felt. . . 

 Puueo,, which always gets the worst of earthquake disturbances felt this one very keenly. Houses cracked and mirrors were broken, but no real damage was done. Two distinct shocks were reported, the first a slight one, and the second coming in six separate waves. Waiakea, which often does not feel shocks that are noticeable in Puueo, felt both these shocks, although the six waves were not so distinct.

 In the Volcanic region the quake was also felt. P.T. Phillips, of the Volcano House, says the direction was west northwest, indicating the source as Mauna Loa rather than Kilauea. . . .



Anonymous, 1922, Yesterday's 'quake a record breaker: Honolulu Advertiser, 11/22, p. 1. 



 Hilo, Nov. 21.--some excitement was caused in Hilo today by a slight earth shock at 3:37 this morning, not so much due to the tremor, which caused no damage, as to the mainland rumor of the previous day that Hilo had been destroyed. . . . .



Anonymous, 1922, Earth tremor is again felt last night in Hilo; previous quake lasted five minutes according to seismograph in Brothers' school: Daily Post-Herald, 11/22, p. 1. 



 Again Hilo quivered last night from a slight earthquake which was just about sufficient in strength to waken light sleepers. According to the seismograph at the Brothers' school there were two separate shocks occurring with a slight interval at 12:20 a.m.

 It is further stated by observers of the Brothers' school seismograph that the earthquake of the preceding night lasted for a full five minutes, the first part of the shock being the strongest and practically the only tremor noticeable without the aid of recording instruments. The dying waves of the shock gradually dwindled with a very small variation traced in the seismograph line.



Anonymous, 1922, Lava lake is now steadily rising: Hilo Daily Tribune, 11/23, p. 1. 



 The lava lake in the Volcano of Kilauea is steadily rising and widening but there has been no exceptional activity of the fire pit in connection with earthquake shocks which were felt in Hilo Tuesday and Wednesday mornings [11/21-22].

 P.T. Phillips, manager of the Volcano House, stated yesterday that the earthquake shocks seemed to come more from the direction of Mauna Loa than from Mauna Kea. . . .



Anonymous, 1922, Real quake backs up rumor of one yesterday; Earth has waves like the ocean at 3:27 a.m.; two distinct shocks; felt at Volcano: Hawaii Herald, 11/23, p. 3. [Repeated from Daily Post-Herald of Nov. 21] 



 . . . .Throughout Hilo it [an earthquake] was felt. . . 

 Puueo, which always gets the worst of earthquake disturbances felt this one very keenly. Houses cracked and mirrors were broken, but no real damage was done. Two distinct shocks were reported, the first a slight one, and the second coming in six separate waves. Waiakea, which often does not feel shocks that are noticeable in Puueo, felt both these shocks, although the six waves were not so distinct.

 In the Volcanic region the quake was also felt. P.T. Phillips, of the Volcano House, says the direction was west northwest, indicating the source as Mauna Loa rather than Kilauea. . . .



Anonymous, 1923, Sleepers awakened by sharp earthquake: Daily Maui News, 01/15, p. 1. 



 Sharp earthquake shocks were felt by numbers of persons in Wailuku early on Sunday morning [Jan. 14], sufficient to make houses groan and squeak. So far as has been heard no damage was done.

 Shortly after 2:30 o'clock there were two shocks experienced, sufficiently strong to awaken persons. The first was followed after a short but distinct interval by a second of about the same intensity. The time of these quakes has been established by observations of a number of persons.

 Reports of an earlier temblor about 1 o'clock are also heard from several persons . . .



Anonymous, 1923, Island is swept by fatal storm; severe earthquake felt: Honolulu Advertiser, 01/15, p. 1, 3. 



 [subheads: One woman crushed to death and heavy loss of property reported; Traffic is suspended, street lights are out and railway held up for hours; earthquake shock is felt; no estimate of total damage]

 . . . "there were two sharp shocks of earthquake felt between 2:15 and 2:30 a.m. . . . .

 The remainder of the article concerns the Kona storm.



Anonymous, 1923, Wild norther thrashes Hawaii: Daily Post-Herald, 01/15, p. 1. 



 The article mainly covers a severe Kona storm that hit the Island of Hawaii. In the midst of the storm an earthquake struck, as described in the following section:

 Earthquake shock

 Another feature of the storm was the rather severe earthquake that was felt at 2:30 a.m. Sunday morning [Jan. 14]. It is reported as shaking many banana trees to the ground, but this may be exaggerated, the trees having been blown down by the storm. The quake was felt practically all over this side of the island. Reports from Laupahoehoe have stated that the shake lasted for several minutes in that district.



Anonymous, 1923, New lava flow in evidence in Halemaumau pit; Subsidence proved to be short-lived, according to Jaggar's latest report: Honolulu Star-Bulletin, 01/17, p. 1. 



 Most of the article describes activity in Halemaumau.

 "A strong earthquake shock about 2:30 a.m. January 14 was generally felt on Hawaii, shaking down stone walls and doing some slight damage at Hilea. this happened in the middle of the Kona storm."



Anonymous, 1923, Mauna Loa erupts; Rumor partly backed; Cowboys see glare: Honolulu Advertiser, 02/01, p. 1. 



 Hilo, Hawaii, Jan. 31.-- . . .

 Cowboys at Keauhou ranch report an earthquake followed by a distinct flare from the summit of Mauna Loa last night. Tommy white says evidence of an eruption was plainly visible in daylight, in the form of smoke over the crater zone.

 The cowboys were at an elevation of 6000 feet when the reflection of fire was seen. According to their report the eruption is more toward the Waimea side than toward Kona or Hilo. they said they were working above Hualalai when they felt the earth tremor and saw fire.

 No earthquake was felt at Hilo. communication with the Volcano station is interrupted because of crossed wires. Waimea, Huehue and Papa report that no glare was visible tonight.

 [This eruption was unconfirmed.]



Anonymous, 1923, Mauna Loa clears up under strong winds from Puna; Puu Oo ranch today reports no signs of smoke; Dr. Jaggar thinks eruption doubtful: Daily Post-Herald, 02/01, p. 1. [Article repeated verbatim in the Hawaii Herald of the same date] 



 

Anonymous, 1923, Report of Mauna Loa eruption is sequel to quake; cowboys of Keauhou ranch say flare of fire followed tremor: Hilo Daily Tribune, 02/01, p. 1. 



 Reports reach Hilo yesterday morning that an eruption of Mauna Loa had occurred Tuesday night [unconfirmed]. According to information gleaned by the Tribune, a party of cowboys of the Keauhou ranch felt a distinct earthquake shock at an elevation of 5,000 or 6,000 feet, the tremor being followed by a flare of fire over the crater [Mokuaweoweo] zone.

 The remainder of the article speculates on the possibility of another Mauna Loa eruption.



Anonymous, 1923, Mauna Loa clears up under strong winds from Puna; Puu Oo ranch reports no sign of smoke; Dr. Jaggar thinks eruption doubtful: Hawaii Herald, 02/01, p. 1. [Article repeated verbatim in the Daily Post Herald of the same date] 



 . . . .

 Mrs. L.S. Aungst, of Kona reported last night [that] earthquake shocks were very frequent. . . .



Anonymous, 1923, Twelve killed at Hilo; $1,500,000 damage at Kahului from tidal wave; windward costs of islands swept: Honolulu Advertiser, 02/04, p. 1, 2, 3. 



 [subheads: Violent upheaval of Pacific believed due to earthquake, probably at bottom of ocean; Fatalities among Japanese on Big Island reported; Hilo and Kahului waterfronts suffer as vessels are torn from moorings and houses wrecked; instruments record quake]

 An account of damage from the tidal wave of Saturday, Feb. 3, 1923. The earthquake and one aftershock were recorded at Honolulu, HVO and Washington DC; distance estimated at 2200 miles from HVO. Additional articles on p. 1, continued on p. 3 are entitled:

 Fishermen of Sampan fleet are swept out; Loss of life partly confirmed by dovetailing reports, but can not be determined for days

 Steamships tossed by huge waves at Kahului; Between Million and $1,500,000 damage done at Maui port; Kilauea set on beam ends; Mahukona hits bottom

 An article complete on p. 1 is entitled:

 Waterfront [at Honolulu] is disturbed by tidal tricks

 An article on p. 1, continued on p. 2, is entitled:

 Waikiki tides play odd tricks of ebb and flow at time of tidal wave



Anonymous, 1923, Madam Pele shows signs of activity: Hilo Daily Tribune, 02/11, p. ? 



 Prospects for a large lake of lava in the crater of the Volcano are somewhat bright following the earthquake of Friday night which caused disturbances and movement of the ground in large quantities there. . . .

 Loosened by the movement of the earth, about 1,000 yards of rock had fallen into the pit from the sides of the crater . . .



Anonymous, 1923, Volumes of smoke reported rising over Mauna Loa; riders on the Hind ranch send word through Aungst that an eruption is in progress: Daily Post-Herald, 02/10, p. 1. 



 . . . .

 The earthquake last night [Feb. 9] was felt all along this line of territory but not at the volcano . . .

 The article mostly speculates about reports of eruption at Mauna Loa's summit. [These were not confirmed.]



Anonymous, 1923, Activity again in Mauna Loa; smoke is seen: Honolulu Advertiser, 02/11, p. 1. 



 Hilo, Feb. 10--A slight earthquake last night caused a rock cave-in of 1000 yards area in Kilauea, Thomas Boles. superintendent of Kilauea National Park, reported today. . . .



Anonymous, 1923, Letters tell of wave's damage on other isles: Honolulu Advertiser, 02/12, p. 7. 



 An account of damage on Kauai from the tidal wave of Saturday, Feb. 3, 1923



Anonymous, 1923, Bottom falls from Halemaumau; lava flowing from Kilauea pit causes earthquakes and fires trees in six crater district: Hilo Tribune Herald, 08/27, p. 1. 



 [subheads: Boles and party make attempt to enter devastated region but are driven back by fumes; huge chunks of lava lodge in tree tops; many acres covered; pit fell six hundred feet and little fire is to be seen at bottom; Prof. Jaggar is on Kona trip; sightseers must hike from lava tubes to see latest flow]

 The country bordering on the six craters district southeast of Kilauea volcano was alive with leaping lava and sulphur gases and split asunder with mighty earthquake shocks all day yesterday [Aug. 26] as a result of the sudden dropping of Kilauea Saturday night [Aug. 25], when the liquid lava practically disappeared from the pit in a similar phenomenon to that of a year ago last May.

 A searching party headed by superintendent Thomas Boles reports that liquid lava is leaping from new earthquake cracks that run from three to ten feet in width. . . .

 The article continues to describe the expedition to the eruption site. "When they arrived in the district between Alae crater and Makaopuhi crater they found fresh cracks in the formation. some being as side as 10 feet from which great clouds of fire, fumes and lava were vomiting."



Anonymous, 1923, Lava lake drops out of Kilauea; fills old pits; flows toward Puna in fiery flood, repeating 1922 activity, draining crater: Honolulu Star-Bulletin, 08/27, p. 1. 



 . . . .

 Saturday night the level of lava in the Halemaumau pit dropped 600 feet, leaving only a tiny glow of fire in the bottom. The lava flowed underground to the southeast, breaking out in the old pits, and causing terrific earthquakes in the territory between Makaopuhi and Alae craters, opening up cracks from three to 10 feet in width.

 The rest of the article describes the eruption near Makaopuhi, emphasizing its similarity with the eruption in 1922.



Anonymous, 1923, Kilauea has active eruption: Honolulu Advertiser, 08/27, p. 1. 



 [subheads: Large area is covered with burning lava; Outbreak comes through fissures caused by recent earthquake; six to seven miles from main pit in direction of Puna forests afire; impossible to approach closer than half mile of volcano's vomiting mouth]

 Hilo, Aug. 26.--A violent eruption of lava on the line of six craters, six to seven miles toward Puna from the main pit of Kilauea occurred this afternoon. Superintendent Thomas Boles of the Hawaii National Park, returning to the Volcano House at 8 o'clock tonight, verifies the outbreak from a new earthquake crack at the east end of the park.

 The entire country immediately west of Makaopuhi crater was badly shattered by the recent tremors and one crack 10 feet wide was formed which is emitting at different intervals clouds of noxious fumes and roaring flames and spattering lava for long distances in some cases festooning trees 200 feet from the crack.

 The remainder of the article describes the eruption, closing with: "The lava in the main pit of Kilauea is still falling and is now down 700 feet."



Anonymous, 1923, Inter-island party is treated to wild bombardment at pit: Hilo Tribune Herald, 08/27, p. 1. 



 [subheads: sinking of pit gives excursionists a real treat; Pele in angry mood over weekend]

 Beginning with an earthquake early on Friday morning [Aug. 24], and culminating in a fearsome bombardment at 11:30 on Saturday night [Aug. 25], the fire pit fell into a "sinking spell," which, according to visitors returning from the pit this morning, has left nothing but a mass of clinkers unrelieved by fire.

 An eyewitness account follows:

 "On the way back to the Volcano house, we went over to Uwekahuna for a last look at the volcano. To our surprise there was hardly any glow, and even as we looked the glow seemed to lessen. We decided to 'go look see.' Just as we arrived at the parking place there was a boom like a big gun. the ground shook, walls fell, and what lava there was flowing showed very great activity.

 "For a matter of a half hour this continued the concussions being very heavy, and coming at short intervals, accompanied by the flight of heavy stones across the pit floor. For the first time in my visits to the volcano I felt frightened." . . . At the time of our arrival several fountains were playing. But during the half hour of our stay, the fountains had practically ceased to exist, leaving nothing but livid cracks, fast losing their radiance. friends of mine who visited the pit on Sunday morning [Aug. 27] described it as 'nothing but a mass of clinkers.'"



Anonymous, 1923, Activity at pit craters of Kilauea continues to furnish thrills: Honolulu Advertiser, 08/28, p. 1, 6. 



 [subheads: New fissures on mountain slopes ejecting great clouds of gas and steam; crowds visit erupted area which covers hundreds of acres]

 The article describes the continuing east rift eruption of Kilauea.

 Hundred new cracks

 . . . A heavy roar was heard from the cracks on Sunday [Aug. 26]. Boles estimates that there are a hundred of these new fissures. Six of them are ejecting gas, smoke and steam while a strong foundry odor comes from others. Many are very deep and of immense length.



Anonymous, 1923, Emptying of Kilauea fire pit spectacular phase of activity: Honolulu Advertiser, 08/31, p. 3. 



 An account of the subsidence of Halemaumau lava lake associated with the Kilauea east rift eruption of August 1923.

 . . . .

 The seismograph recorded many earthquake shocks too slight to be generally felt, but at 5:30 on Saturday morning [Aug. 25] a sharp one startled all in the neighborhood. From then on the lava fell rapidly during the day, with caving in at the sides accompanying the fall. . . .



Anonymous, 1923, Earthquake felt; no harm reported: Maui News, 12/28, p. 1. 



 In various parts of Maui a sharp but short earthquake was felt about 6:45 on the evening of Christmas Day. In doors the sensation was as if a heavy object had fallen occasioning a sudden jar.

 Honolulu reports having felt the quake also but that it was not felt at Ewa and that on inquiry of Hilo no temblor was felt there. It was thought to have been a local disturbance but the fact of its being felt on this island upsets that theory.

 So far as has been heard no damage was done.



Anonymous, 1923, Pele rewards holiday visitors with display: Hawaii Tribune-Herald, 12/31, p. 5. 



 The article begins by describing the activity in Halemaumau.

 "Speaking of the earthquake felt last week [Dec. 28] Mr. Finch said it had been exceptionally severe in the district of Kau and asked if it was felt in Hilo. This must have been the same one as that experienced here [HVO] at about 4:30 last Friday and felt along the Hamakua coast as far as Honomu."

 . . . .



Anonymous, 1924, Hilo feels quake: Hilo Tribune-Herald, 03/29, p. 1. 



 Hilo felt a pretty strong quake at 1:35 a.m. today. Houses in several parts of the town rocked, but no damage was done.



Anonymous, 1924, Earthquakes shake various localities; frighten Puna folk; reports from Kapoho indicate that shocks are more pronounced in that district; men from volcano observatory leave to investigate severity of tremors: Hilo Tribune-Herald, 04/22, p. 1. 



 A description of the earthquake swarm and ground cracking at Kapoho, including various investigations made by HVO.



Anonymous, 1924, Numerous earth shocks on Hawaii: Honolulu Advertiser, 04/23, p. 2. 



 Hilo, April 22--Fifty earthquake disturbances were registered last night by the seismograph at the Volcano Observatory. Henry Lyman of Kapoho telephoned today that he had counted eighty quakes between 6 o'clock last night and 7:30 a.m. today.

 Japanese residents mauka of Lyman's place report noises coming from the lava cracks. Many tremors were felt at Puueo and in Hilo. Similar disturbances occurred during the last three days at Kapoho, and also in Hilo.



Anonymous, 1924, Puna quake more active; earth cracks ten feet deep open today; railway tracks tossed up like waves of sea: Hilo Tribune-Herald, 04/23, p. 1, 6. 



 A description of the earthquake swarm and ground cracking at Kapoho, including various investigations made by HVO. Ruy Finch predicts an eruption At Kapoho.



Anonymous, 1924, Henry Lyman gives information about Puna disturbances; says scene of activity is apparently confined to definite rift in formation: Hilo Tribune-Herald, 04/24, p. 1. 



 A description of the earthquake swarm and ground cracking at Kapoho. Large cracks opened beneath the Railroad Depot, Richard Lyman's house and the Japanese camp. The largest crack, crossing both the Government road and the railroad, is 15 feet wide and one to three miles long. Shocks were coming in at a rate of about one per minute at the rock quarry and one every five minutes at his house.



Anonymous, 1924, Four more earth cracks reported as tremors in Puna district continue: Honolulu Advertiser, 04/24, p. 1, 3. 



 An account of the earthquake swarm, ground cracking and subsidence in Puna and the reactions of the local people to these events.



Anonymous, 1924, Ground near pavilion at Kapoho sinks 30 feet; Oren C. Wilson gives account of earthquakes; district takes on appearance of war invaded area as quakes drove people out from homes; shifting of earth causes many changes in topography--new pool at Warm Springs: Hilo Tribune-Herald, 04/24, p. 1, 6. 



 A description of the earthquake swarm and ground cracking at Kapoho.



Anonymous, 1924, Quakes cause Puna land to sink ten feet: Honolulu Advertiser, 04/25, p. 1. 



 Hilo, April 24--According to reports received here late tonight, land on the Hilo side of Puna pavilion sunk ten feet as a result of the hundreds of earthquakes during the past three days. Large trees in that vicinity are also crashing to earth.

 Cracks continues throughout today and there are now hundreds of cracks, many several feet wide and 30 feet in depth, running toward Mauna Loa. Thomas Boles, superintendent of Hawaii National Park, after visiting the quake zone, reported he had heard lava running beneath the earth's surface, using a geophone for his observations.

 disturbances also continued throughout today but are growing less severe, and it is believed they will cease within a day or so.

 Got tired of counting--. . . A resident of Kapoho counted 328 shocks Wednesday evening [Apr. 23] between 5 and 9 o'clock, when he got tired of counting and went to bed.



Anonymous, 1924, Earth sinks 90 feet at pavilion--new cracks open; volcano shows new gas spot--wall white hot; park commissioner Boles reports pit wall 400 ft. down; peeling off: Hilo Tribune-Herald, 04/25, p. 1. 



 A description of the earthquake swarm and ground cracking at Kapoho, including various investigations made by HVO.



Anonymous, 1924, Earthquakes bring terror to Kapoho; hasty exodus made: Honolulu Advertiser, 04/26, p. 1, 3. 



 [subheads; Natives attribute shocks to removal of stone monuments; district cursed; Myriad cracks, which open wider, split surface of ground; houses in danger]

 An account of the earthquake swarm, ground cracking and subsidence in Puna and the reactions of the local people to these events.



Anonymous, 1924, Earth cracks, sends up heat Kapoho reports: Honolulu Advertiser, 04/30, p. 1. 



 Hilo, Apr. 29--According to a report from Kapoho late tonight a wide crack in the earth between the railway station and the courthouse took place, making traffic impossible. The opening gives out extreme heat, but no steam. Indications are that lava is running beneath the surface.



Anonymous, 1924, Earthquakes replace volcano rock shower; predict tidal waves: Honolulu Advertiser, 05/21, p. 1. 



 [subheads: Kilauea situation is baffling one to scientists, who are encouraged when an outburst takes place; believe missing soldiers only A.W.O.L.; Kau covered with white dust]

Hilo, May 20--The sudden change at Kilauea is baffling to the volcanologists, who cannot determine Halemaumau's next move. The cessation of eruptions followed today with a series of earthquakes, some of them exceptionally violent, has shifted the general situation.

 [Ruy Finch] stated that four heavy earthquakes were felt at Hilea during the day and pointed out that the situation may possibly be relieved by a lava flow either in Puna or Kona. He also asserted that Kau indications point toward a possible tidal wave . . .

 Continual quakes-- . . .a resident of Hilea reported almost continual earth disturbances, several being violent. . . .



Anonymous, 1924, Volcano situation alarming to Finch; quakes continual: Honolulu Advertiser, 05/23, p. 1. 



 [subheads: says pent up steam pressure may cause outbreak elsewhere; crater quiets down when Governor Farrington and party arrive via planes]

Hilo, May 22--. . . .

 Constant earthquakes are being registered on the seismographs and at the Volcano House.

 Oliver Emerson, assistant observer, with a number of scientists, returned here at 9 o'clock tonight after a day's search for new earth cracks and any lava indications. They reported only discovering immense clouds of dust in Kau.

 According to Lorrin A. Thurston, who made a personal investigation at Puna today, that area remains unchanged save for several slight quakes.



Anonymous, 1924, Volcano dangers far from over is Finch's prediction: Honolulu Advertiser, 05/24, p. 1, 3. 



 [subheads: Three explosions during day to relieve pent up gas pressure; visitors are warned by officials to be on alert for sudden burst; Find broken camera which may be evidence of two soldiers' fate; seven army planes at Kilauea; will attempt to land near volcano]

Hilo, May 23--. . . .

 There is no activity at present in Hilo, other than a few scattered and inconsiderable earthquakes. For the past three weeks there have been no earthquakes or activity in Kapoho, Puna, where the previous earthquakes and subsidence were so strong a short time ago. [The statement about Puna contradicts Thurston's report in the May 23 issue of the advertiser]

 Continuous tremble--Hilea, in Kau, which is known as "the home of the earthquakes" which normally has more earthquakes than any spot on Hawaii, is recording an almost continuous tremble on the seismograph but is having no perceptible earthquakes. [This also contradicts a previous report of several earthquakes in this sequence being felt in Kau]

 On the other hand, the Volcano house, which normally has no earthquakes, is experiencing a daily and nightly "flock of earthquakes" . . .



Anonymous, 1924, But one explosion at Halemaumau Saturday; all spectators warned: Honolulu Advertiser, 05/25, p. 1. 



 [subheads: Single outburst equal to previous day's activity; rocks tossed 3000 feet distance by quick series, which lasts fifteen minutes; Finch warns tourists of recurrences of 1790 flow; quake s shake Hilo Saturday morning; steam clouds emerge throughout mild day]

Hilo, May 24--. . . .

 Earthquakes were distinctly felt in Hilo last night [May 23-24], but no tremors were reported from any section today. The night was also comparatively quiet.



Anonymous, 1924, The Kilauea "flying field": Honolulu Advertiser, 05/26, p. 1. 



 A photograph showing three large blocks thrown out of Halemaumau, one of which was still hot when approached. The photo also marks the spot where Truman Taylor was killed. A short remembrance of Taylor is included on an inner page.



Anonymous, 1924, Minor explosions comprise crater's faltering action; main outburst at 5:30 last night failed again to cause violence; Emerson makes trip to firepit rim where eight ton boulders are found strewn about the vicinity; lone strong quake felt: Honolulu Advertiser, 05/27, p. 1. 



 A description of the ongoing explosive eruption.

 A strong earthquake shook the entire Kilauea district at 9 o'clock [a.m. on May 26-daylight savings time?].

Pahala, Hawaii, May 24-- . . . A rather strong earthquake shock was felt here [Pahala] early this morning.



Anonymous, 1924, Quake jolts might cause damage here; Finch raps statement that building safeguards are not needed: Honolulu Star-Bulletin, 05/30, p. 1. 



 Kilauea observatory, Hawaii National Park, May 26--Exception is taken by Roy [sic-Ruy] H. Finch, seismologist at this station, to a statement published in a Honolulu newspaper to the effect that the Hawaiian islands are not intimately associated along the lines of human economic welfare with the earthquake danger of the Pacific coast and that this is not a region where it is necessary to employ special building construction as a safeguard.

 "It is true," Finch said today, "that the Hawaiian group is not connected intimately with the earthquake lines which border the Pacific ocean. Still, so far as the island of Hawaii is concerned, it had a world-shaking quake in 1868 which was destructive to buildings over a radius of miles. On several occasions quakes have occurred under the ocean west of Maui or Molokai, which were felt not only on those two islands but on Oahu and Hawaii.

 Might cause damage here

 "It is quite possible that such slips occur along a fault of appreciable length and a larger movement, easily possible, might cause a shock that could do considerable damage in Honolulu.

 "The possibility of movement of small land masses anywhere in the Hawaiian islands probably will be admitted by nearly everyone. In most of the cases, no doubt, the movement would be superficial and the resulting earthquake perceptible or destructive over a very small area. A recent example of such a phenomenon is that at Kapoho on this island. A block of land three miles long and nearly one mile wide was in motion and a portion of it, at least, dropped from six to eight feet. the movement of this block was accompanied by numerous quakes that caused but slight damage individually. Their total effects were to separate one part of a building from another leaving them at different levels; to drop a portion of a railroad track eight feet and to cause great fissures in the roads and trails. Such a movement certainly would destroy water and gas mains. At a distance of 10 miles from Kapoho the quakes scarcely were felt.

 Possibilities of movements

 "As was pointed out in the foregoing, world-shaking quakes have occurred on the southwest side of Hawaii. If the possibilities of the movement of large land masses are to be considered it might be well to look at the northeast side of the island. If we are to assume the possibility of superficial movements on any of the islands certainly we must include the slope of the plateau in the ocean bottom from which they arise. Let us suppose a slight break originating a short distance under the ocean floor, say 120,000 feet below sea level in the deep northeast of Mauna Kea. such a break would be felt for only a short distance, perhaps.

 "Suppose again such a break to occur at the same depth below sea level at a point 20 or 30 miles nearer the summit of Mauna Kea, or where the elevation is 10,000 feet. Clearly, such a land block in motion would be more than five miles thick, a mass of sufficient magnitude to shake the entire island group.

 "On Hawaii one would be justified in increasing the cost of his building by 30 per cent (an arbitrary figure) to reduce the earthquake hazard. In Honolulu one would be justified, perhaps, in increasing the cost by 5 per cent."



Anonymous, 1924, Professor Jaggar makes inspection of pit this morning; says greater disturbance may occur which will make pit much larger; is pleased with observatory's work in recording activities of present disturbance: Hilo Tribune Herald, 05/30, p. 1. 



 Jaggar muses on the possibility of another eruption like 1790.

. . . .

 A severe earthquake was felt at the Volcano this morning, another was felt in Hilo at 8:42 a.m. Both earthquakes are said to have occurred at the same time.



Anonymous, 1924, Volcano quiet: Honolulu Advertiser, 06/01, p. 1. 



 Hilo, May 31--The volcano remained quiet for the past 24 hours, steam from the pit being the only visible activity. An earthquake shortly after 1 o'clock this morning disturbed sleepers at the Volcano House.



Anonymous, 1924, New lava flow seen in Halemaumau: Hilo Tribune-Herald, 07/21, p. 1. 



 [subheads: Fountains of molten stone start new activity Saturday; cones are being built in pit; Madam Pele's latest display visited by many Hilo people yesterday--surging magma streams and pools cover many acres is estimate of officials; Lava fires again play in the fire-pit of Kilauea. Breaking forth at 3:30 p.m. Saturday afternoon moulten rock made its first appearance in Halemaumau since February; News of the big "come-back" was received in Hilo with joy, and Hiloites hurried to the rim of the pit to take to Madam Pele's latest offering.]

 The article describes the return of lava to Halemaumau following the big collapse in May 1924.



Anonymous, 1924, Hiloites report strong earthquake: Hilo Tribune-Herald, 07/21, p. 2. 



 An earthquake which lasted several seconds and was severe enough in some parts of town to knock pictures and vases down, rocked Hilo yesterday at 1:30 in the afternoon. Puueo residents say that the quake was quite severe in that part of town. A number of persons agree that the quake seemed to come in a wave, which shook their houses in sections at a time as the wave seemed to pass on.



Anonymous, 1924, 'Round-island quake felt: Hilo Tribune-Herald, 08/20, p. 1. 



 An earthquake of several seconds duration rocked Hilo this morning about 6:30. Puueo residents say that the quake was particularly sharp in that section of town.

 According to information received over the telephone from Kona a sharp earthquake was felt in that part of the island at the same time.

 Roy [sic] H. Finch, seismologist at the Kilauea observatory, said over the telephone today that his instruments had registered a very marked tremor at 6:20 a.m. One instrument was dismantled by the force of the oscillation. The disturbance was about 16 miles away from the observatory, Finch added.

 The disturbance was likewise felt at Pahala, dishes being knocked off shelves. No real damage was done there, however.

 The tremor was also felt in the Honokaa region, according to W.G. Lawson, manager of the store there, but the shock was not in the least pronounced.

 According to Henry J. Lyman there was no disturbance in Kapoho, the seat of seismic activities last May which racked the entire region. Word was obtained from the Kapoho quarry, also, that no quakes had been felt there.



Anonymous, 1924, Sharp earthquake shock felt at observatory: Hilo Tribune-Herald, 10/29, p. 1. 



 What was characterized today by Dr. T.A. Jaggar, director of the Kilauea Observatory as "a severe local earth shock: was felt yesterday at 2:20 p.m. in the immediate vicinity of the Volcano House.

 "The quake was unusually hard and it was very local," Dr. Jaggar added. "It was not felt in Kau or Kona. It may have been part of the movement adjacent to the crater proper or perhaps a settling of the blocks around the rim of the big crater along with the general disturbances which have been in evidence since the outbreaks last May. No avalanches were included in the shock and nothing of a volcanic nature has occurred in the pit.

 "The shock reminded me very much of one felt in late October of 1913, only this one was sharper. It shook down vases, overturned chemical flasks and upset bottles."

 Thomas Boles, superintendent of Hawaii National Park, said over the phone today that the quake was entirely local. "People on the Volcano House golf links did not even notice it," he declared.

 Two mild shocks were felt at 11 o'clock this morning, Boles added.



Anonymous, 1924, Seismological notes: Bulletin of the Seismological Society of America, v. 14, no. 3, p. 215. 



 Hilo, Hawaii, September 10, 1924.Two of the severest earthquakes felt on Hilo in years rocked the Honokaa district at 7:10 p.m., September 10th, and sent residents scurrying from their homes and buildings. The shock centered around the Kilauea volcano.



Anonymous, 1925, "Earthquake week" indicated by tremors: Hilo Tribune-Herald, 12/09, p. 8. 



 Two sharp earthquakes, the severest felt here for many months, rocked Hilo last night, the first at 10:19 and the second at 11:45. Neither quake was strong enough to do any damage, however.

 Both quakes were registered at the Volcano Observatory. . . The first quake was in two waves, the first wave sharp and short and the second longer but equally sharp.

 It is reported from Pahala that the 10:19 shake knocked down books and dishes, and moved furniture across the floors.

 The strongest earthquakes recorded at the volcano within a year were the two which occurred Sunday morning, one at 9:20 a.m. and the other at 11:45. Dishes and books were knocked down and the earthquake machine at the Observatory was dismantled. The first quake was accompanied by a large avalanche of loose rock falling into the pit.



Anonymous, 1926, Sharp quakes hit Oahu, Maui Sunday: Hilo Tribune-Herald, 02/08, p. 1. 



 Honolulu, Feb. 8-- a sharp earthquake shock was felt in Maui and Honolulu at 11:30 a.m. yesterday. The local disturbance was noticeable in three sections of the city. It lasted less than a minute. According to word from Maui the shock there "resembled an explosion and was noted by all of central and west Maui."

 The United States observatory station near Ewa registered a local quake at 11:28 a.m. yesterday. . . .

 If the time was about 11:30 a.m. February 7, only a small and apparently feeble tremor was recorded at the Kilauea observatory.



Anonymous, 1926, Maui is shaken by quake Sunday but no damage: Maui News, 02/10, p. 1. 



 Two earthquake shocks were felt on Maui Sunday morning with an interval of about two minutes between them. The second and heavier of the two occurred about 11:30. No damage was done though the heavier quake brought numbers of persons out of doors or peering from windows thinking there had been an explosion.

 The shock was also felt on Oahu, the Advertiser says, and registered on the seismograph at Ewa as having occurred at 11:29:17.

 . . . .



Anonymous, 1926, Earthquake felt all over island of Hawaii Sunday: Hilo Tribune-Herald, 03/01, p. 1. 



 A 'round the island earthquake of about 10 seconds duration rocked the island yesterday morning at 6:41. It was felt in Honomu more sharply than in other sections. . . .

 The quake was not strong enough to do any damage, although at Honomu dishes were knocked from shelves.

 The seismograph at the observatory was dismantled. The shake occurred at 6:41 and was plainly felt at the Volcano House. [Jaggar quoted]

 Telephone reports received this morning from North Kohala, South Kohala, Ookala, Kona, and from the plantations near Hilo, confirm the fact that the quake was felt in all parts of the island.



Anonymous, 1926, Three islands are shaken by earth shocks [Oahu and Maui are shaken by earth shocks]: Honolulu Star-Bulletin, 03/20, p. 1. [Titles in brackets reflect different editions of the paper] 



 [Subheads: Temblor visits Maui, Hawaii and Oahu; windows in Kalihi rattle from force; Violent motion brings people on Valley Island from homes; no damage] [Temblor visits Islands at 10:34 p.m.; windows in Kalihi rattle from force; Violent motion brings people on valley island from homes; no damage]

 Hilo, Hawaii, March 20--A strong earthquake shook all the island at 10:33 o'clock last night, being hardest in Kohala. In Hilo the buildings swayed slightly. A clear record of a long slow movement was obtained by the volcano instruments. Dr. Thomas Jaggar, in charge of the Volcano Observatory, reports that the center was further away than usual and estimates that the disturbance was on the ocean bed about 80 miles off Kohala in a direction between northeast and northwest.

 No reports of a tidal wave have been received. No damage was done by the earthquake. No volcanic activity was reported.

 This morning at 7:30 o'clock there was a severe, but weaker, quake in the same area.

 Hundreds of local people were aroused from their sleep about 10:30 last night when the islands of Oahu and Maui were visited by the most severe local earthquake shock to be recorded in the islands for many years.

 A certain amount of excitement was occasioned in the residential portion of Honolulu, although no apparent alarm was felt. The temblor, according to all reports, reached its maximum intensity in the Kaimuki section of the city, although it was quite noticeable in Manoa, Punahou and on Alewa and Pacific Heights. In the business district, the shock was quite slight, not being felt by those in the streets, but reported as noticeable in various hotels.

 Shock windows

 Residents of the Kalihi valley reported this morning that the shock had been so severe that there was a noticeable motion to light pieces of furniture and a rattling of windows in many residences, a condition which continued for several seconds during the time the temblor was at its maximum severity.

 A local earthquake of considerable intensity was recorded by the seismograph in operation at the United States magnetic observatory near Ewa, Oahu, at 9:04:16 a.m., Greenwich time, March 20, which is 10:34:16 p.m., Honolulu time, March 19.

 The disturbance reached its maximum intensity 32 seconds later and continued for seven minutes. Although the maximum ground movement at the observatory was only one one-hundredth of an inch the record on the seismograph is very pronounced. The instrumental magnification is 150 for this sort of vibration.

 Waves were short

 The waves were short, averaging less than four seconds. The disturbance was not felt at the observatory although several residents at Ewa reported this morning that they had felt the shock.

 According to radio reports from Wailuku, two earthquake shocks in rapid succession shook Maui at 10:30 last night. The first shock was mild and of but a few seconds duration. This was followed immediately by one more violent, which continued for five seconds and brought many people out of their homes. No damages were reported. Both shocks were of the horizontal variety.

 Another shock was reported by the U.S. magnetic observatory near Ewa as occurring at 7:27:45 this morning. The disturbance was very slight and lasted about two minutes.



Anonymous, 1926, Earth disturbance felt in many sections here: tidal wave is reported: Honolulu Advertiser, 03/20, p. 1. 



 Six distinct earth shocks of several seconds duration were felt by hundreds of residents of Kaimuki between 10:30 and 10:33 o'clock last night. Residents of Manoa, Punahou and Alewa Heights also felt the disturbance approximately during those several minutes, but reports indicated the temblor was most severe in Kaimuki. There was no damage.

 The naval radio station at Wailupe. feeling the shock, reported that a miniature tidal wave accompanying it struck their building, jarring it considerably but caused no damage. Two naval operators on duty there last night, said the water rose almost five feet at the instant of the shock.

 The radio corporation plant at Koko Head, according to a message to the Advertiser, reported the disturbance was preceded by a muffled noise, and that the tremor continued at intervals for ten minutes.

 Records on the government seismograph instrument at Ewa will not be developed until today, according to the operator there last night, so the approximate source or direction of the disturbance could not be learned.



Anonymous, 1926, Entire territory feels shocks of quake last night; no serious damage is done although disturbance is felt over large area; point of origin in ocean bed says Prof. Jaggar; Honolulu reports small tidal wave: Hilo Tribune-Herald, 03/20, p. 1, 2. 



 An earthquake of unusual force which was felt quite plainly in Hilo and the island of Hawaii in general was registered throughout the Hawaiian territory between the hours of 10:30 to 10:35 o'clock last night.

 The shock was felt in Hilo at 10:35. It was of sufficient strength to shake a number of ink bottles off a shelf in the upper story of the Tribune-Herald building. 

 It was not strong enough to do any serious damage however and was not accompanied by a tidal wave. The quake seemed to come in two waves, a few seconds apart, and was unusually long. It lasted for about 10 seconds in all, the last wave being longer than the first.

 Word received from Dr. Thomas A. Jaggar, volcanologist at Kilauea, was to the effect that the quake was registered with clearness there. The quake originated about 10 or 80 miles to the north east or north west of Kohala out in the ocean some place, according to Jaggar.

 Word received from Kohala said that the quake had been felt there by nearly everyone and that it was quite strong. Another quake was also felt at Kohala this morning at 7:30 o'clock but was not as strong as last night's shock. No damage was reported.

 Messages received from other parts of the island indicate that the shock was felt generally. No word of a tidal wave at any place on the island has been received however.

 A second shock was felt in Hilo this morning shortly after 7 o'clock. This was a very light quake.

 Honolulu, March 20--Hundreds of residents in various sections of the city and outskirts were momentarily frightened by a series of distinct earth disturbances between 10:30 and 10:35 last night.

 The tremor was stronger from Kaimuki to Koko Head than in other districts. The naval station at Wailupe reported disturbances accompanied by a miniature tidal wave, with the water rising almost five feet.

 Heeia radio station stated that the tremor threatened the radio towers.

 The source of the shock has not been learned as yet.

 Volcano House, March 20--repeats info above

 Honolulu, March 20--The earthquake shocks reported from the island of Hawaii and also felt with severity on Oahu also shook the island of Maui, according to reports received this forenoon.



Anonymous, 1926, Quakes fail to awaken Madam Pele; nothing doing as yet at Volcano; slight shock yesterday: Honolulu Advertiser, 03/21, p. 1. 



 The earthquake shocks felt in Honolulu on Friday night were also noticeable in Hilo, according to reports from the big island, but apparently there is no unusual activity at Kilauea volcano as a result or for that matter as a cause.

 The shocks on Hawaii were felt all over the island, at the same time that the tremors were felt in Honolulu. Observatory scientists at the volcano and in Honolulu have decided that the center of disturbance was about eighty miles off Kohala in a northerly direction. It is interesting to note that on Oahu the shock was felt most severely in Kaimuki district, the closest part of the island to the supposed point of disturbance.

 While Wailupe reported on Friday night that coincidentally with the quake a large wave rolled toward shore at that point Hilo has not reported any unusual tidal activity.

 At the magnetic observatory near Ewa a local quake was recorded as having taken place at 9:04:16 a.m., Greenwich time, which makes the time of the shock here 10:34:16 p.m. [the previous day]. Saturday morning [Mar. 13] a minor shock was felt about 7:30. This was also reported from Hilo.

 Maui reported two shocks on Friday evening in the neighborhood of 10:30 o'clock, one being mild and the other severe.

 No property or personal damage is reported from either of the other islands.



Anonymous, 1926, Earthquake shock of Friday night felt all through Islands: Maui News, 03/24, p. 1. 



 Two earthquake shocks, the first light, the second sufficient to awaken person from a sound sleep were felt on Maui shortly after 10:30 o'clock Friday night [Mar. 19]. There was another shock felt about 7:30 Saturday morning. In Wailuku the vibration seemed to be East and West. Reports from Hilo place the source of the disturbance some 80 miles in a northerly direction from Kahala [sic-Kohala?].

 Hardly more than a slight tremor the first quake attracted little notice but in a few moments there was a severe jolt followed by a rocking or swaying that brought people up standing or even sent some scurrying from their houses. Though general on Maui no damage was reported. Other islands reported that the shock was felt.

 Of the registering of the quake the Star-Bulletin said in part:

 "A local earthquake of considerable intensity was recorded by the seismograph in operation at the United States magnetic observatory near Ewa, Oahu, at 9:04:16 a.m., Greenwich time March 20, which is 10:34:16 p.m. Honolulu time March 19.

 "The disturbance reached its maximum intensity 32 seconds later and continued for seven minutes. Although the maximum ground movement at the observatory was only one-one-hundredth of an inch the record of the seismograph is very pronounced. The instrument magnification is 150 for this particular type of vibration.

 "The wave were very short, averaging less than four seconds. The disturbance was not felt at the observatory although several residents of Ewa reported this morning that they had felt the shock.

 "Another shock was reported by the U.S. Magnetic Observatory near Ewa as occurring at 7:27:45 this morning. The disturbance was very slight and lasted about two minutes."



Anonymous, 1926, Police station walls cracked by earthquake: Honolulu Advertiser, 03/27, p. 1. 



 To date there has been but one structural casualty following the earthquake shock that excited Honolulu citizens on Friday night. Reports followed the quake that pictures had been shaken off walls and furniture shaken about considerably, but none concerning property damage.

 It remained for the police to discover a crack in the plaster of the walls of the police station, where the shock had separated the plaster. That, so far, is the only damage reported.

 Another shock was recorded at the Ewa observatory yesterday morning at 7:27:45 o'clock Honolulu time, according to E.H. McComb, who is in charge of that station. The tremors lasted for two minutes, according to the records, and the waves were not so short as those of the Friday night disturbance. The shock was about one-tenth the intensity of the latter.



Anonymous, 1926, Mauna Loa in eruption: Honolulu Advertiser, 04/10, p. 1. 



 Hilo, April 10--Mauna Loa is in eruption.

. . . .

 Preceding the eruption several earthquakes rocked the island, and it is reported that tidal waves swept over the Kona side of Hawaii. . . .

 There was also a tidal wave at Hilo that was four feet high.



Anonymous, 1926, Kona residents see fires at night; report activity above spot of Alika flow: Honolulu Star-Bulletin, 04/14, p. 1, 2. 



 [subheads: L.S. Aungst reports from Holualoa that smoke hanging on mountainside may mark source of fire; no change in situation at Halemaumau]

 A series of dispatches regarding the 1926 eruption from Mauna Loa's southwest rift zone.

 Hilo, Hawaii, April 14 (12 noon).--Reports from the volcano observatory on the edge of Kilauea are that earth movements recorded by the instruments indicate that action can be expected at any time.

 Roy [sic-Ruy] Finch, assistant in charge of the observatory, says that action of the eruption is similar to that of 1881, when the actual outbreak did not occur until four months after the indications started.

 Some of the 'quakes no doubt have been caused by the flow of lava, says Finch.

 The record of earthquakes for the past few days is April 10, 70; April 11, 34, April 12, 72; April 13, 154; April 14, up to 6:30 a.m., 30.

 . . . .

 The Waiohinu telephone operator timed an earthquake shock Tuesday morning [Apr. 13] finding that it was of a full minute's duration.

 Between 3 and 4 o'clock in the afternoon there were about 50 shocks, very slight, at about a minute interval.

 Mrs., E. Vida, from Wood Valley, reports that the quakes were almost continuous on Tuesday, the shocks merging at times. They were mostly slight but some were moderately heavy.

 The same quakes were felt at Kapapala ranch.



Anonymous, 1926, Flow similar to outbreak in 1881 expected on Isle: Hilo Tribune-Herald, 04/14, p. 1. 



 [subheads: Earth movements indicate lava surging down main rift crack of Mauna Loa; Activity in Halemaumau is now expected any time is report of volcanologist]

Volcano House, April 14

 Earth movements and quakes indicate that lava is moving down the main rift crack of Mauna Loa, and records show that this crack is opening, it is stated here today by Roy [sic-Ruy] Finch, assistant volcanologist.

 . . . .

 Many of the earthquakes felt here are probably from movement of lava, and not from ordinary disturbances, it is stated. the quakes are consistently increasing in number, and this is the chief indication of action soon.

 It is very possible that the coming flow will be similar to that of 1881, when the actual outbreak did not come until four months after the first indication, Finch says.

 A quick return of lava to Halemaumau is expected, even if a flow elsewhere should develop, it is stated.

 The record of earthquakes, compiled at the observatory shows a total of 70 on April 10, 84 on April 11, 72 on April 12, 154 on April 13 and at 6:30 a.m. today, 30.

Waiohinu, Kau, April 14--Reports from ranch hands indicating sighting of smoke in the direction of Mauna Loa's southwest rift. This dispatch continues on p. 2 with no mention of earthquakes being felt.



Anonymous, 1926, Flow coming down hills; Jaggar to hunt flow; Stream may reach govt. road Friday night: Honolulu Star-Bulletin, 04/15, p. 1. 



 [subheads: main flow located; is dividing as it drives down Mauna Loa slope; One branch of molten stream is going towards Honomalino, one toward Waiohinu; night glow on wide front seen; residents above Honomalino district moving out as the hear roaring tide]

 A series of dispatches report the progress of the flows from Mauna Loa's southwest rift zone.



Anonymous, 1926, No danger from volcano action, Norton declares; Says Island 'vibrations' hardly felt; instruments record faintest shocks: Honolulu Star-Bulletin, 04/15, p. 6. 



 . . . .

 "I [L.W. de Vis-Norton of the Hawaiian Volcano Research Association] believe that too much emphasis is being placed on earthquake shocks and movements of the ground in the vicinity of Halemaumau," said Norton. As a matter of fact, something like 95 per cent of these shocks cannot be felt by human beings but are picked up by the extremely sensitive earthquake recording instruments at the observatory. Very many of these shocks come from distant points, mainly along the rift line on Mauna Loa where it is of course quite certain that there is volcanic activity at the present time."

 He continues with mention of daily crack monitoring at Halemaumau and debunks current stories of the whole island rocking from enormous earthquakes. He forecast that lava will soon return to Halemaumau.



Anonymous, 1926, Huge lava flow is sighted: Hilo Tribune-Herald, 04/15, p. 1, 2. 



 [subheads: Stream about 1000 feet wide says witness to outbreak aa formation; Rate of speed estimated at one mile in 35 hours--scene is five miles above Government road at present time]

 Dispatches from Waiohinu, Kealakekua, Kamoa and the Volcano Observatory report the ongoing eruption of Mauna Loa from its southwest rift zone. The volcano House dispatch contains the following:

 "It is perfectly clear that the numerous earthquakes of the past few days have portended a flow on the southwest rift, which developed its first activity probably with the formation of dense sulphur smoke April 13, an opening of the crack farther at the time of the sharp earthquake at 7:45 p.m. on April 13 and began vigorous fountains in the Alika source about 8:30 a.m. April 14.

 "On the higher slope of Mauna Loa the earthquakes were abundantly felt, and some of them were felt right at the summit cones which are in the rift belt itself."



Anonymous, 1926, Details of flow told in report of volcanologist: Hilo Tribune-Herald, 04/15, p. 4. 



 Under the heading of "The April 10 outbreak of Mauna Loa" Jaggar describes the eruption as having begun April 10 about 3:00 a.m. [This is the time of eruption in Mokuaweoweo, clarifying earlier reports of a later start time, focused on the southwest rift]. He continues with a narrative of the eruption, followed by a section of the earthquake swarm.

 Earthquake swarms come

 "There was a 'swarm' of earthquakes preceding the outbreak, though they have been coming in 'swarms' since. The warning quakes which were widely felt over the eastern half of the Island of Hawaii occurred at 1:50 a.m. and 2:04 a.m. or about an hour before the first appearance of lava. Before the occurrence of these shakes, however, at 1:36 a.m. 'harmonic tremor,' a motion that is recorded on the observatory seismographs, only when there is molten lava at either Kilauea or Mauna Loa, was recorded. This type of tremor became very noticeable after the 2:04 a.m. quake and continued so for that day."

 . . . .

 Many earthquakes reported

 "A total of 376 earthquakes were recorded during the week [ending April 14, 1926], 343 of which occurred during the four days following outbreak of Mauna Loa. The majority of the shakes appear to have had their origin along the extension of the Southwest rift of Mauna Loa into the lower Kau country, though some appeared to originate under Mokuaweoweo the summit crater of Mauna Loa and along the northeastern rift." . . .



Anonymous, 1926, Need for road on Mauna Loa shown by present flow: Hilo Tribune-Herald, 04/15, p. 7. 



 A plea by Jaggar for a road to the summit of Mauna Loa, to allow for better monitoring of Mauna Loa eruptions. He emphasizes that no one has ever been able to observe the beginning of a Mauna Loa eruption, particularly those on the southwest rift zone.



Anonymous, 1926, Hoopuloa village destroyed; Relief fund is started by Tribune-Herald: Hilo Tribune-Herald, 04/17, p. 1, 2. 



 [subheads: Lava stream takes all houses in little town; offerings to no avail; Swift moving river now cutting way through new channel on way to sea; many dramatic scenes enacted as havoc is done]

 An account of the destruction wrought by the 1926 eruption from Mauna Loa's southwest rift zone.



Anonymous, 1926, Lava flow is nearing sea: Hilo Tribune-Herald, 04/17, p. 1, 2. 



 [subheads: Pacific now only 1400 feet from end of fire; Honomalino stream now coming across highway in huge aa avalanche; Hikers warned to use care on trail to point where volcano expected to enter ocean some time today]

 Dispatches from Waiohinu and Volcano House describe the ongoing eruption from Mauna Loa's southwest rift zone. The dispatch from Volcano House reports:

 "Earthquakes of sufficient force to dismantle the seismograph were registered here last night between 11 and 12 p.m. and again between 4 and 5 a.m. Minor tremors have been felt all day."



Anonymous, 1926, Kona flow increases; sea boils up; Kau quakes felt; Lava coming down over the doomed village of Hoopuloa: Honolulu Star-Bulletin, 04/19, p. 1, 10, 11, 12. 



 [subheads: Five huge lava waves roll down at Hoopuloa; Police guarding highways to stop over enthusiastic sightseers; public lookout in trees signal downrush of streams going steadily into sea]

 Accounts of the ongoing eruption from Mauna Loa's southwest rift zone.

 . . . .

 Severe earthquakes at 9:06 and 9:46 this morning were reported from Waiohinu but were not felt at Pahala, Kau.



Anonymous, 1926, Signs of new flow on Hilo side; Hoopuloa activity seems halted: Honolulu Star-Bulletin, 04/20, p. 1. 



 [subheads: Pele's wrath appears satisfied by sacrifice of ancient building; Jaggar and Finch go to source of latest activity; crowds of 'lava jaunters' on roads]

 Accounts of the ongoing eruption from Mauna Loa's southwest rift zone.

 . . . .

 The earthquakes registered at the Hawaii Volcano Observatory are still continuing, although there is a slight decrease in their number. From April 14 to the morning of the 18th, there were 250 recorded, none of them of great strength, however. On the average there are about five or six a day strong enough to dismantle the seismograph. Most of the stronger quakes seem to originate on Mauna Loa, about 20 miles from the observatory.



Anonymous, 1926, Flow heads toward ranch; earth tremor shakes this side of island: Hilo Tribune-Herald, 04/22, p. 1. 



 [Subheads: Severe quakes felt in several parts of island; Shock Coming at 4:40 a.m.; felt Severely in Puueo, Hilo; nothing Felt in Kohala; Activity near Mokuaweoweo says Finch, seismologist on duty at Volcano Observatory]

 An earthquake of unusual violence which was felt In many parts of the Island was registered with force in Hilo and vicinity, especially in the Puueo district at 4:40 this morning. The shock was so great that in many homes bottles and other articles on shelves or tables were toppled to the floor. Immediately after the quake struck a cry of "Earthquake," could be heard, people jumped out of bed and turned on the electric lights to see what was happening.

 Quakes Last Ten Seconds

 The quake lasted for about ten seconds, starting with a sudden heavy shock which was followed by another. shock of less strength then settling Into a series of. weaker ones which finally died away.

 Reports from other parts of the island indicate that the quake was felt generally except In the Kohala district.

 Severe Quake Felt

 VOLCANO OBSERVATORY, April 22-Roy [sic-Ruy] A. Finch, seismologist, reports that a quake of great force dismantled the seismograph here at 4:40 o'clock this morning. The shock caused considerable excitement around the Volcano House and at first it was thought that Halemaumau was active again.

 According to Finch no activity Is noticeable in the pit but avalanches of considerable force were still going on. The quake felt this morning according to Finch, who bases his belief on Information received from all parts of the Island, had Its origin under the northeast slope of Mauna Loa or under Mokuaweoweo.

No Quake at Hawi

 HAWI, Kohala, April 22-No earthquake was felt here early this morning by anyone In the district, although reports of a shock of great strength in other parts of the island have been received.

 HONOKAA, April 22-An earthquake of unusual force was felt here at 4:40 this morning. The people here think that Halemaumau has broken out again. Rumors to that affect are everywhere.

 KAPOHO, Puna, April 22 - Two earthquakes were felt here early this morning. The first came at 4:40 o'clock. It was quite strong. The second quake came at 5 o'clock but was not unusually powerful.



Anonymous, 1926, Flow wreaks big damage; ranch lands swept; fear hundreds of cattle cut off; sharp earthquake at Hilo: Honolulu Star-Bulletin, 04/22, p. 1. 



 [subheads: New activity is heralded in smoke, quake; Heaviest shock in years felt; renewed smoke is seen on Kona side; Second flow seems to be flowing; may not reach Government road]

 Accounts of the ongoing eruption from Mauna Loa's southwest rift zone and the damage incurred, principally on local ranches.

 . . . .

 Sharp shock felt on Big Island

Hilo, Hawaii, April 22 (9:35 a.m.)--A very sharp earthquake was felt this morning both at Honomalino and here.

 At Hilo the shock was the sharpest in years. A small garage in Hilo was displaced eight inches.



Anonymous, 1926, Activity to last for some time is expert's opinion: Hilo Tribune-Herald, 04/23, p. 1. 



 [Subheads: Similarity of present flow to Alika stream of 1919 is basis of claim of Jaggar; Noted volcanologist walks to within 50 feet of hot lava while on trip of exploration]

 A brief review of the aftermath of the eruption from Mauna Loa's southwest rift zone. a sketch map shows the path of the lava to the sea, where it overran Hoopuloa village.



Anonymous, 1926, Kilauea report No. 745; week ending April 21, '26: Honolulu Star-Bulletin, 04/23, p. 1. 



 . . . .

 Numbers of local earthquakes per 12-hour interval, beginning the morning of April 14 were 32, 24, 51, 32, 37, 29, 16, 12, 8, 12, 8, 18, 2, the last being the night of April 20-21. The total is 310. . . . Intensity of earthquakes increased as numbers diminished. Three of the quakes of the 20th were of Halemaumau origin.



Anonymous, 1926, Two small tremors felt: Honolulu Star-Bulletin, 04/24, p. 1. 



 Hilo, Hawaii, April 24.--The Volcano observatory at Kilauea last night recorded two small tremors centering under Mauna Loa. . . . The headline implies that these were felt at Hilo.



Anonymous, 1926, Mauna Loa lava flowing slowly: Maui News, 04/24, p. 1. 



 Most of the article describes the lava flow on Mauna Loa's southwest rift zone.

 "Thursday morning [Apr. 22] about 4:30 Hilo was shaken by a severe quake lasting ten seconds. A shed was moved several inches off its foundation."



Anonymous, 1926, Best ranch lands hit by flow, says report from Holualoa: Honolulu Star-Bulletin, 04/24, p. 1. 



 Holualoa, Hawaii, April 22.-- . . . .

 The earthquake felt throughout the district Thursday morning was very slightly felt at Honomalino. . . .



Anonymous, 1926, All Hawaii thrilled by volcano eruption, in Volcano Special Edition: Hilo Tribune-Herald, 04/25, p. 1-8. 



 This Sunday supplement covers the 1926 eruption from Mauna Loa's southwest rift zone in stories, sketch maps and photographs. Story heads as follows:

p. 1

 Complete story on volcano is told by expert; Professor Thomas A. Jaggar relates events leading up to great upheaval; History of Mauna Loa activity of deep interest to all; party closely follows every move

 The continuation of this story on p. 5 contains the following:

 "The earthquakes have become fewer and stronger as both felt and recorded. there was a sharp earthquake felt at Kilauea and elsewhere about 9 a.m. on the 19th.

 "The last earthquake appeared to have been almost simultaneous with the observed stoppage of the flow at Honomalino. . . ."

 Awesome view has varied effect on army of viewers; News of activity causes human stampede toward source of great stream of red fire; No one disappointed by huge show staged by Goddess of old, famous Madam Pele

 Refusal to give fish to Pele is cause of losses

 History of present Mauna Loa flow is told in complete story of activities

 Kona Boy Scouts render real aid at Hoopuloa flow

 Fire in pit may be had for cash

 Landing field at south Point used as airplane base

p. 2

 History of Mauna Loa reveals many disturbances on Island

 Tribune-Herald staff man still ready for lava

p. 3

 Tribune-Herald aided by worthy army of workers; Jazz Gelknap, speedy member staff, tells to whom credit for many dispatches is due; Cooperation of everyone given by many in District where volcanic activity descended

 Graphic record of lava flow seen in photos

p. 4

 Property damage in ill-fated town set at $10,000; Cost to replace will be twice amount, is estimate; people refuse to remove wares; Total destitute is about 60; help for unfortunate given by friends near ruined area

 Many witness sad sight of village burned by lava

 Detailed story of eruption told by viewer

p.8

 Glorious sight greets party at source of flow

 Details of trip taken by Finch full of thrills

 Connection over lava to be ready soon says report

 Halemaumau asks Mauna Loa for lava; Imaginary conversation between Halemaumau and Mauna Loa



Anonymous, 1926, Hard earthquake is felt all over Big Island today: Hilo Tribune-Herald, 06/09, p. 1. 



 A strong earthquake was felt throughout the island of Hawaii at 9:35 this morning, registering with the greatest force at Kapapala.

 The quake was felt all over Hilo, coming the [sic] three successive shocks. At Kapapala articles resting on shelves were toppled over. The seismograph at the Volcano and the one at Hilea were both dismantled by the shock, according to Roy [sic] Finch, assistant volcanologist.

 According to Finch. although the force of the quake was considerable no sign of unusual activity is noticeable at Halemaumau which remains dormant.



Anonymous, 1926, Volcano glow is reported in Kau; Rumors of eruption not verified; many see light in sky: Hilo Tribune-Herald, 10/25, p. ? 



 A glow was seen on Mauna Loa from Honuapo.



Anonymous, 1926, Mauna Loa's eruption of 1926: Hawaiian Annual for 1927, p. 40-46. 



 An eruption lasting only a few hours occurred on April 10, 1926, on the southwest rift zone of Mauna Loa near the South Pit of Mokuaweoweo. On April 14, lava broke out on the southwest rift zone at about 8,000 ft, sending a flow toward Waiohinu and another into Kona. The latter lava entered the bay at Hoopuloa on April 18. The author quotes descriptions of the lava flow and source area from The Volcano Letter (Fiske and others, 1987). An earthquake swarm (70-90 events per day, diminishing to 1-17 events per day) occurred between the times of summit and rift outbreaks. Kilauea remained quiescent.

 

Anonymous, 1926, Seismological notes: Bulletin of the Seismological Society of America, v. 16, no. 2, p. 160-161. 



 Hilo, Hawaii, April 10, 1926.--An eruption of the volcano Mauna Loa, near Hilo, Hawaii, on April 10th, during which the village of Hoopuloa was completely wiped out by lava flow, was preceded and followed by several earthquakes of intensity sufficient to dismount the instruments at the Kilauea Observatory.



Hilo, Hawaii, April 22, 1926.--Terrific earthquakes continued to shake the district of Kilauea during the ten days that Mauna Loa was in eruption. Shocks occurred at 5:10 p.m. on April 20 caused enormous avalanches in Halemaumau.



Anonymous, 1927, Sharp quake wakes island; no harm done; Disturbance purely local, reports U.S. station at University: Honolulu Advertiser, 03/21, p. 1, 2. 



 Honolulu residents were awakened shortly before 5 o'clock yesterday morning by an earthquake shock which is reported as being the heaviest felt here in many years. All day yesterday telephone inquiries poured into the Advertiser to learn if any damage had been done by the temblor or whether Kilauea volcano had resumed activities again. The quake was felt about equally in all parts of the island. An extensive check-up of all sections of the city and windward Oahu showed no damage of any nature. Radio advices received by the advertiser last night from Maui stated that two severe shocks were felt on the Valley Island yesterday morning. The first shock was felt at 6:15 [time wrong according to HVO and HMO records-should be 4:52 and 5:59-see below] and lasted five seconds. shortly afterward another shock was recorded which lasted 23 seconds. No damage was reported.

 Lieut. J.H. Peters of the United States Coast and Geodetic Survey in charge of the seismological station at the University of Hawaii said that the disturbance was purely local, centering on the island of Oahu.

 There were two distinct shocks as recorded by Lieutenant Peter's instruments, the first starting at 4:51:07 a.m. Sunday. this shock reached its maximum at 4:51:50 and died away at 4:59:00.

 The maximum amplitude of the quake was 103 millimeters, equivalent to an earth movement of 1/25 of an inch or 2/25 over all.

 This shock was followed by a second, which began at 5:59 and lasted approximately seven minutes, according to Lieutenant Peters. This shock had the center of its disturbance at a greater distance than the first one.

 Lieutenant Peters said that the shocks were not sufficient to cause any sort of damage.

 The last earthquake on Oahu strong enough to be perceptible occurred almost exactly a year ago.



Anonymous, 1927, Earthquakes felt all over islands; two strong shocks occur on Sunday morning; no undue activity at volcano: Hilo Tribune-Herald, 03/21, p. 7. 



 Two earthquake shocks occurred early yesterday morning and were felt throughout the Islands. The first shock came between 4:51 and 4:59 while the second came at 5:59 and lasted until 6:06 a.m.

 The first shock was strongly felt all over the island of Hawaii according to reports received from various districts. The seismographs at the Volcano Observatory and the Saint Mary brothers school in Hilo were both dismantled by the shock so that the exact duration of the quake could not be learned here. According to observatory officials at the Volcano the quake was evidently of local origin.

 H.M. Wilson, assistant to Dr. Thomas Jaggar, volcanologist, stated . . . that there was no undue activity at the firepit of Halemaumau and that no other shocks have been felt since Sunday morning.

 The quakes awakened many people but did no damage according to reports.

 Washington, D.C., March 21--Georgetown University today registered earthquakes of severe intensity, which were estimated as centering about 4800 miles from Washington.



Anonymous, 1927, Severe shock jars Hawaiian Island group: Honolulu Star-Bulletin, 03/21, p. 1. 



 [Subheads: Heaviest quake in years felt on islands; volcano seismograph dismantled; No damage reported; dishes thrown from shelves on Big Island, however]

Washington, March 21--The seismograph at Georgetown University early yesterday registered earthquakes of severe intensity centering about 4800 miles from Washington.

 Two earthquake shocks occurring early yesterday morning were felt generally throughout the islands . . . . On various points of Oahu the first temblor was sufficiently intense to rouse residents from early morning slumbers, while on Hawaii, the shock dismantled the seismograph instruments at the Volcano observatory.

 The first shock occurred at 4:51:07 a.m., reached its maximum intensity at 4:51:59 and died away at 4:59, according to records at the United States seismological station at the University of Hawaii. A second shock was recorded at 5:59 and lasted approximately seven minutes, records in charge of Lieut. J.H. Peters of the U.S. coast and geodetic survey showed.

 No undue action in the firepit of Halemaumau was reported from the island of Hawaii.

 In Honolulu the first shock was intense enough to rattle dishes and windows, and it was reported that guests at various hotels became alarmed and rushed into the hallways.

 [reference to recording at Georgetown university]

 No damage has been reported as resulting from the quake.

 Hilo, Hawaii, March 20--A severe earthquake occurred here this morning at 4:52 a.m. The shock was felt all over the island, according to reports from the various districts and lasted for nearly a minute. No damage was caused although in many homes bottles and other articles were shaken from shelves.

 [repeats info from hvo]

 Volcano House, Hawaii--A rather severe earthquake shock was recorded on the seismographs at the observatory at 4:52 this morning, of sufficient magnitude to dismantle the recording mechanism so that only the preliminary movement was recorded. Although R.M. Wilson of the local station was awakened by the shock guests at the Volcano House were not disturbed by the tremor. Phone reports from Hilo state that the quake was strong enough in certain localities in town to cause the falling of dishes and in several instances people were frightened to the extent of fleeing from their houses.

 Honokaa, Hawaii, Mar. 20--A very sharp earthquake was felt here this morning at 4:56 o'clock which lasted for several seconds. . . . 

 Wailuku, Maui, March 21.--A severe earthquake shock of 10 seconds duration was felt at 4:55 o'clock Sunday morning throughout the whole island. It was reported to be most severe in Paia and Haiku. No damage was done. The shock was not as severe as the shock which was felt exactly a year ago at 10:30 o'clock at night.



Anonymous, 1927, Islands shaken by hard quake; Sunday morning slumbers disturbed; felt through group but no serious damage is reported: Maui News, 03/23, p. 1. 



 Maui residents were abruptly aroused from their matitudinal slumbers about ten minutes of five o'clock Sunday morning and came up standing or leaping from their beds. There was an earthquake shock so severe that scarcely anyone slept through it, one of the most severe quakes that Maui felt in years. It was felt throughout Maui of greater or less intensity and on Molokai, it became known after the arrival of the Claudine early Monday and with the arrival of the Honolulu papers Monday evening and Tuesday morning it was found to have been general throughout the Islands and to have been indicated by apparatus as far away as Washington D.C.

 Those who were awake shortly before the quake was felt heard a rumbling noise . . . Buildings creaked and squeaked and groaned but no damage is reported to have occurred any where on Maui.

 It is coincidence that the quake of Sunday morning occurred on the day of the anniversary of one of about equal severity. On March 20, 1926 there was a disturbance of about equal violence and length at 10:30 at night. The earth movement seemed different, however, being vertical rather than horizontal. A year ago there was a wider sway, the motion of Sunday being rather up and down. The climax or "twist" seemed to be about the same intensity.

 Following the shake-up in Wailuku there was bedlam among the canine residents . . . .

 In Lahaina side and in West Maui generally the shock was severe. . . . in the vicinity of Honolua the pheasants were thrown into a state of consternation . . .

 Joseph Herrscher of Hana said the shock was felt there but that it was not severe.

 . . . .

 Several from Haiku maintained that it was severest and longest in that section, others contended that it was felt more in Paia and then some of the Kahului and Wailuku residents maintained these two centers bore the burden of the shock . . .

 . . . The shock was severe at the Kilauea observatory, sufficient to dismantle the delicately arranged seismographic instruments, On that island dishes were thrown from shelves and bottles upset.

 At the University of Hawaii in Honolulu the instruments recorded the start of the quake at 4:51:07 and the maximum intensity at 4:51:50 and that it had completely died away at 4:59. A slight shock was recorded there an hour later but appears not to have been noticed on Maui.



Anonymous, 1927, Lava returns to Halemaumau; crowds of people rush to scene of activity: Hilo Tribune-Herald, 07/07, p. 1, 7. 



 [subheads: Without any warning, molten rock reappears in world-famed fire pit; Brilliant glow seen in skies gives first intimation of weird activity; night watchman at volcano house is first to see spectacular drama unfold at the crater of Kilauea]

Volcano House, July 7-- . . .

 Starting at approximately 12:45 a.m., without any of the usual earthquakes or other activities, three huge fountains started spurting molten lava into the air. . . .

 The remainder of the article summarizes the activity in Halemaumau and the following seismic observations:

 "An inspection of the seismograph at the Kilauea observatory this morning revealed the fact that there had been very slight earthquakes at 11:13 and 11:46 p.m. last night. A more severe quake occurred at 3:31 a.m. today.

 "A few days ago a large crack developed in the pit area, and this was followed by several avalanches. It was not thought at the time that this was an indication of lava near the surface, however."



Anonymous, 1927, Volcano stirs; pit is filling: Honolulu Star-Bulletin, 07/07, p. 1, 2. 



 [subheads: Lava spurts 'full blast' at Kilauea; Halemaumau pit breaks out at 1 in morning after slight tremors; Four fountains, 125 five [sic] feet high, play as fire rolls into great hole]

 The article recounts the return of lava to Halemaumau.

 . . . There was no perceptible earthquake to mark the start of the flow, but a rumbling noise was heard at the Volcano. . . .

 . . . .

 Study of the seismographs at the volcano observatory disclosed slight tremors at 11:13 and 11:46 p.m. and a series of slight tremors from 10 p.m. to midnight, as is customary preceding a flow of lava into the pit.

 The seismograph also registered and earthquake at 3:21 o'clock this morning, which woke a few people in Hilo.

A harmonic tremor at 12:32 a.m. was the closest indication of any activity at the pit, as it showed that lava was active underground. The eruption occurred between that time and 1 o'clock.

 Additional articles entitled "Eruptions of 1924 recalled by lava flow" and "With Dr. Jaggar on Alaskan trip Pele gets busy."



Anonymous, 1927, Lava flows again into Kilauea pit: Maui News, 07/09, p. 1. 



 An announcement of a new eruption in Halemaumau, beginning at about 1 a.m. Thursday morning [Jul. 7].

. . . .

 "Prior to the resumption of activity Thursday morning there were no violent quakes, though between 11 and midnight there were mild ones registered by the seismograph." . . .



Anonymous, 1927, Avalanching gains at Halemaumau; new activity expected since slides and shakes which occurred Sunday: Hilo Tribune-Herald, 07/25, p. 1. 



 A great increase in avalanches along the north and northeast walls of Halemaumau pit were noted yesterday. These avalanches and two earthquakes which rocked the island this morning are taken as an indication by some that renewed activity may soon be expected at the crater.

. . . .

 The first earthquake felt was registered at the volcano seismograph at 2:07 a.m. and the second at 6:13 a.m. Both quakes, while light, were felt in Hilo as well as in the volcano district.



Anonymous, 1927, Island of Hawaii rocked by severe earthquake today: Hilo Tribune-Herald, 08/03, p. 1. 



 Subheads:

Tremor is claimed to be worst felt throughout Big Island for many months

Kona and Hilo seismographs as well as Volcano instrument report strong shake

 A sharp earthquake which struck Hilo and all of the Big Island at 9:42 o'clock this morning is said by officials at Kilauea Volcano Observatory to have been the most severe of [illegible] for many months and possibly exceeding the strong shake of March 20.

 Reports from Captain Woods, in charge of the seismograph at Kona, and from the observers of the seismograph at the Brothers School in Hilo tallied with the Volcano Observatory instruments in indicating equally strong tremors at each point. In this circumstance, the officials work indicates that the quake was most probably felt in all of the islands, but so far they have not received reports from elsewhere.

 The shake dismantled both of the seismographs at the observatory, so that only the beginning of the shake was recorded and the officials cannot tell how long the duration was.

Hilo is alarmed

 From all parts of Hilo reports came here of residents being alarmed by the shock, but as far as can be learned no damage was done by the tremor.

 . . . .

[The rest of the report discusses unfounded rumors of volcanic activity associated with the quake]



Anonymous, 1927, Quakes herald volcano action, belief in Kau; Increase of shocks in lower districts thought of significance: Honolulu Star-Bulletin, 08/05, p. 7. 



 Pahala, Hawaii, Aug. 3.--That Pele is grooming herself for another spectacular outburst either at the crater of Halemaumau, where she recently appeared in all her glory or on the top of Mauna Loa, is the belief in Kau, with the increase in frequency of earthquake shocks.

 At 9:42 o'clock this morning, standard time, one of the severest earthquakes ever felt here shook the district. In fact, old timers feel that it was the hardest shock felt since the Alika flow took place in 1919. No severe damage was caused by the shock, except for some breakage, when glassware and other merchandise fell from the shelves of the Kau stores.

 Many residents claim that the shock traveled east and away from the point of greatest activity above Kahuku. J. Silva, a luna in Pahala, who happened to be in one of the fields furthest west, heard the movement of the earth in the direction of Kahuku a few seconds before the shock was felt.

 Other shocks were felt during the day in Kapapala country. the shocks are only a continuance of a series of earth movements felt during the last few weeks.

 Less severe at Volcano

Volcano House, Hawaii, Aug. 4.--an earthquake of magnitude to dismantle the seismographs at the Kilauea volcano observatory was recorded at 9:42 a.m. Wednesday.

 Although felt by only a few guests at the Volcano House, it was more violent at Kona and Hilo, from where reports came of the dislodgment of dishes and rattling of windows. . . .



Anonymous, 1927, Hard quake has center at Kilauea; seismic activity may precede outbreak at volcano: Honolulu Advertiser, 08/06, p. 1. 



 An abstract of the Hilo Tribune Herald article of August 3, with no additional information. [Unfortunate lack of confirmation as to whether the earthquake of August 3 was felt on other islands]



Anonymous, 1927, Slight tremor is felt in Kona area; no damages done though newer teachers in school are excited: Hilo Tribune-Herald, 10/21, p. ? 



 Kealakekua, Oct. 21 (special)

 At 5:58 p.m. last Sunday evening a slight earthquake was felt in Kealakekua and the surrounding district. It was only of a few seconds duration.

 Consternation reigned among the new mainland teachers at Konawaena. They rushed from the room when they felt the house quiver. They declared the walls and windows were nearly shaken loose. In the high school laboratory several electrical instruments were jolted out of commission.

 However not great damage had been reported.

 This is the second noticeable tremor felt in Kona since September the first. The other, early in September, was just a trifle more violent than the one last Sunday evening.



Anonymous, 1928, Pele fails to show up after big earthquake: Hilo Tribune-Herald, 12/28, p. 4. 



 [subheads: Heavy shock on Christmas night aroused hope that pit would be active; Many residents in District are awakened from slumber by violent shake]

Volcano House, Dec. 28--(special)--Despite the hope that the violent earthquake of Christmas night was a forerunner of activity at the pit, no signs of the return of Madam Pele to Halemaumau are noted today.

 The disturbance occurred at 10:15 on Christmas night and was of such intensity as to almost dismantle the seismographs at both the volcano and Uwekahuna observatories. Many residents of the district were awakened by the shake, but no damage was reported at any of the homes.

 Officials in charge of the observatory express the belief that the quake originated somewhere in the vicinity of the volcano. This led to the predictions that Madam Pele was about to stage a comeback, but so far there has been no actual sign of her return.



Anonymous, 1929, Quake centering at Halemaumau rocks Big Isle: Honolulu Star-Bulletin, 02/05, p. 1. 



 Hilo, Hawaii, Feb. 5.--A sharp earthquake rocked the Big Island at 2:25 a.m. today. The quake was felt as far as Kohala and Kona.

 Dr. Thomas A. Jaggar, Jr. says the tremblor had its center at Halemaumau and he was surprised at its wide sweep. Although it was felt only a minute, instruments recorded it as lasting for 10 minutes.

 Jaggar said it may be an indication of impending activity in the volcanic pit of Kilauea, although this is uncertain.

 No damage was done.



Anonymous, 1929, Great avalanches tear away landmarks at Halemaumau: Honolulu Advertiser, 02/11, p. 5. 



 Examination of Halemaumau. February 2, showed the rim gone to a depth apparently 15 feet more or less south and southeast, carrying away such landmarks as the old burned boards of the 1918 outhouse and the pinnacles just inside the rim, as well as the south station. The bronze datum bench mark southeast is on cracked dangerous ground at the extreme edge of the pit. A new tourist viewing platform for viewing the pit has been built at the east rim. The south talus was struck by the great avalanches and set in motion a landslide so as to cover the whole south half of the lava floor. this is much like what happened just a year ago, January 11, 1928. At that time. however. liquid lava was pressed up.

 . . .

 . . . one strongly felt earthquake (intensity IV Rossi-Forel scale) occurred at 2:25 a.m. February 5 so as to awaken sleepers generally. This shock was also felt at Hilo and Kohala, appeared to be local to Kilauea seismographically, and hence may represent a deep earthquake under the east side of the island.

 Tilt for the week was moderate ENE. All the seismographs showed an apparent easterly tilt at Kilauea during the earthquake. This suggests that if subterranean lava was concerned with the earthquake at all, the lava movement was one of rising. . . .



Anonymous, 1929, Three quakes send Hiloites into streets; Shock lasts 7 seconds but no damage done; Jaggar says there's no danger: Honolulu Star-Bulletin, 06/18, p. 1. 



 Hilo, June 18.--Three earthquakes shook Hilo at 8:43, 9:30 and 9:32 a.m. today. The last shock was strong and lasted seven seconds.

 The earthquakes caused much excitement, but no damage. Citizens rushed out of stores and houses into the street.

 The shocks were so strong that they dismantled the seismographs at Kilauea observatory. Dr. Thomas A. Jaggar, in charge of the observatory, stated that the tremors were not alarming, but "just a waving motion." He estimated the seat of disturbance to be 20 or 30 miles away, toward Mauna Loa.

 . . . .The quake caused some avalanching [in Halemaumau]. . . .



Anonymous, 1929, Three quakes are felt here this morning: Hilo Tribune-Herald, 06/18, p. 1. 



 [subheads: T.A. Jaggar estimates that center of disturbance was 30 miles away; Many call newspaper; reports indicate tremors are noticeable in many parts of city]

 Three earthquakes were felt in Hilo today--one sharply defined and two mild.

 According to Dr. Thomas A. Jaggar, in charge of the Kilauea Observatory, seat of the disturbance was from 30 to 40 miles distant from the observatory, probably somewhere in the Mauna Loa region.

 It was 8:43 o'clock this morning when the first tremor occurred. This was barely noticeable in Hilo.

At 9:30 came a second shock. It lasted only a second, but was sufficiently strong to shake buildings.

Two minutes later, at 9:32, the third shock was felt. this one lasted 7 seconds, according to several persons who said they timed it here [P and S of one quake?].

 All Hilo and vicinity felt this third tremor . . . It was especially noticeable in the downtown business section, and shook some of the loosely constructed frame buildings, so that their timbers creaked and rattled.

 Officials and clerks on the second floor of the County building on Waianuenue avenue and Keawe street felt the third quake . . .

. . . .

 . . . "I know we felt the shocks sharply here at St. Joseph's parish house," says Father Sebastian.



Anonymous, 1929, Kona fears eruption of Mauna Loa: Honolulu Advertiser, 09/24, p. 1, 2. 



 Hilo, Sept. 23--Dr. Thomas A. Jaggar reported to the Volcano observatory at Kilauea National Park this afternoon at 3:15 that the center of earthquake shocks that has been rocking the Kona side of this island has been located at the northwest side of Hualalai, and that he believed that there was a possibility of volcanic activity taking place on the Kona side of Mauna Loa.

 The volcanologist declared that the same conditions exist now as in 1801 at the time of the Hualalai flow.

 The seismographs at the volcano observatory today registered 60 earthquakes as having taken place between 2 a.m. Sunday [Sept. 22] and 8 p.m. today.

 Frank Greenwell reported that more than two hundred shocks were felt during the same period at Holualoa, and that today more than 100 took place, most of them more severe than those of Sunday. There was a particularly strong shock reported at 10:31 this morning.

 Reports from all sections indicated that the temblors were strong at North Kona, and mauka of Waikii and Kohala but were quite slight at Kailua. A few shocks were felt in the Puueo section of Hilo on Sunday night.

 Jaggar on Hand; Hilo, Sept. 23--Dr. Thomas A. Jaggar, government expert on volcanoes, is inclined to believe that the continued earthquakes on the Kona side point towards activity probably on the slopes of Mauna Loa rather than Hualalai, it was said at the volcano observatory today.

 Dr. Jaggar is now in the Kona area.

 The observatory instruments indicate the origin of the quakes to be 18 to 30 miles from the observatory.

 They are characterized as typically volcanic, indicative of a rise or fall in the lava column under Mauna Loa.

 Several of the quakes have been felt slightly in Hilo.



Anonymous, 1929, Hawaii eruption Looms; on Hualalai predicted by Dr. Jaggar: Honolulu Advertiser, 09/25, p. 1, 2. 



 [subheads: Hawaii volcano becoming active, says expert, back from Kona quake survey; "Almost anything likely to happen," he declares, calling attention to eruptions throughout the world; tremors are increasing]

 Returning late this afternoon from the Kona region, Dr. Thomas A. Jaggar, government volcanologist, declared that "it looks as though Hualalai is becoming active."

 Dr. Jaggar added that earthquakes around Hualalai are ten times as numerous as those recorded at the observatory. He said that the people of the Kona district are extremely nervous.

 "Something is happening over there," the volcanologist declared, "and it looks as though Hualalai is becoming active, but the situation is very complex. Seismic records indicate the seat of activity at Mauna Loa, while surface indications point to Hualalai. Almost anything is likely too happen."

 The article concludes with discussion of the timing of the earthquakes at the equinox and a discounting of the possibility of a summit eruption of Mauna Loa.



Anonymous, 1929, Quake damages Kona; Holualoa city threatened by terrific spasms: Honolulu Advertiser, 09/26, p. 1. 



 [subheads: Entire island shaken by heavy tremor; landslide plunges into ranch house; Residents flee in terror as buildings rock; Jaggar predicts even heavier shock and eruption within month; mountain climbers find fences and water tanks wrecked by temblor]

 Holualoa, Hawaii, Sept. 25--Several homes and stores were reported damaged tonight when a terrific earthquake rocked the Kona district. Extent of the damage could not be ascertained. The earthquake occurred about 6:23 p.m.

 Hilo, Sept. 25--The entire island of Hawaii was shaken by a heavy earthquake--the strongest recorded during the present disturbance--at 6:23 this evening. Reports indicated that the Kona region bore the brunt of the tremor.

 Reports from Puuwaawaa said a landslide, caused by the shock, plunged down onto the Hind ranch house, smashing part of the foundations. Considerable damage to crockery was reported by residents of Puueo and Waiakea. Hundreds of persons, especially in Kona, fled their homes.

 A party, headed by Luther Aungst, telephone company superintendent, which was climbing Hualalai, where experts expect an eruption, returned toward Kona, reporting that the earthquake had shaken the mountain with terrific force.

 The climbers, who had reached the 4,000 foot level when the tremor occurred, said they found stone walls and water tanks on the slopes of the mountain wrecked by the force of the quake.

 They reported meeting Dr. Thomas A. Jaggar, government volcanologist, who warned them that they could expect still heavier shocks later on.

 Dr. Jaggar was on his way to Puuwaawaa to make observations. He was quoted in the afternoon as saying:

 "We may expect an eruption possibly from the northwest flank of Hualalai within a month, if the earthquakes which have shaken the island of Hawaii for the past five days, particularly in the Kona District, continue."

 Mrs. L. Lucas telephoned from Puuwaawaa that the landslide caused a small panic among the ranchers.

 All buildings were immediately vacated, and the occupants, fearing a larger slide, refused to return for several hours.



Anonymous, 1929, Lull in quakes may be forerunner of eruption: Honolulu Advertiser, 09/28, p. 1. 



 [subheads: Temblors on Hawaii lessen in intensity; Jaggar says this may presage lava outbreak; Kona district still nervous; Hotel's water tank cracked by Wednesday's tremor]

 Hilo, Hawaii, Sept. 27--Earthquake shocks that have rocked the Island of Hawaii for eight days decreased in intensity--a lull that, in the belief of Dr. Thomas A. Jaggar, may be the forerunner of an outbreak of lava in one of the Big Island's volcanoes.

 Both Kona and Hamakua experienced one fairly heavy shake this morning, but it was followed by an afternoon of comparative quiet.

 . . .

 Dr. Jaggar, government volcanologist, who is making observations in Puuwaawaa, reported a quiet day in the Kona area, adding that persons returning from a trip up Hualalai said they found no evidence of either fire or gas in the crater.

 The government expert said he still expects a quake even heavier than that of Wednesday.

 Reports from the Kona region showed that reports of damage resulting from the earthquakes have been exaggerated. One item not previously reported was a large crack which appeared in the water reservoir at the Kona Inn.

 Thomas Strathairn, Hilo agent of the Inter-Island S.N. Company is now making a survey of the entire region.



Anonymous, 1929, Army experts study best method of carrying out Thurston lava curb plan; Engineers to report today on cost of proposal to control havoc from eruption by blasting tubes with TNT charge: Honolulu Advertiser, 09/28, p. 1, 2. 



 A report of a meeting convened to consider the cost of an experiment to test the feasibility of Thurston's plan to divert Mauna Loa's lava flows by setting of explosive charges in skylights of a flow that has developed a lava tube system.



Anonymous, 1929, More than two hundred shocks felt; Kilauea observatory reports extraordinary total for week: Honolulu Advertiser, 09/28, p. 2. 



 An extraordinary large number of seismic disturbances have occurred during the week ending Sept. 25, the total count being 221. . . . The earthquakes appear to originate in North Kona district on the west side of the Island of Hawaii, but are felt all over the island, intensity increasing with distance. Due to crowding and overlapping lines on the seismograms some shocks could not be counted.

Table of earthquakes:

 Number of earthquakes recorded at Whitney

Date very feeble feeble slight moderate

9/18 3 - - -

9/19 6 - - -

9/20 3 1 - -

9/21 19 1 - -

9/22 51 3 3 -

9/23 51 4 1 -

9/24 32 15 6 2

9/25 13 4 3 -



Anonymous, 1929, Eruption imminent, says Jaggar; new quakes hit Hilo: Honolulu Advertiser, 09/29, p. 1, 2. 



 [subheads: Hilo region experiences big shocks; Lava outbreak expected at any time now; Hawaii people still nervous; Three families vacate homes in order to get sleep]

 Hilo, Sept. 28-- . . . .

 The Hilo district experienced several heavy shocks during the day, particularly in Puueo and Kaumana, the strongest tremors occurring at about 7 a.m. and 2 p.m. And the volcano observatory on Kilauea announced that between 50 and 60 quakes were being recorded there daily. One quake, which apparently lasted between two and three minutes, dismantle the seismograph.

 Dr. Jaggar, who is in the Kona district, advised the observatory today that there had been several heavy tremors at Puuwaawaa. He said he looked for volcanic outbreak to come from either Mauna Loa or Hualalai, or from some point between Mauna Kea and Mauna Loa.

 A spirit of nervousness still pervades the entire island, for the people are awaiting with considerable apprehension the extremely heavy quake which Dr. Jaggar believes will precede the impending eruption.

 In fact three families, finding they could get little sleep, have vacated their homes in Puueo to seek some quieter district. Ironically enough, two of the three groups have decided to go to the Volcano house on Kilauea, all of the experts having agreed that there is virtually no chance of an eruption there.

 Reports from Kona indicate that many persons are still sleeping outdoors, as the result of the heavy quake last Wednesday [Sept. 25].

 In Kohala several earthquakes, two of them heavy, were felt last night and today. Other districts report light tremors of wide frequency.



Anonymous, 1929, Eruption on Hawaii may be delayed: Honolulu Advertiser, 09/30, p. 1. 



 [subheads: Series of quakes are growing less frequent; Big landslide is described; Captain tells how wall of Kealakekua cliff fell]

 Hilo, Hawaii, Sept. 29--Quiet reigned on Hawaii's "earthquake front" tonight.

 Following the two heavy tremors that rocked the Kona and Hilo districts yesterday, the quakes diminished both in frequency and intensity today, resulting in a statement by Dr. Thomas A. Jaggar that the expected volcanic eruption may be delayed.

 From the Kona area where he reported all quiet the government volcanologists telephoned that the flow of lava which is causing the earthquakes may have found a new underground tunnel, with the result that, if the tremors continue to diminish, the eruption may be delayed.

 He added that the comparative scarcity in earthquakes may indicate a longer period intervening between heavy temblors.

 Dr. Jaggar's instruments showed that the two shocks yesterday afternoon were even more severe than that which caused considerable damage last Wednesday [Sept. 25], but were dissimilar in nature.

 An account of how a section of the cliff at Kealakekua was hurtled down by Wednesday's quake was brought to Hilo this morning by Captain J.K. Bruns of the motorship Kailua.

 The ship was anchored in Kealakekua at the time of the quake and Captain Bruns said he say a great section of the cliff slide off and plunge onto the rocks below. He believes that because of the peculiar motion of the ship, that a marine disturbance may have accompanied the earthquake.

 Light quakes at wide intervals were reported from Waimea, Hamakua and Kohala today, and the observatory on Kilauea reported that nothing of consequence had been observed there.



Anonymous, 1929, Airplane search for possible lava outbreak: Honolulu Advertiser, 10/01, p. 1, 2. 



 [subheads: Jaggar wants navy ship to circle island; Expert scouts theory of eruption at remote point; 2 big shocks felt at Hilo; Average of 29 quakes an hour recorded in Kona]

 Hilo, Hawaii, Sept. 30--An airplane survey of the island of Hawaii, to determine whether there has been an outbreak of lava in some remote part of the mountains, will be sought by Dr. Thomas A. Jaggar, government volcanologist, now observing earthquake shocks in the Kona district.

 While inclined to discredit reports of such a flow, Dr. Jaggar announced tonight that he will request a navy airplane, which is due at Hilo tomorrow, make a survey to make sure that no outbreak has occurred.

 Dr. Jaggar reported from Puuwaawaa that his seismograph had recorded an average of 29 quakes an hour during the past 24 hours. Most of the tremors were light, but distinct, and were felt only near the center of the greatest underground disturbance.

 Two severe shocks were felt in Hilo and Kona today. One of these, occurring at 11:55 a.m. was extremely heavy, destroying several stone fences on the slopes of Hualalai. The other intense tremor was felt at 12:20 p.m.

 From Kealakekua came a report from R.V. Wood that the seismograph there recorded 70 quakes in the 24 hours ending at 8 a.m. today. Many of these were so indistinct that they could not be felt, Wood said.

 L.S. Aungst of the Hawaii Telephone company stated that he counted 105 tremors at Holualoa yesterday, adding that the quakes seemed to increase in intensity as one neared Puuwaawaa.

 The seismograph at the Kilauea observatory continues to register from 50 to 100 shakes daily.

 . . . No sign of a lava flow was visible on either [Mauna Loa or Mauna Kea].



Anonymous, 1929, Jaggar says lava blast plan feasible; Thurston proposal workable if molten flow is slow one: Honolulu Advertiser, 10/01, p. 1. 



 Jaggar opines that Thurston's plan to disrupt lava channels with explosives would work for an eruption like that of 1881. It would not work for a fast moving flow, like the one that came down the steep slopes of Hualalai in 1801.



Anonymous, 1929, Earthquakes diminish on Big Island: Honolulu Advertiser, 10/02, p. 1. 



 [subheads: Apprehension lessens as Hawaii has quiet day; Jaggar still expects lava; Expert says eruption might not occur for a year]

 Hilo, Oct. 1--Hawaii's "earthquake areas" reported all quiet today.

 Reports from all sections of the Big Island said that earthquake shocks, which have been felt for nearly two weeks, had diminished immensely during the last 24 hours.

 However, Dr. Thomas A. Jaggar, government volcanologist, did not interpret this as meaning that the long awaited volcanic eruption would not materialize.

 . . . . 

 There were several distinct earthquake shocks during the day, but they came at wide intervals. Residents of the Kaumana district reported that at 5:55 this morning there occurred the strongest tremor yet experienced there. Other sections of Hilo were without notable shocks, however.

 While the United Press correspondent was talking with Dr. Jaggar this evening by telephone the volcanologist, who is at Puuwaawaa, interrupted the conversation to cry:

 "Here comes another quake right now."

 This was at 7:25. A moment later Dr. Jaggar returned to the telephone and reported that the quake was the heaviest recorded during the day.

 The seismograph at the Kilauea observatory recorded 20 shocks between 6 a.m. and 6 p.m.



Anonymous, 1929, Maui woman in Kona during earthquakes: Maui News, 10/02, p. 2. 



 A woman reports that the earthquake of Sept. 25, 1929 had the greatest damage in Kona, but was felt very severely, with much consternation of the populace, at Kohala and in Hilo.



Anonymous, 1929, Lava breaks may come in 3 volcanoes; Jaggar says prediction of eruption stands despite quiet: Honolulu Advertiser, 10/05, p. 1, 2. 



 A few earthquake shocks, gradually decreasing in both frequency and intensity, were reported today from the West side of Hawaii, chiefly in the vicinity of Puuwaawaa.

 [Jaggar reaffirms prediction of eruption within a year, more probably within a month, at any one of Hawaii's three volcanoes]

 The seismographs at the observatory were dismantle eleven times by earthquake shocks during the week ending last Wednesday [Sept. 26-Oct. 2].

 [An annunciator connected to the seismographs at the observatory rings a bell to alert the staff when the instruments are dismantled]

 Earthquakes registered. were as follows, by days: September 25, 63; 26, 61; 27, 27; 28, 27; 29, 29; 30, 15; October 1, 19, October 2, 3. September 25 and October 2 are incomplete days coming at the beginning and end of the period covered by this report. It should be stated that many more shocks are felt in West Hawaii, the apparent center of the present seismic disturbance, than are recorded at Kilauea.

 Thirteen shocks give distances of 23 miles, 10 distance 28 miles, 6 distance 30 miles, 7 distance 32 miles, other distances varying from 14 to 46 miles from the observatory.



Anonymous, 1929, Earth quake damages Hilo: Honolulu Advertiser, 10/06, p. 1, 2. 



 [subheads: All districts report fresh disturbances; Constant series of earthquake shocks experienced; Heavy tremors felt in Waimea; Quakes revive reports of impending eruption]

 Hilo, Oct. 5--Heavy damage is reported to have resulted from a heavy earthquake, the most severe of the recent volcanic disturbances, which rocked the Island of Hawaii between 9:21 and 9:22 last night.

 Indirect reports from the Kona section reported that the tremor was by far the worst yet experienced. Several water tanks were reported to have been damaged. It was rumored that two houses at Puuwaawaa were shaken off their foundations.

 In the Hilo district the quake was heaviest at Puueo. People fled from their houses there, and windows and crockery were broken. Residents said trees swayed as though in a high wind. Plaster was knocked from several walls and many clocks were stopped by the shock.

 The Kohala district was reported to have been severely shaken.

 Hilo, Oct. 5--After several days of quiet, volcanic tremors were shaking the island of Hawaii again today.

 From Waimea, Honokaa and Puuwaawaa came reports that earthquake shocks were almost continuous during the night, giving rise to renewed reports that eruptions were imminent in one of the three volcanoes.

 The Puueo district of Hilo experienced a steady procession of temblors, some of them exceptionally heavy, up until three a.m., and residents of Waiakea reported two severe shocks during the night.

 The same two shocks were felt in the city of Hilo.

 Waimea apparently bore the brunt of the night's volley of tremors, the quakes there being the heaviest felt in the district since the earth disturbances began three weeks ago. Quakes at Honokaa were almost continuous, but lighter than those felt in Waimea.

 The Kona district, dominated by Hualalai, where Dr. Thomas A. Jaggar predicts an eruption, was thrown out of its temporary serenity by the new shakes.

 Puna apparently escaped the tremors, for a report from Mountain View said there was no unusual occurrence during the night.



Anonymous, 1929, Quake does little damage: Honolulu Advertiser, 10/07, p. 1, 2. 



 [subheads: Big Island gets heaviest shock in twenty years; local temblor harmless; Hawaii volcanoes remain inactive; Oahu quake caused excitement but no damage; tremor felt in Molokai, not in Midway]

 Saturday night's earthquake was generally felt all over Hawaii, in all sections of Oahu and at Kunakakai, Molokai.

 It caused much minor damage in Hawaii, none in Oahu or on Molokai.

 Kauai and Maui sent no reports of any temblors. The cable company reported that Midway Island reported "all serene."

 Yesterday passed without any further tremors [on Oahu].

 A careful, island-wide check of earthquake results indicated that while all sections of Oahu felt Saturday night's quake, and residents were greatly disturbed by it, little damage of any kind was caused by it.

 The city water department reported one waterpipe broken [on Kailua street, between Fort and Nuuanu].

 Rattling dishes were reported literally from every section of the city. Houses rocked and windows clattered in their frames, but beyond this no damage was reported.

 Many people, residents in the Punchbowl, Pacific Heights and Makiki Heights regions felt the shock very forcibly and some went into their gardens to wait for the tremor to subside.

 It is reported that some cows in the Kapahulu district appeared to be frightened by the strange motion of their stalls and made plaintive noises. Dogs are alleged to have barked out of turn.

 . . . .

 People who happened to be at the beach assert that the sea did a strange sort of "shimmy" motion and shot some extra-high waves a few moments after the shock.

 [A fissure in the ground appeared before the quake, evidently exposed by heavy rain and unconnected with the quake]

 The article continues with additional anecdotal description of reactions to the quake.



Anonymous, 1929, Hawaii quiet again after shock; No tremors reported from any part of Big Island: Honolulu Advertiser, 10/08, p. 1. 



 Hilo, Oct. 7--In vivid contrast with yesterday's aftermath of excitement following the big shake-up of Saturday night, today has been a practically normal day on Hawaii, with few earth tremors. The people of Hilo and all of the rest of the island have returned to their usual calm.

 Belated reports from interior points say that a large number of road cracks have appeared between Waimea and Holualoa. Repair gangs will be started to work at once to cover them.

 From West Hawaii come reports that a few old houses had been shaken down, but no one was injured. Dishes appear to have been the main casualties. Several old walls and water tanks were also broken as a result of Saturday night's powerful temblor.



Anonymous, 1929, Saturday quake is called worst in thirty years: Maui News, 10/09, p. 1. 



 Buildings in all parts of Maui swayed and rocked and squeaked and groaned Saturday evening, under the strain put on them by an earthquake which it is generally agreed was the severest felt on this island in many years. By comparison, the one felt on September 25, was little more than a "tremor." so far as reported there was no serious damage to property, however, and no injury to persons. . . .

 It was at 9:22 that the temblor gave Maui its shaking and the estimates as to how long it lasted varies from 20 seconds to two minutes, a conservative one being from 20 to 30 seconds. It was strong enough and lasted long enough to send some folk scurrying out from their homes or the buildings where they chanced to be and for them to reach the street before the movement ceased.

 . . . .

 Some describe the motion as coming from South to North which is probably correct as it undoubtedly had its source in Kona, Hawaii, and say that it was a "swaying" motion. Others say the rocking was from East to West or West to East. The writer had just reached the top of the stairs at the third floor of the Wailuku Hotel and to him the sensation was as if the building were being twisted . . .

 The rest of the article repeats information on effects on Hawaii and Oahu



Anonymous, 1929, Kona district gets its daily temblor quota; slight earthquakes still felt in Holualoa; two jolts Sunday: Hilo Tribune-Herald, 11/18, p. 1. 



 Although all other districts of the Big Island are comparatively quiet daily, earthquakes are still felt in the Kona district, according to L.W. Aungst, of Holualoa.

 Most of the shocks are so feeble that they are hardly discernible but there is usually one strong one a day, Aungst told the Tribune Herald today.

 Yesterday afternoon there were two sharp quakes, one occurring at 2:18 p.m. and one at 4:02 p.m.. Slight ones continued during the night, and there was a heavier one at 9:23 a.m. today. All were felt, slightly stronger in the Huehue and Puu Waawaa districts which have been the center of the disturbances for the past two months.



Anonymous, 1929, Kona district gets its daily temblor quota; slight earthquakes still felt in Holualoa; two jolts Sunday: Hilo Tribune-Herald, 11/18, p. 1. 



 Although all other districts of the Big Island are comparatively quiet daily, earthquakes are still felt in the Kona district, according to L.W. Aungst, of Holualoa.

 Most of the shocks are so feeble that they are hardly discernible but there is usually one strong one a day, Aungst told the Tribune Herald today.

 Yesterday afternoon there were two sharp quakes, one occurring at 2:18 p.m. and one at 4:02 p.m.. Slight ones continued during the night, and there was a heavier one at 9:23 a.m. today. All were felt, slightly stronger in the Huehue and Puu Waawaa districts which have been the center of the disturbances for the past two months.



Anonymous, 1929, Earthquake is felt here last night at 8:29; Jolt apparently has base near Kilauea, volcano experts say: Hilo Tribune-Herald, 11/21, p. ? 



 A sharp earthquake jarred Hilo at 8:29 p.m. Wednesday, the first shock felt locally in several weeks. . . This shock differed from those of preceding weeks in that it was apparently a local shock. It was not felt in the Kona district . . . .

 . . . the quake was reported as feeble, with origin estimated at 12 miles from the observatory.

 This . . . would indicate that the shock originated in the vicinity of Kilauea, or possible on the northeast ridge of Mauna Loa.



Anonymous, 1929, Earthquakes: Hawaiian Annual for 1930, Sept. 27, p. 128. 



 A brief mention of the earthquake swarm in September and October, 1929, associated with Hualalai. Especially strong earthquakes were reported on September 23 and on October 15.

 

Anonymous, 1929, Seismological notes: Bulletin of the Seismological Society of America, v. 19, no. 4, p. 235-237. 



 Hawaii, October 5, 1929.--Climaxing two weeks of almost constant earthquakes on the island of Hawaii, an earthquake occurred on October 5th which was said to be the most violent shock there in twenty-five years. Dishes were broken in Hilo. Press reports state that furniture was toppled over, water tanks were burst, a stone wall was flung over, and foundations of houses were displaced in Holualoa.

 The town of Puu Waawaa was hit hardest by the shocks. The total damage in the Kona district, on the west side of the island, was estimated at $500,000. The seismograph at the Kilauea Volcano Observatory recorded thirty-five tremors in five hours. Officials at the station reported 244 shocks as being recorded on the seismograph in the week ending October 5th, the instrument being dismantled eleven times by shocks.

 Press reports state that the shock "rocked the entire island for twenty-three seconds."



Hawaii, October 10, 1929.--Earthquake conditions over the island of Hawaii were quieter by October 10th, although one shock was felt all over the island on that date at 6:30 a.m.



Island of Hawaii, October 21, 1929.--Thirty-six earthquakes were felt on the island of Hawaii on October 21st, within one hour and forty-five minutes. The town of Holualoa, eight miles from the extinct volcano, Hualalai, was severely shaken. The shocks were the first heavy ones felt on the island for nearly three weeks.



Anonymous, 1929, Seismological notes: Bulletin of the Seismological Society of America, v. 19, no. 1, p. 57-58. 



 Hilo, Territory of Hawaii, February 5, 1929.--A sharp earthquake was felt at 2:25 p.m. on February 5th on the island of Hawaii. It lasted one minute in the district of Kohala, Kona, and Hilo, but no damage was reported.



Anonymous, 1929, Seismological notes: Bulletin of the Seismological Society of America, v. 19, no. 2, p. 107. 



 Hilo, Island of Hawaii, T.H., June 18, 1929.--Three earthquakes shook Hilo between 8:43 and 9:32 a.m. on June 18th. No damage was done.



Anonymous, 1929, Seismological notes: Bulletin of the Seismological Society of America, v. 19, no. 3, p. 184-185. 



 Volcano Hualalai, Hawaii, September 19, 1929.--Earthquakes rocked the volcano Hualalai throughout the night of September 19th, and caused ranchers in the vicinity to move their cattle and household goods because they feared that, should the shocks continue, the volcano would erupt.



Hilo, Hawaii, September 22, 1929.Fifty-eight earthquake shocks were felt within three hoursnine o'clock to noonnear the volcano Hualalai on September 22d. The shock of strongest intensity felt in Hilo on September 22d occurred at about 2:00 a.m.



Hilo, Hawaii, September 24,1929.More earth shocks were felt in Hilo, near the volcano Hualalai on September 24th. Tropical fruits and nuts were shaken from the trees and houses rocked. Several shocks were felt during the day, one just after noon, lasting twenty-five seconds.



Hilo, Hawaii, September 28,1929.An earthquake rocked the entire city of Hilo, at 7:10 a.m. on September 28th. One of the main streets was badly damaged in two places. The Catholic Church was moved on its foundations, and marred by many cracks. The district of Puu Ooo [sic.], about fifteen miles east of Hilo, appears to be where the shocks are concentrated, and residents were attempting to get away from this place. The Volcano Observatory at Kilauea reported fifty earthquakes in twenty-four hours.



Hawaii, September 29, 1929.Earthquakes continued to rock the island of Hawaii on September 29th, though with less intensity and at longer intervals than those felt within the past week. At 5:00 a.m. the populace was awakened by a series of shocks lasting half an hour, which were reported strong all over the island. The Volcano Observatory reported twenty-five tremors between noon on September 28th and 8 a.m. on September 29th, one of which dismantled part of the instruments.



Hawaii, September 30,1929.Seismic activity in Hawaii shifted to the western slope of the island on September 30th, where 480 earthquakes were reported to have occurred in twenty-four hours. At Holualoa the heaviest earthquake since the activity began on September 19th was felt. The shocks, starting just before noon, lasted an hour and a half.



Anonymous, 1929, New quake warning issued: Honolulu Daily Advertiser, 09/27, p. 1. 



 Several news items cover the earthquake swarm on Hualalai and T.A. Jaggar's forecast for a larger earthquake and possible eruption and tsunami similar to the events of 1868. As of September 24, 246 earthquakes had been felt in the Kona district.



Anonymous, 1930, Earthquake is felt in Kona today as cleanup is started: Hilo Tribune Herald, 01/28, p. 1. 



 [subheads: West Hawaii citizens are working busily to bring order to region; girl is recovering; damage to district still unestimated; will reach many thousands]

 An earthquake of some intensity shook Kona about 10:10 a.m. Mrs. Luther Aungst told the Hilo Tribune-Herald today that the tremor was the most severe since the long series of quakes several months ago [the Hualalai series in Sept.-Oct. 1929]. No damage was done.

 A check with the Volcano Observatory shows that the Kona quake had an amplitude of about three quarters of an inch on the seismograph drum [assume Kona seismograph].

 The rest of the article deals with the aftermath of flooding during a heavy storm.



Anonymous, 1930, Temblor is recorded at observatory; shock similar to quakes last fall felt strongly in kona district: Hilo Tribune Herald, 05/21, p. 1. 



 With an earthquake shock occurring at 6:52 p.m. yesterday, two shocks of the characteristics of those which rocked the Big Island last fall, centering on the Hualalai district, have been recorded on the volcano observatory seismograph during a 24 hour period. The first occurred at 2:47 a.m. Tuesday.

 Both shocks were practically of the same character, and correspond to a distance on the far side of Kona in the Hualalai district," Dr. Thomas A. Jaggar, volcanologist, told the Tribune-Herald today. "They had the same general character of the shocks last fall."

 According to Jaggar there is nothing on the seismograph to indicate a rising of lava, and all is quiet at the pit.

 "All we know at present," he said, "is that there have been two quakes which give evidences of distances around 60 or 70 miles, and which have all the characteristics of those which occurred last fall."

 Both shocks were strongly felt in the Hualalai region, at Puu Waawaa and Holualoa, according to Dr. Jaggar. They were noticed in Hilo, particularly in Puueo as was the case last fall. 

 Very few quakes have been recorded on the seismograph during the past few months, according to Dr. Jaggar. Those that have appeared to give evidence originating to the south in the Kau district and were entirely different from those of yesterday.



Anonymous, 1930, Severe temblor rocks east side of Big Island: Hilo Tribune Herald, 05/26?, p. 1. 



 A sharp earthquake rocked the Big Island at 8:15 last night. The shock was felt in all districts, but apparently was stronger on the eastern side of the island from Hamakua to Kau.

 According to Dr. Thomas A. Jaggar, volcanologist, the shock was entirely local, and as recorded on the seismograph appeared to originate directly beneath the eastern side of the island.

 "The vertical component was strong which is an indication of a local shock," Dr. Jaggar told the Tribune-Herald today. He added that these local shocks have occurred repeatedly when there was no eruption, but that they also came just before an eruption. All is quiet at the pit with no indication of pending eruption.

 Reports from the Kona district, which was the center of the quakes last fall, indicate that the shock was not so severe there as in Hilo. According to Dr. Jaggar, the shock last night was entirely different from those of last week which were of the Hualalai character.



Anonymous, 1930, Earthquake felt in west Hawaii; Puueo and Hilo; shock throws pen off drum of volcano observatory seismograph: Hilo Tribune Herald, 07/22, p. 1. 



 What is thought to have been a Hualalai earthquake shock, shook the Kohala, Kona, Hilo, and volcano districts at 1:35 p.m. today. While mild in character at Hilo and at 29 miles, volcano, the shake was more severe at Puu Waawaa and in Kohala. At Kohala objects were shaken off shelves.

 Luther Aungst, at Holualoa, declared that the quake was the most severe felt in that district this year, in fact, since October of last year when the prolonged series of quakes shook the west side of the island. The Kealakekua seismograph recorded the shock distinctly.

 W. Leslie West at Hawi reported the Kohala district shaken generally, with the quake of sufficient strength to knock objects from shelves. No damage was done.

 At Puuwaawaa the tremor was of considerable violence.

 A report from the volcano observatory says that the east-west pen was thrown from the drum. However, no data on the quake can be obtained until the drum is removed from the instrument this evening. The shock was not felt at the Volcano House. However, it was felt at 29 miles, volcano, in Puueo and in Hilo proper, but recorded slightly in these localities.

 In Kohala the quake was said to have lasted from 20 to 30 seconds. It lasted from 10 to 11 in Holualoa.



Anonymous, 1930, Quake twists Big Island t 8:25 A.M. today; no damage reported after stiff jolt; volcano observatory says tremor had center in pit of Halemaumau: Hilo Tribune Herald, 10/20, p. 1, 3. 



 Striking Hilo with a stiff but relatively harmless jar at 8:25 a.m. today, and earthquake, reported by the Volcano observatory as centering on Halemaumau, was felt all the way around the island, . . . accompanied by avalanching at the fire pit.

 Several bottles were shaken from the shelf in the Standard Drug Company. The Hilo Memorial Hospital reported a disturbing shock in which some medicine containers toppled. A porch table fell in Puueo.

 . . . .

 The Hilo Tribune Herald building shook with some insistence. Typewriters danced the hula on editorial department desks. Solidly built, as the new County building is, it felt the shock heavily. . . .

 [in one building a previously broken large plate glass window was further damaged by the quake].

 In County Auditor Brown's office, also on the street floor of the County building, the ceiling was cracked in several places by the quake, and plaster was shaken from the walls.

 On the second floor of the County building, however, the shock was sufficient to rock steel cabinets.

 [The shock was felt in Honokaa and quite distinctly in Kohala.] Mrs. Luther Aungst, of Holualoa, reported a shock of several seconds duration in Kona, [beginning like a passing truck and developing into a considerable tremble.]

 Puuwaawaa, too, sustained a good jar. At the Hind ranch fixtures were reported swinging as the quake's result.

 In Kau, H.L. Wilhelm [reported] a cloud of dust rising from the cliffs behind Keauhou at the time the quake was reported elsewhere, evidently a landslide.

 The quake was very severe in Waiohinu. . . There was no damage to amount to anything, but articles fell from the shelves of many of the stores.



Anonymous, 1930, Seismological notes: Bulletin of the Seismological Society of America, v. 20, no. 2, p. 101. 



 Hilo, Hawaii, May 20, 1930.--A strong earth shock was felt on the island of Hawaii at 6:52 p.m. on May 20th. It was the second shock within twenty-four hours.



Anonymous, 1931, Tremor felt in all parts of Big Island; Jaggar declares quake had center near Halemaumau; no activity: Hilo Tribune Herald, 01/30, p. 1. 



 The entire island was rocked by an earthquake at 11:35 o'clock last night which, although not severe, was prolonged, lasting approximately 30 seconds.

 No damage was reported in any district.

 Dr. Thomas A. Jaggar, volcanologist, said today that the quake appears to have originated in the vicinity of Halemaumau, apparently closer than the sharp shock felt on the evening of January 16. The pit is quiet, with no indications of immediate activity.

 Luther S. Aungst, of Holualoa, Kona, reported by telephone that the shock was felt throughout Kona, Kohala, Hamakua, and Puna residents also report that the earthquake was experienced in these sections of the island.



Anonymous, 1931, 3 earthquakes felt on island late Thursday; tremors follow within 24 hours of Dr. Jaggar's "Preparedness" talk: Hilo Tribune Herald, 06/12, p. 1. 



 . . . three earthquakes visited the Big Island yesterday.

 The quakes yesterday did no damage, according to a check made by the Tribune-Herald. However, one of them, occurring at 6:62 p.m., was felt generally on the island, reaching on into Kona. Reports from Holualoa indicate that the tremor there was pronounced.

 Persons in the Puueo district in Hilo noticed a definite shake.

 Of the other two earthquakes, one occurred early in the afternoon and the other after 9 p.m. While both show on the seismograph at the Volcano observatory, neither created comment in this city.

 Dr. Howard Powers of the observatory declared that the strongest quake centered on the sides of Mauna Loa, 27 miles from the seismograph.



Anonymous, 1931, Sharp quake rocks Hilo and N. Kona; Dr. T.A. Jaggar declares tremor is deep movement in Mauna Loa: Hilo Tribune Herald, 08/31, p. 1. 



 Hilo and North kona were rocked by a sharp earthquake at 6:54 a.m. Sunday [Aug. 30], which shock was classified today by Dr. Thomas A. Jaggar, volcanologist, as a Mauna Loa earthquake.

 Dr. Jaggar reports that the shock was very light in the volcano district and Olaa, being hardly perceptible at his home.

 "We estimate the origin as about 15 miles distant from the observatory. The evidence of the distance and the way it was felt in Hilo and North Kona indicate it originated on the north side of Mauna Loa," Dr. Jaggar said. "Indications are that the quake was a rather deep movement under the island [Distance inconsistent with description of location.]

 The pens of the seismograph at the observatory were thrown off at about the first movement of the quake.

 An avalanche occurred at Halemaumau at the time of the earthquake, Dr. Jaggar reports.



Anonymous, 1931, New fountains play at Kilauea; floor of pit nearly covered: Honolulu Star-Bulletin, 12/26, p. 1. 



 [subheads: Night display of fire draws large crowds; Cars flock to Halemaumau with spectators staying all night at crater; Strength of eruption is undiminished as lava outpouring continues]

 Most of the article concerns renewal of eruption in Halemaumau, starting Dec. 23, 1931.

 . . . .

 Thirty-four seismic disturbances were registered at the observatory, of which 28 were tremors, and six were very feeble earthquakes, of which four indicated origin distances of four, nine, 14 and 18 miles.

 The last, at 10 minutes past midnight the morning of December 16, was felt at Kapapala ranch. Its duration was approximately 15 seconds and its estimated origin distance agrees with the ranch distance within a mile.



Anonymous, 1931, Lava streams pour from big southwest jet: Hilo Tribune Herald, 12/31, p. 1. 



 [subheads: Activity continues at firepit without letup Today; Madame Pele puts on a brilliant show for visitors Wednesday]

 The article describes the eruption in Halemaumau, including the following:

 "An earthquake was felt in Hilo and in the volcano vicinity about 11:00 o'clock last evening. The quake was recorded on the volcano observatory seismograph as being about 14 miles from the observatory, or on the flank of Mauna Loa.

 "The earthquake of a week ago that preceded the eruption was close to the surface as it was felt only in the immediate vicinity of the volcano. Last night's shock however was more deep seated, being felt at a greater distance from the volcano."



Anonymous, 1931, Seismological notes: Bulletin of the Seismological Society of America, v. 21, no. 3, p. 233. 



 Hilo, Hawaii, June 11, 1931.--A severe earthquake was felt in Hilo at 5:53 p.m. on June 11th, but no damage was reported.



Anonymous, 1932, Earth tremor shakes island; severe earthquake recorded at 4:55 a.m. today: Hilo Tribune Herald, 06/14, p. 1. 



 A severe earthquake was felt here at 4:55 a.m. today.

 The quake dismantled both components of the Bosch seismograph at the volcano observatory and jammed the pen of the verticle [sic] instrument which appears to indicate that the motion at the observatory was a strong verticle [sic] one.

 Records from the observatory show that the distance from the observatory was about 9 miles.

 The quake was felt by practically everyone in Hilo and the volcano, but the quake was not felt on the Kona side of the island.

 No damage has been reported as a cause of the quake.



Anonymous, 1932, Quake lasts full minute; Hilo shaken during temblor Thursday at 10:29 p.m.: Hilo Tribune Herald, 07/08, p. 1. 



 Hilo was shaken Thursday night by an earthquake which lasted a full minute at 10:29 p.m.

 According to the Volcano observatory, the quake was severely felt at the volcano. Observatory instruments showed that the point of origin was about 15 miles from the observatory in the direction of Hilo.

 No definite explanation for the temblor could be made by volcano authorities. They stated that the quake was about the same intensity of that of three weeks ago and that it was probably caused by a crack in the earth's crust.

 No damage has been reported as the result of the quake.



Anonymous, 1932, Much steam at volcano calls forth predictions: Hilo Tribune Herald, 12/05, p. 3. 



 . . . .

 . . . There have been the usual number of earthquakes with only one of any intensity. That one occurred Saturday [Dec. 3] at 1:30 p.m. but was not strong enough to be felt in the volcano district. There have been a few landslides [at Halemaumau], but none of any consequence.



Anonymous, 1932, Slight quakes felt over Hilo; Two small temblors shake city Tuesday afternoon, evening; no pit changes: Hilo Tribune Herald, 12/28, p. 3. 



 Two small earthquakes felt in Hilo, one at 1:23 p.m. and the other at 8:54 p.m. Tuesday may or may not signify a movement of lava beneath the firepit of Halemaumau . . . .

 The tremor at 8:54 p.m. was less than half as strong as the one at 1:23 p.m. Few people felt either.

 The distance of the shakes was between 5 and 6 miles from the observatory. Mr. Jones declared they were about as far from Halemaumau as they were from the observatory, signifying that the quakes originated deep under the earth.

 After the tremor Tuesday afternoon, cracks at Halemaumau were measured and other observations were made, but no change was discovered.



Anonymous, 1932, Puna has series of earthquakes; Kamainas prophesy that Madam Pele will return to firepit soon: Hilo Tribune Herald, 12/29, p. 3. 



 The Puna district has been visited by a series of earthquakes during the past few days, according to Koji Iwasaki of Kamaili. While none of the shocks has been severe, the quakes have been quite frequent, he reports.

 Several shocks have been felt in Hilo recently, but none have been of any moment. . . . kamaainas to prophesy that Madame Pele will soon return to her home in Halemaumau. . . The frequent earthquakes, they say, is another warning of her return.



Anonymous, 1933, Kilauea report; week ending Jan. 1: Hilo Tribune Herald, 01/06, p. 6. 



 . . . .

 A feeble earthquake was felt at 1:21 p.m. Dec. 27. At the observatory the motion appeared to be largely vertical while at Glenwood 9 miles away trees were seen to be bent and swayed. It was also reported from Hilo and Pahoa. The earthquake occurred about 4 statute miles from the observatory. Investigation of the rim of the pit showed that no cracks had opened that day.



Anonymous, 1933, Earthquake is felt on Big Island: Hilo Tribune Herald, 06/23, p. 1. 



 Hilo was rocked by a slight earthquake which occurred about 8:32 p.m. Thursday [June 22]. The quake was felt more sharply in some sections of Hilo than in others.

 At the volcano observatory it was reported that the quake originated about 50 mile from the observatory. Although not felt in the volcano district it was recorded on the seismograph which also recorded several other shocks during the night.



Anonymous, 1933, Earthquake is felt in Hilo Tuesday night: Hilo Tribune Herald, 09/27, p. 1. 



 A slight earthquake, felt in some parts of Hilo, was recorded at Kilauea observatory at 9:15 p.m. Tuesday [Sept. 26].

 According to A.E. Jones of the observatory staff, the quake originated about 18 to 20 miles from the observatory.

 The shock was felt on Reed's Island, in Puueo, and was recorded at the Brothers' School.

 The rest of the article mentions the weekly summary of seismicity provided by HVO.



Anonymous, 1933, Quake reminds Hilo that Kilauea is due to erupt: Hilo Tribune Herald, 10/19, p. 1. 



 A sharp temblor which rocked Hilo at 5:55 this morning awoke citizens to a realization that Professor Zander's widely predicted volcano eruption is about due.

 The earthquake caused no damage but a check-up of the calendar shows that the sixty-day period during which Professor Zander prophesied Kilauea would erupt comes to a close Friday at Midnight.

 The article continues in this vein. [No eruption came.]



Anonymous, 1933, Eruption believed imminent: Hilo Tribune Herald, 10/21, p. 1. 



 [subheads: Explosions heard after earthquake; Volcano district aroused as mysterious blasts are heard; Two severe shocks occur at 9:10 A.M. today, felt all over island]

 a series of local earthquakes, the two most severe occurring at 9:10 a.m. today, in conjunction with two mysterious explosions heard throughout the Volcano district, led national park officials to believe that volcanic activity is imminent, despite the fact that officials of the volcano observatory refuse to make any predictions.

 . . . .

 A number of local earthquake shocks have been felt during the past few days and on Friday morning, following a heavier earthquake, two muffled explosions were heard in the vicinity of the Chain-of-Craters road.

 [A visit to the site was inconclusive. Inquiries regarding blasting in or near the park eliminated that as a possible source of the noise].

 At 9:10 a.m. today a severe shock was felt throughout the island, followed after a few seconds interval by a second shock, equally as severe, The shocks were felt throughout Hilo and were strongly felt in the business and residential districts. The shocks were particularly severe at Kapapala, Kau, where Mrs. Bradford Sumner recounted that they were the most severe of any since the Hoopuloa flow [1926].

 Officials at Dr. Jaggar's office reported the origin of the shocks as approximately seven miles southeast [southwest?] of the observatory.

 A cloud of dust swept the west wall of the large crater and another flew over the pit following the shocks.

 The developments today bring to mind again the prediction of Prof. Zander, who said there would be volcanic activity within 60 days, which period ended at midnight last night.



Anonymous, 1933, Eruption of Mauna Loa, Kilauea, or both, now expected at any time: Hilo Tribune Herald, 10/23, p. 1, 3. 



 An article discussing the possibility of forthcoming eruption.

 "Saturday's seismic disturbances which caused much excitement throughout the Big Island were Mauna Loa quakes, according to Mr. Wingate. Two sharp quakes felt about 9:10 a.m. Saturday [Oct. 21] were followed by a 12-hour period of tremors of diminishing intensity. On Sunday and Monday everything was fairly quiet."



Anonymous, 1933, Recent quakes identical with those in 1926: Hilo Tribune Herald, 10/25, p. 1. 



 [subheads: Dr. Jaggar makes this statement after further study of Saturday's quakes; Soldiers from Kilauea Military Camp to climb Mauna Loa late this week]

 Further study of the record of last Saturday's earthquake has resulted in the announcement from the office of Dr. Thomas A. Jaggar, Jr., volcanologist in charge of the volcano observatory, that those quakes were practically identical in motive and location with the quakes that immediately preceded the Hoopuloa flow of 1926.

 "Keep your eyes on Mauna Loa," advised E.G. Wingate, assistant to Dr. Jaggar, and cast a casual eye now and then in the direction of the Puna rift. Another thing which is believed to have an influence in causing the scientist to expect an early eruption is a feeling of tenseness and expectancy on the part of natives of the islands. This feeling in the past has been remarkably active in preceding eruptions on a number of occasions. The volcanologist of course will not give this as a reason for anticipating an early eruption by [sic] others not bound by science confess that their hunches are strengthened by it. A number of reports received at the volcano observatory from Kona and other locations on the slopes of Mauna Loa will have to substitute statements by the natives that an early eruption is due.

 . . . .



Anonymous, 1933, Mokuaweoweo pit erupts: Hilo Tribune Herald, 12/02, p. 1, 3. 



 [Reports indicate lava is pouring out Kona side; 3 vents erupting; Tremors precede violent activity atop of Mauna Loa at 6:00 A.M. today; three vents send huge smoke clouds 5000 to 6000 feet into the sky; Professor Jaggar and party leave for summit to make scientific observations; telephone reports from McCandless Ranch indicate lava has overflowed] 

Simultaneously with three severe earthquakes Mauna Loa, ancient Hawaiian volcanic mountain, erupted at 6 a.m. today at three separate vents in the summit crater of Mokuaweoweo, pouring out huge clouds of white smoke easily visible from Hilo and other sections of the Big Island.

 . . . .

 First information on the eruption was received by phone from the Mauna Loa rest house from a party of soldiers . . . on their way back to the military camp from the summit.

 The men reported that they were awakened shortly before 6 by three quakes of such severity that they were almost thrown from their beds.

 According to Dr. Jaggar the earthquake at 6 a.m. today occurred after a day of unusual quiet for the seismograph. Immediately following the quake the harmonic tremor, which is recorded whenever there is volcanic activity on the Big Island, commenced, indicating that the eruption occurred simultaneously.



Anonymous, 1933, Four quakes rock Hilo in early hours: Hilo Tribune Herald, 12/27, p. 1, 3. 



 A series of four earthquakes rocked Hilo between 3 and 6 a.m. today, with the sharpest shock occurring at 3:45 a.m.

 Reports from the volcano observatory indicate that the shocks were closer to Hilo than to the volcano area, although the point of origin had not been definitely determined.

 No damage was reported from the quakes.



Anonymous, 1934, Temblor hits Hilo but no damage done; earthquake last night said to have originated ten miles from Kilauea: Hilo Tribune Herald, 03/02, p. 1. 



 An earthquake, the strongest felt in Hilo in many months, rocked a section of the Big Island at 10:25 p.m. last night. No damage was reported from any districts.

 According to reports from the volcano observatory the quake apparently originated about 10 miles away from the observatory, and occurred during a period of exceptional quiet as far as earthquakes are concerned. No change occurred at Halemaumau and there is no indication of any approaching volcanic activity, the observatory reports.

 Telephone reports from various sections of the island indicate that the quake was most strongly felt in the vicinity of Hilo than in any other sections.

 It was felt in the naval camp [KMC] and other sections of the volcano district, and was reported as slight at Puuwaawaa and Kapoho. 

 In Kohala, the Hamakua district and Kau, the shock apparently was not felt.



Anonymous, 1934, Quake gives island good shake today; paint falls from walls of County building; Kilauea is being watched; Instruments at observatory dismantled by heavy earth temblor: Hilo Tribune Herald, 05/10, p. 1. 



 Three new quakes were felt at Kapapala today . . . subsequent to the major tremor at 10:09. . .

 The heaviest of the three occurred at 12:35 and was quite noticeable. Halemaumau pit, after inspection by officials, was reported quiet and later indications were that the quakes were associated with eastern Mauna Loa rather than Kilauea.

 A strong, slow earthquake, felt severely in Hilo, causing people to run from buildings and homes into the streets, rocked the east side of the Big island at 10:09 today.

 In the opinion of Thomas A. Jaggar, volcanologist, the shock apparently has some relation to Kilauea due to the fact that it was only slightly felt in the kona district, and was felt much less severely at Kapapala Ranch than in Hilo and the immediate volcano district.

 . . . 

 In Hilo the shock was severe enough to cause some alarm, and at the County building the white ceiling paint cracked in several places, showering the offices. At the Hilo armory three small cracks appeared.

 The shock was recorded on the seismograph at St. Mary's school in Hilo where the instruments were all dismantled. Brother Lawrence reported the shock as lasting for approximately two minutes. At 10:41 a.m. another minor shock was recorded on the local seismograph.

 Telephone messages from Puuwaawaa ranch indicated that while the shock was felt there it was not severe. L.S. Aungst at Holualoa reported that the shock was hardly perceptible there.



Anonymous, 1934, Quake felt on Maui: Honolulu Star-Bulletin?, 05/11 or 12?, p. ? 



 Wailuku, Maui, May 11.--A slight earthquake, barely perceptible but lasting about six seconds, was felt in 

Wailuku at 10:10 a.m. Thursday . . .

 . . . a filing cabinet rattled during the duration of the quake, but no damage was done.



Anonymous, 1934, Earthquakes are felt in Hilo Sunday: Hilo Tribune Herald, 05/14, p. 1. 



 [subheads: shock less severe than big tremor Thursday but are generally felt; No signs of activity seen as sharp lookout kept at Kilauea and Mauna Loa]

 Hilo was rocked by two earthquake shocks Sunday afternoon [May 13], the first at 3:23 p.m. followed three minutes later by a second and more feeble shock. While generally felt neither tremor was as severe as the one which caused some alarm Thursday morning.

 Reports from the volcano observatory indicate that the tremors were probably more severe in that vicinity than they were right in Hilo.

 . . . .

 North Kohala, May 14--Minor damages were reported by householders as the result of a heavy tremblor [sic] felt here at 10:10 a.m. Thursday. The tremor lasted 26 seconds, starting as a light movement and ending with a sharp shock. The quake was even felt by agricultural workers in the fields. . . .



Anonymous, 1934, Damages by quake: Honolulu Star-Bulletin?, 05/14 or 15?, p. ? 



 North Kohala, Hawaii, May 14.--Minor damages were reported by householders as a result of a heavy tremblor felt here at 10:10 a.m. Thursday [May 10]. The tremor lasted 26 seconds, starting as a light movement and ending with a sharp shock. The quake was felt even by agricultural laborers working in the fields.



Anonymous, 1934, Temblor rocks Hilo at night; Record study being made to determine direction of quake's origin: Hilo Tribune Herald, 06/16?, p. 1. 



 An earthquake, estimated to have originated about 18 miles from the observatory at Kilauea, rocked Hilo last night at 10:45.

 Reports indicate that the shock was more severely felt in Hilo than in the volcano area.

 A study of the records was being made today to determine the direction of the quake's origin.



Anonymous, 1934, Temblor gives island shaking: Hilo Tribune Herald, 06/27, p. 1. 



 An earthquake shock, strongly felt in some sections of Hilo, was recorded on the seismograph at Kilauea Observatory at 7:12 p.m. Tuesday [June 26]. The shock was not hard enough to cause any damage, however, although it was generally felt.

 According to A.E. Jones, seismologist at the observatory, it is estimated that the quake originated about 15 miles from the observatory, and possible [sic] on the south east rift of Mauna Loa.



Anonymous, 1934, Early morning temblor rocks sleepers here; Jones estimates origin of quake about 20 miles from observatory: Hilo Tribune Herald, 08/16, p. 1. 



 An earthquake recorded on the volcano seismograph shortly after 2 a.m. today was strong enough to awaken sleepers in some sections of Hilo. the shock was reported felt by a number of residents in the Puueo district.

 . . . It was strong enough to dismantle instruments and was felt by only a few people in the volcano district.

 This was the first shock to be felt to be recorded for several weeks, according to Mr. Jones who said that there has been a period of unusual quiet in earth movements.



Anonymous, 1934, Entire island is rocked by long temblor; Observatory officials say origin of quake centers in direction of Hualalai: Hilo Tribune Herald, 10/15, p. 1. 



 The entire island was rocked by an earthquake Saturday [Oct. 13] at 7:14 p.m. which lasted for fully half a minute but did no damage. Officials at the observatory estimate that the origin of the shock was 25 miles from the observatory in the direction of Hualalai mountain.

 The shock was more of a gentle swaying motion rather than a sudden sharp shake which characterizes the majority of the quakes felt here. The movement was in two waves with an interval of quiet separating the two motions, and was said by kamaainas to be one of the longest earthquakes ever felt here.

 The quake was felt throughout the Kona district, even down at the beach where they are seldom noticed. No damage of any kind was reported in that section, however, according to Mrs. L.S. Aungst, who said that the shock was the strongest felt there in a long time.

 The quake was also strongly felt in Waimea and in Honokaa, and along the Hamakua coast.



Anonymous, 1934, Island rocked by earthquake at early hour: Hilo Tribune Herald, 10/19, p. 1. 



 An earthquake of moderate intensity, rocked the Big island at 12:21 a.m. today. The shock was hard enough in Hilo to awaken sleepers, but did no damage. 

 E. A. [sic] Jones, seismologist, reported that the quake apparently had originated about 45 miles from the observatory. It was of about the same intensity, although not as long, as the one last Saturday evening [Oct. 13], which was felt throughout the island, and was estimated to have originated in the Hualalai vicinity.

 Three sharp quakes were felt around Waimea at the same time they were felt in Hilo. The three sharp temblors were followed by several of slighter intensity.



Anonymous, 1934, Seismological notes: Bulletin of the Seismological Society of America, v. 24, no. 3, p. 330. 



 Hilo, Hawaii, May 10, 1934.--The entire eastern part of the island of Hawaii was shaken by an earthquake at 10:09 a.m. on May 10th. No damage was done.



Anonymous, 1934, Seismological notes: Bulletin of the Seismological Society of America, v. 24, no. 4, p. 426. 



 Kilauea, Hawaii, September 6, 1934.--An earthquake at 2 a.m. preceded the eruption of Kilauea Volcano on september 6th. No damage was reported.



Anonymous, 1934, Seismological notes: Bulletin of the Seismological Society of America, v. 24, no. 1, p. 73, 76. 



 Hawaiian Islands, October 21, 1933.--An earthquake was felt on the Hawaiian Islands 200 miles south of Honolulu on October 21st. No damage was caused.



Mauna Loa, Hawaii, December 2, 1933.--Sharp earthquakes accompanied the eruption of Mount Mauna Loa on December 2d.



Anonymous, 1935, Heavy quake rocks Hawaii: Hilo Tribune Herald, 01/02, p. 1. 



 [subheads: Shock center is five miles from Kilauea; Little damage reported from temblor but sleep is lost by hundreds; Shock is felt in every part of island; Dr. Jaggar is checking at pit]

 A strong earthquake, registering 2 or 3 in the intensity scale, rocked the entire island at 6:46 a.m. today, causing minor damage and shaking things generally. While there is nothing yet to indicate volcanic activity, a close watch is being kept at Kilauea volcano and also along Chain-of-Craters road in which vicinity the shock appeared to originate, according to estimates of volcanologists.

 A large land slide, caused by the earthquake, occurred on the Hilo side of Hakalau gulch blocking the roadway there. . . .

 At the local drug stores many bottles were knocked from shelves and broken while broken dishes and pictures were reported in some homes.

 Several kamaaina residents of Hilo claim that the shock was one of the most severe, if not the severest, they have ever felt on this island.

 The quake was felt in all sections of the Big Island but more particularly in the southern section and the vicinity of Kilauea. A.E, Jones, seismologist, said that the instruments at the observatory were dismantled by the shock, but it is estimated that the quake originated about 5 miles southeast of the observatory.

 . . .

 The shock was apparently in two separate waves, the first being a slight one, the second a heavy rocking motion. It was felt strongly in all sections of Hilo and even along the shore area where shocks are least felt of any place in Hilo.

 The shock was reported to be very strong in Kona where it was also felt in two distinct waves. In Kau it was reported that the shock was preceded by a deep rumbling sound, followed a few seconds later by the earthquake.

 The Puna district also felt the shock sharply, but in Waimea and Kohala it was reported that the shock was less severe, more particularly so in Kohala.



Anonymous, 1935, Quake rocks Waimea during the night: Hilo Tribune Herald, 01/21, p. 1. 



 [subheads: Dr. Jaggar reports number of tremblors being felt north of Mauna Kea; Volcanologist is surprised at strength of shock as reported from Waimea]

 A earthquake, recorded on the seismograph at the volcano observatory as very feeble, was strongly felt at Waimea, and at Waikii, the Hawaiian Telephone System station on the slope of Mauna Kea, shortly past midnight this morning.

 No reports of the quake being felt in Hilo or other sections of the island were received and Dr. Thomas A. Jaggar, volcanologist, said that the shock was centralized on the north side of Mauna Kea.

 He estimated the origin of the quake at about 37 miles distant from the observatory and reported that frequent have been felt recently on the north side of Mauna Kea.

 In Waimea residents reported that the shock was very sharp while at Waikii it was also reported to have been sharply felt. . . .



Anonymous, 1935, Slight earthquake shocks felt at Hilo: Honolulu Star-Bulletin, 06/12, p. 8. 



 Hilo, Hawaii, June 11--A small earthquake was felt in Hilo at 12:29 p.m. Monday [June 10]. It was reported that the temblor was more pronounced in the Halai Hill than at other points in Hilo.

 The shock was very small in the volcano district where the seismograph recorded a very weak shock at 12:29 p.m. According to Austin E. Jones of the volcano observatory, the earthquake was much stronger toward the Hilo section.



Anonymous, 1935, Hilo damaged in sharp quake: Hilo Tribune Herald, 06/28, p. 1, 5. 



 Two articles are included under one headline

 Whole island is rocked by sharp shock

Origin of shock believed to be under Puna rift, Hilo is worst hit of all areas

Slides occur at pit, sulphur fumes rise but no sure indication of eruption seen

 With the origin of the quake estimated at about 12 miles from the observatory in an area under the Puna rift, the Big Island was rocked on its foundations at a few seconds after 9 a.m. today. While the shock was generally felt throughout the island, it apparently was strongest in Hilo where considerable damage was suffered.

 While numerous slides occurred at the firepit simultaneously with the quake, and sulphur fumes were seen rising in the pit, there was nothing unusual at the crater, according to A.E. Jones, seismologist.

 Mr. Jones reported that the shock in the volcano district itself was not severe, being about moderate intensity. He said however that from reports from Hilo it was much more severely felt here. The seismographs at the observatory and the pit were both dismantled by the shock, Mr. Jones said.

 Mr. Jones declared that he could not say if the shock this morning portends an eruption or the appearance of lava in the firepit.

 While the Kona district yesterday morning experienced one of the worst quakes in the past six years, the entire district being rocked, the shock this morning was not nearly so hard, according to a report from Mrs. L.S. Aungst.

 She reported that yesterday's quake knocked down dishes in the homes, but otherwise did no damage. However all residents agreed that it was one of the heaviest shocks within the past six years, during the period of the Hualalai shocks.

 At Puuwaawaa yesterday's shock was reported as very hard, but today's was less strongly felt although it lasted for a longer period of time.

 In Kohala, Miss Cal Achilles, tribune Herald special correspondent, reported that the shock, although somewhat heavier than the usual tremors, was not hard enough to cause any damage.

 In Honokaa Joseph Pritchard declared that the shock was felt generally but was not considered especially hard.

 At Kapoho, in the Puna district the shock was reported to have been unusually hard. Residents ran from their homes and gathered in the streets, but no damage was reported.

 Mrs. J.B. Campbell of Kapoho said the shock was very hard at first and then lasted for a few seconds afterward as a slight rocking motion.



Anonymous, 1935, Big Island is rocked by quake: Hilo Tribune Herald, 10/01, p. 1. 



 [subheads: Close watch being kept at firepit; Seismograph records almost continuous tremor from 10:35 p.m. to 3 a.m.; Strongest shock occurs just before midnight, no damage reported on island; Tremors were continuing this morning, with a number of feeble shocks recorded on the seismograph at the volcano observatory. A larger one, recorded at 10:37 a.m. was strong enough to dismantle one of the instruments. It was felt in Hilo and the volcano district.]

 Hilo and the Big Island in general were rocked by a series of earthquakes, four of which were strongly felt, between 10:35 p.m. yesterday and 3 a.m. today, with the largest tremor occurring two minutes before midnight, and continuing for nearly 10 seconds. No damage was reported in any districts.

 . . . .

 According to Dr. Jaggar the tremors were almost continuous, as recorded on the seismograph, between 10:35 p.m. and 3 a.m. The two largest shocks occurred at 10:35 p.m. and just before midnight. All were of a long swaying motion rather than the sharp sudden shock which usually causes some damage.

 Dr. Jaggar estimates the distance of the shocks anywhere from 5 to 30 miles, and said that while he has not yet received sufficient data to definitely determine direction it would appear that the shocks originated on the east slope of Mauna Loa, due to the fact that they were less strongly felt at Puuwaawaa and in the Kohala district.

 The shock at midnight caused considerable falling of rocks in the pit. None of the tremors were sufficiently hard to dismantle the seismograph instruments.

 Hilo people generally felt the 10:35 and the midnight shocks, while a number reported feeling several smaller tremors and one about 1 a.m. which was fairly large. Four shocks were reported felt in the volcano district.

 From Kona Mrs. L.S. Aungst reported by telephone that the midnight shock was quite strong and appeared to be a series of tremors. Mrs. George Krause, correspondent for the Hilo Tribune Herald at Honokaa, reported that six distinct shocks were felt there and that all were of the long swaying type. The midnight shock was reported to be the strongest there.

 The shocks were also felt in the Kau district with the one at midnight being the hardest.



Anonymous, 1935, Quake series ends, origin to southeast; total of 30 shocks recorded during 12 hours, believe originated off Puna: Hilo Tribune Herald, 10/02, p. 1. 



 Earthquake activity ceased last night and all was reported quiet this morning following a series of earthquakes which rocked the island Monday night and early Tuesday.

 According to Dr. Thomas A. Jaggar, volcanologist, 30 earthquakes were recorded between 10:30 p.m. Monday and 10:37 a.m. Tuesday, five of them hard enough to dismantle the seismograph instruments at the volcano observatory. In addition an almost continuous tremor was recorded.

 Present indications are that the quakes originated off the Puna coast, definitely away and to the southeast of Kilauea, rather than between Mauna Loa and Hualalai as first indicted, Dr. Jaggar said. this would mean, he said, that some of the big cracks and cliffs between Kilauea and the Puna shore were moving slightly, thus accounting for the slow, swaying motion type of quake. [This type of motion is associated with deep events, not with movement of surface fractures.]

 Dr. Jaggar emphasized that the exact origin of the earthquakes has not been determined definitely and will not until further study is made, but at present indications as judged by the instruments and reports from various parts of the islands, indicate that the origin was to the southeast.

 [This article contradicts the felt reports summarized in the Tribune-Herald the day before. The final locations as reported in The Volcano Letter were beneath Mauna Loa, precursory to the eruption that began on November 21.]



Anonymous, 1935, Island rocked by quake: Hilo Tribune Herald, 11/21, p. 1, 4. 



 [subheads: Sharp watch is kept for eruption; Shock is felt in all districts of island but no damage is reported; Jaggar says quake was moderate, ordinary Mauna Loa shock]

 Honolulu, Nov. 21--Slight tremors were felt in various sections of Honolulu between 1:10 a.m. and 1:20 a.m. today, but no damage was reported. Windows rattled in Waikiki and residents in higher sections said that the shocks were sufficiently strong to awaken them.

 With the origin of the earthquake which rocked the Big Island at 1:20 a.m. today estimated at 18.6 miles from the observatory or about five miles from the summit crater of Mokuaweoweo on Mauna Loa, a close watch is being maintained today for signs of volcanic activity on the mountain.

 H.R. Waesche, assistant to Dr. Thomas A. Jaggar, at the volcano observatory, reported that the shock originated on the north east rift of Mauna Loa in a west-northwest direction, at practically the same location as the September 30 series of quakes.

 The mountain was clear today and there were no signs of smoke or steam from the summit, and there was no indication on the instruments of volcanic activity.

 The quake appeared to be more strongly felt in the northern sections of the island, with Kona, Kohala and Hamakua reporting the shock to be very strong. It was more moderately felt in Hilo, but was strong enough to awaken many.

 According to Waesche the intensity of the quake was intermediate in size between the heaviest shock and the slightest of the September 30 series.

 The entire Kona district reported feeling the quake, from Puuwaawaa down to the beach at Kailua where it is not generally felt. It awakened residents throughout Kohala and in the Hamakua area. Kau also reported the shock strongly felt there. No damage was reported in any districts.

 Dr. Jaggar termed the shock as an ordinary, moderate Mauna Loa quake. Due to the fact that it was felt all over the island and even as far away as Honolulu it was thought to be of deeper origin than some.

 Due to the fact that an eruption from Mauna Loa or Kilauea is long overdue the earthquake is being considered with special interest in the light of indicating possible activity in the near future. Dr. Jaggar has expected for some time that the next outbreak will be from Mauna Loa.

 [Eruption on Mauna Loa began at 6:35 p.m. on this day.]



Anonymous, 1935, Pele angry! Old natives express fear of bombing: Hilo Tribune Herald, 12/28, p. 1, 3. 



 An account of native Hawaiian reactions to the bombing of the flow channels of the Mauna Loa northeast rift eruption. "Pele should not be disturbed." Referring to the drilling attempted at Kilauea [in 1922 and 1923] another kamaaina said "They stuck an iron in Pele's belly. And what happened? Pele went away for a long time." They anticipate destruction of valuable lands on the Puna side of the Wailuku river as a consequence of the bombing. They recall the legend of Pele and Kamapuaa in which they reached a mutual understanding wherein Kamapuaa laid claim to all lands north of the Wailuku river and Pele agreed to confine her flows to the Puna side of the river. [This reflects the Hawaiians' recognition of the natural boundary between Mauna Kea, a dormant volcano and Mauna Loa, still active.]

 "Their opinion is that no artificial measures will succeed in diverting the flow of lava. Pele makes her own path, they explained, and she will surmount bombing stonewalls [sic], and all other obstacles which may be thrown up before her."



Anonymous, 1935, Seismological notes: Bulletin of the Seismological Society of America, v. 25, no. 3, p. 278. 



 Hilo, Hawaii, June 28, 1935.A sharp quake occurring at 9:02 A.M. caused heavy property damage in Hilo and two tremendous slides in nearby Kilauea crater.



Anonymous, 1935, Seismological notes: Bulletin of the Seismological Society of America, v. 25, no. 2, p. 185. 



 Hawaii, January 2, 1935.--Press reports state that the entire island of Hawaii was shaken by an earthquake at 6:46 a.m. on January 2d. Only minor damage was done.



Anonymous, 1936, Earthquake is felt in Hilo; Shock reported feebly at volcano observatory, no damage is reported: Hilo Tribune Herald, 08/14, p. 1. 



 An earthquake, felt as a sharp jolt in the vicinity of Hilo and Olaa was recorded at the observatory seismograph as a very feeble shock at 12:25 yesterday afternoon. 

 Many residents in Hilo and vicinity reported feeling the quake which was not strong enough to cause any damage. It is estimated that the quake originated about 18 miles from the observatory in the general direction of Hilo.

 The pit was reported as quiet today.



Anonymous, 1936, Earthquake estimated of Kilauea origin: Hilo Tribune Herald, 11/17, p. 1. 



 A "slight to moderate" earthquake, recorded on the seismograph at the volcano observatory at 1:08 yesterday afternoon, was reported today by Hugh Waesche, assistant to Dr. Thomas A. Jaggar, volcanologist.

 The shock was felt 5-6 mi southwest of Halemaumau, also was reported in the volcano district, and slightly in Hilo.

 The exact location of the shock center is uncertain but it is believed to have been of Kilauea origin. The pit was quiet today with only a few small slides reported.



Anonymous, 1936, Seismological notes: Bulletin of the Seismological Society of America, v. 26, no. 3, p. 285. 



 Honolulu, Hawaii, May 11, 1936.--Several residents of Makiki and Pacific Heights felt an earthquake which occurred at 5:45 P.M.



Anonymous, 1936, Seismological notes: Bulletin of the Seismological Society of America, v. 26, no. 1, p. 89, 92. 



 Hilo, Hawaii, October 15, 1935.--A series of slight shocks was felt in Hilo, but not elsewhere on the island. the sharpest shocks were felt at 7:20 p.m., and at 1 a.m. on October 16.



Hilo, Hawaii, November 21, 1935.--Heavy seas, combined with what was believed to be a tidal wave following an earthquake, did damage here. Eighteen hours later, Mauna Loa erupted.



Anonymous, 1937, Sharp earthquake is felt throughout Kona district: Hilo Tribune Herald, 01/25, p. 1. 



 A sharp earthquake, felt throughout the Kona district at 7:30 p.m. Sunday was recorded on the seismograph at the volcano observatory as a local shock which originated at a considerable distance from the observatory. 

 Dr. Thomas A. Jaggar, volcanologist, said that indications were that the shock was not from Kilauea, and probably was from the west side of Mauna Loa. It was not felt in the Hilo district or at the volcano.

 Mrs. L.S. Aungst, of Holualoa, reported by telephone this morning that the shock was a quick, sharp one, but that it did no damage.



Anonymous, 1937, Earthquake shocks are felt throughout island: Hilo Tribune Herald, 02/01, p. 1. 



 The entire island was rocked by an earthquake at 7:34 a.m. Sunday . . .

 The Kona district reported a sharp quake shortly after midnight that night. The volcano seismograph recorded a very feeble shock at 12:23 a.m., indicating that the Kona shock was a purely local one and therefore was registered only very feebly at the volcano.

 The rest of the article repeats information given in Volcano Letter 444, p. 5-7.

 The Sunday morning shock was estimated to have originated westward in the direction of Hualalai, according to Mr. Waesche.



Anonymous, 1937, Sharp earthquakes felt by residents in Kohala: Hilo Tribune Herald, 02/18, p. 1. 



 . . . . 

The Kohala district reported two sharp shocks, the first at 9:43 and the second at 11:10 last night. Ookala reported a quake about 9:15 p.m. [Apparently not registered at HVO-see below].

 At the volcano observatory it was reported that three very feeble quakes were recorded on the seismograph, the first at 9:43 last night [not reported in Volcano Letter 444], the second at 2:38 a.m. today and the third at 5:40 this morning [5:20 in Volcano Letter 444].

 The first two shocks indicated origin at a considerable distance from the observatory, while the last quake was of Kilauea origin.

 The quakes were not felt in other sections of the island, as far as could be ascertained.



Anonymous, 1937, Two quakes are felt in island areas: Hilo Tribune Herald, 04/19, p. 1. 



 [subheads: Island-wide shock occurs at 4:10 a.m. Sunday believed of Hualalai origin; Seismic activity more pronounced now than at any time since last outbreak]

 . . . . 

Two earthquakes occurred over the weekend. The first occurred at 4:10 a.m. Sunday [Apr. 18] was felt sharply throughout the island, but more particularly in the Waimea and Honokaa districts. It was reported to be very strong at Waikii on the slopes of Mauna Kea.

 It is estimated that this quake originated between 45 and 50 miles from the observatory, and it is believed to have been of Hualalai origin.

 No damage was reported from the earthquake.

 A shock of Kilauea origin was reported felt by Dr. Thomas A. Jaggar, volcanologist, at 6 a.m. today.

 During the past few weeks the total seismic disturbances has increased until now there is an average of one or two disturbances a day. Recent reports in the weekly Kilauea letter have noted the increased disturbances with the announcement that increased lava movement beneath Kilauea and Mauna Loa is indicated.



Anonymous, 1937, Honokaa and Kohala feel sharp quake: Hilo Tribune Herald, 06/30, p. 1. 



 A sharp earthquake rocked the Kohala and Honokaa districts at 8:45 a.m. today. While felt throughout the northern tip of the Big island, the quake did no damage. Dr. Thomas A. Jaggar, volcanologist, said today that the quake was not sufficiently large enough in the volcano area to be recorded on the seismograph. It was believed that the shock was of purely local origin.



Anonymous, 1937, Sharp quake felt in Hilo Friday night: Hilo Tribune Herald, 07/17, p. 1. 



 A sharp earthquake jolt was felt throughout Hilo and the surrounding district about 7 last night.

 . . . .

 "The shock was distinctly of Kilauea origin," Dr. Jaggar said today. It was not reported felt in west Hawaii.



Anonymous, 1937, Report quakes at the volcano; several landslides in Halemaumau were reported over the weekend: Hilo Tribune Herald, 08/23, p. 1. 



 Several landslides and temblors at Halemaumau pit made the weekend exciting for many of the visitors at the Hawaii National Park.

 Yesterday morning a slight earthquake [very feeble in Volcano Letter 450] was felt in the park district followed by a large landslide at Halemaumau pit where a crack is opening within the pit. Several minor landslides have been occurring at the same spot for the past few days showing that this crack is slowly widening up.

 Early today at 2:55 a.m. a sharp temblor was felt in the [park] district, which according to Dr. T.A. Jaggar of the volcano observatory, was much larger than the one that occurred yesterday morning. [time given as 3:02 in Volcano Letter 450].

 All the recent quakes in the park area have been of Kilauea origin, indicating that there may be some activity in the pit soon. The constant landslides have created much excitement among the park people and a close watch is being kept by the park service.



Anonymous, 1937, Sharp quake rocks Hilo, Volcano area: Hilo Tribune Herald, 10/18, p. 1. 



 An earthquake shock, of Kilauea origin, was felt strongly in Hilo and volcano districts at 12:44 a.m. today. No damage was reported.

 The shock, reported as slight [feeble in Volcano Letter 452] at HVO, was strong enough to awaken sound sleepers. It was especially strong in the Halai Hill and Puueo sections of Hilo.

 H.H. Waesche, assistant to Dr. Thomas A. Jaggar. volcanologist, said that the quake was distinctly of Kilauea origin [Volcano Letter 452 has location beneath Mauna Loa]. He said it was so strongly felt at his home in the park district that he hurried to the observatory to see the records, expecting to find indications of a much more severe shock than the record showed.

 . . . .

 Mrs. Carlos Sebastian reported that the shock was very severely felt at her summer home at 29 miles, Olaa . . . She said that the pheasants in the yard shrieked with terror.



Anonymous, 1937, Prolonged quake awakens Hiloites: Hilo Tribune Herald, 10/25, p. 1. 



 A prolonged earthquake, recorded on the seismographs at the volcano observatory, as slight, was strongly felt in Hilo and the volcano areas at 5:43 a.m. today. 

 Dr. Thomas A. Jaggar, volcanologist, expressed the opinion that the quake was possibly of Mauna Loa origin as the preliminary shake was longer than that which generally accompanies a Kilauea shock.

 The quake, which awakened many Hilo residents, especially those living in the Puueo and Halai Hill sections, was strong enough to rattled windows, but did no damage. 

 . . . .

 The quake was not felt in the Kona district, according to Mrs. L.S. Aungst who reported however that several sharp shocks have been felt during the past few weeks. [Possibly one of these was on October 18; others must have been local to Kona and too small to be recorded at HVO.]



Anonymous, 1937, Sharp earthquake of Kilauea origin rocks park area: Hilo Tribune Herald, 11/29, p. 1. 



 A sharp earthquake, strongly felt at the CCC camp in the volcano district, occurred at 6:30 p.m. Saturday. The shock was so strong that the pit seismograph was completely smashed.

 H.H. Waesche, assistant to Dr. Thomas A. Jaggar, volcanologist, said the shock was of Kilauea origin apparently on the south east rim of the crater where recent quakes have been centered.

 . . . .

 The sharp quake Saturday night was preceded by a smaller one, also of Kilauea origin, earlier in the day.



Anonymous, 1937, Seismological notes: Bulletin of the Seismological Society of America, v. 27, no. 4, p. 57-58. 



 Honolulu, Territory of Hawaii, October 19, 1937.--Sharp earthquakes were felt south of the island of Hawaii. [By dolphins?]



Hilo, Territory of Hawaii, October 25, 1937.--An earthquake at 5:43 A.M. shook Hilo and volcanic areas.



Anonymous, 1937, Seismological notes: Bulletin of the Seismological Society of America, v. 27, no. 1, p. 139-140. 



 Hilo, Hawaii, January 10, 1937.--An earthquake at 10:55 P.M. was felt strongly by residents.



Hilo, Hawaii, January 24, 1937.--At 7:30 P.M. an earthquake was felt in the Kona district.



Hilo, Hawaii, February 1, 1937.--Two earthquakes in less than twenty-four hours were felt in Hilo--the first at 7:34 P.M. on January 31st, which shook the entire island, the second at 12:33 A.M. on February 1, in the Kona section of the western part of the island.



Anonymous, 1938, Earthquake rocks Hilo district: Hilo Tribune Herald, 01/05, p. 1. 



 [An earthquake] shook the town of Hilo at 2:30 a.m. 

 The earthquake, according to a hurried and preliminary report of Hugh Waesche, assistant volcanologist to Dr. Thomas A. Jaggar, was estimated to be 12.6 miles from the volcano observatory, which would place its origin pretty close to the north east rift of Mauna Loa. [Final location given in Volcano Letter 455 was on the south flank of Kilauea].

 Today's quake, which was listed as "slight"--as are quakes which are felt--was preceded by four feeble tremors [not mentioned in Volcano Letter 455] yesterday.

 The quake awakened many of the inhabitants of Hilo, although it was not felt in Kona.

 Dr. Jaggar, in his report to the Chamber of Commerce harbor hearing last month, stated that Hilo was due for a lava flow which more than likely would fill the harbor. He said it was coming within 20 years, according to the cycles of Mauna Loa, but that he thought it would come much sooner.



Anonymous, 1938, Earthquake is felt on all islands; Special plane chartered to fly to Hana to check up on damage to that community; Damage is reported in Honolulu, Maui and on Molokai by severe temblor: Hilo Tribune Herald, 01/24, p. 1, 5. 



 Hana Maui, Jan. 24--This district, which had been cut off from the rest of the territory when communications were disrupted by the earthquake Saturday, was considerably damaged but there were no fatalities.

 Standard Oil Co. tanks collapsed, spilling 30,000 gallons of oil. The roof of the Wanahua church collapsed with damage estimated at $200. Ranch houses reported damage to crockery and windows, All roads to the outside districts are blocked.

 Phone communications were restored early this afternoon.

Honolulu, Jan.,. 24--While the remainder of the territory reported only minor damage and no casualties from Saturday's sharp earthquake, plans were made for a special plane to fly to Hana, Maui island, today because all communication with that community has been disrupted since the earth temblor.

 The next few paragraphs speculate on the location, guessing Maui because of the damage there. Additional damage reports quoted as follows:

 " . . .[on Maui] road cracks a foot wide in the pavement."

 "A temporary water shortage at Lahaina and Kahului [due to landslides cracking pipes and broken storage tanks], cracked roads and buildings were reported from Maui; road and ground cracks were reported on Lanai and Molokai, while highways on Oahu and Kauai apparently escaped damage."

 "The Haleakala road was cracked in many places and the new bridge on the Wailuku-Kahului road was damaged to some extent due to settling."

 "Concrete buildings in Lahaina were cracked."

 "Molokai--the quake opened cracks between two and three inches wide and 25 to 100 feet long on the East Molokai road at Mapulehu. From Ohia to Mapulehu stone walls collapsed. Other damage was confined to crockery and other household possessions."

 "Lanai--a crack 10 feet wide, 15 feet long and seven feet deep was reported in the Maunalei region."

 "Oahu--All roads and bridges escaped damage; no roads blocked although minor landsliding reported."

 "Residents of Manoa valley reported three separate shocks at 10:03, five minutes later and a third short shock at 10:23."

 "At Waikiki, a comparatively light first shock was followed soon by a severe quake."

 "Damage was apparently limited to crockery and glassware."

 The quake was predicted by Mrs. Charles Lochbaum, wife of the preacher at the Apostolic Faith church. While delivering a sermon before a large congregation at about 9 p.m. Saturday, she said "Before the night is over, there will be a strong earthquake."



Anonymous, 1938, Quake is not volcanic one: Hilo Tribune Herald, 01/24, p. 1. 



 New York, Jan. 23--Fordham University seismologists said last night the earthquake in the Hawaiian Islands Saturday night was not of volcanic origin but due to a seismic shift 50 miles below the surface of the earth.

 Instruments at the University registered "fairly severe, short and sharp" shocks at 2:45 a.m. and 2:53 a.m. EST.



Anonymous, 1938, Scientist in warning on bad quake: Hilo Tribune Herald, 01/24, p. 1, 5. 



 [subheads: Volcanologist declares Tokyo, Napier quake will be repeated in Hawaii someday; Urges immediate steps for safe building program especially in Honolulu]

 Jaggar says Honolulu is in the same class as cities that have experienced very large earthquakes. "[I] hope that some action will be taken at once to put into effect the safe building program that I have been advocating for years."

 The rest of the article spells out some recommendations for building construction, such as use of diagonal braces, that have proven to reduce earthquake damage.



Anonymous, 1938, All sections of Big island hit by earthquake: Hilo Tribune Herald, 01/24, p. 1, 5. 



 The longest, and one of the severest earthquakes in years was felt in every section of the Big Island at 10:03 p.m. Saturday, causing considerable excitement but doing very little real damage aside from broken dishes and pictures and disarranged furniture in some homes.

 The quake, which lasted approximately a minute and a half, is estimated to have originated between 100 and 300 miles from this island toward the northwest, which would account for the severe shock reported throughout the Territory.

. . . .

[HVO reported] that every instrument used to record the earthquake was dismantled with the exception of the low magnification instrument at Uwekahuna bluff. On this instrument a complete record of the quake was obtained. . . .

 Further reports of the intensity of the quake on Oahu, Maui and Kauai confirmed that the shock was not local to Kilauea or Mauna Loa. . . .

 The earthquake was described [by HVO] as a slow motion quake followed by a relatively strong shock.

 Reports from the outside districts of the Big Island indicate that the quake was more strongly felt in the Kohala district and certain parts of the Hamakua coast, than in Hilo or other sections of the island.

 According to Mrs. Cal Hannah, Tribune Herald correspondent in Kohala, dishes were broken in many homes throughout the district, pictures were knocked from walls, chandeliers crashed to the floor and furniture was generally disarranged. She also reported small landslides along the Kohala mountain road . . . A series of three quakes were felt, the first about 10:03 p.m., the second at 10:10 and the third at 10:25.

 "It certainly was the hardest quake felt here since the 1929 series, and was the longest one experienced by many people here."

 While no damage was reported in the Hamakua district, the shock was reported severely felt along the coast, with some damage reported at Honomu. Guests at the George Becker home in Honomu declared that many dishes were broken there as china cabinets swayed and their contents crashed to the floor. A large crack appeared in the ceiling, running straight through the house from front to back in the home of John P. Ramsay, manager of the Honomu plantation.

 . . . In Hilo people were awakened and ran into the street in their nightclothes . . . Only damage was reported from the Puueo section . . . In that area some homes reported that stoves and ice boxes were moved as much as two to three inches from their original positions, and dishes, vases and lamps were broken. [no damage reported in the Halai Hills area].

 A complete check around the island revealed that every district experienced the quake more or less severely. Reports from the volcano district itself varied somewhat in that some few residents said they did not feel it, while others claimed it was very severe.

 Mrs. George Duncan, principal of Olaa school, said the quake was severely felt in Olaa, but no damage was reported. She said only one plate in her home was knocked down.

 A report from Mr. Arthur Lyman at Kapoho indicated that the quake was felt as two distinct shocks there, with the second being the strongest, lasting about half a minute. there was no damage.

 A.U. Carter of Naalehu said the shock was "pretty strong." He said additional quivers continued to be felt after the severe shock. No damage was reported in the Kau section.

 At Holualoa Mrs. LB. Aungst said the quake was the strongest since the 1929 shocks but no damage resulted. "It was a very long shock with a swinging motion," she said.

 At Kona Inn, in Kailua, the earthquake failed to disturb more than one visitor in the hotel . . .The manager said that it was one of the longest he had ever felt, and a strong one.

 Mrs. Margaret MacLean at Waimea Hotel, said the earthquake was very strong in that area and caused some damage in the cottages at the hotel where glasses and crockery was broken. "It was the longest one I ever felt and certainly one of the strongest," she declared.

 "Everyone in Honokaa was awakened by the earthquake, but there was no damage . . ."

 Reports from both Puuwaawaa ranch and Puu Oo ranch revealed that while the shock was long and much more severe than the usual run of quakes experienced on this island, it was not as strong as those in 1929. . . No damage occurred at either of the two ranches.



Anonymous, 1938, Epicenter of big earthquake is announced; Origin of shock was in channel midway between Maui and Big Island: Hilo Tribune Herald, 01/24, p. 1, 5. 



 Honolulu, Jan.,. 24--Cmdr. J.H. Peters, of the geodetic survey, today located the epicenter of the earthquake Saturday night [Jan. 22] in the channel midway between Maui and Hawaii on approximately s straight line between Kilauea observatory and the University of Hawaii observatory in Manoa.

 Cmdr. Peters placed the source of the quake at least 125 miles below the earth's surface or 55 miles below the earth's top crust.

 A further check on all islands showed the quake was felt strongly in the Kohala section of the Big Island and on Maui, but there was no further damage reported.

 Cmdr. Peters said the quake was timed as follows at the various observatories: Maui, 10:02-45 seconds; Kilauea, 10:03-20 seconds; University of Hawaii, 10:04-8 seconds.

[continuation on p. 3 missing]



Anonymous, 1938, Hana, Maui worst hit by temblor: Hilo Tribune Herald, 01/25, p. 1, 3. 



 The longest, and one of the severest earthquakes in years was felt in every section of the Big Island at 10:03 p.m. Saturday, causing considerable excitement but doing very little real damage aside from broken dishes and pictures and disarranged furniture in some homes.

 The quake, which lasted approximately a minute and a half, is estimated to have originated between 100 and 300 miles from this island toward the northwest, which would account for the severe shock reported throughout the Territory.

. . . .

[HVO reported] that every instrument used to record the earthquake was dismantled with the exception of the low magnification instrument at Uwekahuna bluff. On this instrument a complete record of the quake was obtained. . . .

 Further reports of the intensity of the quake on Oahu, Maui and Kauai confirmed that the shock was not local to Kilauea or Mauna Loa. . . .

 The earthquake was described [by HVO] as a slow motion quake followed by a relatively strong shock.

 Reports from the outside districts of the Big Island indicate that the quake was more strongly felt in the Kohala district and certain parts of the Hamakua coast, than in Hilo or other sections of the island.

 According to Mrs. Cal Hannah, Tribune Herald correspondent in Kohala, dishes were broken in many homes throughout the district, pictures were knocked from walls, chandeliers crashed to the floor and furniture was generally disarranged. She also reported small landslides along the Kohala mountain road . . . A series of three quakes were felt, the first about 10:03 p.m., the second at 10:10 and the third at 10:25.

 "It certainly was the hardest quake felt here since the 1929 series, and was the longest one experienced by many people here."

 While no damage was reported in the Hamakua district, the shock was reported severely felt along the coast, with some damage reported at Honomu. Guests at the George Becker home in Honomu declared that many dishes were broken there as china cabinets swayed and their contents crashed to the floor. A large crack appeared in the ceiling, running straight through the house from front to back in the home of John P. Ramsay, manager of the Honomu plantation.

 . . . In Hilo people were awakened and ran into the street in their nightclothes . . . Only damage was reported from the Puueo section . . . In that area some homes reported that stoves and ice boxes were moved as much as two to three inches from their original positions, and dishes, vases and lamps were broken. [no damage reported in the Halai Hills area].

 A complete check around the island revealed that every district experienced the quake more or less severely. Reports from the volcano district itself varied somewhat in that some few residents said they did not feel it, while others claimed it was very severe.

 Mrs. George Duncan, principal of Olaa school, said the quake was severely felt in Olaa, but no damage was reported. She said only one plate in her home was knocked down.

 A report from Mr. Arthur Lyman at Kapoho indicated that the quake was felt as two distinct shocks there, with the second being the strongest, lasting about half a minute. there was no damage.

 A.U. Carter of Naalehu said the shock was "pretty strong." He said additional quivers continued to be felt after the severe shock. No damage was reported in the Kau section.

 At Holualoa Mrs. LB. Aungst said the quake was the strongest since the 1929 shocks but no damage resulted. "It was a very long shock with a swinging motion," she said.

 At Kona Inn, in Kailua, the earthquake failed to disturb more than one visitor in the hotel . . .The manager said that it was one of the longest he had ever felt, and a strong one.

 Mrs. Margaret MacLean at Waimea Hotel, said the earthquake was very strong in that area and caused some damage in the cottages at the hotel where glasses and crockery was broken. "It was the longest one I ever felt and certainly one of the strongest," she declared.

 "Everyone in Honokaa was awakened by the earthquake, but there was no damage . . ."

 Reports from both Puuwaawaa ranch and Puu Oo ranch revealed that while the shock was long and much more severe than the usual run of quakes experienced on this island, it was not as strong as those in 1929. . . No damage occurred at either of the two ranches.



Anonymous, 1938, Maui quake damage: Hilo Tribune Herald, 01/26, p. 1, 3. 



 Four photos show damage from the Jan. 22, 1938 quake at several points in the island chain.



Anonymous, 1938, Architects say buildings safe: Hilo Tribune Herald, 01/27, p. 1, 3. 



 Honolulu, Jan. 27--Buildings here are capable of withstanding severe earth shocks without collapsing, three Honolulu architects declared.

 Their statements were prompted by the warning of Dr. Thomas A. Jaggar, Hawaii national park volcanologist, that Honolulu would suffer an earthquake disaster, unless a "safe building" program is adopted immediately.

 Claude A. Stiehl, president of the Hawaii chapter, American Institute of Architects, recommended revision of the city-county building cod to make earthquake proof construction mandatory.

 Two other architects, C.W, Dickey and Hart Wood, Sr., expressed belief that present structures are capable of withstanding earth shocks far more severe than the quake that rocked the archipelago last Saturday [Jan. 22].

 The article continues with discussion of these issues in light of damage done by the Jan. 22 quake.

 [Honolulu was upgraded to hazard zone 2A in the 1990s and building codes were adjusted accordingly]



Anonymous, 1938, Point of origin of quake is estimated: Hilo Tribune Herald, 01/28, p. 1, 5. 



 Point of origin [of the Jan. 22 quake] was the sea bottom about 20 miles west of Kahoolawe and 20 miles south of Lanai, with the source about 50 to 70 miles deep, according to the weekly report of the Hawaiian Volcano Observatory . . .

 The report follows:

 "The strong earthquake was seismologically a near and deep shock capable of registering at great distances. At Kilauea observatory it began at 10h 03m 20s p.m., January 22. It was felt throughout the Territory of Hawaii. Distance of origin seismometrically was 154 miles by Kilauea seismograms, 115 miles by Kona seismograms. The direction was NW by W from first impulses on seismograms of Hilo, Kilauea and Kona. . . . It may have been under one of the profound volcanic breaks through Haleakala, Molokini and Kahoolawe, which extend into a steep wall of step-faults under the sea 12,000 feet deep in the channel south of Kahoolawe. The seismic waves ceased about 11:45 p.m., making the duration of earth motion 1h 42m. The time of shock at the origin was 10h 02m 49s p.m. The depth is computed by difference between convergence point and distance.

 "These data make the epicenter about 138 miles from Hilo WNW, 83 miles from Honolulu SE, 40 miles from Lahaina SSW, and 50 miles from Kahului SW, in 320 fathoms of water. Fordham University in New York reports time of registration there in exact accord with our time at origin. The latitude of epicenter is 20 30', the longitude 157 W.

 "The physical effects were reported as alarm in Honolulu, swaying movement on Hawaii Island, damage in Kohala, Molokai, East Maui, and West Maui, and chasms opened on Lanai. The swaying appears to have been quick and of short duration on Oahu, slow and of long duration on Hawaii. Seismographs in Honolulu and on Hawaii were dismantled, except the strong-motion instrument at main Observatory building opposite Volcano House. The seismogram from this instrument has been published in newspapers. Other instruments, however, recorded times, directions and preliminary tremors, before dismantling. Light flashes were reported at Hilo, and short-wave radio transmission interference occurred. Pheasants squawked, dogs barked and sleepers were awakened.

 "District ranger J.A. Peck reports many tons of rock fell on Haleakala road and cracks appeared on the pavement. Hana reports broken fuel tanks, and much fallen rock. In many places, objects were overturned and heavy furniture moved. Ceiling lights in Hilo swung in a direction NE-SW, transverse to line of origin."



Anonymous, 1938, Chain-of-Craters area badly shaken: Hilo Tribune Herald, 03/02, p. 1, 5. 



 [subhead: Will lava return to craters of Puna?]

 Will there be a repetition of the 1922 activity in the Puna craters? This is the question that has aroused the interest of the entire Hawaii National Park staff following the series of local earthquakes which started Saturday morning resulting in a great shaking up of the ground in this area of the lower Chain-of-Craters road.

 Large cracks have appeared in the road beginning near the Pauahi crater and extending for more than a mile, toward the end of the road, with the largest opening being near Pauahi. Here the road has risen, and cracked entirely across, with a portion of the road on the side caved in. Eleven large cracks extending the width of the road, all running in a southwest direction have appeared. The cracks are several inches wide.

 In addition to the large openings innumerable small cracks have appeared.

 The quaking started early Saturday morning, with about 40 being recorded during an hour's period. A great many of these were slightly felt by residents in the park area. Up to early Saturday afternoon a total of about 77 quakes were recorded.

 The article continues with discussion of road closings and speculation about what might be happening underground.



Anonymous, 1938, Earthquake is felt in Volcano area: Hilo Tribune Herald, 03/02, p. 1. 



 An earthquake of Kilauea origin was felt in the volcano district at 3:15 a.m. today, .it was reported today by Dr. Thomas A. Jaggar, volcanologist.

 Dr. Jaggar said however that it was not as strong as the one of Monday night [Feb. 28] which was recorded as a moderate shock, also of Kilauea origin.

 . . . .



Anonymous, 1938, Big island is hit by quake: Hilo Tribune Herald, 03/07, p. 1. 



 A moderate earthquake of Mauna Loa origin rocked the entire Big island a few minutes before 6 this morning. . . .

 The quake was felt in Hilo and at the volcano as a prolonged shock, with a considerable preliminary shock indicating its origin at a distance from Kilauea. The quake was not particularly strong, but lasted about half a minute, and roused many sleepers.

 Honokaa reported the shock was rather strongly felt there and seemed to be accompanied by an explosive sound. The disturbance seemed to be two distinct shocks there . . .

 Mrs. L.S. Aungst at Kona said the shock was prolonged but not severe and did no damage. 

 The quake was only slightly felt in the Kohala area, according to Mrs. G.L. Hannah at Hawi. Puuwaawaa ranch also reported the quake as slight.

 Dr. Jaggar said the instrument at the observatory was dismantled by the shock. . . .



Anonymous, 1938, Earthquakes continuing to rock district: Hilo Tribune Herald, 05/30, p. 1, 5. 



 [subheads: Indications seen of possible activity in one of Puna craters; Eleven groups of cracks appear in road, sliding occurs in Pauahi crater]

 With the Chain-of-Craters road area in the Volcano district badly shaken by a series of earthquakes which began at 6:03 a.m. Saturday. and are continuing today, although with decreased number and intensity, indications are seen of possible activity in one of the Puna craters, possibly Pauahi crater, which appears to be the center of the disturbance.

 H.H. Waesche, assistant to Dr. Thomas A. Jaggar, volcanologist reported today that 11 groups of large cracks have appeared in the Chain-of-Craters road between Pauahi and. Aloi craters. The largest crack is near Pauahi crater, where a section of the road has caved in. All cracks run in an east-west direction. a great many small cracks have also appeared.

 many small cracks have also appeared.

 Bumps In Road Rises

 In addition to the cracks, the bump in the road near Devil's Throat, which has been noticeable for many months, has risen considerably and is cracked across the top. It is estimated that this bump rose several inches during the major disturbance of Saturday.

 Numerous slides have occurred in Pauahi crater. Three were noted Sunday by rangers stationed on the road, and Investigation showed Much fresh dirt has slid down Into the crater, with a number of slides apparently having occurred on Saturday.

 The tremor started recording at 6:03 a. m. Saturday and continued with intermittent quakes until about 3 P. m. Saturday when there was a tapering off in intensity of the tremors as well as the number of quakes. Tremors were continuing with intermittent quakes today. Harmonic tremors always accompany any an outbreak of lava.

 On Saturday at 6:31 a. m. there was a moderate quake: that awoke residents In the volcano. district. This was followed' by moderate quakes at 6:52 a.m. and 6:57 a.m., all of which were felt at the volcano. They were recorded on the Hilo and Kona seismographs and dismantled the Instruments at Kilauea. 

 During Saturday there also were 10 slight quakes, a few of which were felt, nine feeble shocks, and a large number of very feeble earthquakes.

 During Sunday there were approximately 16 very feeble quakes, one feeble quake at 10 p.m., a slight quake at 9:48 a.m., and another quake at 6:32 p.m.

 Since midnight last night there have been intermittent tremors and about five very feeble quakes. At 1:43 a.m. today there was a slight quake.

 "The shocks are all local shocks, the epicenter being at Kilauea and at Pauahi," Mr. Waesche said.

 "Something very definitely is going on, but just what it is we cannot say now."



Anonymous, 1938, Will lava return to craters of Puna?: Hilo Tribune Herald, 05/30, p. 1, 5. 



 An account of cracks in the Chain-of-Craters road following the earthquake swarm.

 "Large cracks have appeared in the road beginning near the Pauahi crater and extending for more than a mile, toward the end of the road, with the largest opening being near Pauahi. Here the road has risen, and cracked entirely across, with a portion of the road on the side caved in. Eleven large cracks extending the width of the road, all running in a southwest direction have appeared. The cracks are several inches wide.

 "In addition to the large openings innumerable small cracks have appeared.

 "The quaking started early Saturday morning, with about 40 being recorded during an hours period. A great many of these were slightly felt by residents in the Park area. Up to early Saturday afternoon a total of about 77 quakes were recorded.

 Road closed

 "About 4:30 p.m. Saturday, Mr. and Mrs. Carl S. Carlsmith of Hilo were driving over the Chain-of-Craters road and saw the big crack near Pauahi crater. . . . "

 The article continues with speculation about the possibility of and eruption.



Anonymous, 1938, Tremors are continuing in Volcano area: Hilo Tribune Herald, 05/31, p. 1, 5. 



 [subheads: Series of quakes described as 'very significant' as disturbance continues; Indications seen that outbreak of lava is probable in near future]

 Tremors continue, but none felt. The quakes were accompanied by nine hours of continuous harmonic tremor. Eight very feeble quakes recorded between 9 p.m. last night and 8 a.m. today, a very feeble quake at 5:57 a.m.

 The rest of the article talks of road closing and the possibility of eruption.



Anonymous, 1938, Conditions at volcano have quieted; End of disturbance at chain-of-Craters road is indicated today: Hilo Tribune Herald, 06/01, p. 1. 



 . . . .

 A feeble quake at 2:15 p.m. yesterday was the last one to be felt in the series which began Saturday morning . . .

 A settling of the big cracks on the chain-of-Craters road was reported. . . . One of the cracks near Aloi crater, which originally was simply a crack across the road, has now widened to about six inches and is about three or four feet deep. . . .



Anonymous, 1938, Earth disturbances at Kilauea continue: Hilo Tribune Herald, 06/06, p. 1. 



 Most of the article repeats material in Volcano Letter 460. The following paragraph supplements this information.

 "A slight quake was reported at 1:47 a.m. Sunday [June 5; hvo gives feeble at this time], which was generally felt throughout the district. Another slight quake was recorded at 1:15 a.m. today [hvo gives feeble at this time] with three very feeble shocks also recorded after midnight [not in VL 460] A moderate shock about 10:45 a.m. Wednesday [June 1] dismantled the instruments.

 "Mr. Waesche reported today that cracks on Ainahou ranch road, which turns off from the Chain-of-Craters road, were also noted this week."



Anonymous, 1938, Quakes rock Kilauea area; cracks open: Hilo Tribune Herald, 08/08, p. 1. 



 A series of short mild earth tremors have been felt in the Volcano district since 2 o'clock this morning, it was reported by Edward Wingate, superintendent of the Hawaii National Park this morning.

 "There have been several slides in the extinct crater Devil's Throat on the chain-of-Craters road," said Mr. Wingate, "which have caused the cracks of the May 28 disturbance to widen . . . ."

 Small quakes continued at abnormal frequency throughout the day . . .

 Between 2 a.m. and 7:45 a.m. today, there were 100 quakes . . .



Anonymous, 1938, Earthquakes continue in volcano area; Sixty three quakes registered during 12 hour period overnight, Wingate reports: Hilo Tribune Herald, 08/09, p. 1. 



 Shocks, quakes and tremors are continuing today . . .

 Between 8 p.m. Monday and 8 a.m. today 63 quakes were registered . . .

 These disturbances are being felt quite frequently in the Chain of craters region and are usually accompanied by a dull rumble . . .

 . . . .

 . . . there were 100 quakes between 2 a.m. and 7:25 a.m. Monday.



Anonymous, 1938, Kilauea quakes tapering off; New series of disturbances closer to main crater than those of May: Hilo Tribune Herald, 08/10, p. 1. 



 . . . .

 Between 8 a.m. and 8 p.m. Tuesday, 15 quakes were registered, of which some were felt in the volcano area . . .

 . . . there were two slight quakes last night after 8 p.m.



Anonymous, 1938, Kilauea heat study revealed: Honolulu Advertiser, 09/09, p. 1. 



 Preliminary results are reported in a study designed to see if the area of dying vegetation near Puhimau crater on Kilauea's east rift zone is changing and to ascertain the critical temperatures that kill different plant species. A ground temperature of 67 degrees F. [normal for the Chain-of-Craters region and away from the hot area] has not varied since the study was initiated several months ago. "In the area itself the following was found to be true: Where temperatures do not exceed 80 degrees F. no dead vegetation has been observed; at 90 degrees the larger aalii is dead or dying; ohia lehua is killed between 90 and 110 degrees and amaumau ferns begin to die around 120 degrees; while above 140 degrees nothing but a very few small aalii, the sword fern and some grasses and sedges continue to live. the highest temperatures recorded are at the center [of the study area], and beside one of the steam vents it has not varied from 182 degrees F."

 "The study is to be continued for some months to determine whether this area is spreading, diminishing or remaining constant."



Anonymous, 1938, Sharp earthquake is felt in Hilo: Hilo Tribune Herald, 10/26, p. 1. 



 An earthquake, classified as slight at Kilauea observatory, was sharply felt in Hilo yesterday about 12:20 p.m.

 It was reported that the quake probably originated on the northeast rift of Mauna Loa.



Anonymous, 1938, Seismological notes: Bulletin of the Seismological Society of America, v. 28, no. 3, p. 232. 



 Hilo, Territory of Hawaii, May 29, 1938.--A series of earthquakes caused several cracks to appear in a road near Kilauea. Observers kept close watch on the volcano for fear the shocks might be forerunners of an eruption.



Anonymous, 1938, Seismological notes: Bulletin of the Seismological Society of America, v. 28, no. 4, p. 340. 



 Hilo, Hawaii, August 8, 1938.--A series of mild shocks was felt in the volcano district of Hawaii on August 8. Superintendent E.G. Wingate of the Hawaii National Park reported that resulting slides in the extinct Devil's Throat crater widened cracks caused by an earthquake on May 28.



Anonymous, 1938, Seismological notes: Bulletin of the Seismological Society of America, v. 28, no. 2, p. 132. 



 Honolulu, Hawaii, January 22, 1938.At 10:05 P.M. a series of strong earthquakes shook every major island in the Hawaiian group, sending crowds scurrying from houses and theaters. Telephone service was partly disrupted in Honolulu. At the University, plaster walls were cracked and the seismograph was dismantled. On the island of Maui some water pipes were broken and a crevice ten feet wide and fifteen feet long was opened. The earthquake was said to have been the most severe in twenty years. The United States Coast and Geodetic Survey reports an earthquake on January 23 at 8h 32m 8s, G.M.T., with epicenter at 21.2 N, 156.1 W.



Anonymous, 1939, Heavy quake is felt on island: Hilo Tribune Herald, 01/20, p. 1. 



 Believed to have originated under Hualalai or along the southwest rift of Mauna Loa, a heavy earthquake rocked the western and northern portions of the Big Island yesterday afternoon, just before 3.

 First reports of the earthquake were received by the Tribune Herald in a telephone call from Mrs. Luther Aungst, who said that the shock was very strong at Holualoa, lasting about 15 seconds. Other phone calls soon came in from various parts of the Kona district reporting the quake strongly felt. At Puuwaawaa ranch the shock was reported as very strong, lasting there about 30 seconds.

 The quake was reported from Kohala and Honokaa as short and sharp, while the Kau district reported that the shake was only slight in that section. As far as could be learned it was not felt in the vicinity of Hilo.

 Hugh Waesche, assistant to Dr. Thomas Jaggar, seismologist, said the quake was recorded at the volcano as slight, lasting between two and three minutes. It was not felt at the volcano, however.

 There was no damage from the quake, and there were no further disturbances.



Anonymous, 1939, Quake rocks Kona; shock 2nd in week: Honolulu Advertiser, 01/20, p. 1. 



 Hilo, Jan. 19--An earthquake rocked the Kona area at 2:58 p.m. today for about 15 seconds. No damage was reported.

 From seismograph records at the Kilauea observatory Hugh Waesche, assistant to Dr. Thomas A. Jaggar, deduced that the quake apparently originated on Mauna Loa or Hualalai.

 Today's quake was the second in less than a week. A tremor shook Hilo and the volcano sections at 3:30 p.m. Sunday [Jan. 15].



Anonymous, 1939, Hiloites are awakened by short, sharp quake: Hilo Tribune Herald, 03/23, p. 1. 



 Hiloites were awakened by a sharp earthquake jolt at 10:57 last night. . . . It was not felt in the volcano district. It may have originated on the northeast rift of Mauna Loa, or the southeast rift of Kilauea in the Kalapana section.

 Another quake, classified as feeble, was recorded at 5:46 a.m. yesterday.

 The rest of the article repeats material in Volcano Letter 463.



Anonymous, 1939, Mauna Loa quake felt on Big Island: Hilo Tribune Herald, 04/12, p. 1. 



 An earthquake which was reported generally felt on the Big island, registered on the volcano observatory seismograph at 4:18 a.m. today as a slight quake.

 Hugh Waesche, assistant volcanologist, estimated that the quake originated about 20 miles from the observatory, on the northeast rift of Mauna Loa, probably very close to the summit crater,

 . . . .

 the quake in Hilo was strong enough to awaken sleepers. There was no damage.



Anonymous, 1939, Slight quake felt in Hilo early today: Hilo Tribune Herald, 05/08, p. 1. 



 An earthquake, described as slight at the observatory, rattled windows and doors in Hilo at 7:03 a.m. today, but did no damage. 

 According to Hugh Waesche, assistant volcanologist, it is estimated that the quake originated about 22 miles from the observatory. It was believed to have been of Mauna Loa origin, probably near the summit crater.

The quake was slightly felt in the volcano district.



Anonymous, 1939, Strong quake hits Big isle; minor damage: Hilo Tribune Herald, 05/15, p. 1-2. 



 Hilo and the southern section of the Big Island were jolted by a heavy earthquake at 10:27 a.m. today. Apparently of Kilauea origin, the earthquake caused a big landslide into Halemaumau, sending a heavy dust cloud over the pit.

 . . . It was the strongest felt here since the territory-wide quake of January 1938.

 Minor damage, including slight cracks in the county building, and household articles knocked from shelves, was reported.

 All instruments, both at the volcano observatory and at the pit, were dismantled by the quake.

 The quake was described by Mr. Waesche as being of a definite swaying movement, accompanied by vibrations. He said the "felt" part of the quake lasted one minute.

 He added that the shake was from the southeast, probably not more than 10 miles from the observatory.

 . . . .

 An inspection of the [county] building revealed fresh cracks in the public welfare commission office at the east end of the hall. Some pieces of plaster from the walls fell down in the office of county Attorney Martin Pence.

 The shake was especially severe in the county building which is an old brick building. . . .

 The earthquake was also severely felt in the upper stories of the Volcano block, which houses the chamber of commerce office, and the Hilo Drug Co. building.

 At the Hilo Drug store several customers left in a hurry. However, everything on the shelves was left intact.

 At the Tribune Herald office a beam in the bindery and stock department on the second floor loosened about an inch from the ceiling.

 All sections of the Big Island with the exception of the Kohala district reported the quake felt strongly, although no damage was reported. Honokaa and Kona residents said the quake seemed to be two separate jolts, the harder one following a preliminary shock.



Anonymous, 1939, Strong quake is felt on Big isle: Hilo Tribune Herald, 05/23, p. 1. 



 An earthquake, classified by Hugh Waesche, assistant volcanologist, as "moderately strong" shook the Big Island at 2:14 p.m. this afternoon. No serious damage was reported.

 Last for about 30 seconds, the quake, which was stronger than the one last week, dismantled all equipment at the volcano observatory except the strong motion seismograph.

 Mr. Waesche said the quake sent a large cloud of dust over the northwest portion of Halemaumau crater. . . .

 Both in Hilo and at the volcano the shake was felt stronger than the one of Monday May 13 [sic-should be May 15].

 The quake seemed deeper in the earth than the last one. . . .

 At the county building . . .new cracks were reported on the plaster walls above the open windows which shook very hard during the quake.

 Mrs. Ethel King of Honokaa phoned in that Honokaa felt the quake about 2:15 p.m. The quake was reported to be about the same in volume as last week's.

 A report from Captain Cook, Kona, said the quake was felt strongly in contrast to the earlier one which was felt only slightly in West Hawaii.

 Kau reported that the quake was felt "rather strong."

 As in the last quake, Kohala was the only area of the Big Island reporting that it did not feel the shock.



Anonymous, 1939, Deep quake felt on Hawaii, Oahu: Hilo Tribune Herald, 05/24, p. 1, 5. 



 A deep earthquake of marked intensity was recorded at 12:59 p.m. today at the volcano observatory, the third strong shock to be felt since Monday, May 15. The quake was felt strongly in the volcano district, and in Hilo, and generally throughout the Big Island. It was also reported felt in Honolulu.

 A dust cloud rose over the northeast rim of the pit, indicating landslides accompanied the quake.

 Homes throughout the national park district reported objects knocked from shelves by the shock which was reported to be more intense for a shorter period of time than the shock yesterday afternoon.

 No damage was reported in Hilo.

 Hugh Waesche, assistant volcanologist, said that the felt portion was about 15 seconds, with the actual recording continuing for about six minutes. As in the two previous big shocks, all instruments were dismantled with the exception of the strong motion seismograph.

 Mr. Waesche estimated that the quake was of Kilauea origin as the past two ones have been, but said it was probably much deeper and more intense than the other two, judging from the fact that it was reported felt in Kohala; whereas the other two were not felt there, and also because it was felt in Honolulu.

 Mr. Waesche said that the many vertical recordings indicate that the quakes have originated almost beneath the observatory, although very deep down.

 Eighteen tremors including four of five very feeble quakes were recorded on the seismograph between the time of the heavy quake at 2:14 p.m. yesterday, and 8 a.m. today.

 Mr. Waesche reported that seven occurred between 2:14 and 6 p.m. yesterday, five between then and midnight, and six between midnight and 8 a.m.

 He said that this was a slight increase in the number of tremors which have been recorded recently during similar periods and expressed the belief that they were small aftershocks following the 2:14 p.m. quake.

 Indications were that the big quake yesterday originated at the north end of the crater and was very deep. It was about as far northwest of the observatory as the quake last week was to the southeast, being about 13 to 14 miles away.



Anonymous, 1939, Believe shocks were separate: Hilo Tribune Herald, 05/26, p. 4. 



 Seismological experts both in Honolulu and on the Big Island were of the opinion yesterday that the earthquake felt in Honolulu at 1 p.m. Wednesday and the quake which rocked Hawaii at 12:59 p.m. the same day were separate shocks and originated from entirely different points.

 Due to the two shocks being reported within a minute of each other, it was first thought that the quake felt on Oahu originated on the Big Island. 

 A study of the seismograph records obtained on Oahu and Hawaii, however, indicate that the Oahu and Hawaii shocks were not from the same source.

 The first wave of the Big Island quake was clocked at the Kilauea observatory by Hugh A. Waesche, assistant volcanologist, Hawaii national park, at 16.3 seconds after 12:59 p.m.

 Experts point out that if the waves of the Big Island quake had been felt on Oahu they would have been clocked at the University of Hawaii seismograph station 40 seconds after recording at Kilauea, or at 58.3 seconds after 12:59.

 It takes a quake about 40 seconds to travel between Kilauea and Honolulu.

 The Honolulu quake, however, was clocked at 30 seconds past 1 p.m.



Anonymous, 1939, 3 islands feel quake; no damage as tremor shakes territory for 10 seconds: Honolulu Advertiser, 05/30, p. 1, 4. 



 A sharp earth shock jarred the Islands last night with the quake being reported felt on Oahu, Maui and Hawaii.

 No damage resulted from the tremor which shook the Territory at 7:15 p.m. It lasted about 10 seconds.

 The shock registered on the seismographs at the University of Hawaii and at Kilauea on the Big Island.

 In Honolulu the quake was felt most strongly at Tantalus and Wilhemina rise. Mrs. W.A. Ramsay and Mrs. E.B. Williamson, both Tantalus residents reported the quake was felt distinctly.

 The tremor was also reported from Kailua and Waikiki.

 Lt. E.O. Heaton of the U.S. Coast and Geodetic Survey said the quake was recorded in Honolulu beginning at 7:15:09 p.m. and lasted for about 10 seconds. He said recordings on the University of Hawaii seismograph placed the epicenter about 150 miles from Honolulu in a northerly or southerly direction. [HVO records indicate it was southerly.]

 He classed the tremor as a "feeble shock."

 Lt. Heaton said he did not believe the quake was connected with the violent earth shocks reported during the day from Unalaska.



Anonymous, 1939, Sharp earthquake felt in Honolulu is recorded here: Hilo Tribune Herald, 05/30, p. 1. 



 An earthquake, which was strongly felt throughout Oahu last night at 7:15 was recorded on the seismograph at Kilauea volcano observatory for four minutes, with the first wave of the quake registering at 7:14. . . 

 The volcanologist said the quake apparently was the same type of shock as the big earthquake of January 1938 originating in the major rift zone of the entire Hawaiian group.

. . . .

 Lt. Cmdr. E.O. Heaton of the coast and geodetic survey, said that the UH records indicated the epicenter of the quake at a distance of 150 miles in either a northerly or southerly direction. [HVO records indicate it was southerly.]

 He said that the records indicated that the felt portion of the quake lasted 10 seconds although the quake continued registering for about five minutes.

 The quake was not felt on the Big Island.



Anonymous, 1939, 2 earthquakes shake island during night: Hilo Tribune Herald, 06/01, p. 1. 



 [subheads: Moderate to strong shock is felt in Hilo as prolonged quake at 8:50 p.m.; Slighter quake, felt by some in Hilo at 8:33 p.m., no damage is reported]

 Classified as moderate to strong, a prolonged earthquake was felt on the Big Island last night at 8:50. The shock was particularly hard in the volcano district and was felt throughout the Hilo area. Kohala and Kona areas report that the quake was slightly felt there.

 The earthquake was preceded by one at 8:38 p.m. which was recorded as slight. It was felt by a few persons in the Hilo district, but was generally felt throughout volcano area.

 The felt portion of the stronger quake continued for more than half a minute. In Hilo windows and doors rattled for what appeared to be a considerable length of time and the shock was thought to be not as heavy as the last three big quakes during the past weeks.

 No damage was reported.

 Hugh Waesche, assistant volcanologist, said that the slight quake originated about 18 miles from the observatory while the stronger one originated about 17 miles away. He said he was not sure whether they were of Kilauea or Mauna Loa origin, declaring that the distance was correct for either or both volcanoes.

 No change in the firepit Kilauea was reported and the record during the night following the two quakes was comparatively quiet Mr. Waesche said.



Anonymous, 1939, Moderate to strong quake rocks island: Hilo Tribune Herald, 06/12, p. 1. 



 [subheads: Felt portion of shock shortly after 1 a.m. estimated at one half minute; Quake believed to be of Kilauea origin, no damage reported on island]

 An earthquake classified as moderate to strong awakened Big Islanders at 1:11:29 a.m. today with prolonged rattling of windows and doors. although the quake was strong enough to dismantle all instruments at the observatory, no damage was reported.

 According to Hugh Waesche, assistant volcanologist, the quake probably was of Kilauea origin. He said it was the same type of shock as the strong as the four strong quakes experienced on the Big Island during the past month. the felt portion was estimated at about half a minute.

 In Hilo the quake did not seem to be as strong as the previous four shocks although it seemed more prolonged.

 The marked increase in seismic activity of the past few weeks is continuing, Mr. Waesche said, with an almost continuous swarm of tremors or small quakes being recorded on the seismograph.

 There have been a number of landslides into Halemaumau, although none has been particularly large, Mr. Waesche said.



Anonymous, 1939, Early morning earthquake is felt in Hilo: Hilo Tribune Herald, 06/19, p. 1. 



 An earthquake classified as slight to moderate was generally felt in the Hilo and volcano districts at 3:48:45 a.m. today [wrong time? should be one hour later]. 

 . . . .

In Hilo the quake was felt as a prolonged shock which however was not strong.

 Mr. Waesche reported that unusual seismic activity is continuing with as swarm of small quakes being recorded daily. There have been no perceptible changes in the pit or along the Chain of Craters road.



Anonymous, 1939, Big Islanders are awakened by earthquake: Hilo Tribune Herald, 07/01, p. 1. 



 [subheads: Shock classified as moderate occurs at 12:19 a.m., origin near observatory; Felt portion lasts for about 15 seconds, instruments are partially dismantled]

 An earthquake classified as moderate was generally felt in the Hilo and volcano districts at 39 seconds, 19 minutes past 12 this morning.

 According to Hugh Waesche, assistant volcanologist, the quake originated about 10 miles from the observatory to the southeast. The quake continued registering for about six minutes, with the felt portion lasting about 15 seconds.

 Instruments at the observatory were partially dismantled.

 The quake rattled windows and awakened many from their sleep, but did no damage.

 The rest of the article repeats information in Volcano Letter 464.



Anonymous, 1939, Strong earthquake rocks island: Hilo Tribune Herald, 07/14, p. 1. [check in library for page continuation] 



 [Subheads: All districts report shock at early hour; Waesche says shock stronger than any in recent series except May 15 shake; No damage is reported but all instruments dismantled by two major jolts]

 An earthquake classified as strong rocked the entire island of Hawaii at 51 minutes, 13 seconds past 3 a.m. today. Hundreds were awakened from their sleep as windows rattled from the two major jolts of the earthquake. No damage was reported from any section of the Big Island, however.

 According to Hugh Waesche, assistant volcanologist, the quake originated 13 miles from the observatory to the southeast, possibly in the extension of the Puna rift near the east end of Hilina pali.

 The felt portion of the quake lasted from 15 to 20 seconds. All instruments at the observatory were dismantled with the exception of the strong motion instrument.

 Mr. Waesche said that this morning's quake was harder than any in the series felt on the island between May 15 and the first of June with the possible exception of the May 15 shock.

 In Hilo the two major jolts of the shock were distinctly felt, and doors and windows rattled for what seemed to be a prolonged shock. No cracks were reported at the county building or at the Tribune Herald building, both of which were cracked in the May 15 quake.

 Mrs. J.B. Campbell, principal of the Kapoho school, said that the shock there was the biggest felt in a good many years.

 At the Honokaa Club Victor Morita said that his house was full and everyone was awakened by the quake.

 Mrs. C.H. Finlaysan said that the quake was felt generally throughout the Kona district and seemed to be quite a big one, although no damage was done.

 At Puuwaawaa ranch the quake was reported as slightly felt.

 Masaru Takahata, proprietor of the Kau garage at Pahala, said the quake was very sharp in the Kau district.

 In the volcano area the shock was particularly strong, and was felt by practically all residents of the district.

 Along the Hamakua coast the shock was reported strongly felt.

 No change was reported in the cracks along the Chain-of-Craters road or at Halemaumau.



Anonymous, 1939, Earthquakes are reported in Kohala area: Hilo Tribune Herald, 12/14, p. 1. 



 [subheads: Series of quakes rocks buildings in Kohala district during half hour period; Deep rumbling sound accompanies quakes which are described as peculiar]

 A series of earthquakes in the Kohala district between 8:05 and 8:35 p.m. Wednesday [Dec. 13] was reported to have been felt by Kohala residents, who said that the quakes were of a peculiar nature, unlike most quakes felt in Hawaii.

 Mrs. James Walker, wife of Archdeacon Walker, said it almost seemed as if someone had hold of the house and was shaking it at frequent intervals. she has said that the quakes were not hard but seemed to be almost continuous during the half hour.

 Mrs. Cal Hannah, Tribune-Herald correspondent in the Kohala district, also reported that the quakes were of a peculiar type. She said her home was shaken throughout the period.

 Both said the quakes were accompanied by a deep rumbling sound.

 Mrs. Hannah said she thought there were additional quakes Wednesday afternoon about 3, but others in the district did not report any at that time.

 Quakes were also reported in the Kona district last night.

 Hugh Waesche, assistant volcanologist, said this afternoon that there was no record of the quakes on the seismograph and said in all probability they were shallow local quakes which were not strong enough to be recorded at the volcano.



Anonymous, 1939, Peculiar, light quakes continue in Kona, Kohala: Hilo Tribune Herald, 12/15, p. 1. 



 The peculiar, light earthquakes reported in the Kohala and Kona districts continued last night, according to telephone reports from these two districts today.

 Mrs. C.H. Richardson, Kona correspondent for the Tribune-Herald said that the tremors have been felt nightly in the Kona district for the past week. She described the quakes as "unusual" in that they only seem to rattle doors and windows and are accompanied by a rumbling sound, as of thunder. No actual earth movement is felt.

 The quakes in Kona were reported more strongly felt in Honokahau toward the Kohala section.

 In Kohala a distinct quake, although a light one, was reported felt at 8:20 last night.

 Hugh Waesche, assistant volcanologist, said today that the quakes are not recorded on the volcano seismograph, and said that in all probability the shocks are light, local ones which are not of sufficient intensity to be recorded on the instruments.



Anonymous, 1939, Seismological notes: Bulletin of the Seismological Society of America, v. 29, no. 3, p. 515-516. 



 Hilo, Hawaii, May 8, 1939.--At 7:03 A.M. an earthquake rattled windows in Hilo.



Hilo, Hawaii, May 15, 1939.--A sharp earthquake dismantled instruments at Kilauea Volcano Observatory at 10:27 A.M. Simultaneously a large landslide occurred inside the volcano. The earthquake was felt in many sections of the island of Hawaii. It caused cracks in some office buildings and loosened plaster in a newspaper plant.



Honolulu, Hawaii, May 24, 1939.--An earth shock was felt at Honolulu and Hilo, but no damage was reported.



Honolulu, Hawaii, May 29, 1939.--At 7:15 P.M. an earth tremor was felt.



Anonymous, 1940, 60 quakes of Mauna Loa origin reported: Hilo Tribune Herald, 01/25, p. 1. 



 A sharp increase in seismic activity was the most marked development of the week ending January 21 at the Hawaiian volcanoes., according to the report of the volcano observatory.

 Practically all the disturbances originated from Mauna Loa. The volcano siemographs registered only 31 disturbances for the seven days while the Mauna Loa seismograph registered more than 60 disturbances between January 16 and 18.

 "Apparently the northeast rift was the principal center of activity," the report states. "The Mauna Loa seismograph is located at the end of the truck trail at an approximate elevation of 7000 feet on the east slope of the mountain."

 Of the 31 local disturbances which were recorded at the observatory, eight were very feeble earthquakes and 23 were tremors.

 The very feeble earthquakes, all of which were of Mauna Loa origin, were as follows:

 January 16, 11:06 p.m., distance 25.0 miles; January 16, 11:08 p.m., distance 25.0 miles; January 16, 11:33 p.m., distance 12.0 miles; January 16, 11:46 p.m., distance 12.0 miles; January 17, 10:50 a.m., distance 42.0 miles; January 19, 6:28 p.m., distance 27.0 miles; January 20, 12:34 a.m., distance 18.0 miles.



Anonymous, 1940, Hiloites feel sharp earthquake: Hilo Tribune Herald, 03/21, p. 1. 



 An earthquake, recorded as feeble to slight on the volcano observatory seismograph, was generally felt in Hilo at 7:46:15 p.m. Wednesday as a short, sharp shock. This was the first earthquake shock to be felt in Hilo in many months.

 . . . Mr. Waesche said that only one person in the volcano area reported feeling the quake, and it was not reported felt in other sections of the island.

 The rest of the article repeats material in Volcano Letter 467.



Anonymous, 1940, 2 earthquakes felt last night: Honolulu Star-Bulletin, 06/17, p. ? [!not found; duplicates info in another article] 



 At least two sharp earthquakes were felt in Honolulu last night.

 The first, coming just before midnight, lasted several seconds and rattled windows and caused houses to tremble and creak.

 Another slight shock of about two seconds, was felt about 12:15 a.m.



Anonymous, 1940, Strong quake is felt throughout Hawaiian Islands: Hilo Tribune Herald, 06/17, p. 1, 5. 



 Hilo and Honolulu felt another after shock at 12:39 p.m. today. The quake was classified as between slight and moderate and of the same origin as the earlier quakes.

 Kauanakakai on Molokai reported feeling four tremblors about midnight.

 Strong enough to dismantle all the earthquake recording equipment on the Big Island except the strong motion seismograph at the observatory, an earthquake was felt throughout the territory Sunday night [June 16-17] beginning at 11:57:11.8 p.m. the felt portion lasted two minutes.

 The quake was described by Hugh Waesche, assistant volcanologist, as "very similar" to the one in January 1938, except that its origin seemed closer.

 . . . .

 The "felt" part of the quake lasted about two minutes and was sufficiently strong to cause many Hilo families to run from their houses, rattle windows and cause dishes to drop from shelves. It was the strongest quake recorded here since the territory-wide one of 1938.

 All sections of the island--Kona, Kau, Kohala and Hamakua--reported that the shock was felt distinctly.

 Equipment at the observatory showed the origin to be between 110 and 120 miles distant, in a general northwesterly direction.

 It recorded for about an hour. A second quake of slight intensity was felt at 12:14:34.5. This morning at 7:46:46 a.m. a moderate quake was felt. . . .

 In addition to the equipment at the observatory, the quake dismantled the equipment in the Kilauea pit and "probably the one in Kona," he said.

 Oahu and Maui reported feeling the quake, especially the latter island. Honolulu residents were said to have been awakened by the shock.



Anonymous, 1940, Quake shakes city; is felt on outer islands: Honolulu Star-Bulletin, 06/17, p. 1, 5. [Note: The dispatch from Molokai is added from the continuation on p. 5 of a headline article on p. 1 in the final edition of the newspaper; the continuation has the same dispatches from Hilo, Maui and Kauai as reported in this self-contained article on p.1 of the early edition of the newspaper.] 



 The severest earthquake to be felt here since January 22, 1938, rattled dishes and windows in Honolulu, and awakened many persons who were sleeping, as the temblors began at 11:57 Sunday night.

 No damage has been reported as a result of the quake except dismantling of the high magnification seismographs at the University of Hawaii, according to Lt. E.O. Heaton, officer in charge of the coast and geodetic survey's local office.

 According to the records obtained by low magnification instruments, . . . the point of origin has been set 125 miles east of Honolulu.

 The four temblors, recorded at 11:57 p.m., 12:05, 12:15 and 12:20 a.m., were classed as type 4 of the Mercalli intensity scale which describes them as having the sensation of a heavy truck striking a building.

 Hilo, Hawaii, June 17--A strong, prolonged earthquake lasting about a minute was felt throughout the island of Hawaii at midnight Sunday. The temblors caused many Hilo families to run into the streets and in several instances articles fell from shelves. A series of small temblors have been felt in Hilo since midnight.

 Wailuku, Maui, June 17--Two sharp earthquake temblors were felt here at midnight Sunday and at 12:17 a.m. today. No damage has been reported.

 Lihue, Kauai, June 17--A slight earthquake shock was felt throughout Kauai at midnight Sunday. No damage has been reported.

 Kaunakakai, Molokai, June 17--Four earthquake temblors were felt here around midnight Sunday, the strongest being at the Puuohoku Ranch, where windows rattled and dishes were displaced. No damage was reported.



Anonymous, 1940, Sharp quake is felt here at midnight: Honolulu Advertiser, 06/17, p. 1. 



 An earthquake of moderate intensity wakened many Honolulans at midnight last night, and rattled windows and dishes.

 According to Lt. E.O. Heaton, officer in charge of the Honolulu field station of the U.S, Coast and Geodetic Survey, the quake was not quite so strong as that of Jan. 22, 1938, although both high magnification seismographs at the University of Hawaii observatory were dismantled.

 Records of the temblor, which began at 11:57:29 p.m., and lasted about two minutes, was obtained on low magnification instruments.

 Lt. Heaton said epicenter of the quake was 125 miles due east of Honolulu.

 No damage from the temblor was reported, although the shock was felt strongly in Hilo and on Maui as well as in Honolulu. No reports were obtained immediately from other islands.



Anonymous, 1940, Earthquake is felt here: Hilo Tribune Herald, 07/16, p. 1. 



 An earthquake classified as a "moderate shock" [was recorded] yesterday afternoon about 4:45 p.m. The temblor was strong enough to dismantle the instrument . . . .

 From out Kohala Mrs. G.L. Hannah reported that the quake was strong, lasting for a full 30 seconds. starting at 4:45 p.m. No damage was reported in the district.

 In Hilo the quake was slight but was felt by a number of people.

 . . . .



Anonymous, 1940, Mild quake felt throughout Hilo: Honolulu Advertiser, 07/18, p. 9. 



 Hilo, July 16--A moderate earthquake was recorded on the volcano observatory seismograph about 4:45 p.m. yesterday and was slightly felt in Hilo and some sections of the Big Island.



Anonymous, 1940, Seismological notes: Bulletin of the Seismological Society of America, v. 30, no. 3, p. 307. 



 Honolulu, Hawaii, June 17, 1940.According to the Hawaiian Volcano Observatory Report, a moderate earthquake which was felt by many persons on all the islands of the Hawaiian group occurred at 7:46 A.M. on June 17. It originated apparently about 111 miles north-northwest of Kilauea.



Anonymous, 1941, Quake felt in East Hawaii: Hilo Tribune Herald, 04/21, p. 1. 



 A moderate earthquake felt throughout East Hawaii dismantled equipment at the Kilauea observatory and in the pit Sunday [Apr. 20], according to volcanologist Ruy H. Finch.

 The "felt" portion of the quake lasted about 30 seconds. Origin was about three and a half miles from the observatory.

 The quake occurred at 11:46 a.m. [10:46 in Volcano Letter 472], and was preceded by a series of lesser quakes.



Anonymous, 1941, Heavy earthquake hits Big Island: Hilo Tribune Herald, 09/25, p. 1. 



 One of the strongest earthquakes in several years hit the Big Island at 7:18 a.m. today, dismantling all seismographic equipment at the Kilauea observatory, breaking bottles and dishes and cracking plaster walls in homes and public buildings.

 The quake was classified at the observatory as "moderate to strong," and of Mauna Loa origin. The motion was north-south. The long, slow rocking movement caused landslides in Halemaumau. . .

 Particularly hard hit were Pahala and Kapapala. . . .

 Kona reported that it was the most severe quake since 1929, while superintendent Ed Wingate said it was the most severe on the Hilo side since 1933.

 One Pahala resident said it was the worst earthquake in that district in 30 years. The first shock he said was felt at 7:30 a.m. plantation time and lasted for a full minute. That was followed by seven or eight tremors, the last occurring at 8:45 a.m.

 Dishes and lamps fell off shelves and bottles were broken at the Pahala hospital and it was reported minor damage to a juice pulper at the Hawaiian Agricultural Co.

 Kohala reported the quake was felt strongly and their was no damage. Naalehu and Puna also reported that the quake was strong but apparently not as severe as at Pahala and Kapapala.

 The Kapapala school water tank was reported to have fallen down and at Honuapo oil tanks were repeatedly shaken. There were small landslides on roads in the Kau district.

 The earthquake was felt in varying degrees in Hilo. Keaukaha reports feeling the quake slightly or not at all. Waiakea homesteads reports feeling the quake strongly.

 Slight cracks in the plaster were reported in the new wing of the Federal building and in the County building.



Anonymous, 1941, Volcano report: Hilo Tribune Herald, 10/30, p. 2. 



 An earthquake that occurred at 8:54 a.m. October 25, was felt at Hawaii National Park, Hilo, and Kohala. Its origin appears to have been under the northern slope of Mauna Kea.

 . . . .

 During the past month there has been a rather persistent opening of the concentric cracks around Halemaumau. The movement for the current week, however, was distinctly less than for the preceding week. Of the 26 localities that are regularly measured 10 opened 6.5 millimeters, one closed one millimeter and 17 remained unchanged.



Anonymous, 1941, Intense seismic activity on Big Island continues: Hilo Tribune Herald, 11/15, p. 1. 



 Seismic activity-the most intense since 1938-continued on the Big Island today, with more earthquakes reported last night and early this morning.

 The strongest quake, according to Ernest Schultz, junior geologist at Hawaii National Park, was recorded at 6:53 a.m. today. Other quakes were at 2:04 and 4:07 a.m. [the latter two not listed separately in Volcano Letter 474].

 A quake was felt in Hilo at 5:34 p.m. Friday [Nov. 14].

 In the 48 hours preceding 1:30 p.m. Friday, the Mauna Loa seismograph at 6700 feet recorded 85 seismic disturbances, Mr. Schultz said. Of these, one at 8:06 p.m. Thursday [Nov. 13] was classified as slight, one at 6:02 a.m. Friday was feeble; 11 others were very feeble and 72 were tremors.

 Origin of all the quakes and tremors, Mr. Schultz added, was believed to be approximately 50 miles north of Kilauea.



Anonymous, 1941, Quake strongest in Waimea area: Hilo Tribune Herald, 11/18, p. 1. 



 Dishes and bottles were reported broken at Waimea early this morning by an earthquake which was also strongly felt in Hilo.

 Approximate time of the quake was 2:53 a.m., according to superintendent Edward G. Wingate who said it apparently originated south and west of Waimea.

 The quake would be classified as not over slight at Kilauea, but may have been moderate at Waimea, he added.

 . . . .



Anonymous, 1941, Volcano report: Hilo Tribune Herald, 11/21, p. 5. [This report gives details of time and distance not given in Volcano Letter 474] 



 The whole island of Hawaii has been shaken during the past week by a series of earthquakes whose origin has been tentatively placed in the Waimea tableland between the Kohala mountains and Mauna Kea. No material damage has to date been reported from this seismic activity. At the Volcano observatory 68 seismic disturbances have registered, making the local seismic index 25.50. the index for last week was 2.25.

 The earthquakes were recorded as follows:

 "moderate" 1

 November 16, 9:41 a.m., distance 52.7 miles, felt by many persons in all portions of the island, no damage reported. This quake was also recorded but not felt in Honolulu.

 "slight" 1

 November 15, 6:53 a.m., distance 51.2 miles, felt island-wide by a few persons, by many in Kohala, North Kona and Hamakua area.

 "Feeble" 1

 November 15, 6:37 p.m., distance 51.9 miles, felt in northern portion of the island and by several persons in Hilo.

 "Very Feeble" 13 (beginning with the quake of November 13, all were felt at Waimea, the majority were felt in Kohala, Hamakua, and North Kona; a few were felt at Kilauea.

 November 11, 2:41 a.m., distance 16.3 miles; felt by a few persons at Kilauea only.

 November 13, 3:07 p.m., distance 53.0 miles

 November 14, 0:51 a.m., distance 51.7 miles; 5:03 a.m., distance 53.3 miles; 5:47 a.m., distance probably 53.3 miles; 9:53 a.m., distance probably about 52 miles; 9:54 a.m., distance probably about 52 miles; 9:55 a.m., distance probably about 52 miles; 4:07 p.m., distance 54.2 miles; 5:34 p.m., distance 51.2 miles.

 November 15, 1:27 p.m., distance probably about 50 miles.

 November 16, 2:32 a.m., distance probably 51.2 miles; 2:35 a.m., distance 50.7 miles.

 "Tremors" 52, of which one was reported felt at Kapapala ranch, one at Hookena and Kapapala ranch, November 12, and 5 were felt at Waimea, Kohala, Hamakua and north Kona November 14 to 16.

 In addition to the 68 seismic disturbances recorded at the observatory, 73 tremors and 4 very feeble earthquakes were recorded on the Mauna Loa seismograph.

 The article concludes with reports other than earthquakes.



Anonymous, 1941, Quakes appear coming to end: Hilo Tribune Herald, 11/24, p. 1. 



 The spell of earthquakes that started 3:50 p.m. November 12, 1941, with epicenter near Puu Holoholoku, southwest of Waimea, appears to be coming to an end. On November 20 but one tremor with origin in the above locality was recorded at the Volcano observatory in Hawaii National park, although 20 tremors registered prior to 9 a.m. on the Mauna Loa seismograph.

 Puu Holoholoku is on the northwest slope of Mauna Kea at an elevation of 2900 feet. During the series, a total of 275 shakes was recorded on the Mauna Loa seismograph by 8:51 a.m. November 20, which is the instrument nearest the epicenter. According to P.E. Schultz, seismologist of the observatory, the actual breaks that occasioned the shakes took place 27 miles below the surface. The depth of focus explains why the shakes were felt over so wide an area and yet caused no material damage in the vicinity of the epicenter. Good records were written on the Haleakala seismograph. Many of the shakes were felt on Maui and a few of the stronger ones were perceptible on Oahu. A few small landslides occurred at road cuts along the Hamakua coast, but no break in the crust was found at the epicenter.

 The amount of energy released by the earthquakes was considerable, Mr. Schultz said. It is fortunate that the energy was released in small amounts over a considerable period of time rather than in a culminative shake. the fact that the energy release took place gradually indicates a considerable mobility even under Mauna Kea, he added.

 In view of the fact that the earthquake originated under the northwest slope of Mauna Kea, their occurrence does not portend any immediate volcanic activity. It has been noted, however, that shakes originating in this vicinity and farther east do occasionally occur a year or so prior to an outbreak of Mauna Loa.



Anonymous, 1942, Eruption expected; How about blackout?: Hilo Tribune Herald, 02/09, p. 1. 



 Kamaainas of the Big Island are expecting an eruption at Kilauea crater sometime in the near future, it was reported today by one of them.

 "We feel it coming," was their only comment.

 Some say they have been feeling a series of earthquakes in the past few weeks.

 "There's no getting away from it--we know it's coming," say these people.

 (What will happen to Hilo's blackout if the volcano erupts at this time?)



Anonymous, 1942, Quakes felt here: Honolulu Star-Bulletin, 02/12, p. ? 



 Several earthquake temblors, none of which was prolonged, were felt in downtown Honolulu and other areas of the city shortly after 11 [assume war time] this morning



Anonymous, 1942, Strong quakes cause damage, crater slides: Hilo Tribune Herald, 02/21, p. 1. 



 Dishes and bottles crashed to the floor, plaster cracked and parked cars shook when two strong earthquakes were felt in Hilo shortly after 9 a.m. today [time off by one hour?].

 Classified as "moderate to strong," the quakes dismantled all seismological equipment at Kilauea and caused slides in both Kilauea and Halemaumau craters.

 Kilauea observatory officials said that while the shocks may have seemed to be separate, it was actually one long continuous quake. [These are listed in Volcano Letter 475 as separate quakes.]

 Origin of the quake was not known at press time.

 . . .



Anonymous, 1942, 2 strong quakes felt in Hilo: Honolulu Star-Bulletin, 02/21, p. 1. 



 Hilo, Feb. 21.--Two strong, sharp earthquakes, classified as moderate to strong, were felt in Hilo shortly after 9 a.m. [Hawaii war time, one hour later than Hawaii standard time] today.

 The shocks broke dishes, cracked plaster and shook parked cars.

 All equipment at the volcano observatory was dismantled by the quakes, which caused slides in both Kilauea and Halemaumau.

 Origin of the shocks is not known.



Anonymous, 1942, Volcano House liquor stock lost in quake: Hilo Tribune Herald, 02/22, p. 1, 4. [Times given are Hawaiian War time, one hour later than Hawaiian Standard time] 



 . . . yesterday morning's strong earthquakes caused all the bottles of liquor which were on shelves in the bar and in the stock room to fall down and break, causing an estimated loss of $300.

 "I [George Lycurgus, manager of the Volcano House] was having my daily workout as usual when the ground in front of me started to swerve as I was about to approach the fourth green . . .

 Here are the vital statistics on the quakes as reported by Volcanologist Ruy H. Finch:

 The preliminary determination of the location of the quakes puts them on the northeast slope of Mauna Loa, about 16 miles west, northwest of the observatory.

 They dismantled all the seismographs that are located on the east side of the island.

 While the ground was still swaying under the influence of the first quake at 9:11 a.m., another and stronger shock occurred at about 9:14 a.m. At 9:15 and 9:29, two very feeble shocks were recorded.

 Then, at 9:37 there was another shake, strong enough to dismantle the east-west component of the seismograph at the Volcano House. There was another feeble shake at 10:17.

[The remainder of the article talks about the natural steam heating system at the Volcano House]



Anonymous, 1942, Quake felt here after midnight: Hilo Tribune Herald, 03/21, p. 4. 



 A deep-seated earthquake was felt generally in Hilo at 12:04 a.m. today.

 Superintendent Edward G. Wingate said the quake dismantled seismic equipment at Kilauea.

 No damage was reported.



Anonymous, 1942, Flow stops 11 miles from Hilo; Reporter finds going tough on visit to fire goddess: Hilo Tribune Herald, 05/18, p. 1, 2. 



 The article describes the end of the Mauna Loa northeast rift eruption, indicating that rigid censorship associated with the wartime blackout of Hilo prevented any mention of the eruption (which began April 26) until this date.



Anonymous, 1942, Flow stops 11 miles from Hilo; Bombs used to divert course of eruption: Hilo Tribune Herald, 05/18, p. 1, 2. 



 Most of the article describes the chronology of the Mauna Loa northeast rift eruption. The following two paragraphs are of special interest.

 Why it was kept secret--"Army authorities said today the reason the eruption was kept secret until now was because it was felt that the glow might serve as a beacon that would attract the enemy."

 "It was to divert this flow [described in the preceding paragraph as a 'huge wall of lava which moved irresistibly down toward Hilo's water supply, causing more danger to the city than any flow in 61 years' that army bombers--as they did in 1935--roared over the stream of lava, dumping tons of bombs. The effectiveness of the bombing has not been made known. It may take a trek up the rugged mountain skin to find out. This was done after the 1935 eruption and it was found that the bombing had diverted the lava."



Anonymous, 1942, Local earthquake recorded at volcano: Hilo Tribune Herald, 07/09, p. 1. 



 An earthquake described as between slight and moderate was recorded at 3:59 a.m. [daylight saving time in effect-subtract one hour] on the seismograph at the volcano observatory, it was reported by Dr. Ruy Finch, volcanologist. The temblor was strong enough to dismantle the seismograph, and was felt in the Hilo district.

 Dr. Finch estimated the origin of the quake to be more than 50 miles northwest of the volcano district.

 Several very small earthquakes were recorded Wednesday afternoon [July 8].

 The earthquake was strongly felt by residents of the Waimea district, it was reported.



Anonymous, 1942, Seismological notes: Bulletin of the Seismological Society of America, v. 32, no. 4, p. 236. 



 Hilo, Hawaii, April 26, 1942.Eyewitnesses to the eruption of Mauna Loa volcano, which started on April 26, stated that heavy tremors were felt every few minutes and that they were apparently caused by readjustments in the boiling cavern under the cone of the mountain, according to the Associated Press.



Anonymous, 1942, Seismological notes: Bulletin of the Seismological Society of America, v. 32, no. 2, p. 63. 



 Hawaii, September 25, 1941.The following report was received from the Hawaiian Volcano Observatory: "The strongest earthquake since 1929 occurred on September 25 at 7:19 A.M. The epicenter was 15 miles distant from the Observatory and has been tentatively located 5 miles deep on the east flank of Mauna Loa, 3.5 miles northeast of the Kapapala Ranch House and about eight miles northeast of Pahala. All Observatory seismographs were dismantled, including the Haleakala seismograph on Maui. The quake was felt sharply over the whole island of Hawaii and by some persons in Honolulu. Several thousands of dollars damage was done at and near Pahala. Several road fills cracked and shoulders failed. Furniture was overthrown, dishes were broken and some persons were injured in flight from their homes. Pharmaceuticals and package goods were smashed in falling from shelves at Pahala. Plaster was cracked and a few windows and pipe connections were broken. Several dry stone walls on the Kapapala Ranch were thrown down in part. Landslides were caused in Halemaumau which produced large dust clouds to rise above the pit." The United States Coast and Geodetic Survey reports an earthquake on September 25, 1941, at 17h 48m 37s, G.M.T., with epicenter at 19  N, 155 W, in the Pacific near the Island of Hawaii.



Hawaii, November 16, 1941.--According to a report from the Hawaiian Volcano Observatory, an earthquake of moderate intensity was felt at 9:41 A.M. by many persons in all parts of the Island of Hawaii. No damage.



Anonymous, 1944, 'Quake shakes Hilo early this morning: Hilo Tribune Herald, 12/27, p. 1. 



 A sharp temblor shook Big islanders out of their beds shortly before 5 this morning [daylight saving time]. The shock, lasting a few seconds, did not cause any damage in Hilo, as far as can be determined.

 R.H. Finch, volcanologist at the Hawaii national park, said the earthquake, which he described as pronounced, about 5 a.m. was followed by two smaller quakes at 6 and 7 a.m.



Anonymous, 1945, Hilo residents feel earthquake: Hilo Tribune Herald, 07/13, p. 2. 



 Residents in several sections of Hilo felt an earthquake which some describe as "fairly strong" early today.

 Ruy H. Finch, volcanologist, reported a "moderate" earthquake was registered on the Volcano observatory seismograph at 3:15 a.m. today, lasting more than five minutes on the instrument.

 He said the quake dismantled the east-west component of the seismograph.



Anonymous, 1945, Seismological notes: Bulletin of the Seismological Society of America, v. 35, no. 3, p. 46. 



 Hawaii, December 27, 1944.R. H. Finch, Volcanologist in Hawaii National Park, reports: "The strongest earthquake experienced here since September, 1941, occurred at 4:41 A.M. (War Time), December 27. Some objects were toppled from shelves over a large part of the Island of Hawaii. It was plainly felt as far away as Oahu. All seismographs on Hawaii were dismantled. The shaking was most pronounced in the Kau district or the southwestern part of the island, where a few water pipes were broken and some stone fences thrown down. The origin was about 1.9 miles below the center of Mokuaweoweo, the summit crater of Mauna Loa." Windows rattled and many persons were awakened in Honolulu.



Anonymous, 1946, Strong quake rocks regions in Volcano, Kau: Hilo Tribune-Herald, 09/05, p. 1. 



 An earthquake described as "the strongest we've had in quite awhile" rocked the volcano and Kau regions at 1:22 p.m. Wednesday, it was reported today by seismologist Howard A. Powers at the Volcano observatory.

 No damage was reported, however.

 Powers placed the temblor's epicenter under the south slope of Mauna Loa. He said the quake was felt for several seconds and was perceptible on the instruments considerably longer

 . . . .



Anonymous, 1946, Earthquake total here in September smallest in months: Hilo Tribune-Herald, 10/06, p. 1. 



 Seismographs on Kilauea and Mauna Loa recorded only 33 earthquakes during September, it was reported today by Volcanologist Ruy H. Finch.

 "This is the smallest month's total for the last five months," he said.

 Finch disclosed that most of the shakes originated under Mauna Loa.

 Two perceptible quakes, he said, occurred September 2 and 4.

 One of these, which occurred at 1:22 p.m. September 4, was felt in Honolulu. [This seems unlikely as magnitude is close to 4. It was barely recorded by the Milne-Shaw seismograph on Oahu.]

 "An earthquake accompanied by a sharp, explosive like noise was felt at Kapapala ranch at 3:33 a.m. September 18, the volcanologist's report stated.

 "It must have had a very shallow focus for it produced but a very feeble record on the observatory seismographs 18 miles away," the volcanologist commented.

 . . . .



Anonymous, 1946, 49 earthquakes recorded here in October: Hilo Tribune-Herald, 11/05, p. 1. 



 There are signs of increasing uneasiness of Mauna Loa, Volcanologist Ruy H. Finch of Hawaii National Park reported today.

 . . . .

 Forty nine earthquakes, most of them originating under Mauna Loa, were registered at the volcano observatory last month, Finch said. Ten earthquakes not recorded on observatory seismographs were registered at Mauna Loa, he added.

 An earthquake October 10 which was widely felt on Maui and scattered points on this island originated deep under the Hualalai coast, Finch disclosed.

 The volcanologist said the earthquake of October 29, which rocked most of the eastern half of Hawaii, originated deep under the east slope of Mauna Loa.



Anonymous, 1946, Seismologists plan wave alarm system: Hilo Tribune-Herald, 11/05, p. 1. 



 "The seismograph at Kilauea volcano may soon be equipped with an alarm system to warn Big Islanders in the event of an earthquake of a magnitude sufficient to cause tidal wave . . ."

 The body of the article describes how the warnings would be transmitted to the homes of HVO staff members Howard Powers and Ruy Finch any hour of day or night. It also describes the uncertainties involved in determining whether a given earthquake will generate a tsunami. Powers closes with a plea for pan-Pacific cooperation.

 " . . . a system offering rapid communication between scientists in all Pacific areas would enable seismologists to compare notes and send out tidal wave warning far ahead of the wave itself."

 [Spurred by the death and destruction on the island of Hawaii incurred by the tsunami of April 1946, this warning system anticipated the much later founding of the Pacific Tsunami Warning Center on Oahu.]



Anonymous, 1947, Strong quake is felt here: Hilo Tribune-Herald, 03/20, p. 1. 



 A strong earthquake originating under the east slope of Mauna Loa Wednesday night [Mar. 19] dismantled seismographs at HVO. The quake was more shallow ["deep" in VL] than others recently. The temblor was especially strong in the vicinity of Naalehu and Kapapala. Observers at Kapapala described it as the strongest in several years. It was also felt in Hilo and vicinity.



Anonymous, 1947, New signs of uneasiness under slumbering volcano here noted: Hilo Tribune-Herald, 06/30, p. 1. 



 A series of earthquakes registered at the Mauna Loa seismograph in Hawaii national park during the past six weeks topped off by a disturbance last Thursday afternoon {June 26] which was severe enough to dismantle the instrument at Mauna Loa station are interpreted by Ruy H. Finch, volcanologist, and Howard Powers, seismologist, as signs of uneasiness under the slumbering volcano.

 Finch said that while these signs are "very weak," the series of 'quakes in the past few weeks "might be the beginning of a pattern of indicative earthquakes."

 The 'quake last Thursday, recorded about 2:30 p.m., was felt all the way from Hilo to Naalehu.



Anonymous, 1947, Earthquake felt here: Hilo Tribune-Herald, 08/18, p. 1. 



 An earthquake at 9:55 a.m. dismantled one seismograph and was felt as far as Hilo.

 "Ruy H. Finch, volcanologist, tentatively placed the origin of the quake under Mauna Loa. He said it was the most pronounced disturbance in about two months."



Anonymous, 1947, 5 Earthquakes shake Big Island in 24 hours: Hilo Tribune-Herald, 08/19, p. 1. 



 Hawaii's "sleeping beauties"--Kilauea and Mauna Loa volcanoes--tossed uneasily in bed today kicking up five feeble to moderate earthquakes in 24 hours.

 However, Ruy H. Finch, Hawaii national park volcanologist, placed "no special significance" to the series of earthquakes, describing them as "general uneasiness."

 Finch said the earthquakes--one of them described by Naalehu and Kapapala residents as "strong"--originated at different depths.

 The last of the series of earthquakes was recorded at 6:44 a.m. today. Naalehu and Kapapala residents reported it was "much stronger" than the first quake which shook the Big Island from Kau to Hilo at 9:52 a.m. on Monday Aug. 18].

 Finch said the 6:44 a.m. earthquake today originated at moderate depth under the east slope of Mauna Loa.

 The first of the series, the one at 9:52 a.m. Monday, was of moderate intensity, originating five miles southeast of Kilauea, in deep focus and probably on the fundamental rift under Mauna Loa and Kilauea.

 This quake was felt as far as Hilo.

 A feeble quake was recorded at 10:01 a.m. Monday, followed by another at 2:11 p.m. Monday. The latter quake was described as feeble, probably originating under Mauna Loa.

 Another feeble quake, probably of Mauna Loa origin, was recorded at 1:22 a.m. today.



Anonymous, 1947, Big Isle quake not linked to volcanic activity: Hilo Tribune-Herald, 09/22, p. 1. 



 An earthquake which shook the Big Island for three and a half minutes early Sunday originated along the fundamental rift between Mauna Loa and Mauna Kea and was not related to any volcanic activity, volcanologist Ruy H. Finch reported today.

 Revising an earlier evaluation of the temblor as only slight, Finch said today that complete reports showed that the quake rocked the island from Waimea to Hilo and as far west as Pahala in Kau.

 No damage was reported. Many persons described the quake as a slow rocking or swaying. It was intense for only about 20 seconds and in some areas was accompanied by a rumbling noise. The quake occurred at 5:50 a.m.

 The volcanologist said the quake originated about 15 miles under the Humuula area on the 7000 foot saddle plateau between Mauna Loa and Mauna Kea.

 Seismographs at both recording stations on Mauna Loa were dismantled, Finch said.

 He added that seismographs at the park observatory registered a feeble earthquake under Kilauea volcano at 7:40 a.m.

 He said there was no relation between the Kilauea quake and Sunday's temblor on the Mauna Loa-Mauna Kea rift.

 There is no unseasonal tilt or ground swelling to indicate imminent surface activity from either Kilauea or Mauna Loa, Finch emphasized.



Anonymous, 1947, Earthquake puts KHBC off the air: Hawaii Tribune-Herald, 09/30, p. 1. 



 An earthquake 15 miles under Kilauea volcano, so strong it toppled over the antenna of Radio Station KHBC in Hilo, rocked the Big Island at 4:05 a.m. today.

 Volcanologist Ruy H. Finch described the temblor as the strongest here in two years.

 He said the movement was both horizontal and vertical.

 "It is the first time our vertical seismograph has been dismantled in two years," Finch reported.

 All the instruments at seismographic stations at the observatory, beneath the Volcano House, at Hilo, Naalehu, Mauna Loa, Kapapala, and Kona were dismantled.

 Its epicenter, he said, was about 15 miles under Kilauea and about eight or ten miles east southeast of the Volcano House. [not the location given in the Volcano Letter]

 . . . . William J. Kiml. Co. at 61 Kalanianiole street, reported this morning that the earthquake caused a large hole, resembling a cave, to be formed on the ground at the rear of the store. The round hole is three feet deep and four feet in diameter.

 . . . .

 Brother Strauss, seismologist at St. Mary's school in Hilo, described the quake as "violent" and said it was followed by two weaker temblors at five minute intervals.

 There were no other reports of damage.

 People throughout the island were roused from bed.

 Many persons reported they felt it for well over one minute.



Anonymous, 1947, Deep earthquake originates under Kilauea volcano: Hilo Tribune-Herald, 12/15, p. 1. 



 A deep earthquake originating 20 miles under Kilauea volcano rattled windows and dishes at 10:10 a.m. Sunday in the Hilo, Volcano and Kau districts.

 Ruy H. finch, volcanologist at Hawaii national park, said the quake was felt quite plainly in the park region and was accompanied by a rumble. It dismantled seismographs at Mauna Loa and at the park observatory.

 The quake had a pronounced vertical motion, Finch said.

 "Although it was quite deep, by itself it has no other significance," Finch said, "other than indicating slight uneasiness."



Anonymous, 1947, 3rd quake in 5 days shakes Hilo: Hilo Tribune-Herald, 12/24, p. 1. 



 The third earthquake to originate under Mauna Loa in five days awakened Big Island residents at 6:38 a.m. today.

 The earthquake was the fourth to shake the Big Island in the past 10 days, for a deep earthquake originated under Kilauea volcano Sunday, December 14.

 Ruy H. Finch, volcanologist at Hawaii national park observatory, characterized the earthquake as "slight" and said it originated under the east flank of Mauna Loa.

 It was particularly noticeable in the Puueo section of Hilo.

 "It might be developing into a pattern," Finch said, although he added there is not yet any indication of an eruption. He explained that a volcano sets up a definite pattern when there has been a series of 5 to 6 temblors in one locality or a series of long vibrations.

 The recent temblors, he said, have not been in the same locality.

 following the Kilauea volcano quake of December 15 [sic; actually Dec. 14] there was a "widely felt" quake Saturday December 20, originating under Mauna Loa, and a severe earthquake Monday morning, also under Mauna Loa.



Anonymous, 1947, Volcanologist sees no sign of early activity: Hilo Tribune-Herald, 12/05, p. 1. 



 . . . .

 "Following the distinct earthquake of October 31, which originated high up on the rift extending from Mokuaweoweo to Kealakekua Bay," the report [from HVO] said, "the kona seismograph recorded two small shakes along the same rift. This rift was active in 1877, producing a small lava flow in Kealakekua Bay.

 "On November 23 there were two periods of continuous tremor each lasting over three minutes. The tremor was more like that which accompanies an outbreak of Mauna Loa than like individual earthquakes. the tremor originated at Kilauea . . . "



Anonymous, 1948, Kilauea earthquake recorded: Hilo Tribune-Herald, 01/09, p. 1. 



 Seismographs at Hawaii National Park registered a fairly deep earthquake southwest of Kilauea volcano at 4:30 p.m. Thursday.

 Dr. Howard A. Powers, seismologist at the park, said the quake was felt in the volcano district and parts of Hilo. No special significance is attached to the temblor.



Anonymous, 1948, Mauna Loa earthquake shakes Isle: Hilo Tribune-Herald, 01/15, p. 1. 



 A moderate earthquake, fitting into the general pattern of restlessness exhibited by the island's sleeping beauty, Mauna Loa, was felt here at 6:16 a.m. today.

 The temblor, which lasted several seconds in the Puueo section of Hilo, was felt, although not severely, in the Volcano region and other sections of the Big Island.

 Dr. Howard A. Powers, seismologist at Hawaii national park, said the moderate quake originated on the east slope of Mauna Loa and was of moderate depth.

 Deflating any hopes for an immediate eruption of the volcano, he said that the earthquake fits into a pattern of uneasiness but that there are usually a series of temblors one soon after the other just before an eruption.



Anonymous, 1948, Earthquake felt here: Hilo Tribune-Herald, 01/27, p. 1. 



 A moderate earthquake, originating on the northeast slope of Mauna Loa, was registered on the seismograph at Hawaii national park at 11:02 p.m. Monday [Jan. 26], Howard A. Powers, park naturalist, said today.

 As far as is known, the earthquake was felt over a wide area, Powers said.

 The quake was felt by residents of the Puueo section of Hilo, a part of the city quite sensitive to earthquake shocks.

 . . . .



Anonymous, 1948, Quake rocks wide area of Big Island: Hilo Tribune-Herald, 03/10, p. 1. 



 An earthquake, originating either under Hualalai or Mauna Kea, was recorded on Hawaii national park seismographs at 3:46 p.m. Tuesday [Mar. 9].

 Ruy H. Finch, park volcanologist, said the quake was felt over a wide area, including Hilo and Waimea. . . .

 . . . .

 An earthquake at 8:30 a.m. Tuesday was felt in the Volcano region. The temblor originated under Mauna Loa



Anonymous, 1948, Strongest quake in 3 months rocks Big Isle: Hilo Tribune-Herald, 03/20, p. 1. 



 A sharp temblor shook the Big Island at 4:18 p.m. Friday [Mar. 19], an earthquake described by Ruy H. Finch, volcanologist at Hawaii National Park as the strongest in three months.

 Finch said the quake originated about 15 miles under Kilauea volcano, along the fundamental rift upon which the entire island rests. He described it as a vertical quake, and was strongly felt in the volcano area.

 The temblor was felt in most areas of Hilo and was followed by weaker temblors at 4:31 p.m. There are no indications of an impending eruption at Kilauea.



Anonymous, 1948, Hualalai quake shakes Volcano area: Hilo Tribune-Herald, 05/24, p. 1. 



 Volcanologist Ruy H. Finch said today that an earthquake originated deep under Hualalai at 11:33 a.m. Saturday [May 22].

 The temblor was felt in the volcano district.

 . . . .



Anonymous, 1948, Earthquake felt in Oahu early today; downtown Honolulu buildings damaged: Hawaii Tribune-Herald, 06/28, p. 1. 



 The early morning earthquake which jolted Oahuans out of their beds caused considerable damage in downtown Honolulu. . .

. . . 

Among the buildings damaged were:

 Castle and Cooke, cracked walls

 Theo. H. Davies Co., cracked plaster and window panes

 Bishop National Bank, plaster cracks

 Bishop Trust Co., cracked plaster and window panes

 Cunha, cracks

 Hockings, plaster cracks

 Waite, plaster cracks

 Dillingham Transportation, wall cracks on makai side

 Alexander and Baldwin, Ltd., elevator shaft plaster, stairway between 2nd and 3rd floors cracked. Broken fluorescent lights in 4th floor offices

 In addition nearly every house in the Manoa housing unit was without water and plumbing this morning. Most of the houses were moved two or three inches off their foundations and pipes were broken by the earthquake.

 At the Bishop Museum, bookcases were toppled and preserved samples of marine life were knocked over. A wooden carving of an Hawaiian God was smashed. A 31/2-foot statue of an Hawaiian spearman moved about six inches in its case. Glass was broken in the building.

 Actually stopped by the ground tremor that rattled windows and nerves all over the island was the ten-ton bronze and steel timepiece in the Aloha Tower. Probably the most severely shaken man in the Territory at the time of the quake, was Henry Ah Sing, the tower night watchman.

 He was on the tenth floor of the building. His written report to Harbormaster James this morning says: "It was a very severe quake. The tower was very well shaken.

 The temblor shook Oahu at 11 seconds after 1:41 a.m. today, awakening most island residents with its intensity.

 No cases of direct injury from the shock were recorded.

 The quake . . . was not felt on Hawaii or Kauai.

 [inset-info from the Big Island]: The temblor was registered at HVO at 1:42 a.m. and was of short duration. [Finch] estimated the epicenter as 125 to 150 miles away, possibly in the vicinity of Molokai.

 The earthquake was felt here in Hilo waking many people. but was not of sufficient intensity to sound the alarm at the volcano observatory.



Anonymous, 1948, Quakes felt in Volcano district: Hilo Tribune-Herald, 07/30, p. 1. 



 Seismologists at Hawaii national park today were studying possibilities of an early eruption of Kilauea volcano.

 Residents of the volcano district were jarred by two "fairly sharp" temblors at 2:28 and 2:31 a.m. today.

 Dr., Howard A. Powers, seismologist with the United States geological survey here, said the quakes are believed to have originated under the south-west slope of Kilauea.

 He said no activity had been recorded under Kilauea for several months and that the two quakes early today might prove significant.

 . . . .

 The earthquakes were felt generally in the Volcano district, although there were no reports from residents in other districts.

 Dr. Powers said the origin of the two quakes was believed to be of only moderate depth under the south-west slope.



Anonymous, 1948, Quake pattern hints uneasiness under Kilauea: Hilo Tribune-Herald, 08/05, p. 1. 



 Earthquakes originating at a depth of about six miles and east of Kilauea crater furnish the most conspicuous signs of uneasiness under Kilauea that have been noted during the last two or three years, according to the monthly report [by] R.H. finch, volcanologist at the Hawaiian volcano observatory in Hawaii national park.

 These earthquakes-seven of them-were recorded July 30, and six of the seven were perceptible, the report said.

 If the quakes are followed by similar ones with a decrease in depth of foci or a rapid northeast tilt, the evidence of uneasiness at Kilauea will be more positive, according to the report.

 A total of 41 earthquakes were recorded on the observatory seismographs during July. Thirty seven of these, the report said, were recorded at Mauna Loa and 19 at Kilauea.



Anonymous, 1948, Quake under Mauna Loa rocks Hilo: Hilo Tribune-Herald, 09/13, p. 1. 



 A heavy earthquake, felt all the way from Hilo to Naalehu, rocked the southern end of the Big Island at 8:22 a.m. today.

 Ruy H. Finch, volcanologist at Hawaii national park, said the tremblors were "interesting" because they were deep under Mauna Loa, in contrast to the shallow origin of most recent quakes.

 The shock, he said, was strong enough to set off the alarm which is connected with the Kilauea seismograph, and continued long enough to keep the buzzer going for over two minutes.



Anonymous, 1948, Seismological notes: Bulletin of the Seismological Society of America, v. 38, no. 4, p. 293. 



 Honolulu, Hawaii, June 28, 1948.A series of sharp earthquakes starting at 1:38 A.M. (4:38 A.M., P.D.T.) broke some store windows, dislodged plaster and briefly disrupted electricity in some sections of Honolulu. The movement apparently centered near the island of Molokai, but no major damage was reported there. The principal effect was on Oahu in the Honolulu area, where damage was not great; however, the shock was strong enough to cause a landslide that blocked one road.



Anonymous, 1949, No special significance attached to quake: Hilo Tribune-Herald, 01/08, p. 1. 



 A confusing article about the earthquake at 12:55 a.m. Jan. 8, quoting Ruy Finch as saying the quake was located "at a considerable depth 10 miles southwest of Hilo" and Brother Pleimann, operator of the Hilo seismograph at St. Mary's school, as saying the quake was located "33 miles from Hilo in a direction which would indicate the northeast rift of Mauna Loa."

 [The location given in Volcano Letter 503 is "10-15 miles deep under Alae crater," a description at odds with both newspaper statements.]

 The quake dismantled the Hilo seismograph and was nearly strong enough to dismantle the seismograph at HVO.



Anonymous, 1949, Quake rocks Big Isle; lava flow to Kona virtually stopped: Hilo Tribune-Herald, 01/08, p. 1. 



 Most of the article describes the eruption in and around the south rim of Mokuaweoweo.

 "A sharp earthquake rocked the Big Island at 12:55 a.m. today, awakening residents of the Kilauea volcano area, Hilo and other areas.

 Volcanologist Ruy T. [sic] Finch said the temblor was nearly strong enough to dismantle the seismograph at Hawaii national park.



Anonymous, 1949, Volcano hidden, heavy 'quake rocks Hilo area: Hilo Tribune-Herald, 01/15, p. 1. 



 "Hilo this morning was rocked by a heavy earthquake at 6:40. The temblor dismantled the east-west component of the seismograph at St. Mary's school here . . ."



Anonymous, 1949, 'Quake originates under Mauna Loa: Hilo Tribune-Herald, 01/16, p. 1. 



 The heavy earthquake which rocked the Big Island at 6:40 a.m. Saturday [Jan. 15; Volcano Letter 503 gives time (in error?) as 12:40 a.m.] is believed by Ruy H. Finch, director of the Hawaiian volcano observatory at Hawaii national park, to have been deep under the east slope of Mauna Loa.

 . . . .

 The quake dismantled the seismograph located at St. Mary's school in Hilo, but not the one at Kilauea which, however registered a very heavy disturbance.

 The temblor was felt in all parts of the island, particularly in Kona, Kau, Puna and Hilo.

 Mr. Finch said the severity and location of the quake may be "an indication of what is about to happen" rather than of significance in the current Mauna Loa eruption.

 He believes the epicenter is deep under the fundamental rift below the island floor itself which is 15,000 feet below sea level.



Anonymous, 1949, 2 earthquakes shake wide area on Big Island: Hilo Tribune-Herald, 01/21, p. 1. 



 Two earthquakes apparently originating at widely separated point on the Big Island were recorded on seismographs here [hvo], Ruy H. Finch, director of the Hawaiian Volcano observatory reported today.

 A moderate earthquake at 2:28 p.m. Thursday [01/20] originated at Kohala or the northwestern part of Mauna Kea. It was widely felt, and described as "very distinct" at Honokaa. It was also felt at Kona and Kohala and very slightly at the Volcano.

 The other earthquake dismantled the Mauna Loa seismograph but the time and intensity have not been determined.

 The rest of the article updates the Mauna Loa eruption, indicating that only one fountain is playing.



Anonymous, 1949, Third quake in two days recorded here: Hilo Tribune-Herald, 01/27, p. 1. 



 Two earthquakes Wednesday [Jan. 26] and one just after midnight today, all apparently originating under Mauna Loa, are a common occurrence when the volcano is erupting, Ruy Finch, director of the Hawaiian volcano observatory, said today.

 A moderate earthquake, about 8:30 a.m. Wednesday, was plainly felt in Naalehu, as was a slight temblor at 11:47 p.m. Wednesday. The latter originated under the eastern slope of Mauna Loa.

 One at 12:04 a.m. today was also under Mauna Loa.



Anonymous, 1949, Heavy temblors shock Kilauea area: Hilo Tribune-Herald, 02/27, p. 1. 



 The strongest earthquake in Hilo in several years rocked this side of the island for at least two minutes Saturday afternoon. No damage was reported.

 Dr. G.A. Macdonald of the U.S. Geological Survey station in Hawaii National Park, said the Kilauea seismograph was dismantled during the first few seconds of the temblors, which began at 1:57 p.m. He said the quake was apparently centered in the Kilauea area.

 Father Bernard Pleimann, caretaker of the seismograph at the old St. Mary's school on Waianuenue Avenue, said the quake was strong enough to dismantle both components of the instrument.

 National Park headquarters also reported that the quake was very pronounced there.



Anonymous, 1949, No pattern develops yet in 'quake series: Hilo Tribune-Herald, 02/28, p. 1. 



 The half dozen smaller earthquakes that have followed the big jolt Saturday afternoon showed no definite pattern pointing to possible renewed volcanic activity.

 Dr. G.A. Macdonald, geologist at the Hawaiian volcano observatory, said this morning it would take several weeks to develop such a pattern.

 The small quake at 1:20 p.m. Saturday occurred in Mokuaweoweo crater, he said, and the large one at 1:55 emanated from the northeast rift at an altitude of 7,000 feet. It dismantled the instruments at the observatory and one at Saint Joseph's School. Dr. Macdonald said it lasted for two minutes and was felt at least from Naalehu to Hilo, perhaps in a wider area.



Anonymous, 1949, Strong quake shakes Kapapala area in Kau: Hilo Tribune-Herald, 05/23, p. 1. 



 A sharp earthquake originating under uneasy Mauna Loa was registered at the Kilauea seismograph at 10:25 a.m. today according to Ruy H. Finch, director of the Hawaiian volcano observatory.

 It was also recorded on the St. Mary's [Hilo] seismograph. 

 Mr. Finch said the quake was felt particularly strongly in the Kapapala area of Kau.

 The director said there are increasing tremors from Mauna Loa, running as frequently as 25 to 30 a day. This, he explained, follows the 1940 pattern, and indicates that the current activity is dying out. As the lava becomes more viscous, the imprisoned gas is not as free to escape, and is hence more explosive.



Anonymous, 1949, Strong quake rocks several Big Isle areas: Hilo Tribune-Herald, 09/02, p. 1. 



 The Kau, Volcano and Hilo areas were shaken at 12:53 yesterday afternoon by a "strong" earthquake which originated on the Kaoiki fault three or four miles north east of Kapapala ranch, Kau, the volcano observatory geologist said today.

 Geologist G.A. Macdonald said the quake, which continued for five minutes dismantled the Mauna Loa seismograph.



Anonymous, 1949, 'Quake pattern under extinct Mauna Kea intrigues scientists: Hilo Tribune-Herald, 11/18, p. 1-2. 



 A rapid fire series of earthquakes in a pattern often indicative of an impending eruption occurred November 4 directly under the summit of Mauna Kea at a depth of 20 miles.

 The remainder of the article discusses how unusual it is to have earthquakes beneath Mauna Kea and reviews other earthquake sequences associated with Mauna Kea. He opines that, since the earthquakes just registered are at a similar depth to the deeper ones below Mauna Loa, any pressure developed under Mauna Kea would most likely be transferred to Mauna Loa. He indicates that HVO is handicapped in their understanding of Mauna Kea seismicity by the lack of any knowledge of tilt at the summit of the mountain.



Anonymous, 1949, Quake felt throughout island: Hilo Tribune-Herald, 11/25, p. 1. 



 An earthquake whose epicenter was believed to be under Mokuaweoweo crater was felt by most of the island this morning at 7:59.

 Volcanologist Ruy H. Finch said it was sufficiently strong to dismantle a component of the Hawaii national park observatory seismograph and both components at the 6,600-foot level on Mauna Loa. 

 Mr. Finch placed the point of origin between 12 and 15 miles below the summit of Mauna Loa.



Anonymous, 1949, Seismological notes: Bulletin of the Seismological Society of America, v. 39, no. 3, p. 223. 



 Pacific Ocean in the Hawaiian Islands region, April 10, 1949.The Jesuit Seismological Association reports an earthquake at 23h 48m 20s, with epicentral region 260 N, 1750 W, which is in the Pacific Ocean on the southwest slope of the Hawaiian Island ridge near Lisianski Island.



Anonymous, 1950, Cloud patterns over Mauna Loa stir rumors: Hilo Tribune-Herald, 02/14, p. 1. 



 . . . . .

He [Ruy Finch] reported that the earthquake that shook the volcano area yesterday about noon was "slight". At first it was thought to originate under Kilauea but now Mauna Loa is believed to be the point of origin, he said.

 The tremor yesterday was the second in the previous 18 hours. Another "slight" quake was recorded at 8:09 Sunday morning [Volcano Letter 507 gives time as 6:09]. Its center was Makaopuhi crater, the volcanologist said.

 Sunday's quake dismantled one component of the Mauna Loa seismograph, according to Mr. Finch, who pointed out the tremors were of no special significance.



Anonymous, 1950, Heavy 'quake rocks Volcano, Hilo and Kau areas early today: Hilo Tribune-Herald, 03/25, p. 1. 



 An earthquake which stirred many Big Islanders out of their sleep this morning was recorded on the Hawaiian volcano observatory seismograph at 5:43. The jolt was felt particularly strong in the Naalehu, Hilo and Hawaii National Park areas.

 Volcanologist Ruy H. Finch described its intensity as "moderate to strong." The disturbance dismantled both components at the 6,600 foot level on Mauna Loa and on the St. Joseph's school seismograph in Hilo. One component on the Volcano House instrument was disturbed.

 Therefore, the epicenter was not definitely determined, but Mr. Finch tentatively set the point of origin under the eastern slopes of Mauna Loa.

 Though unrelated, a smaller shock was registered yesterday at 2:13 p.m., and felt at the observatory and at 29 Miles Volcano. It was similar to the March 17th quake [2:35 a.m.] originating from the Kilauea area, Mr. Finch said.

 Several others have originated there during the month, he added, indicating some uneasiness of the crater.



Anonymous, 1950, Quake seen as signal Mauna Loa is restless; officials place origin under southwest rift: Hawaii Tribune-Herald, 05/30, p. 1. [Identical information given as a dispatch from Hilo in Honolulu Star-Bulletin, May 30, 1950] 



 An earthquake Which rocked the Big Island shortly after 3 yesterday afternoon was the latest and by far the most severe of a series all believed to have originated in approximately the same location under the southwest slope of Mauna Loa, according to volcanologist Ruy H. Finch of the Hawaiian Volcano Observatory. 

. . . .

 The temblors lasted well over 5 minutes.

 A group of mainland tourists were given a thrill when the earthquake shook loose and sent hurtling to the bottom of the pit small sections of earth around the rim of Halemaumau.

 The quake, recorded at 3:15 p.m., was clearly felt throughout Hilo and in most parts of the island. Mr. Finch said the quake dismantled the components of the HVO seismograph and broke the one at Konawaena School.

 The components of the seismograph at the former St. Mary's School in Hilo also were dislodged.

 Brother Bernard Pleimann reported that the delicate machine continued to record tremors several minutes after he had replaced the components.

 Hilo residents reported chinaware was broken and pictures and light fixtures were sent swinging during the quake.

 Kona police said canned goods in several stores were knocked to the floor as a result of the tremors.



Anonymous, 1950, Light tremors are recorded: Hilo Tribune-Herald, 05/31, p. 1. 



 Two light tremors believed to be after shocks of Monday's [May 29] jolting earthquake, were recorded by the Hawaiian volcano observatory seismograph yesterday.

 Volcanologist Ruy H. Finch said the first shock was recorded at 2:30 p.m. and another at 5:29 p.m. He said both were believed to have originated under Mauna Loa, but not at the same locations.

 Brother Bernard Pleimann, caretaker of the seismograph at St. Joseph's, said the latter earthquake was recorded here in town as very weak.



Anonymous, 1950, Kona reports some damage from temblor: Honolulu Advertiser, 05/31, p. 2. 



 Hilo, Hawaii, May 30--Kona police reported extensive but minor damage as a result of a severe earthquake which rocked the Big Island shortly after 3 p.m. Monday.

 Police said that cracks one inch wide were visible along the main highway between Captain Cook and Honaunau, and in several sections along the highway shoulders gave way, causing boulders to roll from the walls.

 Machado's store, located on the main highway at Capt. Cook shifted approximately one inch from its foundation which separation was clearly visible. Four large water tanks split open as a result of the first tremor. Many merchants reported goods tumbled from their shelves.

 The tremors continued throughout the night. The first rocked Kona at approximately 3:15 p.m. and others of less intensity were felt at 7 p.m., 10:45 p.m. and at 11:05 p.m. The initial quake was accompanied by a terrific rumbling.

 Ruy H. Finch, volcanologist of the Hawaiian Volcano observatory, believes that if an eruption is brewing it will appear in the southwest rift rather than on the northeast flank of Mauna Loa.

 The quake dismantled the components of the Kilauea seismograph and also broke the one at Konawaena high school.

 Hilo residents reported broken dishes and fallen picture frames, but no injuries were reported throughout the Big Island.



Anonymous, 1950, Earthquake aids fisher's luck: Hilo Tribune-Herald, 06/01, p. 1. 



 How does an earthquake feel at sea?

 Walter Eklund of Hilo said while fishing five miles off Keauhou during Monday's severe tremors, the boat began to shake and the party heard repeated "deep thuds" on the bottom of the boat.

 He was one of 12 persons aboard the Hiki No, fishing boat of E. Parker of Honolulu. The earthquake brought good luck to one of the guests, Dudley Louis of Honolulu. A swordfish, out of excitement, struck his line immediately after the tremor, Mr. Eklund said.



Anonymous, 1950, Lava wipes out Hookena; none reported dead in little Kona village: Hilo Tribune-Herald, 06/02, p. 1. 



 An account of the destruction of Hookena village. The lava took three and one half hours to reach the highway and overrun the village.



Anonymous, 1950, Brief summit action preceded flank flow: Hilo Tribune-Herald, 06/02, p. 1. 



 Last night's flank flow of Mauna Loa was preceded by an unusually short summit eruption, Volcanologist Ruy H. Finch said today.

 He estimated that the summit activity lasted only about four hours before the mountain split at the seams above the 8,000 level.

 Flank flows usually follow a much longer period of summit activity, Mr. Finch informed.

 The seismograph at the volcano observatory at Hawaii national park, he reported, indicated that activity began at 9:04 last night.



Anonymous, 1950, Naalehuans felt quake before new eruption: Hilo Tribune-Herald, 06/02, p. 1. 



 An earthquake at 9:30 last night gave Naalehuans first warning of the coming eruption. A peculiar rumbling noise, "something between the sound of a truck in the hills and thunder," was also heard. . . .

 The rest of the article describes reaction to the new eruption.



Anonymous, 1950, Mauna Loa eruption going big; no sign of flow letup is observed: Hilo Tribune-Herald, 06/03, p. 1. 



 A description of the ongoing Mauna Loa southwest rift eruption. An inset in the article has the following seismic information:

 . . . .

 One tremor, big enough to be felt, was recorded at 10:10 a.m. yesterday. Mr. Finch said it was heavier than the earthquake which occurred at 9:30 Thursday night shortly after volcanic activity began.



Anonymous, 1950, Hundreds evacuated from Kona: Hilo Tribune-Herald, 06/03, p. 1. 



 An account of the effects on the population on Mauna Loa's west flank by the 1950 eruption from Mauna Loa's southwest rift zone. Hundred of persons were displaced by lava flows that crossed the road in several places, trapping persons in between.



Anonymous, 1950, Lava destroys Ohia Lodge; fourth river of lava crashes into ocean: Hilo Tribune-Herald, 06/05, p. 1, 2. 



 An account of the destruction of a wayside inn by the eruption from Mauna Loa's southwest rift zone. The article continues with additional description and comment on the eruption.



Anonymous, 1950, More tremors under Mauna Loa are reported: Hilo Tribune-Herald, 06/06, p. 1. 



 Harmonic tremors originating under the erupting shoulder of Mauna Loa continued today, Volcanologist Ruy H. Finch reported.

 He said the series of tremors recorded on the Hawaiian volcano observatory seismograph were punctuated sharply by a heavy earthquake at 3:09 a.m. and another at 9 a.m. yesterday.

 The first one was sufficient intensity to dismantle the instrument, he said, and the later one was strong enough to be felt. The seismograph is approximately 30 miles from the lava's origin point. Smaller tremors, indicating continued energy in the mountain's southwest rift, followed.

 The remainder of the article repeats material in Volcano Letter 508 regarding the seismicity surrounding the eruption, with the exception of the following passage:

 "The May 29 quake appear to have jostled the blocks around the Halemaumau rim for some of the rim cracks opened slightly and others showed a slight closing."



Anonymous, 1950, Crew now roughing out road over lava flow; new stream comes down mountainside: Hilo Tribune-Herald, 06/13, p. 1. 



 Most of the article describes the ongoing Mauna Loa southwest rift eruption. The following passage gives additional information on the seismicity:

 "Two rather strong earthquakes were registered at the Hawaiian volcano observatory Sunday [June 11] but Dr. Macdonald said these did not necessarily mean the termination of the flow is approaching because there have been quakes during the whole period of flow.

 However, during the last flow [1949 eruption in Mokuaweoweo], the eruption quieted down after several earthquakes."



Anonymous, 1950, Only a glow remains of eruption; 2 strong earthquakes at crater registered; volcano haze stays: Hilo Tribune-Herald, 06/14, p. 1. 



 Most of the article describes the aftermath of the Mauna Loa southwest rift eruption. The following passage gives additional information on the seismicity:

 "Two strong earthquakes were registered yesterday [June 13], one at 2:05 p.m. and a second at 7:30 p.m. both originating under the southern rim of Mokuaweoweo, the Mauna Loa summit crater.

 But Ruy H. Finch, volcanologist at the Hawaiian volcano observatory, attached little importance to them.

 There have been earthquakes every day during the current eruption although the one last evening was somewhat stronger than usual.

 Harmonic tremors accompanying the eruption are definitely diminishing, he said, although they still indicate intermittent surging of lava.



Anonymous, 1950, 108 quakes recorded in 12 hours: Hilo Tribune-Herald, 08/03, p. 1. 



 One hundred and eight earthquakes were registered on the Kilauea seismograph in Hawaii national park yesterday between the hours of 8 a.m. and 8 p.m. 

 Dr. Macdonald said all the quakes were shallow in origin and near the north edge of Kilauea crater. 

 . . . .

 Several of the quakes were felt by residents of the Volcano and 29 miles districts.



Anonymous, 1950, Hilo's new seismograph station at St. Joseph's school opened: Hawaii Tribune-Herald, 11/19; 20; 21, p. 1. 



 A new seismograph of HVO design (Loucks-Omori) was dedicated three weeks after installation. The two-component instrument replaces the one-component instrument located in the former St. Mary's school.



Anonymous, 1950, 300 quakes rock region of Volcano: Hilo Tribune-Herald, 12/09, p. 1. 



 Beginning at noon yesterday [Dec. 8] the volcano area up to 10:30 this morning was rocked by over 300 earthquakes, according to R.H. Finch, volcanologist at the Hawaiian volcano observatory at Kilauea volcano. 

 Mr. Finch said examination of tilt meters, one located on the floor of Kilauea crater, shows strong southwest tilt, indicating a decrease in pressure under Kilauea.

 He said the center of the sinking apparently is under Halemaumau, the fire pit of Kilauea.

 The pressure under the volcano began building up last spring, but leveled off early in the summer.

 The two strongest quakes were at 7:29 p.m. Friday and at 5:43 a.m. this morning. Each one dismantled the east-west component of both the Kilauea and Mauna Loa seismographs.

 Mr. Finch said all the quakes are centered under Kilauea and are of fairly shallow origin.



Anonymous, 1950, More earthquakes rattle Big Isle; Expert sees less chance for eruption of Kilauea: Hilo Tribune-Herald, 12/11, p. 1. 



 Earthquakes, averaging 200 in 24 hours, continued to rattle the southern end of the Big Island over the week-end, with the Kau district registering the strongest shocks.

 Ruy H. Finch, volcanologist at the Hawaiian volcano observatory, said this morning that tilt meters indicate the whole series of quakes mean a collapse of the pressure under Kilauea. This pressure began building up last spring, reviving hope that once more there would be some fiery action in the spectacular pit, the Halemaumau.

 Mr. Finch believes the current disturbances mean the collapse of this pressure and hence less likelihood of action in Kilauea. However, he is not discounting the possibility that the current disturbances could mean a weaker structure, and undoubtedly there is molten lava surging very deep underneath.

 Some of the quakes have entered under Halemaumau itself, Mr. Finch sad, but all the strongest ones have originated southwest of Kilauea or near the southwest end of this vast crater.

 some half a dozen of the series of earthquakes, which were continuing this morning, have been strong enough to dismantle seismographs at Kilauea and on the southern slopes of Mauna Loa.

 The disturbances have been felt most strongly at Kapapala and Naalehu, but Hilo has felt them too, particularly in the Puueo and Kaumana districts. Some have been felt in Keaukaha.

 Mr. Finch and Dr. Gordon A. Macdonald, observatory geologist, made a field trip into Kau today to see if there are new cracks or other surface evidences of the disturbances, which began Friday [Dec. 8] and have continued since.

 The machine at the seismograph station at St. Joseph's school [Hilo] was dismantled twice, at 8:40 Saturday night and again at 9:23 Sunday night.

 Brother Bernard Pleimann, in charge of the station, said the 9:25 p.m. Sunday quake was the strongest of the series which started last Friday.

 Incidentally, it was the firs time that the new station had recorded a group of local quakes.



Anonymous, 1950, 'Quakes subside; only 85 in the last 24 hours: Hilo Tribune-Herald, 12/12, p. 1. 



 Earthquakes which had been shaking the southern end of the Big Island at an average of about 200 a day since last Friday noon had diminished to 85 in the 24-hour period preceding 7:30 a.m. this morning, according to Ruy H. Finch, volcanologist at the Hawaiian volcano observatory.

 Mr. Finch said this morning the whole pattern is due to sinking under Kilauea caldera, even though the point of origin of the quakes has varies by as much as 15 miles.

 The remainder of the article repeats material covered in the Tribune-herald article on Dec. 11.



Anonymous, 1950, Earthquake rocks Volcano, Hilo areas: Hilo Tribune-Herald, 12/26, p. 1. 



 A plainly felt earthquake accompanied by a loud rumble and a roar startled many Hilo and volcano residents out of their day-after-Christmas sleep early this morning.

 It came at 2:55 a.m. and its point of origin was placed about 6 miles southeast of the Hawaiian Volcano observatory on the rim of Kilauea crater, according to observatory officials.

 The roar lasted at least three seconds.

 The big quake was followed by a very feeble one at 3:15 a.m., probably centered in the same location.

 There was no immediate report from the St. Joseph's school seismograph station.



Anonymous, 1950, Seismological notes: Bulletin of the Seismological Society of America, v. 40, no. 4, p. 307. 



 Pacific Ocean, south of the Island of Hawaii, June 14, 1950.The Survey reports an aftershock (of the earthquake of May 29, 1950) at 05h 47m 47s, G.C.T., with preliminary epicenter 19 N, 155.5 W, which is in the Pacific Ocean just off the southern coast of the Island of Hawaii. [Note: an earthquake at the time given is not listed in the Volcano Letter, nor is the location given reasonable as an aftershock of the May 29th earthquake]



Anonymous, 1950, Seismological notes: Bulletin of the Seismological Society of America, v. 40, no. 3, p. 250-251. 



 Hawaii, May 29, l950.The most severe earthquake felt in years shook the entire island of Hawaii at midafternoon. Volcanologist R. Y. Finch of the Hawaii Volcano Observatory said he believed the shock originated under Mauna Loa, one of the world's most active volcanoes. This was confirmed on June 2 when the volcano, in a spectacular eruption, sent the heaviest lava flow of the century to the sea. In some places the lava was said to be flowing at the rate of 40 miles an hour. Sixty to 80 families were driven from their homes as parts of their villages were engulfed. Another earthquake on June 5 shook the still erupting Mauna Loa as it sent a fourth river of lava pouring into the sea. The latest flow drove 30 more families from their homes.

 The Survey gives the time of the first shock as May 30, 01h 16m 16s, G.C.T., with preliminary epicenter 19.5 N, 156 W, which is just off the west coast of the island of Hawaii, west of Mauna Loa. Pasadena estimated the magnitude to be 6.25.



Anonymous, 1951, 'Quake is felt: Hilo Tribune-Herald, 01/06, p. 1. 



 An earthquake of moderate intensity shook the Big Island early this morning.

 It was recorded on the Hawaii Volcano observatory seismograph at 4:48 a.m. and its origin placed about 35 miles from Kilauea crater by Dr. Gordon A. Macdonald, geologist at the observatory.

 He said reports that the quake was felt have been received from Hilo and Naalehu but none from the Volcano area as yet.

 Because it was felt over such a wide area is that it was of fairly deep origin, he said.



Anonymous, 1951, Rickety County building shows worst damage from earthquake: Hilo Tribune-Herald, 04/23, p. 1. 



 The rickety county building appeared today to be the major casualty of yesterday's short but sharp quake.

 Trophies were smashed, loaded bookshelves collapsed and fluorescent lights were unhinged by the tremblor itself. Its after effects shook up the morale of many of its daily occupants.

 County Attorney Albert M. Felix' offices were littered with plaster, broken bits of wood and termite leftovers. Mr. Felix was quoted by his secretaries as saying "It's dangerous in here" . . . .

 The remainder of the article repeats details of the damage and describes reactions of persons to the quake.



Anonymous, 1951, Quake rocks Big Island: Honolulu Advertiser, 04/23, p. 1. 



 [subheads: Tremor also noticed here; Hilo damage; 'Terrific' jolt starts landslides on slopes of Halemaumau with huge clouds of dust]

 A violent earthquake shook the Big Island volcano area yesterday afternoon, and reports from the Volcano House, on the rim of Kilauea crater, said the "terrific" jolt started landslides boiling down the slopes of Halemaumau crater, throwing up huge clouds of dust.

 There were widespread reports of minor damage in Hilo, and electric power was cut off from the Big Island's Volcano area. A flood of calls to the Advertiser's switchboard showed the tremor was felt throughout Honolulu.

 The quake was recorded at 2:52 p.m. by Dr. Gordon Macdonald, director and volcanologist in charge of the Hawaiian Volcano observatory on the Big Island. Macdonald said it was the strongest he had ever felt, and was the most severe since 1929. He said the quake was of an intensity 6 on the Rossi-Sorel [sic] scale. . . .

 The shock, which preliminary investigation located deep under Kilauea, dismantle all seismometers in the Big Island network. Macdonald said suspension wires on the tilt meters were broken, for the first time in his experience. He added that the wires were of the strength and thickness of piano wire. He said there seemed little indication of volcanic activity resulting from the quake.

 Webbly Edwards, at the Volcano House, said avalanches in the Kilauea crater threw up dust clouds 1,000 feet high and knocked down lamps and furniture in the hotel. George Lycurgus, owner and manager of the hotel, said "I have never felt such a violent earthquake in years--since 1890."

 . . . .

 [According to Frank Oberhansley, superintendent of Hawaii national park] "There has been settling of the roadbed between the volcano House and the Kilauea overlook. At the Hilina Pali, there were many slides and big rocks were shaken into the sea."

 Tim O'brien, Advertiser correspondent in Hilo, said two quakes had shaken that city, one at 5:54 a.m. and one at 2:53 p.m. Intensity of the first quake was estimated at two or three on the Rossi-Sorel [sic] scale. . . .

 He added that the first early morning quake woke many persons in Hilo but that there was little damage at that time. In the later quake Hilo police reported a large plate glass window at the Tropique furniture store in downtown Hilo was seriously cracked. . . .

 . . . [the police headquarters] "danced" and cars were noticeably rocked outside the building. He said the city of Kulani [sic; Kaumana?], about five miles above Hilo, was hardest hit.

 [According to a local resident] a coca-cola bottle was knocked off the table and household goods fell off shelves when the quake started. She said the house was swinging so dangerously that she rushed into the yard for safety.

 Hilo station went off the air temporarily, and O'Brien reported golfers at the Hilo municipal golf course plainly felt the fairways "moving."

 In Wainaku, about a mile north of Hilo, . . . a liquor store suffered the loss of several bottles knocked off the shelf and broken as his store was rocked by the quake.

 In Hilo, a plate glass window was broken at the 

Territorial department of labor office at 60 Waianuenue St.

 In Honolulu, first reports of the disturbance came from the Royal Hawaiian hotel, where a 7th-floor switchboard operator told the Advertiser her "switchboard started rocking at 2:53 p.m. and shook for about 40 seconds." Calls followed from Woodlawn, Manoa valley, Nuuanu valley and downtown Honolulu, with varied reports of having "felt an earthquake."

 At Pearl Harbor, magnetic observatory of the coast and geodetic survey observer D.C. McGowan verified the Hawaii report of a Kilauea quake at an intensity of 6, Rossi-Sorel [sic] scale--the heaviest ever recorded in Pearl Harbor for the Big Island.



Anonymous, 1951, Big Isle quivers from more quakes: Honolulu Star-Bulletin, 04/23, p. 1. 



 Hilo, April 23--"I am not predicting a thing--yet," said Dr. G.A. Macdonald, director of the Hawaiian Volcano Observatory today, on the prospects of an eruption of one of the Big Island's two active volcanoes.

 "But something may develop later on as the pattern of earthquakes develops," he added.

 He said he had counted at least 22 additional quakes since the big shaker at 2:52 p.m. Sunday, one fairly strong one at 6:35 and another at 4:41 this morning.

 Dr. Macdonald said he could not yet pinpoint the origin of the big shake yesterday, but that indications are it was either under Kilauea or under the northeast rift of Mauna Loa.

 He said indications thus far point to Kilauea.

 The disturbance was deep--25 or 30 miles.

 The shock yesterday was so great that all seismographs on this island were dismantled, and for this reason it is difficult to calculate the location of the epicenter.

 "We depend on the time between the original and secondary waves to figure distance," Dr. Macdonald said, but the second wave was not registered because the first shock dismantled the instruments.

Shock scale

 He said that under the Mercalli scale . . . intensity of yesterday's shock was 7. . . .

 The after shocks are continuing . . .

 The shocker yesterday precipitated a series of landslides into Halemaumau, the Kilauea fire pit, with dust clouds rising over 1,000 feet into the air. Falling of earth and rock into the 800 foot deep pit was continuing today as the after shocks disturbed the area.

Some park damage

 Superintendent Frank Oberhansley of Hawaii National Park said there was some damage to highways in the park area, and at one point on the crater rim drive, about a quarter of a mile east of the Volcano House, there was some actual subsidence, and new cracks had opened.

 There was a landslide on the eastern side of the outer crater, he said. Nick Lycurgus and a guest were hiking in the area at the time. They decided to go across the floor of the crater and they noticed an increase in the amount of heat of the steam coming from the cracks after the big shock.

 Mr. Oberhansley said there also were a couple of slides in the Hilina Pali area.

 . . . .

 Considering the intensity of the temblors yesterday, there was very little physical damage, either in Hilo or around the island. A good many broken dishes were reported, a few plate glass windows were cracked, and a water main in the Kaumana area of Hilo was reported broken. But the quake caused tremendous excitement everywhere as buildings seemed to sway like palm trees in the tradewinds.

Recorded here at 2:53

 In Honolulu the "rather severe" temblor was recorded at 2:53 p.m. on instruments here with an intensity of 5 on the modified Mercalli scale, which is considered moderately strong.

 The civil aeronautics authority on the Big Island reported the quake lasted about two minutes.

 There were some here in Honolulu who reported having felt the tremors.

 Hawaiian Electric Co. reported to the geodetic station that the quake was felt up to its second floor.

 Mrs. David Wilson, of 2818-A Loi St. in Manoa valley called the Star-Bulletin reporting her house was shaken for about a minute with her windows rattling during that time.

 Another person called from Star road on Pacific Heights reporting feeling the quake at 2:52 p.m.

 Police received only two calls, both from the Kaimuki area, reporting feeling the quake.



Anonymous, 1951, Quake pattern watched for hint of possible eruption; Aftershocks still being registered: Hilo Tribune-Herald, 04/23, p. 1. 



 "I am not predicting a thing--yet," said Dr. G.A. Macdonald, director of the Hawaiian volcano observatory, on the prospects for an eruption of one of the Big Island's two active volcanoes.

 "But something may develop later on as the pattern of earthquakes develops," he added.

 He said he had counted at least 22 additional quakes since the big shaker came at 2:52 p.m. Sunday [Apr. 22], one fairly strong at 6:35 and another at 4:41 this morning.

 Dr. Macdonald said he could not yet pinpoint the origin of the big shake yesterday, but that indications are it was either under Kilauea or under the northeast rift of Mauna Loa. He said indications thus far point to Kilauea. The disturbance was deep--25 or 30 miles.

 The shock was so great that all the seismographs on this island were dismantled, and for this reason it is difficult to calculate the location of the epicenter.

 . . . .

 He said that under the Mercalli scale, most generally used, intensity of yesterday's shock was 7. In this scale, 12 would be the maximum, or total destruction.

 The shocker yesterday precipitated a series of landslides into Halemaumau, the Kilauea fire pit, with dust clouds rising over 1000 feet into the air. Falling of earth and rock into the 800-foot deep pit was continuing today as the after shocks disturbed the area.

 Superintendent Frank Oberhansley of Hawaii National Park said there was some damage to highways in the park area, and at one point of the crater rim drive, about a quarter mile east of Volcano House, there was some actual subsidence, and new cracks had opened.

 There was a landslide on the eastern side of the outer crater [Kilauea caldera] and . . . an increase in the amount and heat of the steam coming from the cracks after the big shock.

 Mr. Oberhansley said there also were a couple of slides in the Hilina Pali area.

 Considering the intensity of the temblors yesterday, there was very little physical damage, either in Hilo or around the island. A good many broken dishes were reported, a few plate glass windows were cracked, and a water main in the Kaumana area of Hilo was reported broken. But the quake caused tremendous excitement everywhere, as buildings seemed to sway like palm trees in the tradewinds.

 Brother Bernard Pleimann said a quake at 4:54 a.m. yesterday dismantled the east-west component of seismograph at St. Joseph's school in Hilo, and that yesterday's shocker dismantled both components. Since yesterday, he said the instrument has recorded three noticeable tremors.



Anonymous, 1951, Kilauea is uneasy, says volcanologist: Honolulu Star-Bulletin, 04/24, p. 1. 



 Hawaii National Park, April 24--"Kilauea volcano is distinctly uneasy," Dr. Gordon A. Macdonald. director of the Hawaiian volcano observatory, said today.

 "Thus far, however, there has been no pattern of earthquakes or tilts which would indicate an imminent eruption."

 Dr. Macdonald gave a prepared statement following an intensive study of the near-record earthquake Sunday afternoon and the aftershocks from the big shakeup which are still continuing.

 "The intensity 7 earthquake on the afternoon of April 22," the scientist said, "originated at a depth of 25 to 30 miles in the vicinity of Kilauea crater.

 "It was preceded at 4:53 on the morning of the 22nd by a moderate earthquake which originated on the east rift of Kilauea about five miles south of Glenwood and at a depth of 31 miles.

 Shocks continuing

 "The big earthquake has been followed by many aftershocks which are still continuing. The present count is about 30. The aftershocks have all been of shallow origin, their foci lying at depths of less than 10 miles.

 "They have originated on both the east and southwest rifts of Kilauea as well as under the crater itself.

 "Very little ground tilting has occurred since the big earthquake."



Anonymous, 1951, Kilauea is still uneasy; new tremors felt: Honolulu Advertiser, 04/24, p. 5. 



 Hilo, Hawaii, April 23--Unrest continues under Kilauea volcano on the Big Island as after-shocks, following the severe earthquake of Sunday afternoon, register frequently on seismographs of the Hawaiian Volcano observatory.

 Dr. Gordon A. Macdonald, director of the observatory, said 23 earthquakes of varied intensity were recorded up to 9 a.m. today, with the heavier movements being felt by many residents in the Hilo area, 30 miles away.

 The remainder of the article discusses the cleanup of Hilo after the large quake.



Anonymous, 1951, Strong quake is registered early today: Hilo Tribune-Herald, 04/26, p. 1. 



 An earthquake describes as "strong" by Dr. Gordon A. Macdonald, director of the Hawaiian volcano observatory, was recorded on Kilauea and Hilo seismographs at 3:57:44 this morning.

 . . . .

 After shakes from the big shaker last Sunday afternoon are continuing, with nine quakes, including the strong one early this morning. recorded in the 24 hour period between 8 a.m. Wednesday and 8 this morning. . . .

 The earthquake was registered here at the seismograph at St. Joseph's school, according to Brother Bernard Pleimann where it classified as slight.



Anonymous, 1951, Early morning temblor rocks Island of Hawaii: Hilo Tribune-Herald, 08/21, p. 1. 



 Most Big Islanders were rudely awakened shortly before 1 this morning as the most "distinctive strong earthquake" was recorded at 12:57:09 causing extensive damages in the Kona district as well as in other parts of the island.

 Gordon Macdonald, volcanologist, reported to Hilo police at 7:30 a.m. that the earthquake showed no sign of an early eruption. This one happened on the western side of Mauna Loa and lasted from three to four minutes.

 He classified this as one of the strongest to hit this island with an intensity rating of 8 on a scale with a maximum of 12.

 In the most heavily struck towns of Honaunau, Kealakekua and Napoopoo, damage to buildings, water tanks, homes and business establishments were estimated at $50,000.

 All communication to Kona was disrupted at 1:25 a.m. and Hilo police have been in constant contact with Kona with chief of police Anthony Paul directing.

 Reports from Kona reveal that Honaunau school has been completely wrecked and Shimizu's store in the City of Refuge was also demolished to the extent of $7,900. Another school nearby, believed to be Hookena, was also partially wrecked.

 A report of a small tidal wave at 3:10 a.m. at Napoopoo was dispelled when it was learned that the disturbance was caused by earth of the cliff falling into the sea.

 Police reported that a portion of the cliff measuring approximately one quarter of a mile fell into Napoopoo bay.

 . . . .

 Only one injury was reported up to this morning [due to collapse of home] . . .

 Damages so far, as received by Hilo police, revealed that 34 water tanks were wrecked as well as five homes with two of the latter being completely destroyed.

 Also, 14 stores were partially wrecked. Five of them are of the combination store-home type. Wrecked also were two warehouse buildings.

 About one and a half mile of road was torn out in the Honaunauwaena-Palipoko-Kahauloa-Keei section with the paved portion cracked open and the sides caved in.

 Heavy quakes also hit Honokaa, Kapaau, Kohala and Puna around 1 this morning but no damage has been reported . . . .

 Residents in the towns reported lighter quakes which followed at about 1:30 a.m.

 Pahalans also felt the strong quakes but reported no damages except for canned goods being knocked off the shelves. Kapapala ranch and homesteads and Moaula also reported no damages.

 The quake was strongly felt at Naalehu, where some homes were moved from their foundations and communication was put out of order.

 Hiloans likewise felt the effects of the quake with little or no damages. But housewives reported that dishes, canned goods, and little knick knacks were knocked from their positions.

 The remainder of the article deals with emergency response to the quake.



Anonymous, 1951, Quake in rift felt in Hilo: Hilo Tribune-Herald, 09/11, p. 1. 



 A nocturnal tremor . . . was felt in Hilo around 12:30 a.m. today.

 Verifying the shaker, Dr., Gordon A. Macdonald, geologist at the Hawaii volcano observatory, said the latest temblor registered a duration of two and a half minutes on the observatory seismograph. However he pegged it as "feeble, with an intensity of about 1 on a scale with a maximum of 12. Observatory time was 12:26:30 a.m.

 Felt in the vicinity of Halai Hill, the tremor came with a jolt that rattled dishes smartly, setting them clicking for a few moments as the shock waves tapered off. Dr. Macdonald labeled the quake intensity as "slight" in Hilo.

 About noon today, Dr. Macdonald said the location was computed to be on the northeast rift of Mauna Loa about the 11,000 foot level on the Hilo side of the volcano.

 However, a check with Police Chief Anthony Paul failed to turn up any indication of the quake center.

 Police headquarters in the Kona area received no reports of the tremor.

 . . . .



Anonymous, 1951, Quake rocks Big Isle, but brings no sign of impending eruption: Hilo Tribune-Herald, 09/17, p. 1. 



 An earthquake which shook the Big Island at 1:43 Sunday morning dismantled the Kilauea and Mauna Loa seismographs, but brought no evidence of impending volcanic action, according to Dr. G.A. Macdonald, director of the Hawaiian volcano observatory.

 . . . .

 Although the quake was felt strongly in Hilo, the Volcano area, Pahala, Naalehu and Kona, no serious damage was done anywhere.

 the quake's intensity was four as compared with seven and a half for the recent Honaunau shaker, Dr. Macdonald said.



Anonymous, 1951, Fairly strong earthquake shakes Kona: Hilo Tribune-Herald, 09/24, p. 1. 



 A "fairly strong" earthquake shook Kona at 7:01 last night.

 . . . .

 The quake was strong enough to dismantle the seismograph at Konawaena high school, Howard Tatsuno, seismograph operator, reported.

 There were no immediate reports of damage.

 Dr. Macdonald said the quake probably originated on the fault on the north side of Kealakekua bay.

 Dr. Macdonald said this morning he had received no reports that the quake was felt elsewhere.



Anonymous, 1951, Light quakes shake Hilo, Kona areas: Hilo Tribune-Herald, 09/25, p. 1. 



 Hilo and Kona were patronized by their own earthquakes last night.

 . . . .

 The Hilo tremor, sufficient to jiggle dishes and bric-a-brac audibly for a matter of seconds, was timed at 11:18 p.m. Dr. Macdonald said its origin was indicated to be about 15 miles from Hilo and probably on the northeast rift of Mauna Loa, according to the Hilo seismograph.

 Both registered by the observatory, two Kona shakers were timed at 12:53 a.m. and 1:26 a.m.

 The latter, Dr. Macdonald said, was a fair sized tremor and might have been felt in Kona, although so far there have been no reports received to that effect.



Anonymous, 1951, New seismograph is installed in observatory vault: Hawaii Tribune-Herald, 09/26, p. 1. 



 A new seismograph of Neumann-LaBarre design was installed in the Uwekahuna vault. It is a more sensitive horizontal seismograph than those previously in use. It is a companion to the sensitive Sprengnether vertical seismograph installed a few months ago. The seismometer was installed by Roland F. White of the Coast and Geodetic Survey. White is head of the Honolulu Magnetic Observatory at Barber's Point, Oahu.



Anonymous, 1951, Strong earthquake rocks Big Island: Hilo Tribune-Herald, 11/08, p. 1. 



 An earthquake classified as "strong" shook the Big Island at 9:35 this morning.

Dr. Gordon A. Macdonald, volcanologist in charge of the Hawaiian volcano observatory, said a preliminary determination was that the epicenter was probably under Mauna Loa.

 He happened to be at the St. Joseph's seismograph station [Hilo] at the time; it was a "strong" tremblor, he said, and dismantled both components of the machine.

 . . . .

 No damage was reported for today's quakes. The 9:35 shaker was felt all over the island. Occupants of solid buildings, such as the Federal building and the Tribune-Herald structure as well as those in the rickety County building were equally jolted.

 Hilo police said no damage was reported.

 A half minute long tremblor was left [sic; felt?] at Kona, according to Police Officer Daniel Cambra. He had received no reports of damages in the first minutes after the quake.



Anonymous, 1951, Kahuku ranch is hard hit by quake yesterday: Hilo Tribune-Herald, 11/09, p. 1. 



 The quake which hit the Big Island yesterday morning appears to have been centered under the southwest rift of Mauna Loa, according to Dr. G.A. Macdonald of the Hawaiian volcano observatory.

 Kahuku Ranch, in that area, this morning the only damage thus far known from the quake. According to Manager Ernest Morton, stone fences were tumbled down, a few dishes were broken in the ranch house and some concrete sidewalks cracked.

 . . . .



Anonymous, 1951, 'Quake felt: Hilo Tribune-Herald, 12/07, p. 1. 



 A strong earthquake was felt all over the Hilo and Volcano districts at 8:19 last night.

 . . . .

 The disturbance, although felt strongly in Hilo, did not dismantle the observatory seismographs, Dr. Macdonald said.



Anonymous, 1951, Seismological notes: Bulletin of the Seismological Society of America, v. 41, no. 4, p. 401-402. 



 Honolulu, T.H., August 21, 1951.A series of violent earthquakes rocked the Hawaiian Islands on August 21. Twenty buildings were shaken down and fears were aroused that the slumbering volcanoes of Mauna Loa and Mauna Kea would erupt. The major damage was centered on the big island of Hawaii. Roads were torn up, and a gigantic quarter-mile section of rock cliff toppled into the ocean along the Kona (western) coast. The first jolt hit the island at 12:57 A.M., Hawaiian time (3:57 A.M., P.D.T.), and was followed by another big shake at 1:31 A.M. Smaller shocks were reported felt for several hours afterward. Most of the damage was centered around the town of Honaunau. Communications between the eastern and western sides of the island were disrupted for several hours. Estimates of the number of wrecked or damaged water tanks ranged from 50 to 200. The main earthquake wrecked 13 houses, a school, and a store, and damaged 200 other dwellings. Property damage was estimated at between $750,000 and $1,000,000, but the water loss was the most critical. Only two persons were reported injured, despite the widespread havoc.

 The Survey gives the time of the shock as 10h 56m 57.5s G.C.T., with provisional epicenter 19.75 N, 156 W' which is on the west coast of the island of Hawaii, northwest of Mount Hualalai. Pasadena estimates the magnitude as 6.75; Berkeley, 7. An aftershock of this earthquake was recorded on August 22 at 08h 47m 51s, G.C.T. [Correct location is on Kealakekua fault zone, 19.5 N, 155.95 W]



Anonymous, 1951, Seismological notes: Bulletin of the Seismological Society of America, v. 41, no. 3, p. 248-249. 



 Honolulu, T.H., April 22, 1951.--The island of Hawaii was shaken by an earthquake at 2:52 P.M. (Hawaiian time). Windows in downtown Hilo were shattered, but no other damage was reported. There were no casualties. The Director of the Hawaiian Volcano Observatory has furnished the following note:

 This earthquake was felt strongly all over the island of Hawaii, with an intensity of about V, or possibly a weak VI, in the epicentral area, and was also felt by many people on the islands of Maui and Oahu. On the southern part of the island of Hawaii many small objects were overturned, and some dishes were broken. Pendulum clocks commonly were stopped. There were many earth slips in roadcuts, and many rockslides in Halemaumau pit, on the walls of the Kilauea caldera, and at the big Hilina Pali fault scarp near the south coast of Kilauea. All of our seismographs at Kilauea, on the southern slope of Mauna Loa, and in Hilo were dismantled on the arrival of the P phase. The piano-wire suspensions on the Mauna Loa (Hawaiian-type) seismograph and on the horizontal pendulum tiltmeters at the western side of Kilauea caldera broke, dropping the heavy masses on the piers. The earthquake originated on the east rift zone of Kilauea volcano, judging from the numerous aftershocks and one moderate shock which preceded it probably within five miles east of the caldera, and judging from its rather uniform intensity over the entire southern part of the island it occurred at considerable depth for Hawaiian earthquakes, probably 25 or 30 miles.

 The Survey gives the time of the earthquake as April 23 at 00h 52m 21s, G.C.T., with provisional epicenter 19 N, 155.5 W. Pasadena estimated the magnitude as 6.5; Berkeley, 6. [Correct location is deep beneath Kilauea's upper east rift zone, 19.42 N, 155.25 W]



Anonymous, 1951, Seismological notes: Bulletin of the Seismological Society of America, v. 41, no. 1, p. 79. 



 Hawaii, December 10, 1950.A news dispatch from Honolulu states that residents of the Island of Hawaii felt a series of more than 300 minor earth tremors during the preceding twenty-four hours. The earthquakes were of fairly shallow origin and caused no damage in inhabited areas.



Anonymous, 1951, Seismological notes: Bulletin of the Seismological Society of America, v. 41, no. 2, p. 171. 



 Hawaii, T.H., December 11, 1950.The Survey reports an earthquake at 07h 25m 06s, G.C.T., with preliminary epicenter 19.5 N, 155.5 W. This location is in Hawaii National Park east of Mauna Loa.



Anonymous, 1952, Strong-'quake rocks Hilo: Hilo Tribune-Herald, 02/02, p. 1. 



 A short strong earthquake jerked some Hiloans awake at 1:16 this morning, but police received no reports of damage.

 . . . .

 Officials at St. Joseph's seismograph station termed the tremblor "quite a strong" one. One needle, the north-south component was dismantled.

 Re action [sic] among Hiloans was varied. Some sleepers were jerked violently awake. Others queried about the shaker asked: "What quake?"

 Exact time of the quake was listed by Dr. Macdonald at 1:16:26 a.m.



Anonymous, 1952, Earthquake felt strongly in Kapapala: Hilo Tribune-Herald, 02/12, p. 1. [Quake not tabulated in Volcano Letter 515] 



 A quake was felt strongly this morning at the Kapapala Ranch headquarters but was recorded as feeble at the Volcano observatory, reported volcanologist Dr. Gordon A. Macdonald.

 Ranch manager Allan Johnston reported the quake and said it felt like a short sharp bump.

 Dr. Macdonald said the quake was recorded at the observatory at 6:44:33 a.m. and originated close to the Kapapala Ranch headquarters, probably along the Kaoiki fault parallel to the Kau highway on the Mauna Loa slopes.

 No damage due to the quake was reported and intensity of the tremblor was estimated at about 4 on the Mercalli scale of 12.

 . . . .



Anonymous, 1952, Waves wash Kalapana area: Hilo Tribune-Herald, 03/18, p. 1. 



 Small seismic waves--causing plenty of excitement--but no damage--moved into the Kalapana section of the Big Island about 6 last night, caused by a severe submarine earthquake centered 15 miles offshore, southwest of Kalapana village.

 The next paragraphs discuss the seismic swarm--170 events so far. The quake dismantled the east-west, but not the north-south, component of the HVO seismometer.

 A check at Kalapana showed the waves came in far enough to reach the ponds near the schoolhouse at the village itself, and also the ponds across the road from the park.

 . . . No damage was done and no one was hurt.

 The waves, according to the schoolchildren, did not move into the Black Sand beach area at Kaimu. They flooded into the area near the village itself and southwest of there on the Kau side.

 A check at Kumukahi lighthouse on the southeast tip of the island showed no high waves there, nor was the quake felt.

 The school children at Kalapana said they didn't feel the quake that set up the waves.

 . . . .



Anonymous, 1952, Earthquake generated waves wash Kalapana area; disturbance causes excitement; no damage: Hawaii Tribune-Herald, 03/18, p. 1-2. 



 Small seismic waves--causing plenty of excitement but no damage--moved into the Kalapana section of the Big Island about 6 last night, caused by a severe submarine earthquake centered 15 miles offshore, southwest of Kalapana Village.

 More than 170 earthquakes in the last 48 hours have been recorded [at HVO].

 The most severe of these, the one which sent waves into the Kalapana area, was registered at 5:59 p.m. It dismantled the east-west component of the seismograph although the north-south component "rode it out."

 A check at Kalapana showed the waves came in far enough to reach the ponds near the schoolhouse at the village itself, and also the ponds across the road from the park.

 The waves did not move into the Black Sand Beach area at Kaimu. They flooded into the area near the village itself and southwest of there on the Kau side.

 A check at the Kumukahi Lighthouse on the southeast tip of the island showed no high waves there, nor was the quake felt.

 The schoolchildren at Kalapana said they did not feel the quake.



Anonymous, 1952, Earthquakes off Kalapana continue: Hilo Tribune-Herald, 03/19, p. 1. 



 Most of the article describes the ongoing seismic swarm, the potential tsunami danger, and the possibility of undersea eruption.

 "The area in which the earthquakes are originating lies beneath the ocean off the south shore of the Big Island about 15 miles south-southwest of the village of Kalapana . . . The depth of the quakes is somewhat uncertain, but appear to have been about 10 to 25 miles. On the average there appears to have been a progressive decrease in the depth of origin . . ."



Anonymous, 1952, Quakes off Kalapana continue; school is closed today, Friday: Hilo Tribune-Herald, 03/20, p. 1. 



 Most of the article describes the ongoing seismic swarm, the potential tsunami danger, and the possibility of undersea eruption.

 "There appears to be some evidence that the shoreline in Kalapana may be rising, . . [based on observations of a Park employee] that the rocks offshore were higher out of the water than normally.

 Dr. Macdonald's instruments at the Volcano also show a northwest tilting of the ground, supporting this theory. This tilting would indicate a rise at Kalapana, said the expert."



Anonymous, 1952, Quakes off Kalapana continue for 6th day: Hilo Tribune-Herald, 03/21, p. 1. 



 Most of the article describes the ongoing seismic swarm.

 "Indications that the Kalapana shoreline is rising continued, . . . [based on summit tilt] . . ."



Anonymous, 1952, Undersea quakes shift to point off Kau coast: Hilo Tribune-Herald, 03/22, p. 1. 



 Undersea earthquakes off the Big Island still rocked the ocean floor today but an apparent westward shift of the epicenter was noted by a temblor expert.

 . . . .

 Dr. Gordon A. Macdonald, in charge of the Hawaiian Volcano observatory, said his readings indicated many of the shakers may now have shifted to a point 10 miles off the Punaluu, Kau shoreline.

 However, Dr. Macdonald thinks some of them are still epicentered at the original point, about 15 miles south southwest of Kalapana. The shift is from 22 to 25 miles westward from the first center.

 The shift of the epicenter, according to Dr. Macdonald, appears to mean that the steep undersea slope, actually a fault cliff or scarp, [at] Kalapana is in a progressive shift westward.

 Indications that the shoreline at Kalapana may be rising continue, said Dr. Macdonald. His instruments still show some westward tilt.



Anonymous, 1952, Quakes off south coast of Big Isle near 3,000 mark: Hilo Tribune-Herald, 03/31, p. 1. 



 The frequency of earthquakes in the swarm off Kilauea's south coast is diminishing. Dr. Macdonald explains this as follows:

 "It is possible the strain on the fault is being taken off by a lot of small disturbances, instead of a few large ones," the scientist said. He explained that if the fault has a high frictionable [sic] factor, it would take greater pressure to move the mass. But if the mass is free to move, it will keep slipping and the resulting disturbances, or earthquakes, will be of lesser degree and Dr. Macdonald believes this is what is happening.

 . . . .



Anonymous, 1952, [Earthquakes] in Kilauea volcano; new series of tremors continuing: Hilo Tribune-Herald, 04/07, p. 1. 



 The first part of the article discusses a new series of earthquakes beneath the summit and east rift zone of Kilauea. These are in addition to the few quakes still being recorded off Kilauea's south shore.



Anonymous, 1952, Quake jolts Hilo, but no damage is reported: Hilo Tribune-Herald, 04/11, p. 1. 



 A sharp moderate quake, accompanied by a roar, jolted the Hilo area at 10:50 last night, but no damage was reported today.

 . . . .

 In Hilo the tremor rattled windows and dishes. It awakened some sleepers. The roar was described as something similar to the roar of an airplane.

 In Kapapala and Naalehu, the quake was felt as "quite strong." Dr. Macdonald's instruments at the volcano recorded the jiggling as lasting about six minutes.



Anonymous, 1952, Light quake felt in Hilo, Volcano areas: Hilo Tribune-Herald, 04/14, p. 1. 



 . . . .

 [A quake] at 7:50 p.m. Saturday was felt in the Hilo and Volcano area.



Anonymous, 1952, Earthquake felt on Big Isle from Kona to Hilo: Hilo Tribune-Herald, 05/24, p. 1. 



 A "strong" quake centered off Napoopoo shook the island from Kona to Hilo Friday [May 23} but best gauging today was that it was "appreciably smaller" than last August's [Aug. 21, 1951].

 Damage was confined to Kona, where there were landslides, road damage, water tank breakings and merchandise swept off shelves. . . .

 Near Napoopoo, on Kealakekua bay, two land slides occurred, one of them into the sea. . . .

 After shakes were continuing today but were of small caliber.

 . . . .

 The quake struck at 12:13 p.m. Friday and was recorded on the Volcano instruments for 23 minutes. . . .

 In Kona it came like one big shock, apparently mauka to makai, reported Lt. Anthony Cambra, head of the Kealakekua police station. It knocked out the police transmitter . . .

 So strong was the shock that it "badly damaged" the Kona seismograph in the charge of Howard Taubman at Konawaena school.

 . . . It was "quite a strong" one in Hilo, too, said Sister Mary Thecla, in charge of the St., Joseph's seismograph. There the components were knocked off.

 Dr. Macdonald said his preliminary estimate placed the epicenter in the sea about five miles off Napoopoo. This is the general region where last August's epicenter was.

 Here's a glance at the damage:

 1-- Slides temporarily blocked the Captain Cook to Napoopoo road . . . Some old cracks in the road were reopened, boulders fell on the road . . .

 2--The bottom fell out of one water tank at Konawaena school. Three were leaking badly and six others were slightly damaged.

 3--A stone retaining wall was broken at three places near the Konawaena teacher's cottage and the retaining wall near the gymnasium was bulging.

 4--Underpinnings at the teacher's cottage at Hookena school were broken and braces cracked. The concrete floor in the school cafeteria caved in at several places.



Anonymous, 1952, Earthquake shakes isle from Kona to Hilo; minor damages in Kona; aftershocks continue: Hilo Tribune-Herald, 05/24, p. 1. 



 A "strong quake centered off Napoopoo shook the Big Island from Kona to Hilo Friday. . . 

 Damage was confined to Kona where there were landslides, road damage, water tank breakings and merchandise swept off shelves. Damage reports so far were small compared to those of the big Kona shaker last August 21.

 Near Napoopoo on Kealakekua Bay two landslides occurred, one of them into the sea. . . .

 The quake struck at 12:13 p.m. Friday ad was recorded on the Volcano instruments for 23 minutes. . . .

 In Kona it came like one big shock apparently mauka to makai. . . It knocked out the police transmitter. . . .

 So strong was the shock that it "badly damaged" the Kona seismograph at the Konawaena school.

. . . It was "quite a strong" one in Hilo, too. There the components were knocked off.

 Here's a glance at the damage:

 1-slides temporarily blocked the Captain Cook to Napoopoo road. . . Some old cracks on the road were reopened, boulders fell on the road and repair work undone.

 2-The bottom fell out of one water tank at Konawaena school; three were leaking badly and six others were slightly damaged.

 3-A stone retaining wall was broken in three places near the Konawaena Teacher's College and the retaining wall near the gymnasium was bulging.

 4-Underpinnings of the teacher's cottage at Hookena school were broken and braces cracked. The concrete floor in the school cafeteria caved in at several places.



Anonymous, 1952, Big Island may have not two but three active volcanoes: Hilo Tribune-Herald, 07/01, p. 1. 



 In this article Gordon Macdonald, director of the Hawaiian volcano observatory, revises his interpretation of the swarm of earthquakes that occurred off the south shore of Kilauea, beginning in March. Whereas before he had interpreted them as movement on a submarine fault scarp, he now suggest they may have been associated with an undersea volcano.

 [This is 15 years before Loihi was identified. Modern interpretation favors Macdonald's original idea.]



Anonymous, 1952, 2 quakes shake Hilo; eruption still going strong: Hilo Tribune-Herald, 07/07, p. 1. 



 Most of the article discusses the ongoing eruption in Halemaumau.

 "Two earthquakes were recorded during the night on the Kilauea seismograph . . . .

 Both were classified as "slight." The first one came at 10:56 p.m. and the other at 4:42 a.m. Both were felt in Hilo."



Anonymous, 1952, Three sharp quakes jolt parts of Isle: Hilo Tribune-Herald, 07/09, p. 1. 



 Three sharp earthquakes jolted this end of the island this morning, all of them believed centered under Kilauea volcano . . .

 The first came at 6:54 and was classified as "feeble" by the observatory. The other two came within seconds of each other at 8:10 and both were felt from Naalehu through the volcano area to Hilo.

 . . . .



Anonymous, 1952, Seismological notes: Bulletin of the Seismological Society of America, v. 42, no. 3, p. 273, 275, 279. 



 Off south coast of Hawaii, T.H., March 18, 1952.The Survey reports an earthquake at 03h 57m 35s, G.C.T., with preliminary epicenter 19 N, 155.5 W. This location is in the Pacific Ocean off the south coast of Hawaii.



Hawaiian Islands, April 7, 1952.The Survey reports an earthquake at 07h 09m 51s, G.C.T., with provisional epicenter 21 N, 157 W, and depth of focus about 60 km. This location is in the Kaloni Channel between Molokai and Lanai islands. News reports stated that windows were rattled in the Diamond Head area of Oahu.



Off the west coast of Hawaii, T.H., May 23, 1952.The Survey reports an earthquake at 22h 12m 26s, G.C.T., with provisional epicenter 20 N, 156 W. Pasadena estimates the magnitude of the shock as 6. The Director of the Hawaiian Volcano Observatory has contributed the following information:

 "The strong shock of May 23 at 12:12 (Hawaiian time) originated on the Kealakekua fault near Napoopoo, apparently close to the place of origin of the big earthquake of August 21, 1951. It was felt all over the island of Hawaii, and by some persons on Maui. Damage in the central Kona area included dishes, groceries, and bottles knocked from shelves, cracks in pavements, slides from roadcuts, some water tanks damaged, some windows broken, and tombstones overturned. The intensity near the epicenter was 6 in the modified Mercalli scale. The breaking of dishes extended as far as Naalehu (38 miles southeast of the epicenter). The epicenter lay just west of the island of Hawaii, at approximately 19 29' N, 155 58' W."



Anonymous, 1952, Seismological notes: Bulletin of the Seismological Society of America, v. 42, no. 1, p. 97, 103. 



 Hawaiian Islands, September 16, 1951.The Survey reports an earthquake at 11h 42m 57s, G.C.T., with preliminary epicenter 20 N, 155.5 W, which is on the island of Hawaii near its north coast.

 The Director of the Hawaiian Volcano Observatory reports that a strong earthquake, felt over much of the island of Hawaii, occurred at 11h 42m 558, G.C.T., on September 16, 1951. It originated beneath the southeast slope of Mauna Loa about 10 miles southeast of Kilauea caldera, at approximately 19 19' N, 155 25' W. Its origin probably was on the Kaoiki fault. It was followed by about 20 small aftershocks, also apparently originating on the Kaoiki fault. The intensity near the epicenter was approximately 5 on the Modified Mercalli scale. Four miles southwest of the epicenter, at Kapapala, objects were thrown from shelves. No appreciable damage was done however. [HVO location is correct]



Southern Hawaii, November 8, 1951.The Survey reports an earthquake at 19h 34m 13s, G.C.T., with preliminary epicenter 19 N, 155.75 W, which is near the southern tip of the island of Hawaii. The Director of the Hawaiian Observatory reports that all of the seismographs on the island of Hawaii were dismantled by the earthquake, the Mauna Loa instrument by the preliminary waves, but the others by the secondary waves. The earthquake was felt all over the island, and was felt strongly over the southwestern part. On the Kahuku Ranch, near the southernmost point of the island, objects were thrown down, many dishes were broken, and extensive damage was done to stone walls. Both instrumental data and the field investigation place the epicenter on the southwest rift zone of Mauna Loa at about 4,500 feet altitude, 15 miles N 15 W of the southern point of the island (19 11.5' N, 155 43.2' W). The very rapid decrease in the amount of damage away from the epicenter attests that the origin was very shallow, but no surface faulting has been found. [2nd location given is correct]



Anonymous, 1952, Seismological notes: Bulletin of the Seismological Society of America, v. 42, no. 3, p. 272-273. 



 Hawaiian Earthquakes, March 13-April 20, 1952.According to the Director of the Hawaiian Volcanic Observatory, between March 13 and April 30 seismographs of the Hawaiian Volcano Observatory recorded 4,553 local earthquakes. Most of them originated along a narrow linear zone trending approximately east-west, 8 to 15 miles south of the southeastern shore of the island of Hawaii, in latitude 19 00' to 19 12' N, and longitude 154 55' to 155 33' W. The total length of the active zone was about 44 miles. The line appears to mark a hitherto unrecognized fault, or system of faults, similar to the one that lies along the southeastern slope of Kilauea volcano above sea level. Eighteen of the earthquakes were strong in the classification in use at the Volcano Observatory (intensity approximately 4 M.M. near the south shore). Several of them were felt over much of the southern part of the island. A much larger numbed probably exceeding 100, were felt in the vicinity of Naalehu, which lies west of, and nearly in line with, the active fault. A strong earthquake at 03:58 (G.C.T.) on March 18 caused a small tsunami at the village of Kalapana.



Anonymous, 1953, 2 earthquakes felt strongly at Kapapala, Naalehu: Hilo Tribune-Herald, 03/26, p. 1. 



 Dr. Gordon A. Macdonald, chief of the Hawaiian Volcano observatory, reported two earthquakes, one occurring last night at 6:19 p.m. and one this morning at 1:40 p.m. [sic-a.m...].

 He described the earlier one as "moderate" and added that it was felt "strongly" at Naalehu and Kapapala.

 Mrs. Myrtle Hansen of Naalehu estimated the intensity at four on the modified Mercalli scale of 12, and Allan Johnston, manager of Kapapala ranch, estimated the intensity at three.

 Dr. Macdonald said that it was "apparently a good sharp earthquake which alarmed people but did no damage." He said the quake was centered 25 miles from the observatory in a west to southwest direction.

 The quake this morning, Dr. Macdonald reported, was described by Mrs. Hansen as two to three on the Mercalli scale. The distance was about the same as the earlier one.



Anonymous, 1953, 3 more seismograph stations to be set up at Big Isle schools: Hilo Tribune-Herald, 06/10, p. 1. 



 Plans are underway by the geological survey service [sic] to add seismograph stations at Waimea, Pahoa and Naalehu schools, bringing the total number of stations on the Big Island to nine. 

 Bids are being let following local approval for the sites selected.

 The new stations are part of a plan to set up a net of stations on the Big Island and the triangulation of earth disturbances and collecting of data will be "improved a good deal," the volcanologist [Gordon Macdonald] said.

 The three stations will facilitate work on the southwest rift of Mauna Loa, the east rift of Kilauea and the entire northern area of the island, he explained.

 New instruments for the stations are being constructed now by Burton C. Loucks, instrument maker at the observatory with the assistance of John C. Forbes..

 Mr. Forbes, assistant instrument maker, is now on Maui working on the reestablishment of the seismograph on Haleakala.

 Presently seismographs are located at the Volcano House [Whitney vault], east flank of Mauna Loa, Konawaena [Kealakekua, Kona] and St. Joseph's [Hilo] schools, and two at Uwekahuna, one high and one low magnification.

[The new seismographs were put in operation as follows: Pahoa, April 1 1954 (Volcano Letter 524, p. 9); Kamuela, June 9, 1954 (Volcano Letter 524, p. 10); Naalehu, between July 1 and September 30, 1954 (Volcano Letter 525, p. 8-date not given).]



Anonymous, 1953, Slight quake felt in Hilo: Hilo Tribune-Herald, 06/16, p. 1. 



 Although classified as "feeble," a slight earthquake registered last night on the seismograph at Kilauea Volcano observatory [at 8:33 p.m.] was felt in Hilo.

 Direction traveled by the temblor through Hilo was along a line from Waiakea toward Mauna Kea, its progress being noticeable from successive gentle jostling sounds of windows and doors as it progressed.

 . . . .



Anonymous, 1953, Earthquake shakes Hilo and Volcano; Kilauea is still uneasy: Hilo Tribune-Herald, 07/07, p. 1. 



 Most of the article discusses the uneasiness of Kilauea and the possibility of eruption.

 " . . . the quickie quake was timed at 8:25:48 p.m. . . .

 . . . since it was felt in both localities, Dr. Macdonald placed its origin somewhere between Volcano and Hilo."



Anonymous, 1953, Quake felt throughout islands; Kona reports strong tremor: Hilo Tribune-Herald, 08/22, p. 1. 



 An earthquake of "moderate" to "strong" intensity generally shook all the Big island last night at 7:45:42 p.m.

 Reports from Honolulu said a temblor was felt there at the same time too.

 Police here had no reports of damage today.

 Dr. Gordon A. Macdonald, head of the Hawaiian Volcano observatory, reported today the quake was "moderate at the observatory and was epicentered "probably in Kona somewhere" or under Mauna Loa if deep enough.

 . . . .

 In Kona, he said, the shock was "strong," the strongest in a year or more.

 It "rattled everything rattleable" there in Kona, the quake expert said.

 Dr. Macdonald had reports of the quake from Kona, Naalehu, Kapapala, Volcano and Hilo.

 Police in Kohala said it was felt there too. It came on strong, died off, came strong again and then gradually faded, police said.

 It was felt as "pretty strong," said an officer. A Honokaa officer and a Laupahoehoe resident both also said the quake was "pretty strong" in their respective areas.

 In Hilo, the jolt apparently was not of uniform intensity. Some timid residents got up ready to move outdoors when it shook and said it was a "pretty good" quake.

 A resident of Piihonua said a light fixture on the ceiling was unhinged and the light is now hanging by wire. 

 But some residents of Waiakea Homesteads and Houselots said they didn't even feel the quake.



Anonymous, 1953, Strong quake reported in Kona, Volcano areas; Other parts of Big Island also shaken: Hilo Tribune-Herald, 08/24, p. 1. 



 Another earthquake shook most of the Big Island early yesterday and was recorded as "strong" in Kona and Volcano.

 Dr. Gordon A. Macdonald, head of the Hawaiian Volcano observatory, said as a preliminary location that the epicenter "appeared to be beneath Hualalai." He timed it at 12:53 a.m.

 He did not have any "good" depth indication, but said he believed the quake originated at a place shallower than Friday night's [Aug. 22] temblor.

 Both Volcano and Mauna Loa stations recorded the jolt as "strong," he said. Miss Amy Greenwell, volunteer observer in Kona, reported the shake was felt "strongly through Kona," Dr. Macdonald said.

 There were no damage reports.

 In Kona it was not as strong as Friday night's but in the Volcano area it was stronger.

 . . . .

 Dr. Macdonald said the quake was felt "pretty widely" on the Big Island. He had reports from Volcano, Kapapala, Naalehu and Kona. It was felt in Hilo, too.

 He had no reports in yet from Kohala.

 [The location given in Volcano Letter 521, "beneath southwest slope of Hualalai about 3 miles east of Holualoa" is inconsistent with it being recorded "strong" on the Whitney and Mauna Loa stations.]



Anonymous, 1953, Kilauea shows distinct uneasiness; Lookout set up after series of earthquakes: Hilo Tribune-Herald, 10/27, p. 1. [Information repeated in Honolulu Advertiser of Oct. 28] 



 Hawaii National Park--Earthquake activity under Kilauea volcano appears to slack off somewhat this morning, after a series of more than a dozen disturbances between 3 p.m. Monday [10/26] and 8 this morning resulted in a close watch of Halemaumau by personnel of the Hawaiian Volcano observatory.

 Dr. Gordon A. Macdonald, director and volcanologist, said this noon the earthquakes appear to be centered under the east rift of Kilauea volcano, under the area known as the Chain of craters.

 . . . .

 "More than 12 earthquakes were recorded at the Hawaiian Volcano observatory between 3 p.m. Monday and 8 a.m. today, some of them strong enough to dismantle the seismograph at the Volcano House.

 "Their points of origin have not yet been definitely located, but they appear to have been beneath Kilauea volcano. No marked tilting has yet occurred."



Anonymous, 1953, Kilauea quiet again after quake series: Hilo Tribune-Herald, 10/28, p. 1. [Information repeated in Honolulu Advertiser of Oct. 29] 



 Hawaii National Park--Kilauea volcano, after a period of disturbance evidenced by a series of earthquakes Monday night, apparently has subsided . . .

 After more than a dozen quakes between 3 p.m. Monday and 8 a.m. Tuesday, the volcano has been quiet. Only a few minor quakes were registered Tuesday morning, and none since then.

 . . . .



Anonymous, 1953, Twelve quakes rock Big-Isle Volcano area: Honolulu Advertiser, 10/28, p. 1, 6 [same article]. 



 Repeats information in Hilo Tribune-Herald of Oct. 27.



Anonymous, 1953, Pele relaxes after brief disturbance: Honolulu advertiser, 10/29, p. 9. 



 Repeats information in Hilo Tribune-Herald of Oct. 28.



Anonymous, 1953, Quake shakes Hilo homes: Hilo Tribune-Herald, 11/30, p. 1. 



 Big Island volcanic activity stirred up two earthquakes last evening, the second, which was felt in Hilo at 8:42:44 p.m. being just short of intensity to do damage.

 The first quake, localized to the Volcano area and actually occurring within Kilauea crater in the vicinity of Halemaumau firepit, was clocked at 7:43:43 p.m.

 Coming an hour later, the heavier tremblor which shook Hilo homes sharply appeared to originate about 10 miles east of the volcano, it is said by Dr. Jerry Eaton, volcanologist in charge of Hawaiian Volcano Observatory during the absence of Dr. Gordon A. Macdonald.

 Dr. Eaton said that on the Mercalli scale, the second quake had an intensity rating of 3. . . . .

 The quake wave hit Hilo with a joggly sharpness, with its motion traveling through from approximately southeast to northwest. It came with a first heavy shock followed by a lighter sustained motion that rattled windows and doors vigorously.

 Estimating from reports of the second shock being felt in Hilo, Dr. Eaton judged it to originate about 10 miles east of Volcano area and at a moderate depth of about 10 miles.

 . . . .



Anonymous, 1953, Seismological notes: Bulletin of the Seismological Society of America, v. 43, no. 2, p. 183. 



 Mauna Loa, Hawaii, January 15, 1953.The Director of the Hawaiian Volcano Observatory reports that at 02:04 A.M., Hawaiian Time (12:04 G.C.T.), on January 15 a fairly strong earthquake originated beneath the southeastern slope of Mauna Loa near the headquarters of Kapapala ranch, with approximate epicenter 19 19' N, 155 26' W. Objects were upset and knocked from shelves as far away as Hilo, 37 miles distant. Residents of the southern part of the island of Hawaii were generally awakened, and the shock was felt as far away as Honolulu, 210 statute miles northwest. The epicentral area intensity was about 5.

 The Survey gives the time as 12h 04m 33s, G.C.T., with provisional epicenter 19 N, 156 W. Berkeley estimates the magnitude as 5-5.5. [HVO location correct]



Anonymous, 1954, Smart Sunday quake is felt in Hilo area: Hilo Tribune-Herald, 02/01, p. 1. 



 An earthquake temblor, computed at about three on the modified Mercalli scale jarred Hilo sharply Sunday at 11:48:26 a.m., but no damage was reported.

 Dr. Jerry P. Eaton, seismologist at Hawaiian Volcano observatory, said the shock was a sustained one from start to finish, having little build-up or taper off. He said it registered for about a minute and a half and probably was felt for about 45 seconds.

 . . . .



Anonymous, 1954, Volcanologist says tremors worst since '52: Honolulu Star-Bulletin, 03/30, p. 1, 12. 



 Hawaiian Volcano Observatory, March 30--Two "very strong" earthquakes jolted the Big Island early today--frightening residents . . .

 . . . the quakes which occurred at 6:40 and 8:42 this morning are the strongest since the series of about 5000 shakers that preceded the eruption of Kilauea on June 27, 1952.

 About half a dozen after shocks followed the second quake.

Centered near Hilo

 "All evidence points to the center being near Hilo and about 13 to 20 miles deep," Dr. Gerry [sic] P. Eaton, seismologist at the observatory, said.

 The rim of Halemaumau pit at Kilauea volcano has been sealed off to sightseers because of the danger of the rim being loose enough to collapse.

 Huge dust clouds rose from Halemaumau this morning as strong landslides followed the quakes.

Windows broken

 Preliminary damage reports put worst destruction at the Puueo section of Hilo, where dishes were rocked off shelves, windows were broken or cracked and in a few cases the floors of old houses buckled.

 Edwin Silva reported that his home in the Puueo section was moved about two inches by the temblors, and that there are slight cracks in the ground around his and his neighbors' homes.

 He said damage at the home of his neighbor, Mrs. Annie Chow Hoy, will probably run into hundreds of dollars for damaged china and plate glass. . . .

 . . . the second quake shook 50 per cent of the plaster off the 12 by 24 foot projection room of the Palace Theater. . . .

Populace frightened

 A frightened populace ran out of Hilo offices and stores when the second quake occurred, swaying buildings and shaking goods off of store shelves.

 . . . in a grocery store when the second quake occurred, bottles of jams, jellies, pickles, everything fell to the floor.

 The first quake that shook Big Island residents out of their beds was felt for about a minute. It kept the volcano observatory seismograph in motion more than 20 minutes and had a magnitude [sic-intensity] of five on a scale of 12.

Second shock heavy

 The second quake was stronger but of shorter duration in ground motion, and recorded a magnitude [sic-intensity] of seven.

 Shortly after the second quake occurred, the Hilo Tribune-Herald's radio-teletype circuit between Hilo and Honolulu went out. . . .

 . . . .

 The Tribune-Herald's new building at the corner of Kinoole Avenue and Mamo Street, swayed back and forth during the second quake, causing those in the newsroom to hang onto the desks while lighting fixtures overhead swung slowly back and forth.

 Plaster rained from the ceiling of the rickety Hawaii County Building . . .

 The Keaukaha area, which seldom feels the many earthquakes coming from the Big Island's volcanoes, was shaken by today's temblors, but not enough to break dishes.

Second felt stronger

 Mrs. Myrtle Hansen, Star-Bulletin correspondent at Naalehu, said the quake lasted "for a long time." The second felt stronger, she said, followed by several smaller ones at about five-minute intervals.

 Mrs. Hansen ran out of her house after the second one and felt the ground sway back and forth as though "it wasn't the ground anymore."

 A check of the neighborhood, however, revealed no damage or injury except for a vase and other loose objects being knocked to the floor at Kapapala Ranch, east of Pahala.

 Mrs. Francis Lincoln, Kona corespondent, reported from Holualoa that both quakes were felt there but they were gentle as "being rocked in a cradle." There were no reports of damage, she said.

 Mrs. Lena C. Short, reporting from Kohala, said the quakes were also light in that area and no damage has been reported. She was preparing breakfast and almost missed feeling the first one.

 The chimney was knocked off the Olaa home of C.E.S. Burns, manager of the Olaa Sugar Company. The ceiling on the third floor caved in, and walls were cracked in some of the rooms.



Anonymous, 1954, Two strong quakes hit island; moderate damage is reported; no eruption pattern seen yet.: Hilo Tribune-Herald, 03/30, p. 1, 8. 



 Two strong earthquakes and possibly a half dozen minor temblors shook the Big Island today, alarming thousands and doing moderate damage. Some houses were jarred loose from their foundations, big plate glass windows were cracked, scores of smaller window panes were broken, dishes were smashed and plaster knocked off ceilings and walls.

 Dr. Gordon A. Macdonald, in charge of the volcano observatory, termed the two big quakes the strongest since the series of about 5000 shakes in the spring of 1952 preceding the Kilauea eruption.

 The more violent of the two major quakes struck at 8:42 a.m., and was listed as intensity VII. . . . The first, which rocked the island at 6:40 a.m., was listed at intensity V.

. . . 

 Although reports indicated they were felt around the island, the area ranging from Naalehu to Hilo appeared rocked the sharpest. Kona and Kohala reports said the shocks were about intensity II.

 There were no reports of human casualties, but tragedy was narrowly averted at a home on Reed's island when the brick back wall collapsed and a similar front wall cracked.

. . . .

 Although the two jolts were felt by islanders for about a minute, they were actually recorded at HVO for about 20 minutes after they began.

 Components of the HVO seismograph were dismantled by the shocks, but the strong motion instrument rode out the movements.

 The first of the quakes . . . knocked some dishes off shelves at Halai Hill and slopped coffee out of cups . . .

 Usually late risers were frightened out of bed. Parents grabbed their drowsy children to scramble outside.

 A short circuit was caused at Ainoole, Onomea mauka , and electric services to seven homes was cut off.

 The major damage came with the second quake, which was violent enough to be felt by motorists in moving vehicles. One reported he was swayed from side to side and bounced up and down.

 The school department reported 54 windows broken at Kalanianiole school. A "considerable" number, including 17 in the auditorium, were broken at Hilo High school.

 Other schools sustained damage to lighting fixtures.

 Some homes in Puueo were shifted about two inches on their foundations.

 Hotel Palm Terrace reported half inch cracks in the concrete floor of its laundry room, weakening a chimney, which had to be taken down, and a quarter inch crack the length of its parking lot.

 Heavy equipment, such as ice boxes were shifted. . . .

 A kamaaina resident of Reed's Island said it was the worst jolt she felt in 50 years.

 Plate glass windows were cracked at Von Hamm Young Co. and at Dot's Babyland.

 Merchandise tumbled off grocery store shelves.

 In the rickety County building . . . books fell off shelves and plaster rained from the ceilings. . . .

 In one home in Puueo, the bathroom flooring cracked, wall paper was torn and lanai pillars knocked lopsided.

 the Tribune-Herald building, a solid structure, "shook like a boat," one occupant said. Outside telephone and electric wires shook like banjo strings.

 Water out of fish bowls splattered to the floor in some homes.

 . . .

 In Olaa the chimney was knocked off the home of C.E.S. Burns, Olaa Sugar Co. manager, and the ceiling on the third floor caved in. Sides were cracked in some rooms.

 . . . .

 The Hilo seismograph at St. Joseph's school was completely dismantled by the second big quake. Data obtained from the local seismograph was transmitted to Dr. Macdonald by Sister Beatrice.

 At the county library, books were spilled out of their cases, and one plate glass was cracked.

 The clock on the county supervisor's chamber wall was smashed to the floor.

 At the Bank of Hawaii, a big chunk of plaster fell off a column top and smashed the plate glass top of a desk. . . . There were numerous plaster cracks and one plate glass window was cracked.

 Honolulu reports said there were no quakes on the other islands.

 At Lyman House Memorial museum, not the oldest of structural veterans of earthquakes in Hilo area, considerable damage was reported . . . .

 Actual damage was confined principally to the shattering of glass panes in museum display cases. With the first quake at 6:40:6 a.m.. several of the old brittle panes "popped."

 A preliminary survey disclosed that apparently there was no breakage of museum china or glass display pieces many of which are wired in place on their shelves.

 However, old lamps were knocked over and some pictures were thrown down from the walls. Shell and other collection displays were quite jumbled about.

 The old Severance clock, which is over 90 years old and has been through many Big Island quakes, was stopped in its ticking by both of this morning's heavy temblors.

 Mrs. Welsh said she set to work immediately following the first shake to restore order, but that her early efforts were all undone by the second and heavier upheaval.



Anonymous, 1954, No Big Island eruption seen after earthquakes: Honolulu Star-Bulletin, 03/31, p. 12. 



 Hawaiian Volcano Observatory, March 31--There is no evidence whatsoever that either Kilauea or Mauna Loa will erupt soon despite yesterday's temblors, Dr. Gordon A. Macdonald said today.

 Seismographs at Kilauea crater returned to comparative inactivity after the severe shocks yesterday morning. A third quake felt only at the volcano was recorded at 11:19 a.m. and two others reported "feeble" were recorded during the night.

 Evidence yesterday indicated the center may be near Hilo and about 15 to 20 miles deep.

Conflicting evidence

 But conflicts in evidence make it impossible to tell where the location is. "We may never know," Dr. Macdonald said.

 Part of the evidence puts the epicenter along the northeast rift of Mauna Loa and equally strong data points to the east rift of Kilauea Crater, he said.

 . . . .

 Dr. Macdonald said a crack has appeared in the Chain of Craters Road in Hawaii National Park and that Halemaumau fire pit is still closed to visitors because of the danger of possible landslides.

 He also reported a broken water pipe at the Volcano House.

 Meanwhile Kulani Prison Camp on the Northeast slope of Mauna Loa may lose 200,000 gallons of water from yesterday's quakes.

Water tanks cracked

 . . . the bottoms of four 50,000 gallon water tanks cracked. . . . Motor equipment, which had been jacked up for repair, was knocked off its props and slightly damaged . . .

 In other damage reports

 1--Glass equipment in Hilo High School's chemistry department suffered heavy damage. In the buildings, plaster cracked off from ceilings and walls and window panes were broken.

 2--A plate glass window was [incomplete]



Anonymous, 1954, Big Island uneasy after two quakes: Honolulu Advertiser, 03/31, p. 1, 6. 



 [Datelined Hilo, March 30, the following items supplement information given in the Honolulu Star-Bulletin articles of March 30 and 31]

 Damage throughout the island was widespread but not serious.

 At Hilo's federal building, a concrete and slate corridor sustained a jagged rip. Inside the Third Circuit courtroom the portraits of former judges danced on the wall. Only one fell, however. . . .

 Across the street from the federal building, a large plate glass window at the Von Hamm-Young Co. was broken. Drugs and liquor in the company's warehouse were rocked from shelves, scattering liquid and glass.

 Super markets . . . replacing canned goods and sweeping out the remains of bottles.

 Hilo drug stores [had many bottles broken].

 [at Hilo High School] plaster was falling from ceilings and walls, nine window panes were shattered and 40 cracked . . . .

 The high school chemistry room sustained the most damage. Glass equipment, including the Hoffman apparatus used in testing electrolysis, was shaken from tables and shelves and shattered on the floor.

 . . . the termite-infested [County Building] started to swing and sway. Plaster sprayed from the ceiling and walls . . .

 Old wooden buildings, however, survived in better style than some modern models. A 5 x 7 foot plate glass window at the new Public Library was shattered, small cracks veined floors, and plaster dust showered many sections of the structure.

 . . . stacks of books [were] bowled over by the first quake. . . When the second jolt struck . . . he swayed with the building, watched all the books fall down again. . . .

 A high chimney at Hotel Palm Terrace, made of native stone, was so badly damaged by the quake it had to be removed as a safety precaution. Hotel operator John Lee reported considerable damage to a wall aquarium and bar in the Lava Pit, the establishment's dining room.

 Motorists in motion at the time of the second quake said they felt something had gone wrong with the steering mechanism.

 . . . .



Anonymous, 1954, Big Island quiet after 'big shake': Hilo Tribune-Herald, 03/31, p. 1. 



 Three "very feeble" earthquakes were recorded by the Hawaiian Volcano observatory this morning, following Tuesday's two strong and about six minor jolts.

 The next paragraphs discuss dollar estimates of damage, totaling at least five figures.

 The three new quakes occurred this morning at 12:30 a.m., 1:30 a.m. and 5:46 a.m. . . .

 . . . .

 . . . in the face of conflicting evidence [epicenters could be] on the east rift of Kilauea or the northeast rift of Mauna Loa.



Anonymous, 1954, Quake thumps Big Island for holiday starter: Hilo Tribune-Herald, 07/04, p. 1. 



 An earthquake rate at intensity 4 on the modified Mercalli scale of 12 was felt in Hilo, Volcano and Kapapala ranch at 11:52:34 a.m. Saturday.

 Some things were reported toppled from shelves but no damage was listed.

 . . . .

 Some persons did not feel the shock but heard noises described as "something like two box cars crashing." Dr. Eaton explained the jolt came strongly and its frequency was high enough to be heard as sound.

 The temblor dismantled the more sensitive instruments at the observatory. In Hilo it was felt for just a few seconds. In Kapapala it was reported felt for 20 seconds and the observatory instruments recorded the rocker for several minutes.

 . . . there were a few slides at Halemaumau pit but . . . they were not very large.



Anonymous, 1954, New quakes point up uneasiness of Kilauea: Hilo Tribune-Herald, 10/08, p. 1. 



 . . . .

 A moderate quake, which was felt sharply by Hiloans at 8:56 p.m., was estimated to be about 20 miles from the observatory. A preceding slight shock at 6:43 p.m. was placed about 10 miles distant.



Anonymous, 1954, Seismological notes: Bulletin of the Seismological Society of America, v. 44, no. 4, p. 619. 



 Near northeast coast of Hawaii, T.H., July 3, 1954.The Survey reports an earthquake at 21h 52m 33s, G.C.T., with preliminary epicenter 20.5 N, 155.5 W, which is in the Pacific Ocean about 25 miles north of Hawaii, T.H. The earthquake was reported felt at Hilo. [Correct location is deep beneath Kilauea at 19.37 N, 155.2 W]



Anonymous, 1955, 5 sharp earthquakes shake up Pahoa area: Hilo Tribune Herald, 02/25, p. 1. 



 Pahoa residents were again shaken up as about 70 minor earthquakes, and five sharp tremors hit the area Thursday and this morning, but no damage was reported.

 The strongest tremors occurred at 3:06, 7:45, and 9:23 p.m. Thursday and 5:50 and 6:30 this morning . . .

 . . . the Pahoa seismograph was dismantled five times . . . at 3:15, 6:39, 9:15 and 10:30 Thursday and 6 a.m. this morning.

 . . . .

 The quakes recorded Thursday and this morning bring the total so far this month to over 200 in the Pahoa area. On February 13, more than 49 quakes were recorded at Pahoa between 1 and 6 a.m.

 During January, the Pahoa station recorded 140 quakes as against 127 during December.



Anonymous, 1955, Minor quakes still recorded in Pahoa area: Hilo Tribune Herald, 02/26, p. 1. 



 . . . .

 Of the many minor earthquakes, the strongest was recorded at 3:15 p.m. Friday.

 On Thursday and Friday morning about 70 minor quakes and tremors hit the Pahoa area. This series brings the total number of quakes in the area to over 200 for the month.

 During January the Pahoa station recorded 140 quakes and December 127.

 The quakes in the Pahoa area do not indicate that an eruption of Kilauea is forthcoming, according to the Hawaiian Volcano Observatory.

[Eruption began Feb. 28]



Anonymous, 1955, Crack opens on highway near Volcano: Hilo Tribune Herald, 03/28, p. 1. 



 A sharp earthquake at 4 p.m. Sunday [Mar. 27] opened up a two inch crack on the Mamalahoa highway about one-fourth mile on the Hilo side of the National Park administration building in the Kilauea area.

 The road to Kau was passable.

 When smaller cracks appeared near the Thurston Lava tube Sunday afternoon the Chain of Craters road was closed on the advice of Dr. Gordon A. Macdonald, volcanologist. This morning the Chain of Craters road was reopened to the public. 

 Since the dismantling of the seismograph Sunday afternoon,, there has been minor tremors, but, none strong enough to dismantle! the seismograph, according to a Hawaiian Volcano observatory spokesman.

 On the Hilo side of the crack on the highway, there was a vertical displacement of an inch and the horizontal displacement was 13/16ths of an inch.

 The quake also broke two water pipes. One of the pipes broken was in the home of Dr. Macdonald and one in the basement of the Assistant Park Superintendent W. Leon Evans. Vases and lamps were also knocked over by the sharp quake and dishes were broken .

 Meanwhile, Dr. Macdonald returned to Pahoa this morning after rushing back to the Kilauea area Sunday afternoon upon receipt of the earthquake report.

 At that time Dr. Macdonald said that there was a possibility of the Kilauea floor dropping further. "The floor has dropped over two feet during the past three weeks," he said. 

 He added that the dropping of the floor was due to the removal of support and pressure because of the drainage of lava in the present Puna eruption.

 Using the 1924 eruption as an analogy he explained that during that eruption the ground sank in the east rift zone of the Kilauea crater, the site of the present eruptions, and the walls of the Halemaumau pit collapsed with heavy steam explosion. Violent earthquakes, he said, preceded the drop of the crater floor.



Anonymous, 1955, Quake shakes Big Isle; no damage is reported: Hilo Tribune Herald, 04/01, p. 1. 



 A rolling quake roused Big Islanders from Kona to Kau and Hilo at 4:25 this morning. The Hilo seismograph was dismantled.

 No damage, however, was reported to police.

 Dr. Gordon A Macdonald, volcanologist, said the quake probably originated in the Kaoiki fault, which separates Kilauea and Mauna Loa.

 The quake, he said, is part of the general series accompanying the sinking of the Kilauea crater floor. The sinking is due to the reduction in volcanic pressure caused by drainage of lava in Puna, he added.

 He said this morning's quake caused less damage than the one that ripped open a two-inch crack across Mamalahoa Highway one-fourth mile on the Hilo side of the Hawaii National Park administration building Sunday afternoon.

 The volcanologist received reports that the quake was felt strongly in Naalehu, the Glenwood-Mountain View area, Pahoa and the volcano crater region. He said Allan Johnson, manager of Kapapala Ranch, about 8 miles northeast of Pahala, towards Kilauea, reported that objects were knocked off mantels and shelves.

 . . . .

 The quake's impact in Kona area brought lights blinking on up and down mauka slopes and villages as dwellers were aroused.

 Howard Tatsuno, Konawaena teacher who tends the seismograph there, reported the instrument was dismantled by the temblor, which he described as not sharp but severe and having a gradual rolling motion. He located the shock as coming from the southwest rift of Mauna Loa.



Anonymous, 1955, Quake felt in Pahoa area; CDA officials see no cause for alarm: Hilo Tribune Herald, 04/22, p. 1. 



 An earthquake strong enough to dismantle the Pahoa High School seismograph was felt shortly before 6 this morning in the Puna eruption area but reports of renewed volcanic activity were declared unfounded by civil defense officials.

 Kongo Kimura, who is in charge of the Pahoa seismograph, said the quake was the first to dismantle the machine since the eruption stopped two weeks ago. It was recorded at 5:57 a.m.

 He said minor quakes were being registered about one a day after volcanic activity stopped. There were, however, two moderate quakes recorded Tuesday [Apr. 12, according to VL, not Apr. 19 as might be assumed from the article date].



Anonymous, 1955, Second quake in week shakes Hawaii Island: Hilo Tribune Herald, 08/14, p. 1. 



 For the second successive Sunday, Big Islanders were roused by an earthquake. Starting about 2:28 a.m. the quake lasted about five minutes, but was felt only a few seconds . . . The quake on August 7 was of the same duration.

 . . . .

 Damage from Sunday's quake was limited to cracked paint and plaster at the Kapapala Ranch . . . and a few articles knocked down from shelves. . . intensity estimated at 5 . . .



Anonymous, 1955, Seismological notes: Bulletin of the Seismological Society of America, v. 45, no. 4, p. 341-342. 



 North of Hawaii, T.H., August 7, 1955.The Survey reports an earthquake at 17h 17m 32s, G.C.T., with preliminary epicenter 20.5 N, 155.5 W, which is in the Pacific Ocean north of Hawaii Island. The tremor was felt on Hawaii and Maui Islands. [Correct location is 20.06 N, 155.65 W]



Honolulu, T.H., August 14, 1955.--The strongest earthquake in more than a year struck the island of Hawaii early on August 14. Some damage was reported at a ranch south of Kilauea crater. The Survey gives the time of the earthquake as 12h 27m 58s, G.C.T., with preliminary epicenter 19.5 N, 155.5 W, which is in Hawaii National Park east of Mauna Loa. [Correct location is deep beneath Kilauea's south flank at 19.3 N, 155.3 W]



Anonymous, 1955, Seismological notes: Bulletin of the Seismological Society of America, v. 45, no. 3, p. 252. 



 Hawaii, T.H., April 1, 1955.The Survey reports an earthquake at 14h 24m 238, G.C.T., with preliminary epicenter 19.5 N, 155 W, which is near Pahoa, eastern Hawaii. The tremor was felt at Hilo and on the Kona coast. [Correct location is deep beneath Kilauea caldera at 19.4 N, 155.3 W]



Anonymous, 1955, Seismological notes: Bulletin of the Seismological Society of America, v. 45, no. 3, p. 246. 



 Pahoa, Hawaii, February 28, 1955, and later.The long dormant volcano Puulena erupted on February 28, touching off a forest fire and forcing near-by villagers to flee. Not once in 180 years had the crater on the eastern tip of Hawaii Island shown the slightest sign of life. A sugar company had built a plantation around it. Soon after 8 A.M., February 28, a crack opened near the crater and exploded. Less than two hours later about one and a half acres in the cane field had sprouted fissures and lava was spouting 15 to 20 feet in the air. A river of hot lava, estimated to be about 20 yards wide, began cutting through the cane field, flowing toward the black beaches of Hawaii's eastern shore. On March 4, flames, white-hot lava, and acrid volcanic ash belched hundreds of feet into the air. All 350 residents of the explosive area were evacuated. Earth tremors at the rate of 100 an hour were recorded on March 5, as the town of Pahoa with its population of 900 swollen by several hundred refugees prepared for a mass flight at a moment's notice. About midnight the earthquakes began diminishing in frequency. On March 9 new and stronger earthquakes jolted the volcano-devastated Puna district at the rate of one a minute. The earthquakes centered south of the general area where during the previous week 600 residents were evacuated and damage was estimated at $3,200,000. On March 13 three new eruptions ripped the east flank of Kilauea volcano. Lava flows from the crater cut the main road between Pahoa and Kalapana villages with a 150-foot lava pool, destroying lush fields and a dense forest section. At least 500 residents of six coastal villages within three miles of the eruption area were ordered evacuated. Shortly before dawn, March 16, a massive river of red-hot lava 1,000 feet wide poured into the ocean over a 20-foot bluff, sending steam 2,000 feet into the air. It was the first time a lava flow had reached the sea since the 1950 eruption of Mauna Loa. On March 16 four sharp earthquakes dismantled the seismographs at Pahoa.



Anonymous, 1956, Seismological notes: Bulletin of the Seismological Society of America, v. 46, no. 1, p. 77. 



 Hawaii, October 27, 1955.--The Survey reports an earthquake at 02h 55m 40s, G.C.T, with preliminary epicenter 20 N, 155.5 W, which is in northern Hawaii, north of Mauna Kea. [Correct location is beneath Mokuaweoweo at 19.5 N, 155.6 W]



Anonymous, 1956, Fifty years ago--1906: Honolulu Advertiser, [p. no. unknown]. 



 An earthquake shook Hilo at 6:40 o'clock this morning, and shortly afterwards hundreds of dead fish were strung along the beach. The fish apparently were scalded by a submarine eruption off Keaukaha.



Anonymous, 1962, Seismological notes: Bulletin of the Seismological Society of America, v. 52, no. 1, p. 147. 



 Hawaii, July 23, 1961, 15h24m15.1s GCT, 19.5 N, 155.2 W. focal depth about 44 km. (USGS). Felt: Islands of Hawaii and Oahu. Two quakes were felt. There are no reports of injuries or property damage



Anonymous, 1962, Seismological notes: Bulletin of the Seismological Society of America, v. 52, no. 2, p. 464. 



 Hawaii Island, Hawaii, September 25, 1961, 05h29m00.8s GCT, 19.9 N, 155.3 W, focal depth about 82 km. (USGS). Magnitude 5.75-6 (Pas). Minor damage at Hilo The quake came shortly after a new volcano eruption was reported in a dense area of the Puna Forest Reserve



Anonymous, 1963, Seismological notes: Bulletin of the Seismological Society of America, v. 53, no. 1, p. 212. 



 Hawaii Island, Hawaii, June 28, 1962, 04h27m18.4s GCT, 20.0 N, 155.6 W, focal depth about 25 km. (USCGS). Magnitude 5.75 (Brk), 5.25-5.5 (Pal [Pas?]). Slight damage on Hawaii.



Anonymous, 1964, Seismological notes: Bulletin of the Seismological Society of America, v. 54, no. 1, p. 456. 



 Hawaii, August 26, 1963, 18h49m19*s GCT, 19.8 N, 155.6 W, focal depth around 5 km. (USCGS). Felt. Magnitude 4.40.2 (CGS).



Anonymous, 1964, Seismological notes: Bulletin of the Seismological Society of America, v. 53, no. 2, p. 853. 



 Hawaii Island, Hawaii, October 23, 1963, 20h24m05.5s GCT, 19.4 N, 155.5 W, focal depth about 5 km. (USCGS). Felt. Magnitude 5.00.4 (CGS).



Anonymous, 1973, Hawaii, in Lander, J.F., ed(s)., Seismological notes: Bulletin of the Seismological Society of America, v. 63, no. 6, p. 2207-2209. 



 Hawaii. The following earthquakes were felt: 

April 23, 1973, 07h07m53.0s, 19.97N, 154.67W, focal depth about 30 km (HVO). Felt on Hawaii and Maui (Hawaiian Volcano Observatory). Magnitude 4.7 (HVO ML), 4.2 (ERL mb).

 April 24, 1973, 16h16m21.9s, 19.917N, 155.733W, focal depth about 40 km (HVO). Felt on Kamuela (Hawaiian Volcano Observatory). Magnitude 4.2 (HVO ML).

 April 26, 1973, 20h26m28.0s, 19.933N, 155.100W, focal depth about 50 km (HVO). "Epicenter under Akaka Falls in the Honomu area north of Hilo on Hawaii Island (Big Island). Press reported a number of persons, at least 11, were injured on Big Island, some required hospital treatment. Damage was estimated at $4.18 million. A state of emergency was declared over most of Big Island with the exception of Kona, Ka'u, and North Kohala districts. A maximum intensity of VIII has been tentatively assigned to the epicentral area. The shock was reportedly felt on all islands of the State of Hawaii. 

 "The following is from press reports: 'Initial reports of at least $500,000 damage to four schools which were closed. Damage at Hilo's Pier 1 was estimated at $350,000 for necessary repairs alone. State roads sustained more than $100,000 in damage, the heaviest damage occurring along the critical Laupahoehoe Gulch areas where the Belt Highway was closed at three points most of Thursday. It was limited to local and rigidly controlled one-way traffic on the 27th, virtually cutting off the Belt Highway from through traffic to Waimea and Kona from Hilo. The country roads received an estimated $600,000 in damages for immediate repairs. Damage to the waterworks in the Kaiwiki, Kaiele, and Papaikou areas caused 10 major problems costing $278,000 to repair. Several hundred residents north of Hilo remained without water throughout the 27th.''' 

 "The following was also reported by the press: 'Hilo and Hakalau: It was reported that massive problems were encountered by the electric and telephone companies. Many powerlines were down between Hilo and Hakalau. Power was switched off between Pepeekeo and Hakalau to reduce shock hazard. Hawaiian Telephone reported only one exchange was out of order, this at Kawailani. Seven major landslides along the Hamakua Highway, closing off 3 gulches and completely cutting off the Laupahoehoe Point Beach Park. At Wainaku Overlook, police barricaded the entrance to the Overlook because of ever-widening cracks of 8 to 10 in the roadway; 50-to-75-yard-long cracks in the Earth along Kaiwiki Road in Wainaku. At Hilo Harbor, Pier 1, a 1,200-ft concrete pier was split from end to end by a 2-to-l-in crack; two other piers sustained lesser damage. Downtown Hilo was ordered closed. All traffic came to a halt. Moving cars couldn't keep their course and began to bounce around. Extensive damage at Hilo. One man was pinned in the rubble of a collapsed building, the Typewriter Center; a home in Hilo's Puueo district reportedly collapsed. Many windows broken. Traffic lights knocked out. Plaster fell from many buildings to the sidewalk. All around the block bordered by Kamehameha Avenue, Haili Street, Keawe Street, and Kalakaua Street, many plate glass windows were shattered. There were no reports of major damage at the Hilo Airport, but cracks were observed in the airport restaurant walls. In the control tower, men were forced to hold onto a rack to keep their balance. Papaikou, Haaheo, and Kaumana districts, north and west of Hilo, sustained heavy damage to waterlines. Many residences were without water. Some homes in Papaikou and Kaumana were reportedly shaken loose from their foundations. 'On the Amauulu slopes just north of Wailuku River, an older plantation house collapsed. It was reported (no specific locations given) that 17 homes were shaken off their foundations and that five collapsed completely. On the 27th, most electric, telephone, and gas services had been restored to all areas of the Island except for isolated outages in the Wainaku, Kaiwiki, Amauulu, and Kaumana areas. Lines between Pepeekeo and Hakalau which had been knocked down were back on poles. Telephone line service dropslines from poles to individual homeswere knocked out in the Amauulu, Kaiwiki, and Wainaku areas but most were replaced by the 27th. Engineer for Hilo Gas Company reported that all gas customers, except in isolated cases in Wainaku and Kaumana, were being served on the 27th. In downtown Hilo one building collapsed and another was tilted into an adjoining building. Damage to home on Halaulani Street was extensive. Most homes on Halaulani have rock foundations, which were shifted several inches from their original locations. Most rock walls around the foundations caved in after the severe shake. Leeward side of Hawaii Island: Actual damage on the leeward side was confined to broken dishes, windows, and falling bottles, for the most part. The only damage figure reported was 5500 in falling merchandise at the Parker Ranch Shopping Center. At Waimea, a chimney collapsed at a restaurant and fell through the roof. In Kona, damage was confined to falling dishes and cracked windows. Kona police reported receiving no indications of serious property damage. A landslide was reported at Kealakekua Bay, where rocks reportedly came crashing down in a cloud of dust. Minor rockslides were visible along the Belt Road. At Pohakuloa minor damage to the Post Exchange and Club, with bottles falling all over. Also, at Pohakuloa, there was a 1/4-inch crack running across Bradshaw Field, an old Army airstrip.'

 "A questionnaire card canvass was made by the Seismological Field Survey of 90 postmasters in the State of Hawaii; to date (May 31) about 60 questionnaires have been returned. The following are maximum effects and intensities at places reporting through the questionnaire canvass: Intensity VII-VIII at Hakalau (ground cracked; landslides; water disturbed; tombstones overturned; pipelines broken; no water for 3 or 4 days). Honomu (many landslides; many tombstones fell; damage great), Hilo (ground cracked; landslides; water disturbed; chimneys, tombstones, elevated water tanks cracked, twisted, and overturned; plaster cracked; windows cracked; damage moderate), Ninole (ground cracked; landslides; water disturbed; chimneys, tombstones, elevated water tanks, etc., cracked, twisted, and overturned), Ookala (ground cracked; landslides; water disturbed; some chimneys, tombstones, elevated water tanks, etc., twisted and overturned; some homes moved slightly off foundations), Paauhau (landslides; tombstones cracked, twisted, and overturned; windows cracked), Papaikou (ground cracked; landslides; water disturbed; all the hollow tile steps crumbled; stone walls crumbled; pipeline broke; cesspool fell; all objects on shelves fell; furniture overturned; plaster fell; window cracked; damage great), Papaaloa (general panic; ground cracked; landslides; water disturbed; water tanks cracked, twisted, and overturned; leaky roof; furniture shifted; plaster fell; windows cracked; damage moderate), and Pepeekeo (ground cracked; landslides; water disturbed; chimneys, tombstones, elevated water tanks, etc., shaken severely; plaster cracked, broke, and fell; windows cracked; damage moderate)" (Nina Scott). Magnitude 6.3 (PAS), 6.1 (BRK) 6.2 (HVO), 6.0 (ERL mb), 6.1 (ERL Ms).



Anonymous, 1982, Hawaii, in Person, W.J., ed(s)., Seismological notes: Bulletin of the Seismological Society of America, v. 72, no. 1, p. 339. 



 Hawaii

March 5, 1981 14h09m39.8s, 21.02N, 156.99W, focal depth about 10 km (GS). Slight damage (VI) and landslide on Molokai. Felt (V) on Oahu and (IV) on Lanai, Maui, and Hawaii (Hawaiian Volcano Observatory). Magnitude 5.5 (HVO ML 5.0 (GS mb).



Anonymous, 1985, Hawaii, in Stover, C.W., ed(s)., United States Earthquakes, 1982: U.S. Geological Survey Bulletin 1655, p. 39-44. [The same data were published quarterly in U.S. Geological Survey Circular 896A-D (authorship divided among Stover, C.W., Minsch, J.H., Reagor, B.G., Dunbar, P.K., and Baldwin, F.W., 1982).] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Anonymous, 1987, Hawaii, in Stover, C.W., ed(s)., United States Earthquakes, 1983: U.S. Geological Survey Bulletin 1698, p. 46-56, 113-116, 132-133. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]

 Summary by R.Y. Koyanagi.



Anonymous, 1989, Central Pacific Ocean, in McClelland, L., Simkin, T., Summers, M., Nielsen, E., and Stein, T.C., ed(s)., Global volcanism 1975-1985; the first decade of reports from the Smithsonian Institution's Scientific Event Alert Network (SEAN): Englewood Cliffs, NJ, Prentice Hall, Inc., chap. 13, p. 405-460. 



 Sections on Loihi, Kilauea, and Mauna Loa summarize events reported to the Smithsonian Institution's Scientific Event Alert Network (SEAN) during the years 1976-1985. The evolution of the plume associated with the 1984 eruption of Mauna Loa is illustrated by pictures taken from the NIMBUS-7 satellite on March 25, 26, and 27 (p. 459).



Arnadottir, T., Segall, P., and Delaney, P., 1990, A fault model of the June 26, 1989 Kalapana earthquake derived from geodetic and seismic data [abs.]: Eos, Transactions, American Geophysical Union, v. 71, no. 43, p. 1561. [AGU fall meeting, San Francisco, CA, Dec. 3-7, 1990, Program and abstracts] 



 On June 26, 1989, a M6.1 earthquake struck the south flank of Kilauea volcano, Hawaii. This is the largest south flank event since the 1975, M7.2 earthquake. The focal mechanism for the 1989 earthquake indicates seaward slip on a low-angle fault at about 9 km depth. Large tectonic earthquakes play an important role in deforming Kilauea, however their mechanisms are still controversial. We are studying the deformation caused by these earthquakes to better understand the intra-volcanic seismicity and structure. and particularly the processes that lead to seaward displacements of Kilauea's south flank.

 Leveling repeated after the 1989 earthquake along a road crossing the east rift zone of Kilauea, about 15 km east of the epicenter, shows subsidence over a 10 km wide area, with a maximum of 24 cm just south of the rift-zone axis. Where the level line reaches the coast, 5 cm of uplift was measured.

 We model the observed vertical deformation using a rectangular dislocation. with uniform slip, embedded in an elastic half-space. Initial values of the fault parameters were estimated from the best double couple solution and the seismic moment. A forward calculation shows that this a priori model produces subsidence that is less than the observed and the wavelength of the deformation is too broad. We used a nonlinear inversion scheme (NPSOL) which employs a sequential quadratic programming algorithm, to estimate the fault geometry that best fits the data. We found that a low-angle thrust at a depth of 4 km comprises the best fit in a least-sum-of-squares sense. The discrepancy between this estimate and the epicentral depth of the main shock suggests that the subsidence is dominated by displacements produced by other seismic sources, located east of the main shock. In fact, large (M=4) shallow aftershocks were observed in this area.

 Further work on this earthquake will need to incorporate a study of the observed zone of ground surface rupture near Kalapana and an investigation of more complex fault geometries. Trilateration and GPS data are also available to further constrain the fault model.



Arnadottir, T., Segall, P., and Delaney, P., 1991, A fault model for the 1989 Kilauea south flank earthquake from leveling and seismic data: Geophysical Research Letters, v. 18, no. 12, p. 2217-2220. 



 The geometry of the fault that ruptured during the M6.1 south flank earthquake on Kilauea volcano in 1989 is determined from leveling data. The elastic dislocation, in a homogeneous elastic half-space, that best fits the data is found using a nonlinear inversion procedure. The best fitting model is a gently dipping thrust fault that lies at 4 km depth. This is significantly shallower than the 9 km hypocentral depth determined from the local seismic network. Two-dimensional finite-element calculations indicate that at least part of this discrepancy can be attributed to the focusing of the surface deformation by the upper few kilometers of compliant, low-density lavas. We conclude that it is important to include realistic elastic structure to estimate source geometry from geodetic data.



Arnadottir, T., Segall, P., Beroza, G., and Delaney, P., 1991, Depth discrepancy between fault models derived from geodetic and seismic data for the 1991 earthquake [abs.]: Seismological Research Letters, v. 62, no. 1, p. 35. [Living on the Edge, Joint Meeting of the Seismological Society of America and the Geological Society of America Cordilleran Section, San Francisco, CA, Mar. 25-27, 1991 (Abstracts)] 



 A Magnitude 6.1 earthquake struck the south flank of Kilauea volcano, Hawaii, in June 1989. The focal mechanism for the earthquake indicates seaward slip on a low-angle fault at about 9 km depth. Three different geodetic data sets (leveling, Electronic Distance Measurements (EDM) and Global Positioning System (GPS)) were collected before and after the earthquake (1988-1989) by the staff of the Hawaiian Volcano Observatory.

 We model the observed surface deformation using a rectangular dislocation, with uniform slip, embedded in an elastic half-space. The initial values of the fault parameters were estimated from the best double-couple solution and the seismic moment. We use a nonlinear inversion algorithm to estimate the fault geometry that best fits the leveling and EDM data separately and then for both data sets combined. The fault plane solution that best fits the geodetic data is a shallow (about 5 km deep), low-angle, north-dipping thrust fault. In all cases the depth of the fault found from the geodetic data (5 km) is considerably shallower than the depth of the hypocenter determined from the seismic data (9 km).

Preliminary forward modeling suggests that the fault that best fits the GPS data is also located at shallow depths (J. Dvorak personal communication). We plan to include the GPS data in the inversion to further constrain the fault model. Additional fault depth information may be available from ground acceleration data collected by the USGS Branch of Engineering Seismology and Geology on a strong motion array in Hawaii.

 We are currently investigating possible explanations for the depth discrepancy, in particular what effect layering (e.g. soft layer at shallow depth) has on the surface deformation caused by slip on a low angle thrust fault. The observed surface deformation could also be caused by shallow secondary faulting triggered by the main shock or complex rupture on multiple faults.



Ashley, A.M., 1904, Meteorological summary for month of October: Pacific Commercial Advertiser, 11/18, p. 5. 



 Hawaii--Kohala reports earthquake shocks on Oct. 14 and 23; Puueo reports earthquake shock on Oct. 14.

Oahu--U.S. Experiment Station reports earthquake shock on Oct. 14; Waiawa and Ahuimanu report earthquake shock on Oct. 14.

Maui--Kipahulu reports two slight earthquake shocks on Oct. 14.



Ashley, A.M., 1904, Meteorological summary for month of November: Pacific Commercial Advertiser, 12/19, p. 9. [Repeated in Hawaiian Gazette of Dec. 20, 1904] 



 Pepeekeo--light earthquake at 8 p.m. of the 13th.



Ashley, A.M., 1904, Meteorological summary for month of November: Hawaiian Gazette, 12/20, p. 3. [Repeated from Pacific commercial Advertiser of Dec. 15, 1904] 



 Pepeekeo--light earthquake at 8 p.m. of the 13th.



Ashley, A.M., 1905, Weekly Crop Bulletin for the week ending April 29, 1905: Pacific Commercial Advertiser, 05/02, p. 6. [Date given as 4/21 in Lyman earthquake diary] 



 A heavy earthquake shock was experienced at Naalehu, Hawaii at 12:53 p.m. on April 22, but caused no damage.



Ashley, A.M., 1905, Weekly Crop Bulletin for the week ending May 6, 1905: Pacific Commercial Advertiser, 05/10, p. 6, 12. [Repeated in Hawaiian Star of May 10, 1905] 



 . . . During the afternoon and evening of the 3rd instant several sharp earthquake shocks were felt in practically all sections of the big island.

Papaikou--5 heavy shocks, no damage.

Laupahoehoe--5 sharp shocks during afternoon of the 3rd.

Honomu--2 sharp shocks in afternoon, several lighter shocks during evening of the 3rd.

Hilo--5 shocks felt.

Kaumana--4 sharp shocks felt on the 3rd, and one early in the morning of the 4th.

Kohala-- sharp earthquake shock on afternoon of 3rd.

Kamuela--light earthquake shock on afternoon of 3rd.

Kealakekua--earthquake shock on afternoon of 3rd.

Olaa--several earthquake shocks on afternoon of 3rd and early morning of the 4th, the shock at 4:15 p.m. of the 3rd being the heaviest in years.

No felt reports from Kau, Kapoho or Kona

Earthquake felt in Hilo at 1 a.m. on May 4, followed by more shocks at intervals during the wee hours of the morn.

Earthquake felt at Olaa and Kaumana [Hilo] at 1 a.m. on May 4;



Ashley, A.M., 1905, Weekly Crop Bulletin for the week ending June 3, 1905: Pacific Commercial Advertiser, 06/06, p. 6, 12. 



 Several light earthquake shocks occurred in Hawaii during the week.

 Honomu--sharp earthquake shock at 10:00 a.m. of May 28

 Kohala Mission--earthquake shock at 9:27 a.m. of May 28

 Kamuela--smart earthquake shock at 10:25 a.m. of May 28 [wrong time?]

 Kealakekua--earthquake shock around 9:15 a.m. of May 28



Banks, N.G., and HVOstaff, 1980, Kilauea Volcano's November 1979 eruption [abs.], in Conference in Natural Sciences, 3rd, Hawaii Volcanoes National Park, June 4-6, 1980, [Proceedings]: Conference in Natural Sciences, 3rd, Proceedings, p. 12. 



 Kilauea Volcano erupted November 16-17, 1979 on its upper east rift zone. The eruption was preceded by a seismic swarm that started at 0900 hr March 15. Summit deflation and inflation at the eventual eruption site began simultaneously but one half hour after the onset of the seismic swarm. Copious emission of steam began east of Pauahi Crater at 0805, November 16, but no lava was erupted t from these cracks. At 1818, the sounds of fountaining and falling spatter was heard from vents east of the steaming cracks. At 0821, lava welled up out of a fissure in northwestern Pauahi and soon established low fountains. Seven minutes later, observers arrived at the eastern vents and observed a curtain of fire 5-10 m high and 100 m long. These eastern fountains migrated eastward and ceased activity at 0915. At 1130, two more vents opened in Pauahi Crater, followed shortly by opening of a fourth vent crater and cessation of activity of the one that opened at 0821 hr. Over the next 1 1/2 hours, five more vents opened progressively westward of the crater. Slightly before 1600, activity at the western vents began to wane and, within the next hour, ceased. Lava production at the three still-active vents in Pauahi Crater remained relatively constant until 0100 November 17, followed by gradual waning and cessation of activity at 0730.

 The eruption was small (500,000-700,000 m3), with low fountains and fairly viscous, possibly low-temperature lava compared to lava erupted at nearby Mauna Ulu (active 1969-1974). The 1979 lava was initially olivine-poor, and emitted only small amounts of SO2 from active and dying fountains. However, appreciable amounts of SO2 were emitted from the steaming area east of the crater and at leading edges of opening vents. Field, petrologic, seismologic, geoelectric, geochemical, and deformation data suggest that the lava for the eruption came from a shallow magma source that had resided for some time in the rift zone. The right-stepping pattern of vents and cracks suggests that a left lateral shear couple was present during the eruption.

HVO released a press statement three weeks prior to the eruption stating that the likelihood of an eruption on Kilauea had increased significantly. Observers were at the site prior to the outbreak of lava.



Banks, N.G., Klein, F.W., Moore, R.B., Jackson, D.B., and Okamura, A.T., 1981, Kilauea Volcano's November 1979 eruption [abs.]: Eos, Transactions, American Geophysical Union, v. 62, no. 45, p. 1072. [AGU fall meeting, San Francisco, CA, Dec. 7-11, 1981, Program and abstracts] 



 Kilauea Volcano erupted November 16-17, 1979, on its upper east rift zone, preceded on November 15 by a seismic swarm beginning at 21:00 (local time) and by summit deflation and simultaneous inflation at the eruption site beginning at 21:30. Continuous, strong harmonic tremor began at 07:00, November 16, and steam emission from old cracks east of Pauahi Crater began at 08:05. Eruption followed at 18:18 at vents east of the steaming cracks. At 08:21, eruption began in Pauahi Crater, followed at 09:15 by cessation of activity at the eastern vents. Two more vents opened in the crater at 11:30, and opening of a fourth at 11:40 was followed immediately by cessation of activity of the 08:21 vent. Over the next 1 1/2 hours, four vents opened progressively westward of the crater.

 Slightly before 16:00, activity at the western vents began to wane progressively eastward and, within the next hour, ceased. Lava production at the three still-active vents in Pauahi Crater remained relatively constant until 01:00, November 17, followed by gradual waning and cessation of all surface activity at 07:30. Harmonic tremor ceased and inflation of the summit began November 18.

 The eruption was small (~500,000 m3), with low fountains and fairly viscous, relatively low-temperature lava. The lava was initially olivine-poor and emitted relatively small amounts of SO2. Field, petrologic, seismologic, geoelectric, geochemical, and deformation data suggest that the 1979 lava came from a shallow magma source and had resided for some time in the rift zone. Structural data suggest the presence of a slight left lateral shear couple on the erupting fissures.



Beisser, M., Gillard, D., and Wyss, M., 1991, Historic earthquakes in the Hawaiian Islands [abs.]: Eos, Transactions, American Geophysical Union supp., v. 72, no. 17, p. 189. [AGU spring meeting, Baltimore, MD, May 28-31, 1991, Program and abstracts] 



 In this century 7 earthquakes with magnitudes 6.4 and greater occurred in Hawaii and the Hawaiian archipelago. Five of them took place before the WWSSN was installed in 1964. Because of that only very few records of these earthquakes exist. No fault plane solutions or reliable depth estimates are available.

 We have studied 4 of these major historic earthquakes with magnitude M > 6.5. Three of them (September 26, 1929, M=6.4; October 5, 1929, M=6.5; August 21, 1951, M=6.9) were located in the western part of the island of Hawaii and the January 22, 1938, M=63/4 was located offshore north of the island of Maui. Except for the 1951 event, which was instrumentally well recorded, the magnitudes of these earthquakes were estimated by comparing isoseismal maps of the historic events with the isoseismal maps of instrumentally recorded events which occurred after 1950.

 To determine the fault-plane solution and the source depth we used a new method based on waveform modelling of P- and S- body waves of only one or few three component stations. We digitized historic records of these events from stations around the world. The reflectivity method was used to compute synthetic seismograms. The parameter space of strike, dip and rake is scanned systematically to find the minimum misfit between synthetic and observed rates. The depth is found by trial and error modelling of the duration of the P-wave package.



Beisser, M., Gillard, D., and Wyss, M., 1994, Inversion for source parameters from sparse data sets: test of the method and application to the 1951 (M=6.9) Kona, Hawaii, earthquake: Journal of Geophysical Research, v. 99, no. B10, p. 19,661-19,678. 



 We have tested a method originally developed by Beisser et al. (1990) to retrieve the source parameters (strike, dip, rake, and depth) of sparsely recorded earthquakes from the inversion of teleseismic waveform data. The complete wave train of all body waves is modeled using the reflectivity method. The parameter space of strike, dip, and rake is searched to find the source orientation which leads to the minimum misfit between the observed and the synthetic seismogram. The 1983 Kaoiki, Hawaii, earthquake (MS=6.6) was chosen as a test case. The inversion of the full data set (16 stations) gave a fault plane solution similar to the best double couple moment tensor solution of Harvard University and National Earthquake Information Centre. These three solutions were averaged to create a standard solution. Sparse data sets were simulated by decimating the full data set, and the resulting fault plane solutions were compared with the standard. We found that as few as one to three stations were sufficient to retrieve the focal mechanism of the 1983 Kaoiki event. We applied this technique to the 1951 Kona, Hawaii, earthquake (MS=6.9). A total of four stations and nine components were used to model the source parameters of this earthquake. The depth was estimated at 13+3 km. The fault plane solution was a decollement type with a near-horizontal plane dipping at about 15 to the southwest and a near-vertical plane striking NW-SE. This observation supports a tectonic model for the Kona coast similar to that of Kilauea's south flank; the upper crust is pushed away from the center of Hawaii, slipping westward along a near-horizontal plane of weakness.



Benoit, J.P., and McNutt, S.R., 1996, Global volcanic earthquake swarm database 1979-1989: U.S. Geological Survey Open-File Report 96-69, 333 p. 



 CONTENTS

Development And Description of The Global Volcanic Earthquake Swarm Database 4

 Introduction 4

 Database Structure And Description 5

 Volcano Table 6

 Earthquake Swarm Table 6

 Eruption Table 7

 VOLCAT Organization and Parameter Description 7

 Morphology, Tectonic Framework, Elevation, and Edifice Relief 9

 Range of Erupted Products 11

 SWARMCAT Organization And Parameter Description 12

 Swarm Dates, Durations and Uncertainties 12

 Definition of A Swarm and Swarm Duration 13

 Swarm Type 13

 Event Types 14

 Quality Grades (QC) 15

 Maximum Magnitude, Intensity, And Depth 15

 Cumulative Energy, Energy Release Rate, And Repose 16

 Earthquake Counts And Magnitude Detection Threshold 17

 Seismograph Information 17

 Previous Swarms And Other Reported Information 17

 References, Comment, and Key Phrase fields 18

 ERUPTCAT Organization and parameter description 18

 Data Sources 22

 Erupted Volume, Plume Heights, Silica Content, And The Vex 22

Preliminary Results 23

 Swarm Duration 23

 Earthquake Magnitude 25

 Data Limitations And Discussion 26

 Improvements And Future Work 27

 Acknowledgments 28

 References 29

 Appendix A 31

The Global Volcanic Earthquake Swarm Database 32



 Figures

Figure 1. The number of events verses time is schematically shown for the three types of earthquake sequences 4

Figure 2. An example record from the global Volcanic Earthquake Swarm Database 6

Figure 3. Schematic diagram of the temporal relations between volcanic earthquake swarms and eruptive activity 14

Figure 4. The mean depth of volcanic earthquake swarms 16

Figure 5. Histogram of the durations of volcanic earthquake swarms 24

Figure 6. Comparison of the distribution of earthquake swarm durations that precede eruptive activity (Type I and durations that are not associated with eruptive activity (Type III) 25

Figure 7. Comparison of the distribution of magnitude of the largest shock (Mmax) within swarms that precede eruptive activity (Type I) and swarms that are not associated with eruptive activity (Type

III) 26

 Tables

Table 1. Regional organization 7

Table 2. List of volcanoes in the GVESD 8

Table 3 Volcano morphology 10

Table 4 Tectonic framework 10

Table 5 Erupted products 11

Table 6. Reporting uncertainties 12

Table 7. Event types 15

Table 8. Other reported observations 18

Table 9. ERUPTCAT Table 19



Bergman, E.A., and Solomon, S.C., 1982, Oceanic intraplate earthquakes and stresses near large bathymetric features [abs.]: Eos, Transactions, American Geophysical Union, v. 63, no. 18, p. 444-445. [AGU spring meeting, Philadelphia, PA, May 31-June 4, 1982, Program and abstracts] 



 The role of large bathymetric features In controlling nearby intraplate seismicity is investigated for two earthquakes: the Hawaiian event on 4/26/73 and the Kerguelen Plateau event on 5/3/73. Focal depths and source mechanisms are constrained by body wave synthesis. To determine if bending or topographic stresses, perhaps superimposed on a regional stress field, can explain the mechanisms of these events, we employ analytic solutions for axisymmetric bending stresses for disk loads on a floating elastic plate.

 The Kerguelen event has a normal fault mechanism with T-axis tangential to the plateau. The focal depth of 20 km below sea level could place the event either above or below the neutral plane. In neither case, however, can any combination of bending and topographic stresses alone account for the mechanism. Nor is a regional extensional stress field considered likely. The observed fault type can be generated by bending stresses below the neutral plane if the vertical component of stress is above lithostatic and pore pressure is non-zero. Thermal or magmatic effects of the nearby hotspot may account for this result.

 At a depth of 48 km, the Hawaiian earthquake is near the bottom of the elastic core of the plate. The strike-slip mechanism and the reported mechanisms of other events require the greatest horizontal stress to be radial to the island, a result which cannot be due to bending stresses in an unbroken plate. A finite element model is used to investigate bending stresses near the tip of a semi-infinite line load with a fracture beneath it. Again, non-zero pore pressure is necessary to achieve the observed fault type. Increased vertical stress is unnecessary.

 In these two cases, local stresses dominate any regional stress field and control the style of deformation. Further investigation is aimed at quantifying these stresses as a means of placing bounds on regional stress magnitudes.



Best, W.J., Johnson, L.R., and McEvilly, T.V., 1974, ScS and the mantle beneath Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 55, no. 12, Dec. 12-17, 1974, p. 1147. [AGU fall meeting, San Francisco, CA, Dec. 12-17, 1974, Program and abstracts] 



 The Hawaiian earthquake (Ms=6.1) of 26 April 1973 radiated a strong S pulse downward which can be observed on the high gain long period E-W seismograph at Kipapa (D=3.1) as multiply reflected ScS for up to six two-way mantle transits. These arrivals at near-vertical incidence (i<1) provide an accurate estimate of total crust-mantle travel time and attenuation under the Hawaiian ridge between Hawaii and Oahu. The observed two-way surface-core time is 9361 sec. With the ellipticity correction (-1 sec) this travel time is smaller by 0.7, 5.3, and 5.7 sec than times for J-B Tables, Jordan model Bl, and Gilbert-Dziewonski model 1066, respectively. Average mantle Q for the 30-50 sec period waves observed is 30010% with no clear indication of frequency dependence. Tectonically, the earthquake seems to be a strike-slip fault with a small normal component, having principal compression and tension axes striking N70E and N30W, respectively. These directions indicate compression normal to, and extension along, the Hawaii-Maui portion of the ridge.



Bevens, D., Takahashi, T.J., and Wright, T.L., ed(s)., 1988, The early serial publications of the Hawaiian Volcano Observatory, 3 v.: Hawaii National Park, Hawaii Natural History Association, v. 1, 565 p.; v. 2, 1273 p.; v. 3, 1224 p. 



 A reprinting of the weekly and monthly bulletins published by the Hawaiian Volcano Observatory from 1913-29 and the four special reports published in 1912, 1917, 1938, and 1949. The work is reprinted in three volumes. The first volume covers the four special reports of HVO, one special bulletin, and a bibliography of papers on Hawaiian volcanism and seismicity covering the period 1779-1955. [The latter forms the core of the Wright and Takahashi (1989) annotated bibliography.] The second volume covers the weekly and monthly bulletins issued by HVO from 1913 through 1921. The third volume continues the monthly bulletins through the end of publication, in mid-1929. [Subsequent summaries are included in The Volcano Letter, published from 1925-55, recently reprinted in one volume {Fiske and others, 1987}.] All volumes are indexed. The first special report describes the founding of the Hawaiian Volcano Observatory and Kilauea's activity from 1909 to 1912, including an account of the first temperature measurements made in Halemaumau lava lake. The second report, by H.O. Wood, discusses cyclical variation of Kilauea's eruptive activity, including tabulated summaries of the yearly activity from 1823 through 1911. [This is a very useful summary, drawing from the reports of the 19th century observers and the Volcano House Register {Bevens, 1988}.] Wood calculates and plots a strain curve, based on combined lunar-solar tidal cycles, and shows that times of maximum and minimum volcanic activity show some correspondence to these cycles. The third special report, by C.K. Wentworth, describes ash formations on the island of Hawaii. The fourth special report, by T.A. Jaggar, discusses explosive volcanic activity. Jaggar compares the phreatic activity at Kilauea in 1924 with the activity of Mt. Pelee. The weekly and monthly reports each contain a narrative description of eruptive activity during the period and list the earthquakes recorded at Kilauea summit in the Whitney Laboratory of Seismology. Some issues include special reports of experiments conducted at Kilauea, or of expeditions to Mauna Loa. [A missing set of bulletins covering the period 1912-13, between the first special report of HVO and the weekly summaries which open Volume 2 of the reprinted serial reports), was published later by Jaggar {1947, p. 9-88}.]

[These reprinted volumes, and the reprinted Volcano Letter, are the primary source of information on Hawaiian volcanism and seismicity in the period 1912-55. Many of the reports are beautifully illustrated with photographs of eruptions and the various features of interest in Halemaumau lava lake at the time of continuous activity up to 1924.]



Bishop, A., 1824, [no title], in Missionary Letters, 8 v: Honolulu, HI, Hawaiian Mission Children's Society, v. 1, p. 171-174. [Letter to Jeremiah Evarts dated November 27, 1824] 



 [p. 171-172] . . . There are some facts concerning the volcanic appearance of the Island of Hawaii, that I do not recollect to have ever seen mentioned in any publication. A particular detail of this appearance will be given in our notes of the tour to be attached to the journal. . . Hawaii may be literally called an Island of volcanoes. . . Not only are all the mountains full of craters (x), but the plains also are broken up in many places, by the bursting out of subterranean fires [vents?, tumuli?]. At least three fourths of the whole appears to have been at different times overrun with lava. This is now lying in many places to great depth; (the shores are formed entirely of lava.) Along the whole of the Western, S. Western & Eastern parts the shores are formed entirely of lava, that has poured their desolation down the sides of the mountains into the ocean, and formed a perpendicular steep of rocks from 50 to 200 feet above its level. We could never have conceived of such immense quantities of lava ever finding its way for so many miles from the place of its eruption, had we not witnessed by actual observation the paths it has made. In many places the lava is so ancient as to be covered with a deep soil, that produces in abundance all the various kinds of vegetation that grows on the Island. This is more particularly observed on the sides of the mountains, where the daily showers and the other operations of nature in developing a surface and producing a vegetable mould. But in all these places where such quantities of lava are found, there are no springs of fresh water, or streams. All the rains that fall descend immediately into the earth to rise no more. . . .[Bishop continues with conjecture that the Sandwich Islands have been subjected to volcanoes and earthquakes, and may be the remains of a great continent, now no more.]



Bishop, A., 1825, [no title], in Missionary Letters, 8 v: Honolulu, HI, Hawaiian Mission Children's Society, v. 2, p. 605-617. [Letter to Jeremiah Evarts dated October 24, 1825] 



 [p. 612-613; headed for Kilauea from 10 miles mauka of Olaa, Jan. 5, 1926] . . . "For many miles before we arrived, the air was choked with sulphurous smoke, which was very offensive and at times almost suffocating. Arrived at the crater about 11 o'clock, by a path that led around the southern side, at this time the windward, our approach to the other quarter being deemed unsafe. We found the crater much altered from what it was in the summer of 1823 when I visited it in the company of with Mr. Ellis and others. I was greatly surprised to find, that within a few months, since the visit of Lord Byron and company in June [1825], the crater had been filled to all appearances to the height of 400 feet with from a hundred blasting furnaces and completely obscured the sides of the crater on the north and east, together with the greater part of the interior of the volcano. As the wind occasionally blew away the smoke, I could discover an immense number of fires, some spurting forth from cones that rose 50 to 100 feet above the surface of the surrounding crest of lava, and others boiling with greatest agitation like cast caldrons of liquid fire, and every now and then sending forth a gust of vapor and smoke with a great noise, when the sight would again be obscured from view. The distance from where we stood, down to the surface of the burning lava, was seemingly not more than 200 feet. The natives inform me that after rising a little higher the lava will discharge itself as formerly towards the sea, through some aperture underground."

 [p. 616] . . Observations 1. Geological structure of the island

 Bishop opines that the entire island is covered with lava, concluding with: . . . "Mr. Goodrich, in digging a well at Hilo, passed through a stratum of the earth to a depth of 10 feet, when he came upon a bed of volcanic rock that exhibited precisely the same appearances that are presented on a bed of uncovered lava. The same indications are everywhere visible at the bottom of those numerous ravines on the northern shore, viz. that they were once in a state of fusion. It is not improbable that at some remote period of antiquity the whole island exhibited one vast Volcano from the foundation to the tops of its highest mountains."



Bishop, S.E., 1871, Hale Pa'i [Earthquake]: Hawaiian Mission Children's Society, 02/20, p. ? 



 Bishop writes [describing the damage to his house by the earthquake of 2/19/1871] "The cracks in Halepai walls have opened a little."



Bishop, S.E., 1887, Hawaii's great wonder! The lava flow of 1887: Hawaiian Gazette, supp., 02/15, p. 1. 



 A summary account of the earthquake swarm and eruption of 1887. Except for description of a trip to the lava flow made on January 28-30, no information is given not already reported in more detail in the Gazette of Feb. 1, 1887. Bishop concludes his report with a description of an extensive layer of yellow ash extending from the Kahuku cliff to the vicinity of Honuapo. At the coast the ash overlies a small cinder cone. Bishop correctly infers that the ash layer is evidence of a large explosive eruption in the not-too-distant past.

 Bishop's letter is followed by a short communication from D.H. Hitchcock, datelined Hilo, February 3, 1887, who remarks that "We are experiencing slight shocks almost every day and night, up to last night [Feb. 2]."

 Hitchcock's comment are succeeded, in turn, by an account by R. Grieve of a trip on board the Kinau, visiting the now-dead [Jan. 31] flow where it entered the ocean.



Bishop, S., 1906, Dr. Bishop's views: Pacific Commercial Advertiser, 09/06, p. 7. 



 "The report of earthquake disturbances in and about Hilo, and not in any other place on Hawaii, indicates a peculiar seismic condition," said Dr. Sereno Bishop yesterday. "If the report is true about the shocks being felt only at Hilo it suggest to my mind the development of volcanic features in Puna.

 " Not for nearly seventy years have similar reports come from Hilo, and seventy years ago there was a volcanic development in Puna, when a new crater was in the process of formation.

 "The appearance of scalded fish along the Hilo coast, of course, shows an unusual submarine disturbance."



Bishop, S., 1907, An expert opinion on local quakes: Pacific Commercial Advertiser, 03/15, p. 1. 



 Dr. Sereno Bishop, who is as well known in the United States as he is in Honolulu as a writer on scientific subjects, is especially recognized as an expert on seismic phenomena. His opinion in the latter direction has just had rather unique recognition. He has been asked by a number of well known insurance companies to prepare a statement as to the likelihood of earthquake shock in these islands, based on his observation and research. He has done so, and his opinion is likely to affect the insurance rates here to the great advantage of policy holders. The companies lost heavily in the San Francisco disaster and are said to be fighting shy of countries where such losses may recur. Dr. Bishop's report will reassure them.



Blickhahn, H., 1954, Lava dikes for Hilo again urged; would insure safety from Mauna Loa: Hilo Tribune-Herald, 04/02, p. 1. 



 Hilo is drowsing complacently in the path of a potential flow of molten lava that could destroy much of the city and fill up the harbor beyond any hope of reclamation.

 A graphic picture of this danger was painted last night at a civil defense meeting here by Dr. Gordon A. Macdonald, volcanologist in charge of the Hawaiian Volcano Observatory.

 Dr. Macdonald again described the "insurance" that is possible against such a disaster in the form of a series of stone dikes across the natural pathway leading from the northeast rift of the slumbering giant, Mauna Loa.

 These dikes are a new conception, since no one has ever attempted any manner of coping with flowing lava except:

 1--To bomb the flow

 2--To drop everything and run

 Yet Dr. Macdonald is convinced that deflection is possible.

 Before him, the late Thomas A. Jaggar was convinced of the same thing, and it was Dr. Jaggar, in 1938 [1937], who devised the first plan for a lava barrier to encircle the city. since then, the series of deflection dikes as illustrated herewith is accepted as the more practical plan.

 The next paragraphs discuss the frequency of flows from Mauna Loa coming in the Hilo direction and the logistical difficulties of bombing given the time available and the weather conditions.

 Deflection barriers, he said, would be aimed at diverting the flow away from the city. "We're convinced these walls will work under the right conditions and would assure a great deal more chance of success than the possibility of bombing."

 The barrier pattern worked out by Dr. Macdonald includes three straight walls, one about nine miles long, one about three miles long and one about a mile long, as illustrated [map with article], with possibly a fourth wall high up on the mountain to deflect the flow toward the other side of Mauna Loa.

 "The 1881 flow toward Hilo deposited 200,000,000 cubic yards of lava," Macdonald said. "The 1950 flow on the Kona side deposited over 800,000,000 cubic yards. If you add 400,000,000 cubic yards to the 1881 flow, I'm sure your imagination will show you what could happen to Hilo. Once the Harbor is filled up it cannot be dredged.

 "As to the cost of the barriers, I've heard various estimates, but that's for the engineers.

 "The cost is a matter of whether this insurance is worth buying."



Bodle, R.R., 1944, Hawaiian Islands, in United States Earthquakes, 1942: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, serial no. 662, p. 16. [Compiled as United States earthquakes, 1941-1945, and reissued by the National Earthquake Information Center, 1969] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Bodle, R.R., 1945, Hawaiian Islands, in United States Earthquakes, 1943: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, serial no. 672, p. 20. [Compiled as United States earthquakes, 1941-1945, and reissued by the National Earthquake Information Center, 1969] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Bodle, R.R., 1946, Hawaiian Islands, in United States Earthquakes, 1944: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, serial no. 682, p. 24. [Compiled as United States earthquakes, 1941-1945, and reissued by the National Earthquake Information Center, 1969] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Bodle, R.R., and Murphy, L.M., 1947, Hawaiian Islands, in United States Earthquakes, 1945: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, serial no. 699, p. 18. [Compiled as United States earthquakes, 1941-1945, and reissued by the National Earthquake Information Center, 1969] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Bolt, B.A., 1993, Volcanoes, tsunamis and earthquakes, in Earthquakes: New York, W.H. Freeman and Co., chap. 8, p. 137-142. 



 [no abstract]



Bond, E., 1881, [On the earthquake of September 30, 1881]: Hawaiian Gazette, 10/12, p. 3. 



 That earthquake [of Sept. 30, 1881] was a long way ahead of anything of the kind I ever felt. More than twenty cracks in our meeting-house walls. A few seconds more would have left us without a place of worship. The 1868 shake did not disturb the walls at all. Books, medicine vials, fruit-jars, &c., pitched from the shelves pellmell. We have reason for thankfulness that no greater damage was done.

 The shock was about 5 o'clock a.m., Sept. 30th.



Booth, D.C., Wyss, M., and Gillard, D., 1990, Shear-wave polarization alignments observed at Kaoiki, S.E. Hawaii [abs.]: Geophysical Journal International, v. 101, no. 1, p. 290. [UK Geophysical Assembly, 14th, Plymouth, Apr. 18-20, 1990, Abstracts] 



 Large earthquakes (5.5 < M < 6.6) occur at approximately ten year intervals in the Kaoiki fault zone between the Kilauea and Mauna Loa volcanoes in Hawaii, the most recent occurring in 1983. Shear-wave records from a Kaoiki station in the years 1979-1983 were examined for shear-wave splitting and possible precursory behaviour. After a sequence of surprises, they revealed the presence of time-delayed arrivals with orthogonal polarizations, and the polarization alignments of the first split arrival correlate with the direction of maximum horizontal stress, which is diagnostic of extensivedilatancy anisotropy. However, frequent saturation of the recorded shear-wave components in the present data set does not allow us so far to distinguish between anisotropy, scattering, or wave conversion at interfaces near the receiver as the cause of the observed splitting and polarization alignments, or give an adequate sample for temporal variation studies.



Bosher, R.F., 1980, The December 1965 Kilauea Volcano earthquake swarm, and its relation to concurrent Koae fault system cracking and east rift eruption [abs.]: Geological Society of America Abstracts with Programs, v. 12, no. 7, p. 390. [Geological Society of America, 93rd annual meeting, Atlanta, GA, Nov. 17-20, 1980] 



 The Koae fault zone, a structural feature of Kilauea Volcano, forms a boundary between the volcano's south flank and summit caldera. An earthquake swarm, accompanied by extensive cracking in the Koae, and a minor east rift eruption, took place during the time period December 24-31, 1965. Locations, depths, magnitudes, and focal mechanisms have been determined for approximately four hundred earthquakes. The majority of the earthquakes lie within the NE trending Koae system, with additional scattered events to the south. A lineation of earthquakes, paralleling the Koae along its entire length, is observed. A large clustering of earthquakes are situated in the central Koae. Depths are generally shallow, within the upper five kilometers of the crust. Duration magnitudes range from 1.5 to 3.5. Prior to the cracking and eruption, earthquake activity was low. The distribution and orientation of earthquakes along the Koae, suggests the fault system acts as a hinge for the release of stress built up by the volcano during periods of magma inflation and deflation. Large scale relaxation of the volcano, following a lengthy inflation period and subsequent magmatic extrusive event, was probably responsible for the earthquake swarm of Kilauea Volcano, late December, 1965.



Bosher, R., and Duennebier, F.K., 1985, Seismicity associated with the Christmas 1965 event at Kilauea Volcano: Journal of Geophysical Research, v. 90, no. B6, p. 4529-4536. 



 A seismo-volcanic event of unusual intensity and location occurred during a 6-day period beginning on Christmas Eve 1965 at Kilauea Volcano. This event, centered on the Koae fault zone, was marked by thousands of small earthquakes, extensive ground cracking, harmonic tremor, and a minor eruption on the east rift. The Koae fracture zone lies between the east rift zone and the southwest rift zone of Kilauea, thus separating the south flank from the summit caldera. Historical records reveal a seismic gap between the rift zones. The Christmas 1965 activity filled this gap except near its eastern and western boundaries abutting the east and southwest rift zones. This event is different from other seismic gap-filling events in that (1) it was marked by an earthquake swarm rather than a main shock-aftershock sequence, (2) it was partly volcanic in nature, and (3) it did not occur on a plate boundary. This paper discusses this event with emphasis on its seismic character and its significance in terms of Kilauea tectonics and volcanism.



Bosserontd'Anglade, M.G., 1987, An excursion to Kilauea Crater, in A tree in bud; the Hawaiian kingdom, 1889-1893: Honolulu, University of Hawaii Press, chap. 9, p. 129-151. [Translated by Alfons L Korn. Originally published under pseudonym, G. Sauvin, as Un Royaume Polynesien, Iles Hawai, in Paris by E. Plon, Nourrit et Cie] 



 A popular account of a trip to Kilauea with brief mention of Mauna Loa.



I. FROM PARIS TO HONOLULU -- 1

 Departure. On the Atlantic Ocean. New York City.

 Across the United States. Niagara Falls, Chicago, 

 the Rocky Mountains. California. San Francisco.

 The Pacific.

II. THE HAWAIIAN PAST -- 16

 Formation of the archipelago, origion of the people.

 Native civilization before the arrival of Europeans.

 Discovery of the islands by Captain Cook. Kamehameha

 I, founder of the kingdom.

III. MODERN HAWAII -- 32

 Kamehameha II, the American missionaries.

 Kamehameha III, difficulties with foreign powers.

 Kamehameha IV, treaty of 1857 with France.

 Kamehameha V, M. de Varigny, eruption of Mauna Loa.

 Lunalilo. Accession of Kalakaua.

IV. HONOLULU -- 47

 The city. The people, prosperity and luxury. The

 business district and public buildings. Chinatown.

 The French mission. Waikiki. Nuuanu Valley.

 

V. A CONSTITUTIONAL KANAKA KING -- 64

 Kakakaua, the treaty with the United States. The

 coronation. Peaceful revolution. The constitution

 of 1887. Impressions of a sovereign. Hawaiian

 tradition and modern parlimentary government.



VI. THE DEATH OF KALAKAUA -- 78

 The arrival of the Charleston. The king's body is

 borne to the palace. Iolani Palace. A death watch.

 Funeral ceremonies. The new queen and the heiress

 apparent. Hookupu. Kalakaua and Rochefort.



VII. BEDECKED WITH FLOWERS -- 92

 The Kanaka. Chants and legends. The language.

 The religion. Kamehameha School and the museum.

 An old Hawaiian dwelling. Feasts and dances. The 

 hula. Manoa Valley.



VIII. PROGRESS -- 109

 Anglo-Saxon civilization. The part-whites. Politics.

 public instruction. A coeducation college. Pleasures

 of "society." Clubs and associations. A ball at the palace.



IX. AN EXCURSION TO KILAUEA CRATER -- 129 

 From Honolulu to Hilo. The Big Island and its

 capital. The trip to the volcano. Kilauea Crater.

 The tourist register. Hawaii's south coast. Kealakekua Bay.



X. BUSINESS -- 152

 The businessman. The sources of wealth. Commerce.

 A sugar plantation. Prosperity.



XI. AMONG THE LEPERS -- 162

 The queen's visit to Molokai. Father Damien. The

 lepers and leprosy. The asylum and hospital. The 

 Bishop Home for Lepers.



Brazee, R.J., and Cloud, W.K., 1959, Hawaiian Islands, in United States earthquakes, 1957: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, p. 42-43. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Brigham, W.T., 1868, The eruption of the Hawaiian volcanoes, 1868: Boston Society of Natural History Memoirs, v. 1, p. 564-587. 



 A description, compiled from several sources, of the lava flows, cataclysmic earthquakes, and mud flow of 1868. The paper includes a list of the earthquakes felt in South Kona by C.G. Williamson (1868a). Brigham presents maps of Kilauea as surveyed by himself in 1865 and after the 1868 eruption; he cites an unpublished letter from T. Coan containing observations similar to those in Coan (1869). He notes that relative movement took place on the Hakuma fault at Kalapana, even though the entire area subsided. Brigham disagrees with Coan regarding the relation between the Kilauea and the Mauna Loa rift eruptions, feeling that they are independent.



Brigham, W.T., 1868, [Eruption of Mauna Loa on the Hawaiian Islands] [abs.]: Boston Society of Natural History Proceedings, v. 12, p. 82-83. 



 A very brief account of some features of the earthquakes and eruption of 1868.



Brigham, W.T., 1868, Eruption of the Hawaiian volcanoes: Hawaiian Club Papers, Oct., p. 40-45. 



 Brigham describes the events of 1868, quoting from others. He mentions the earthquake swarm, mudflow, tsunami, both eruptions of Mauna Loa [the date of the summit eruption erroneously given as March 28], both eruptions of Kilauea, and the draining and return of lava to Kilauea caldera. He gives a good description of the cracking around Kilauea caldera following the earthquake swarm and subsidence. He states that the earthquake shocks were superficial and ascribes them to great rainfall, which provided water to interact with the magma. He hypothesizes that in the absence of rainfall, there would have been a quiet eruption; instead, the interaction of water with magma triggered a premature eruption at both volcanoes, evidenced by the small volume of lava erupted. [The identification of the eruption as "premature" agrees with modern interpretation of the events of 1868. There is no support for the idea that the earthquake swarm was due to magma-water interaction.]

 

Bryan, W.A., 1915, Natural history of Hawaii: Honolulu, Hawaiian Gazette Co., Ltd., 596 p. [Pages 89-188 cover the material abstracted] 



 Bryan briefly describes the physiography and geology of islands in the Hawaiian Chain, with more detail on the island of Hawaii. He describes the 1801 eruption of Hualalai and historic eruptions of Mauna Loa and Kilauea up to, and including, the year 1914. He summarizes conditions in Kilauea caldera from 1823 to 1910, including depths of collapse and refilling, and describes his own experience in visiting Halemaumau lava lake in 1909. He describes the great crack which crosses the Halemaumau trail as opening on November 4, 1889, and "Little Beggar," a rootless spatter vent as forming on March 31, 1884. [The 1889 crack is still visible on the caldera floor; Little Beggar was covered in the later 19th century.] He points out agreement of scientific observation with Hawaiian legends regarding the travels of the goddess Pele from Kauai to Kilauea, and gives a good description of Kapiolani's defiance of Pele in 1824. He [erroneously] views Kilauea and its rift zones as having originated by deep, explosive activity and cites Kilauea as an example of a "welling" crater in which lava can fill only so far before collapse occurs.



Bryan, C.J., 1991, The magnitude 6.1 25 June 1989 Kilauea south flank earthquake and aftershock sequence: a seismic perspective [abs.], in Big Island Science Conference, 11th, Hilo, HI, Apr. 18-20, 1991, Proceedings: Big Island Science Conference, 11th, Proceedings, v. 11, p. 13. 



 A magnitude 6.1 earthquake occurred within the southeast flank of Kilauea Volcano on June 25, 1989. It was the largest earthquake to have occurred on Kilauea since the magnitude 7.2 Kalapana earthquake in 1975, and was felt on the islands of Hawaii, Maui, and Oahu. Aftershocks occurring during the remainder of June were concentrated in two zones. The first extended approximately 40 km parallel to the East Rift Zone of Kilauea with a depth range of 513 km. The second lay normal to the East Rift Zone and formed a southeast elongation of about 15 km extending from near Kalapana through the area of localized ground cracking to approximately 8 km offshore.

 I determined fault-plane solutions for the main shock and the largest aftershocks of the sequence. For the main shock the short-period seismic data collected at the Hawaiian Volcano Observatory yields a thrust solution with one nodal plane of strike 183  5 and dip 35  5 and with a second nodal plane of strike 130  5 and dip 60  5. In contrast, from the teleseismic data, Chen and Nabelek (1990) found a NE striking shallowly NW dipping thrust solution for this event. Focal mechanisms determined from local network short-period data for coastal aftershocks are similar not only to the teleseismic fault-plane solution for the main shock but also to fault-plane solutions determined for earthquakes of ML 3.0 occurring at depths of 8 to 12 km between January 1986 and June 1989 (Bryan and Johnson, 1991). This result suggests a complex rupture sequence in which rupture initiation, represented by the short-period mechanism, is significantly different from the average rupture process as represented by the teleseismic mechanism. Rupture may have begun along a plane other than the inferred interface between the volcanic pile and the pre-volcanic sea-floor and propagated into and along this interface.

 This earthquake provided an opportunity to compare the seismic and volcanic effects from locally occurring ML=6.1, ML=6.6, and ML=7.2 earthquakes, all of which were reasonably well-constrained by dense instrumental coverage. Non-instrumental observations may also be integrated for comparison to the M = 7.5-8.0 Kau earthquake of 1868, the largest earthquake to have struck the Hawaiian islands in historic time. All events were apparently quite similar and most differences in their respective effects can be attributed to size and/or epicentral location.



Bryan, C.J., 1991, A possible triggering mechanism for large Hawaiian earthquakes [abs.]: Eos, Transactions, American Geophysical Union supp., v. 72, no. 44, p. 331. [AGU fall meeting, San Francisco, CA, Dec. 9-13, 1991, Program and abstracts] 



 Differences in fault-plane solutions determined from short-period local-seismic-network data and long-period teleseismic data for recent large Hawaiian earthquakes suggest that the initial rupture processes in large Hawaiian events are not characteristic of the overall rupture processes. The focal mechanism determined from short-period seismic data for the ML = 7.2 1975 Kalapana main shock shows low-angle thrusting according to some workers, but moderate to steep thrusting according to others, whereas the focal mechanism calculated from long-period seismic data shows low-angle thrusting. As a more definitive example, both the mapping of cracks and the focal mechanism derived from short-period seismic data for the ML = 6.6 1983 Kaoiki earthquake show strike-slip motion, whereas the teleseismically determined fault-plane solution shows low-angle thrusting. Finally, the fault-plane solution calculated from short-period seismic data for the ML = 6.1 1989 Kilauea south flank earthquake is identical to that determined by some workers for the 1975 main shock from short-period data and suggests that rupture initiated as a moderately to steeply dipping thrust. In contrast, focal mechanisms determined from short-period local-seismic-network data for aftershocks of ML > 3.0 as well as the mechanism determined from long-period teleseismic data for the main shock suggest that the overall rupture process in the 1989 sequence represented low-angle seaward sliding of the south flank of Kilauea Volcano.

 Thus, stress release in large Hawaiian earthquakes may be characterized by a complex rupture sequence in which one or more small events trigger large-scale flank displacement. These triggering events may activate rupture surfaces different than those along which the long-period moment release occurs and, hence, may represent release of a local stress concentration that is superposed atop the regional stress field.



Bryan, C.J., 1992, A possible triggering mechanism for large Hawaiian earthquakes derived from analysis of the 26 June 1989 Kilauea south flank sequence: Bulletin of the Seismological Society of America, v. 82, no. 6, Dec., p. 2368-2390. 



 Examination of short-period seismic data from the ML = 6.1 Kilauea south flank earthquake and aftershock sequence indicates that the rupture process in large Hawaiian earthquakes is more complex than previously modeled. In contrast to the low-angle thrust solution determined for the mainshock from long-period teleseismic body waves by other workers, I find an intermediate- to high-angle reverse solution; I find, however, that focal mechanisms for coastal aftershocks of ML > 3.0 are similar to the teleseismic mechanism for the mainshock.

 A difference in focal mechanisms determined from short-period local network seismic data and from long-period teleseismic data has been noted for other recent large Hawaiian earthquakes. Both the mapping of surface cracks and the focal mechanism derived from short-period seismic data for the ML = 6.6 1983 Kaoiki earthquake show strike-slip motion, whereas the centroid moment tensor solution shows low-angle thrusting. The focal mechanism calculated from short-period seismic data for the ML = 7.2 1975 Kalapana mainshock shows low-angle thrusting according to some workers, but intermediate- to high-angle reverse faulting according to others, whereas focal mechanisms calculated from long-period seismic data show low-angle thrusting.

 This result suggests that rupture initiation in large Hawaiian earthquakes, as represented by the short-period focal mechanisms, differs significantly from the overall rupture process, as represented by the teleseismic mechanisms. I propose that small earthquakes trigger the large-scale energy release at the bases of the volcanic edifices, the type of energy release often observed in large Hawaiian earthquakes. These triggering events may occur along rupture surfaces that differ from those along which the long-period moment release occurs and thus may represent release of a local stress concentration superposed upon the regional stress field.



Bryan, C.J., 1992, Seismic studies on the island of Hawaii and Loihi Seamount: Honolulu, University of Hawaii, Ph.D. dissertation, 140 p. [In Hawaii reference collection] 



 Models for flank dynamics of Hawaiian volcanoes relate seismicity in the Hawaiian islands to volcanic edifice growth. In most models, tectonic earthquakes occurring along a subhorizontal detachment surface or weak zone at the base of the volcanic edifice are the principal means of releasing accumulated flank stresses. The persistence of and damage caused by basal sliding earthquakes underscore the importance of understanding these events. Not only will this knowledge yield better models of volcanic growth, but it has important implications for seismic hazard assessment.

 Focal mechanism and slip analysis for a set of small basal sliding earthquakes show that the southern third of the island of Hawaii is composed of at least three rigid blocks that slide horizontally along the edifice basal interface. Relative motion between these blocks may be accommodated by oblique opening across their shared boundaries.

 Differences in fault-plane solutions determined from short-period local-seismic-network and long-period teleseismic data for recent large Hawaiian earthquakes suggest that the rupture processes in large basal sliding earthquakes may represent complex patterns of stress release within the volcanic edifices. Rupture may initiate as small events that trigger the large-scale energy release at the bases of the volcanic edifices, the type of energy release often observed in large Hawaiian earthquakes. These triggering events may activate rupture surfaces that differ from those along which the long-period moment release occurs and, thus, may represent release of a local stress concentration superposed upon the regional stress field.

 Finally, seismic data from a Loihi swarm are examined to determine a crustal velocity model for Loihi Seamount and to assess systematic mislocation incurred by locating Loihi earthquakes with only the stations of the Hawaiian Volcano Observatory permanent seismic network. An insufficient number of ocean bottom seismometers, poor site locations, and poor coupling to the bottom precluded realization of these goals.

 Information learned from these studies combined with that from studies of the temporal and spatial patterns of seismicity and stress release within the volcanic edifices will yield a much more complete understanding of volcanic growth and deformation processes.

 

Acknowledgments ............................................................................................iii

Abstract ..............................................	v

List of Tables ........................................	x

List of Figures ....................................................................................................xi

Chapter 1: Hawaiian Seismicity: An Introduction .......................................1

 1.1 Background ......................................................................1

 1.2 Tectonic Earthquakes .......................................2

 1.3 Volcanic Earthquakes ........................................5

Chapter 2: Block Tectonics of the Island of Hawaii from a Focal Mechanism Analysis of Basal Slip .............		7

 2.1 Abstract ...............................................................................7

 2.2 Introduction .....................................................................8

 2.3 Seismic Hazard ...............................................................13

 2.4 Data Analysis ..................................................15

 2.5 Kilauea South Flank ...........................	19

 2.6 Mauna Loa Southeast Flank .....................	33

 2.7 Mauna Loa West Flank ..........................	36

 2.8 Conclusions ...................................	36

 2.9	Acknowledgments ..............................	40

Chapter 3: A Possible Triggering Mechanism for Large Hawaiian Earthquakes Derived from Analysis of the 26 June 1989 Kilauea South Flank Sequence ..........................	42

 3.1 Abstract ...........................................................42

	3.2 Introduction ..........................		43

	3.3 Tectonic Models .......................		45

	3.4 Earthquake Locations ..................		48

	 3.4.1 Main Shock .......................		48

	 3.4.2 Aftershock Distribution ..........		49

	3.5 Focal Mechanisms ......................		56

	 3.5.1 Main Shock .......................		56

		3.5.2 Aftershocks 		69

	3.6	 Focal Mechanisms for and Interpretations of the 29 November 1975 and the 16 November 1983 Earthquakes ...........................................	76

		3.6.1 1975 Kalapana Earthquake ........................	78

		3.6.2 1983 Kaoiki Earthquake ..........................	83

	3.7	Discussion and Conclusions ............................	84

	3.8	Acknowledgments .......................................	86

Chapter 4: An Ocean Bottom Seismometer Deployment on Loihi Seamount ....................................	87

	4.1 Abstract ..........		87

	4.2 Tectonic Setting ..............................		87

	4.3 Morphology of Loihi ..................................	89

	4.4 Loihi Seismicity .....................................	91

	4.5 OBS Experiment .......................................	94

	4.6 Data Selection .......................................	96

	4.7	Data Processing and Data Quality .......	96

	4.7.1 OBS Data .........................	96

	4.7.2 HVO Data .........................	119

	4.8	Data Analysis ..........................	124

	 4.8.1 OBS Data .........................	124

		 4.8.1.1 Goals ......................	124

		 4.8.1.2 Procedure ..................	124

	 4.8.2 HVO Data .........................	125

	4.9 Significance of a Better Data Set and Future Work 129

References .......			132



Bryan, C., and Cooper, P., 1995, Ocean-bottom seismometer observations of seismic activity at Loihi Seamount, Hawaii: Marine Geophysical Researches, v. 17, p. 485-501. 



 This study reports the result of deep ocean-bottom seismometer recording of an undersea volcanic event in progress. An array of five three-component, isolated sensor ocean-bottom seismometers (ISOBS) was deployed for 28 days on the summit and flanks of Loihi Seamount, Hawaii, to monitor seismicity. The deployment was prompted by reports from the Hawaiian Volcano Observatory (HVO) of a swarm of small-magnitude events located beneath the active submarine volcano in late September, 1986. Monitoring of this earthquake swarm by the University of Hawaii commenced 1 October 1986. Although seismicity tapered off rapidly after 11 October, more than 200 events were located. Systematic changes in spatial clustering during the initial swarm activity suggest changing patterns of stress within this crustal volume, possibly due to induced stress resulting from magma movement in the underlying crust or deep portions of the edifice.

 Most of the very shallow (< 10 km) events were located beneath the summit and southwest flank of the elongate edifice. No shallow tremor was observed despite a search through the data, although such tremor may have ceased prior to deployment of the ocean-bottom seismometers (OBS). Constraints on the association between seismicity and observed topographic and tectonic elements of Loihi are also of primary importance. Many of the earthquakes located near the steep flanks generated rock falls that were recorded on the OBSs. This is consistent with the results of dredge and bottom photography data indicating that the flanks are covered with fragments of shattered lava pillows and flows. Dike intrusion and mass wasting are major influences on the morphology of Loihi. Intact flows have been observed near the deep portion of the south rift zone: however. few events were located in that region during this swarm.



Buchanan-Banks, J.M., 1983, Reconnaissance map showing thicknesses of volcanic ash deposits in the greater Hilo area, Hawaii: U.S. Geological Survey Miscellaneous Field Studies Map MF-1499, scale 1:24,000. 



 INTRODUCTION

This study was undertaken to determine the thickness and distribution of volcanic ash deposits in the greater Hilo area, Hawaii, as a step toward evaluating their susceptibility to failure during earthquake shaking. On several occasions their instability has resulted in serious damage. For example, the 1868 earthquake (m=7+), following a prolonged rainy period, caused a debris flow of hillside ash deposits that killed 31 people in Wood Valley (Brigham, 1869). The 1973 Honomu earthquake (m=6.2) resulted in more damage from shaking to areas underlain by ash deposits in the older part of Hilo than in other areas, and soil slips in ash, as well as rockfalls, were common along the roads north of town (Nielsen and others, 1977).

 Three geologic units are represented on the accompanying map the ash deposits, a clay bed that locally underlies the ash, and the bedrock material.

 CONCLUSIONS

Reconnaissance geologic mapping of volcanic ash deposits in the greater Hilo area suggests a repetitive history of eruption, deposition, and severe weathering. Ash deposits believed to be erupted mainly from Mauna Kea Volcano are interbedded with and overlain by Mauna Loa lava flows in the study area.

 The thickest deposit of ash observed is 6 m and occurs south of the Wailuku River. North of the Wailuku River, the ash thickness undoubtedly has been decreased by sugarcane harvesting procedures that mechanically remove some ash while loosening the surface of the remaining ash. This results in accelerated erosion during rainy periods as well as an increase in downslope movement of the disturbed material.

 The ash deposits in the study area are classified as medium to very sensitive. Although slopes with these sensitivities are more likely to fail during earthquake shaking than slopes with slight sensitivity, the ash deposits in the map area show no evidence of large-scale slope failures. However, ash deposits with a sensitivity and water content similar to those in the Hilo area failed at Wood Valley during the 1868 earthquake, which occurred during a prolonged rainy period. The combination of a large magnitude earthquake, prolonged shaking, and saturated ash deposits apparently has not occurred in the Hilo area since the deposition of the ash some 24,000 years ago. Thus, although the sensitivity of the ash indicates a high possibility of failure during earthquake shaking, the probability of large-scale failure in the greater Hilo area does not appear high.

 On the other hand, numerous small soil slips in ash and rock falls have been documented as a result of earthquake shaking and during heavy rains. These failures occur where the deposits are steepest, as well as along road embankments and stream banks where the material is unsupported. Whether such failures occur on a small or a large scale, they can be financially and personally devastating to an individual. Damage to property and danger to people can be minimized by careful site selection and appropriate earthquake-resistant design of structures.

 The clay bed that locally underlies the ash may also fail during heavy rains as well as during earthquake shaking. Owing to its greater impermeability and finer particle size, it may cause water to accumulate at the base of the overlying ash, increasing pore pressure and thereby reducing stability.



Buchanan-Banks, J.M., 1987, Structural damage and ground failures from the November 16, 1983, Kaoiki earthquake, island of Hawaii, in Decker, R.W., Wright, T.L., and Stauffer, P.H., ed(s)., Volcanism in Hawaii, 2 v.: U.S. Geological Survey Professional Paper 1350, v. 2, chap. 44, p. 1187-1220. 



 On November 16, 1983, at 0613 (HST), a magnitude 6.6 earthquake occurred on the island of Hawaii at a depth of 12 km midway between the active volcanoes of Mauna Loa and Kilauea. The right-lateral strike-slip faulting was probably generated by compressional stresses caused by inflation of the crustal magma reservoirs of both volcanoes. The earthquake shaking was felt for nearly one minute and caused substantial damage to structure- in the southeastern part of the island. Landslides occurred on steep slopes throughout the island and, together with cracking of the ground and vibrational settling of subsurface materials, caused temporary closure of some roads. Fortunately, only a few people received minor injuries as a result of the earthquake; this was most likely because it struck at an early hour, when most people were still in bed



Burgmann, R., and Denlinger, R., 1995, The role of the Hilina fault system in the deformation of the mobile south flank of Kilauea Volcano, Hawaii [abs.], in, Geophysics and the environment, International Union of Geodesy and Geophysics (IUGG), 21st General Assembly, Boulder, CO, July 2-14, 1995, Abstracts, Week A: [s.l.], [s.n.], p. A455. 



 The Hilina fault system stretches over approximately 25 km along Kilauea's south flank and is characterized by up to 500 m high, south-facing normal fault scarps (Hilina Palis). Geologic and geophysical data show that the south flank of Hawaii is rapidly moving southward separated from the Big Island of Hawaii by Kilauea's southwest and east rift zones and underlain by a subhorizontal detachment at the base of the volcanic edifice at ~10 km depth. This detachment partially slipped in at least two historic earthquakes in 1975 and 1989. Kilauea's south flank resembles a large landslide block and it has been speculated that it may be able to fail catastrophically. Evidence for past huge, tsunami-generating landslide failures are abundant along the Hawaiian island chain. The Hilina Palis have been interpreted in a variety of ways, ranging from headscarps of relatively shallow (<1-2 km deep) listric landslides to steep deeply reaching normal faults that accommodate subvertical block motion in the south flank.

 We are investigating the subsurface geometry of the Hilinas and their role in the deformation of the south flank block through a careful analysis of surface exposures, microseismicity patterns, geodetically measured deformation, and mechanical modeling. Ground breakage during the M=7.2 1975 Kalapana event was nearly continuous along the Hilina faults with up to 2 m of normal displacement. The width of the zone of large, geodetically measured horizontal and vertical displacements coincides with the width of the Hilina fault system, the distribution of coseismic offsets along it, and the width of a large topographic bench 30-50 km offshore. This suggests that the normal faults prayed an important role in a composite rupture in 1975 and in the long-term development of the south flank. These observations are complicated by evidence for a large shallow failure near Apua Pt. in 1975 that affected several coastal sites. We develop first-order elastic models of deformation associated with the 1975 earthquake that satisfy geodetic and tsunami data to better constrain possible geometries and depths of rupture along the Hilina faults. Published temporal and spatial microseismicity patterns and focal mechanisms show that normal faulting events occur primarily following large detachment events due to the sudden stress redistribution caused by fault slip. Reverse faulting dominates at other times, suggesting that the extending magmatic rift system is pushing Kilauea's south flank seaward. This analysis suggests that the Hilina fault system is a deeply rooted zone of steeply dipping normal faults that are directly linked to the seismo-magmatic cycle of Kilauea's south flank.



Burgmann, R., and Delaney, P.T., 1996, Deformation caused by the 1975 Kalapana earthquake beneath the south flank of Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F138. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 Shaking and tsunamis generated by detachment-type earthquakes are among the most substantial of Hawaii's natural hazards. The flanks of Kilauea and Mauna Loa Volcanoes have experienced large historic events that apparently ruptured along the base of the volcanic edifice. Trilateration, leveling, and tilt measurements collected by the Hawaiian Volcano Observatory constrain the source mechanism of the November 29, 1975, M=7.2 Kalapana earthquake, which originated at 8-9-km depth beneath Kilauea's south flank. In addition to detachment slip, up to 2.5 m of ground rupture was triggered along about 25 km of the steeply SE-dipping Hilina normal-fault system. The zone of largest horizontal and vertical displacements occurs downslope of the Hilina system, where there was as much as 8 m of seaward displacement and 3 m of subsidence along the seacoast. The 1975 displacements are well explained by elastic dislocations having about 10 m of basal slip, on a 30-by-45 km plane striking N65E, together with about 2-3 m of opening along the rift system. The largest model residuals occur downslope of the Hilina fault system, demonstrating that shallow normal faulting was responsible for the large ground-surface displacements along the seacoast. Several difficulties contribute to uncertainties in our results. (1) Substantial deformations occurred during the collection of geodetic measurements; for instance, pre-earthquake trilateration measurements span the 1974 eruption along the southwest rift zone and measurements following the earthquake coincided with substantial postseismic deformation. (2) Large deformations not related to the earthquake occurred during the year that comprises our geodetic interval. (3) Geodetic network apertures are narrow in comparison to the size of the zone of ground-surface motion. These factors lead to uncertainties in our interpretation and perhaps contribute to an estimated geodetic moment that greatly exceeds the seismic estimate.



Butler, R., and Langston, C.A., 1976, The Hawaiian earthquake of April 26, 1973: a double event [abs.]: Eos, Transactions, American Geophysical Union, v. 57, no. 12, p. 954. [AGU fall meeting, San Francisco, CA, Dec. 6-10, 1976, Program and abstracts] 



 A detailed study of long period teleseismic P and S waves from the WWSS and Canadian Networks reveals that the subcrustal earthquake (Ms=6.1) near Hilo, Hawaii on April 26, 1973 was a double source. The methods of P wave first motions, phase identification, and wave-form synthesis in conjunction with a generalized inverse technique are used to constrain the sources. The first event may be successfully modelled by a 42 km deep north-south striking fault with a rake of 155, a symmetric triangular time function 3.4 seconds in duration, and a moment of 4.3xl025 dyne-cm. The second source is similar in depth, size, and orientation, though striking more to the west. The spacio-temporal separation of the second event relative to the first is approximately 4 seconds in time and 25 km N60E in distance.



Butler, R., 1981, The April 26, 1973 Hawaii earthquake: a precursor to reactivation of volcanism at Mauna Kea? [abs.]: Earthquake Notes, v. 52, no. 1, p. 73. [Seismological Society of America, 76th annual meeting, Berkeley, CA, Mar. 23-25, 1981 (Abstracts)] 



 The 1973 Hawaii earthquake occurred north of Hilo, at a depth 40 to 50 km The location was beneath the east flank of Mauna Kea, a volcano dormant historically, but active within the last four thousand years. Aftershocks were restricted to 55-35 km depth. The event and its aftershock sequence are located in an area uncharacteristic of background seismicity associated with the Mauna Loa and Kilauea calderas. The earthquake was a double event, the epicenters trending NE-SW. The events were of similar size and faulting mechanism. The fault plane solutions obtained by seismic waveform analysis are a strike-slip fault striking EW and dipping 55S, the auxiliary plane a NS vertical plane with a faulting plunge of 35. The maximum compressive axis is aligned with the gravity gradient from the island. The fault plane striking EW parallels a surface feature, the Mauna Kea east rift zone. The earthquakes were clearly not associated with volcanic activity normally associated with Mauna Loa and Kilauea and may indicate a deep seated prelude to a resumption of activity at Mauna Kea.



Bycroft, G.N., 1981, Anomalous free field recordings at certain seismograph locations: U.S. Geological Survey Open-File Report 81-318, 17 p. 



 Introduction.

 Accelerographs are used to measure both the "free-field" motion of the ground during an earthquake and the motion of points on a structure.

 In general free-field accelerograms exhibit a somewhat random signal and to the eye show no particular character or dominant frequency. This is better shown by a spectral analysis. However, occasionally a record is obtained which does not fit this general pattern. It is then generally difficult to decide if the record is true or spurious. The record may indeed be true being the result of a highly unusual local terrain, that is there may be a large underground rock lying in a low velocity medium nearby or an underground cavity, trench, or tunnel of such dimensions as to impose an atypical character on the record. A low velocity layer overlying rock may produce a dominant surface wave. On the other hand, the record may be anomalous because of instrument malfunction, improper or loose mounting, or local noise. The recording may appear to be normal but actually has been compromised by soil-structure interaction. The effect of soil-structure interaction is discussed by Bycroft for the case of typical free-field instrument locations consisting of a concrete pad and a housing to protect the instrument. He showed that for low-velocity terrain and typical housings of the heavier type the higher frequencies can be substantially magnified. For convenience, instruments are often located in the basement of buildings. In this case the motion of the structure modifies the free-field motion. Many studies have been made which show that soil-structure interaction in certain cases has a substantial effect on the motion of the foundation and hence on any recordings made there.

 A typical study on this effect is that by Hadrilek and others. By taking spectral ratios of a basement recording and a nearby free-field instrument recording of a common event it is shown that the natural frequencies of the structure appear in the basement recording. Crouse and Jennings discuss similar soil-structure interactions at the Hollywood Storage Building. Some examples are now given of some further records that are suspect or show evidence of soil-structure interaction.



Bycroft, G.N., 1982, Anomalous free-field recordings at certain seismograph locations (California, Hawaii): U.S. Geological Survey Open-File Report 82-0318, 19 p. 



 "Hawaii Earthquake of November 29, 1575 Record at Honokaa Fig. 7 shows the location of various instruments on the Island of Hawaii. A recording of the November 29, 1975 earthquake obtained at Honokaa is shown in Fig. 8 and consists primarily of a 7 Hz oscillation. This is a most unlikely accelerogram. The record obtained at Hilo showed none of this character. An investigation was made to find an explanation for this unusual record. The instrument is located on the concrete floor of the county service building in Honokaa. The building has a steel frame with corrugated iron roof and walls and is much too light for soil-structure interaction to be significant. The 6" thick concrete floor lies on 30" of crushed rock over 3 to 4 ft of top soil and then competent rock. The structure lies close to the edge of a small cliff at the bottom of which there is a road. Measurements of the noise level on the floor and at various points on the structure were made using a Kinemetric VM-l.

 Trucks passing on the road below produced significant readings. Fig. 9 shows part of a record taken on the floor close to the seismograph location during the passage of a truck on the road below. A strong 7 Hz signal dominates the record. Thus it appear that this location is an unusual one in that an excitation produces an oscillation of 7 Hz. It is known that this region is permeated with large lava tubes up to 30 ft. in diameter and of considerable length. It is possible that these tubes form a structure having a 7 Hz natural frequency and that an excitation from any source will excite this frequency."



Byerly, P., and Herrick, C., 1954, T phases from Hawaiian earthquakes: Bulletin of the Seismological Society of America, v. 44, no. 2A, p. 113-121. 



 We have searched the Volcano Letter for the years 1928 through 1950 to find the times of occurrence of the larger Hawaiian earthquakes which might have given rise to T phases at the Berkeley network of seismographic stations. Those selected to be investigated are classified by the Volcano Observatory as moderate to very strong. A moderate earthquake in their classification will completely dismantle their seismographs. In the years 1928 through 1951, 138 moderate to very strong earthquakes were recorded by the Volcano Observatory. Of these only 10 gave rise to definitely recognizable T phases at the University of California stations. These T phases were recorded on Wood-Anderson and Benioff short-period seismographs at the Berkeley, Mount Hamilton, Palo Alto, University of San Francisco, Shasta, and Mineral seismographic stations. Seven additional observations of T from Hawaiian shocks were added in 1952. All are listed in table 1. They are plotted in figure 5.



Cannon, E.C., and Burgmann, R.B., 1998, GPS mapping of 1975 Kalapana earthquake ground deformation, Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 79, no. 45, p. F978. [AGU fall meeting, San Francisco, CA, Dec. 6-10, 1998, Program and abstracts] 



 Earthquakes in 1868 and 1975 of M>7 have struck the south flank of Kilauea Volcano, Hawaii. Earth scientists interpret the south flank as a mobile block, bounded to the north by Kilauea Volcano rift zones, and at 10-12 km depth by a shallowly north-dipping decollement surface. Internal to the south flank, normal Hilina and Koae fault systems dissect the south flank block. When the decollement surface ruptured during the November 29, 1975 M=7.2 Kalapana earthquake, south flank surface displacements approached a maximum of 3 m vertical subsidence and 8 m horizontal motion seaward. 1975 Kalapana earthquake surface deformation along the Hilina fault system produced fractures in 1969-1974 Mauna Ulu surface flows. Mapping Kalapana earthquake ground deformation of Mauna Ulu flows will improve our understanding and evaluation of south flank coseismic displacement, kinematic models and seismic hazard assessment.

 We employ two systems of GPS equipment to map surface deformation of the 1975 Kalapana earthquake. Field mapping with GPS equipment can record positions of footwall and hangingwall traces of ground deformation, and piercing points across rupture traces. Real-Time Kinematic GPS equipment provides immediate positions with 1 cm horizontal and 2 cm vertical position accuracy. Positions from handheld differential GPS equipment post-processed at the end of each field day provide 2-5 m horizontal and 4-10 m vertical position accuracy. Factors which dictate the type of equipment used include: required level of position accuracy, terrain, vegetation, battery usage. Data processing of field data in map view, and in profile view strike-parallel and strike-perpendicular to fault traces, will be used to calculate ground displacement. These findings will be compared to geodetic measurements collected after the 1975 Kalapana earthquake. Preliminary data analysis shows ground deformation does not concentrate along a single fracture, but rather over a distributed brittle shear zone of 10s to 100s of meters width. En-echelon extensional fractures suggest a strike-slip component of movement on normal Hilina faults.



Caplan, A.J., Duennebier, F., and Okubo, P., 1997, Seismicity of the 1996 Loihi Seamount eruption [abs.]: Geological Society of America Abstracts with Programs, v. 29, no. 5, p. 7. [Geological Society of America, 93rd Annual Cordilleran Section meeting, Kailua-Kona, HI, May 21-23, 1997] 



 The earthquake swarm which began on July 16, 1996 on Loihi seamount was the largest ever recorded on a Hawaiian volcano. The initial phase of activity, lasting for three days and consisting of 72 located events, was followed by 30 hours of quiescence. The main body of the swarm began on July 20, averaging over 88 events per day for the next ten days and over 12 events per day for the subsequent 12 days. Hypocentral locations were calculated for over 1200 events using data from the seismic network operated by the Hawaii Volcano Observatory (HVO). Initial hypocentral locations suggested a sharply delineated plane of seismicity between 13 and 14 km depth, shallowing to the south. The HVO network lies north of Loihi seamount, and there are no permanent seismometers located elsewhere near Loihi, hence these initial locations were found to be imprecise. Data from an ocean bottom seismometer (OBS), enabled us to approximate a new velocity model for the area beneath Loihi seamount. The new velocity model allows us to relocate swarm events with tighter constraints on earthquake location. The majority of events cluster near the summit of the volcano. Those events for which we have both HVO and OBS data lie at depths of approximately 8-9 km. These depths are consistent with petrologic data which suggest the presence of a Loihi magma chamber near depths of 9-10 km. Due to locator bias, depths on events for which we have no OBS data are poorly constrained.



Caplan-Auerbach, J., Okubo, P., Duennebier, F., and Kong, L., 1996, Characteristics of the 1996 Loihi seismic swarm [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F397. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 On the evening of July 16, the largest earthquake swarm ever measured on a Hawaiian volcano began on Loihi seamount. Between July 16 and August 9, over 4000 seismic events were detected by the Hawaii Volcano Observatory (HVO). We have calculated hypocentral solutions for over 1200 of these events. The initial phase of activity, consisting of 72 located earthquakes beneath the south and southwest flanks of Loihi, continued for two days. After 30 hours of quiescence, activity resumed on July 20 and continued at a high rate for the next two weeks, averaging over 88 events per day for the next 10 days and over 12 events per day for the subsequent 11 days. Unlike early activity, events in this main phase of activity clustered near the summit of the seamount and extended along a NNW-SSE trend roughly paralleling Loihi's rift zones. Although activity quieted significantly after August 9, HVO continued to record elevated seismic activity on Loihi for many weeks. Hypocentral locations for the majority of events in this swarm sharply delineate a band of activity between depths of 10 and 14 km, dipping toward the island of Hawaii from SSE to NNW. Bathymetric measurements and observations from a submersible vessel in early August revealed pronounced changes in topography at Loihi summit. The potential relationship between topographic changes and the earthquake swarm make shallow earthquakes of particular interest. Prior to July 23, very little shallow activity was recorded on Loihi. Between July 23 and July 30, however, shallow activity increased and approximately 40 events were located between 0 and 7 km. This period also marks the onset of increased deep (20-35 km) activity. Waveforms associated with this swarm are very similar in appearance and first arrivals are nearly uniformly directed down. We hypothesize that the swarm was tectonic in origin and that any volcanic events associated with this swarm may have been triggered by tectonic adjustments beneath the southwest flank of Loihi.



Carlowicz, M., 1996, Earthquake swarm heats up Loihi: Eos, Transactions, American Geophysical Union, v. 77, no. 42, p. 405-406. 



 If Fred Dunnebier and his colleagues had completed their work when they wanted to, they'd be out of business by now.

 Dunnebier and his colleagues at the University of Hawaii has planned to have their Hawaii Undersea Geo-Observatory (HUGO) set atop the flattened summit of the Loihi seamount, near Pele's Vents, in February. The automated underwater volcano observatory-now funded by a $900,000 grant from the National Science Foundation and aided by the donation from AT&T of time on a cable-lying ship and of fiber optic cable-was designed for the study of midplate volcanism and hydrothermal venting at the only active, midplate seamount volcano readily accessible from the United State. HUGO includes seismometers, tilt meters, bottom pressure sensors, cameras, and thermal and chemical sensors that would deliver real-time observations via the cable to researchers 45 km away at the U.S. Geological Survey's Hawaiian Volcano Observatory on Kilauea.

 But HUGO is still high and dry. Had the station been deployed as scheduled - it was delayed by funding and logistical difficulties - it would now be in wreckage. Its planned site is now buried 300 m deeper than it was three months ago.

 From July 16 to August 9, the Loihi seamount was the site of the largest swarm of earthquakes ever recorded near any Hawaiian volcano. At least 4377 quakes were recorded within the month, with more than 100 of those tremblors registering stronger than magnitude 4. For 10 consecutive days starting July 20, and average of 88 earthquakes rocked Loihi each day, with the strongest event measuring 5.0 Mw on July 27.

 As a result, a cone full of hydrothermal vents, once known as Pele's Vents, has had to be renamed Pele's Pit as a crater 550 m wide by 300 m deep opened where once there was a summit (Figure 1a and b). The event has spurred two expeditions to the seamount and inspired a late addition to the science program for AGU's Fall Meeting in San Francisco.

 The Loihi (Hawaiian for "long one") seamount rises 3500 m from the Pacific floor, just 32 km southeast of the big island of Hawaii and it is believed to be fed by the same 50 km-wide hotspot that ultimately feeds Kilauea and Mauna Loa. With its summit about 1000 m below the ocean surface, Loihi is a Hawaiian island-in-waiting-expected to pop its head above the water in 50,000 to 100,000 years. First discovered in 1954, Loihi was thought to be a Cretaceous seamount until a seismic swarm and the discovery of glassy lava in the 1970's changed researchers' thinking about the history of Loihi and all the Hawaiian volcanoes.



Carter, L., and Dvorak, J., 1991, Differential submergence along the coast of Hawai'i [abs.], in Towards the Pacific Century: The Challenge of Change, Pacific Science Congress, 17th, Honolulu, May 27-June 3, 1991, Proceedings: Pacific Science Congress, 17th, Proceedings, p. 16. 



 A tide-gauge operating in Hilo Bay since 1935 has indicated current submergence at a rate of 4 mm/yr. About half of this rate is contributed by the worldwide rise in sea level: the remainder is lowering of the Earth's crust around the island (1) by the weight of the volcanoes and (2) by the removal of magma from depth and its eruption or shallow intrusion in the volcanoes.

 Much faster rates of submergence have occurred during some large earthquakes: as much as 3.5 m of submergence occurred during the magnitude 7.2 earthquake along the southeast coast on 27 November 1975. A much larger earthquake on the east side of the island on 2 April 1868 may have resulted in as much as several meters of coastal submergence. These types of events were probably devastating to Hawaiian coastal communities, resulting in disappearance of fishponds and destruction of coastal villages by earthquake-produced tsunamis.

 Drowned coconut palms, possible underwater burial caves, and submerged stone walls record the effects of large earthquakes on the east side of the island. No unambiguous evidence has been recognized on the west side to indicate submergence at a long-term rate faster than the 4 mm/yr now recorded in Hilo Bay. Stone structures at Kahaluu, 3 km south of Kailua, and Kawaihae are about 3 m below the level of present high tide. If these structures were originally built at the high-tide mark, then an average subsidence rate of 4 mm/yr would place them at their current underwater level in 750 years. The position of possible stone platforms off the west coast near Wawahiwaa, south of the new Kona airport, in 16m of water cannot be explained by long-term subsidence at 4 mm/yr since the Hawaiian occupation, which did not begin earlier than 2,000 years ago. If these stone features are artificial, then the position of these features either record the occurrence of large earthquakes, or they must have been built at least a few meters below sea level. The latter possibility raises the intriguing questions: How extensive were underwater stone constructions of the Hawaiians, and what were the uses of these structures?



Cayol, V., Dieterich, J., Okamura, A., and Miklius, A., 1998, High rates of flank deformation prior to the 1983 eruption of Kilauea, Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 79, no. 45, p. F956. [AGU fall meeting, San Francisco, CA, Dec. 6-10, 1998, Program and abstracts] 



 After a magnitude (M) 7.2 earthquake in 1975 and before the start of the ongoing eruption in 1983, deformation of Kilauea volcano was the most rapid ever recorded, with rates of extensions of 25 cm/year across the summit. Three-dimensional numerical modeling showed that this deformation was created by the dilation of a dike-like magma system within Kilauea's rift-zones coupled with aseismic creep over a narrow area of a low-angle fault beneath the south flank. This model provides a mechanism for the south-flank earthquakes. First, the highest south-flank microseismicity occurs where the Coulomb stresses implied by this model most favor fault slip. Second, the epicenters of the M7.2 1975 and the M6.1 1989 earthquakes are located on the part of the lowangle fault locked in this model, but where Coulomb stresses indicate that slip is favored. Rates of rift zone opening averaged 40 centimeters a year resulting in a magma supply rate of 0.19 cubic-kilometer per year, twice as large as other estimates, but consistent with supply rates estimated after 1983. This study also shows that the decrease in south-flank displacements that occurred in 1983 can be solely attributed to a change in magmatic activity from intrusive to continuously eruptive.



Cheever, H.T., 1871, The island world of the Pacific (1st ed.): New York, Harper & Brothers, 406 p. [Pages 280-352 cover the material abstracted. Reprinted in 1859 by Collins, London, 304 p.] 



 A description of Kilauea caldera in January 1850. The author describes Sulphur Bank and the southeast solfatara and recognizes the alteration of the rock by hot, sulfurous vapors. The only active lava lake mentioned is Halemaumau, said to be a mile in greatest diameter and 30 or 40 ft below its rim. Activity is said to have been much less than a year before, during a visit by Mr. Paris. Cheever summarizes Strzelecki's (1838) descriptions of the caldera. The two views of Kilauea, one by moonlight, are in the year 1840, taken from the Narrative of the United States Exploring Expedition (Wilkes, 1845). The author quotes Dibble (1843) on the 1790 eruption of Kilauea; he also quotes Stewart (1828), Ellis (1825), Coan (1841), Wilkes (1845), and Bingham (1847), in addition to quoting unpublished letters (authorship unknown) covering activity at Kilauea. He poses, from a philosophical and religious perspective, general questions regarding the nature of volcanic activity. He concludes with an account of earthquakes felt in 1850 and an account of an earthquake swarm in 1838 taken from S.J. Lyman (1859).



Chen, W.-P., and Nabelek, J., 1990, Source parameters of the June 26, 1989 Hawaiian earthquake [abs.]: Eos, Transactions, American Geophysical Union, v. 71, no. 17, p. 562. [AGU-MSA spring meeting, Baltimore, MD, May 29-June 1, 1990, Program and abstracts] 



 The June 26, 1989 Hawaiian earthquake (Mo ~4x1018 Nm) occurred beneath the East Rift zone along the southern flank of the Kilauea Volcano, in the epicentral region of the 1975 Kalapana sequence (main shock's Mo ~2x1020 Nm). We determined the source parameters of the main shock of the 1989 sequence by inverting teleseismic P and SH waves recorded at teleseismic distances and compared our results with those of four other large evens that occurred beneath the Island of Hawaii: the 1973 event (Mo ~5X1018 Nm) east of the Mauna Kea volcano, the foreshock and main shock of the 1975 Kalapana sequence, and the 1983 Kaoiki event (Mo ~1x1019 Nm) between the Mauna Loa and the Kilauea volcano.

 Both the mechanism (strike = 53, dip = 82, rake = 104) and focal depth (13 km) of the 1989 event are similar to those of the foreshock and main shock of the 1975 sequence, Unlike the long (~60 s), smoothly varying source time function of the 1975 main shock, however, the 1989 event is only about 10 s long, with two distinct bursts of moment release about 8 s apart. It follows that if one were to view the 1989 event as a landslide (single force model of Eissler and Kamamori [JGR, 1987]), the sliding block must have undergone two rapid cycles of acceleration-deceleration

 The two Kalapana sequences and the Kaoiki sequence all occurred in a region of high background seismicity, southeast of the summit of the Mauna Loa. In addition, the four largest events of these three sequences occurred at a depth of approximately 10 km, and their mechanisms consistently show thrust faulting with a steeply dipping nodal plane striking northeasterly and a nearly horizontal nodal plane (presumably the fault plane based on aftershock distributions) dipping northwesterly. The 1973 event near Mauna Kea, on the other hand occurred away from the region of high seismicity near Mauna Loa and Kilauea and has a large focal depth (~40-50 km) and an oblique strike-slip faulting mechanism. Thus it appears that approximately 10 km beneath the southeastern flanks of Mauna Loa and Kilauea, there exists a major detachment surface, whereas the Hilo event might reflect an intraplate stress field



Chiu, A.N., Lum, W.B., Nielsen, N.N., and Koyanagi, R., 1984, Damage survey of the Kaoiki, Hawaii earthquake of November 16, 1983: Earthquake Spectra, v. 1, no. 1, p. 173-195. 



 "An earthquake, magnitude 6.6 on the Richter scale, occurred on November 16, 1983, 6:13 a.m. on the island of Hawaii. The epicenter was about 50 kilometers (30 miles) southwest of the town of Hilo with a depth of about 12 kilometers. Figure I shows the location of the epicenter of the quake.

 Following the Kaoiki Earthquake of November 16, 1983, the Earthquake Engineering Research Institute and the American Society of Civil Engineers appointed a task committee to survey the damage from the quake.

 The purpose of the report is to document representative damage from the earthquake and to offer constructive suggestions to mitigate future damage from similar quakes."



Christiansen, R.L., 1974, Volcanology: Geotimes, v. 19, no. 1, p. 33. 



 A long-continued eruption at Kilauea, on the Island of Hawaii, underwent major changes. Activity at a lava lake in Mauna Ulu, a 41/2-year-old satellitic shield on the east rift zone, was stable through most of 1972 and early 1973. Then in May, shortly after a magnitude-6.2 earthquake rocked the island, a short-lived eruption broke out up-rift in an area previously untouched by lava in human history. For the rest of the year episodes of summit deflation, draining of the lava lake, surface faulting, and up-rift fountaining alternated with re-inflation of the Kilauea summit area and intermittent lava-lake activity at Mauna Ulu.



Clague, D.A., and Denlinger, R.P., 1993, The M7.9 1868 earthquake: Hawaii's active landslides [abs.]: Eos, Transactions, American Geophysical Union supp., v. 74, no. 43, p. 635. [AGU fall meeting, San Francisco, CA, Dec. 6-10, 1993, Program and abstracts] 



 On April 2, 1868, a great earthquake with an estimated M7.9 struck the island of Hawaii. Recently acquired bathymetric data and recognition of the important role of enormous landslides in shaping the Hawaiian Islands provide a new framework to reinterpret the 1868 earthquake.

 At about dawn on March 27, an eruption began at the summit of Mauna Loa and migrated down the southwest rift zone. The eruption was accompanied by numerous felt earthquakes that increased in frequency and strength as the eruptive fissures extended downrift. Seismic activity increased until March 28 at 13:28, when an M7.0 earthquake occurred near Kahuku on the southwest rift zone. Ground cracks west of Waiohinu offset the road, apparently as a result of this earthquake. The voluminous 1868 flank eruption began on April 7 near the epicenter of the M7.0 earthquake.

 Analysis of the offshore bathymetry supports an interpretation that the epicenters until April I are on a landslide block on the southeast flank of Mauna Loa. This Punaluu landslide is bounded by the southwest rift zone of Mauna Loa on the upslope side, the western edge of the Kaoiki fault zone on the northeast side, and a fault zone extending to the southeast from the bend in the southwest rift (near Kahuku) on the southwest side. Offshore, the Punaluu landslide is located south of Loihi Seamount.

 The M7.9 earthquake that occurred 5 days after the M7.0 earthquake could have been a triggered event. Ground cracks mapped on Kilauea in 1868 indicate that the large landslide comprising the entire south flank of Kilauea moved seaward during the M7.9 event. These ground cracks paralleled the southwest rift zone on Kilauea and then turned seaward near the end of the southwest rift. Wyss and Koyanagi concluded that the epicenter was located near Pahala. We propose that the epicenter was located to the east of their postulated site, near the western end of the southwest rift zone of Kilauea, and that the entire south flank of Kilauea slipped seaward during this event. This Hilina landslide is defined on land by seismicity and ground deformation and offshore by a large bench with closed basins.

 Our interpretation differs from that of Wyss and Koyanagi who proposed that a single landslide block slid during the entire sequence of earthquakes. The mobile block they propose was bounded by the southwest and northeast rift zones of Mauna Loa the eastern edge of the Kaoiki fault zone between Mauna Loa and Kilauea, and by the east rift zone of Kilauea. The two landslides we propose, one on Mauna Loa and one on Kilauea, surround Loihi Seamount. These two landslides were probably contiguous before Loihi Seamount grew on the flank of Mauna Loa and disrupted it.

The Hilina and Punaluu landslides are not the only active landslides in Hawaii. The Kealakekua landslide, similar in scale to the Punaluu landslide but located on the west flank of Mauna Loa just south of Kealakekua Bay, was last active in 1951 and 1952 when M6.9 and M6.0 earthquakes occurred there.



Clark, E.W., 1829, [no title], in Missionary Letters, 8 v: Honolulu, HI, Hawaiian Mission Children's Society, v. 3, p. 762-766. [Letter to Henry Hill dated June 20, 1829] 



 . . . . We found the volcano in greater action than when I was there in Feb. . . . Mr. G [Joseph Goodrich] confirms the opinion of Mr. Chamberlain respecting the depth of the crater. He says the whole bottom of the crater has assumed a new appearance since he was here before. It is but a short distance now from the black ledge to the bottom. It is evident the crater must in time overflow its banks, unless a subterranean outlet shall be found for the lava.



Clarke, F.L., 1887, The lava flow: Pacific Commercial Advertiser, 02/14, p. 2. [Excerpted in American Journal of Science, 3rd ser., v. 33, p. 310- 311] 



 Having finished his observations around Kilauea, Mr. Clarke left for Hilea, Kau, stopping on the way at points where the effects of the earthquakes which preceded and accompanied the flow had been most sensibly felt. At the old Reed and Richardson Ranch, now the residence of Julian Monsarrat, the shocks had been alarmingly severe, and of the same nature, apparently, as those which produced the great mud flow in this locality in 1868. The principal shocks seemed to be from the interior of the mountain, with no rolling or undulating motion, but rather as severe blows directed outward. The effect produced was to throw down all the stone walls built along the side of the mountain, and running N.E. and S.W. There are a number of light wooden buildings standing within an area of perhaps five acres, and all of these, together with the main dwelling were pushed as it were, eight or ten inches down hill, i.e. toward the S.E. by the shocks. A great many pieces of crockery and other articles on shelves on the N.W. side of the house were thrown down, and other evidences left of the peculiar character of the shocks. Some water pipes three miles up the mountain were broken and other damage done.

 At Pahala Mill, a few miles further on, and nearer the sea, but little damage was done. A large water tank was dislodged from its foundation, falling toward the west. One of the boilers was loosened from its settings and some steam connections broken. But little damage was done to the stone walls, those that were tumbled down falling to the west. Mr. Foster, the manager, reported that two of the springs, high up in the mountains, which formerly supplied parts of the flume system of the plantation, had disappeared since the earthquakes. At Punaluu no damage to speak of was done, while at Hilea--a few miles further on and a little further back from the sea beach--the shocks were much more numerous and violent.

 [The rest of the artiicle describes Clarke's visit to the 1887 flow and vent area]



Coan, T., 1852, [no title]: The Polynesian, v. 8, no. 47, 04/03, p. 1. 



 Coan describes a trip on Feb. 23-27 to view the active 1852 lava flow. He describes the many sounds emanating from the lava as it is flowing and cooling. He visited the source vent, but could get no closer than 40 yards to windward and estimates that it would not have been safe to come within two miles on the leeward side. He estimates the rate of flow from the base of the source cone as being perhaps 10 miles per hour.



Coan, T., 1868, [On the earthquakes and eruption of 1868]: American Journal of Science, 2nd ser., v. 46, p. 106-109. 



 An account of the catastrophic earthquakes from March 27 to April 2, 1868, in the southern part of Hawaii, and of the accompanying tsunamis and the eruptions of Mauna Loa and Kilauea. Coan quotes J.D. Paris, who indicated that Mauna Loa activity began on the 27th and ended on the 28th, and extended from the summit halfway down the southwest rift zone. He also quotes F.S. Lyman (1868a, b), who theorizes that the tsunami was precipated by a submarine eruption. This paper is preceded by Dana (1868) and is followed by F.S. Lyman (1868a) and Whitney (1868b). [Some errors of fact in this article are corrected in a footnote to a subsequent article {T. Coan, 1869}.]



Coan, T., 1868, The greatest volcano in the world: Harper's New Monthly Magazine, v. 37, Sept., p. 553-559. 



 The author briefly mentions the Hawaiian Chain and describes the island of Hawaii and its volcanoes. He gives a popular account of a trip to Kilauea caldera and Halemaumau lava lake and a detailed description of overflow from Halemaumau [date unspecified]. He briefly mentions Mauna Loa activity and summarizes the 1868 eruption; descriptions of the earthquakes, landslide, and tsunami are mainly quoted from T. Coan (1868a, c). The author concludes by recounting some of the legends about Pele.

 

Coan, T., 1868, The great volcanic eruption: Missionary Herald, July, p. 219-221. 



 Coan gives an account of the 1868 earthquake swarm and mudflow and the destruction they caused. He briefly mentions the summit eruption of Mauna Loa on March 28, which lasted for one day, and notes that the southwest rift eruption of Mauna Loa occurred after the big earthquake on April 2 and before April 9. He also notes that lava in Kilauea caldera raged with intense fury and that an eruption broke out in Kilauea Iki before April 2. After April 2, activity at Kilauea summit ceased, following a collapse of several hundred feet.

 

Coan, T., 1869, Notes on the recent volcanic disturbances of Hawaii: American Journal of Science, 2nd ser., v. 47, p. 89-98. 



 Coan describes the seismic disturbances and eruptions of 1868, including a thorough description of damage done by the earthquake of April 2, 1868. Aftershocks were still being recorded at the time the article was submitted. He reports that much of the southern shore subsided in response to the earthquake, from 4-6 ft at Kalapana to as much as 7 ft at Keauhou. Sea waves up to 20 ft high were measured, and a landslide was triggered in Wood Valley. Coan reconstructs the course of the landslide and infers its mechanism, concluding that it was cold, only moderately lubricated by water, and driven by gravity alone following the initial separation caused by the earthquake. [This is consistent with modern observation of earthquake-induced debris flows.] The author describes Kilauea caldera in August 1868 as containing a black ledge 100-600 ft wide, within which the previous central plateau had sagged gently down to a depth of 300 ft. Halemaumau was a pit 3,000 ft across and 500 ft deep, situated within the black ledge. No molten lava was visible. He gives an accurate description of five small patches of 1868 lava on Kilauea's southwest rift. [This account was overlooked by later workers, and the 1868 lava was mismapped until the classic work of Stearns and Clark {1930}.] He gives a good description of the 1868 Mauna Loa southwest rift eruption, comparing it to the entry of the 1840 Kilauea flow into the sea at Nanawale Bay. He disputes Brigham's (1868b) map, which shows the 1859 lava flow as larger than that of 1855. He describes a peculiar and unexplained rise and fall of sea 3-6 ft every 15 min on August 14-16. [This paper is a more complete and careful interpretation of events reported in earlier references by Coan {1868a-d.]



Coan, T., 1870, The volcano of Kilauea, and great earthquake waves: American Journal of Science, 2nd ser., v. 49, p. 269-271. 



 The author describes Kilauea caldera in 1869 and the 30-ft sea wave (distant earthquake) which struck Hilo and Kalapana on July 25 of that year. The central area of Kilauea caldera was an immense pit, below a black ledge. The crust had subsided 400 or 500 ft as one piece, leaving plants still growing upon it. [Although not stated explicitly, this must refer to the 1868 collapse.] He reviews the 1868 earthquake damage, confirming that the Puna coast settled 6-8 ft, and that aftershocks were still being felt in 1869.



Coan, L.B., 1884, Titus Coan: a memorial: Chicago, Fleming H. Revell, 248 p. [Pages 65-67, 75-85, 99, 117-120, 138, 157-159, 218-219 cover the material abstracted] 



 This memorial, assembled by Titus Coan's second wife, includes both letters written by Coan and testimonials to Coan from his friends and colleagues. Coan's letters briefly mention the Mauna Loa eruptions of 1849, 1855-1856, 1859, and 1877. He describes the effects of the great earthquake of April 1868, and the tsunami of May 1877. He also recounts a visit on foot to the vents of the 1855 eruption on Mauna Loa's northeast rift zone and describes Kilauea caldera in 1866, noting how much lava had been added since 1840. In response to a request from J.D. Dana, Coan looked for, but did not find, elevated coral-reef rock around the shores of Hawaii island. Among the many testimonials to Coan, W.D. Alexander best acknowledges Coan's ability as a scientist: "Although he had not enjoyed any special scientific training, and made no pretensions to the character of a professional geologist, he was a good observer of sound judgement. . . . To him Geology is indebted for a continuous record of the Hawaiian volcanoes for more than forty years. . . . No history of the two volcanoes of Mauna Loa and Kilauea can be written which will not be largely based on Mr. Coan's writings."



Coffman, J.L., and von Hake, C.A., 1975, Hawaiian Islands, in United States Earthquakes, 1973: Washington, DC, U.S. Government Printing Office, U.S. Environmental Data Service report, p. 44-52. [Published jointly by the U.S. Department of Commerce, National Oceanic and Atmospheric Administration (NOAA) and Department of the Interior, U.S. Geological Survey (USGS).] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Coffman, J.L., and Stover, C.W., 1976, Hawaiian Islands, in United States Earthquakes, 1974: Washington, DC, U.S. Government Printing Office, U.S. Environmental Data Service report, p. 74-77. [Published jointly by the U.S. Department of Commerce, National Oceanic and Atmospheric Administration (NOAA) and Department of the Interior, U.S. Geological Survey (USGS). The same data were published quarterly in U.S. Geological Survey Circular 723A-D by Simon, R.B., Stover, C.W., and Person, W.J., 1976.] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Coffman, J.L., and Stover, C.W., 1977, Hawaiian Islands, in United States Earthquakes, 1975: Washington, DC, U.S. Government Printing Office, United States Environmental Data Service report, p. 54-61. [Published jointly by the U.S. Department of Commerce, National Oceanic and Atmospheric Administration (NOAA) and U.S. Department of the Interior, Geological Survey (USGS). The same data were published quarterly in U.S. Geological Survey Circular 749A-D (authorship divided among Simon, R.B., Stover, C.W., Minsch, J. H., and Person, W.J., 1977).] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Coffman, J.L., von Hake, C.A., and Stover, C.W., ed(s)., 1982, Earthquake history of the United States: Boulder, CO, U.S. Department of Commerce; U.S. Department of the Interior, Geological Survey, 208 p.; 50 p. supplement (1971-1980). 



 A listing of significant Hawaiian earthquakes is given on p. 121-126 (through 1970) and p. 28a-31a (1971-1980). Keyworded earthquakes are those with intensity V or greater.



Cooper, P., 1987, Loihi Seamount microseismicity [abs.]: Eos, Transactions, American Geophysical Union, v. 68, no. 44, p. 1553. [AGU fall meeting, San Francisco, CA, Dec. 6-11, 1987, Program and abstracts] 



 An array of five 3-component ocean bottom seismometers monitored earthquake swarm activity at Loihi Seamount during the time period Oct. 1-31, 1986. A preliminary analysis of the first 8 days' recording shows nearly continuous seismic activity at the summit - occasionally up to 1-3 events per minute - for the first 3 days, with activity tapering off during the next 5 days. Both deep and shallow events are observed during this active phase. Earthquake activity on the flanks is at a much lower level relative to the summit, with events occurring at a rate of up to 10-20 per hour during the first 3 days of peak activity. Many of the large Loihi events were recorded by the HVO land-based array, as well. Preliminary locations place most of the seismicity at or near active hydrothermal vents. Flank events may be associated with mass wasting of the volcanic edifice. The lack of flow structures on the upper flanks (based on SeaMARC II side-scan mosaics) together with the proximity of most of the seismicity to known hydrothermal vents suggests that the earthquakes are not associated with an extrusive event. Analysis of these data continues; preliminary locations for the full data set will be presented.



Cooper, P., and Duennebier, F., 1988, OBS monitoring of Loihi Seamount microseismicity [abs.]: Eos, Transactions, American Geophysical Union, v. 69, no. 44, p. 1320. [AGU fall meeting, San Francisco, CA, Dec. 6-11, 1988, Program and abstracts] 



 Loihi is a juvenile intraplate submarine volcano that may prove to be a window into the past activity and morphostructural history of intraplate volcanoes of the Hawaiian type. Monitoring of a recent earthquake swarm at Loihi Seamount began Oct. 1, 1986, when an array of five 3-component ocean bottom seismometers was indtalled on the summit and flanks of the seamount. Activity was continuously monitored for 28 days. Allhough activity tapered off dramatically after Oct. 11 we obtained over 120 well located events Most of the events were located along the summit of the elongate edifice. No shallow tremor was observed despite a systematic search through the data. Several earthquakes along the sleep flanks have genarated rockfalls which were recorded on the OBSs. This is consistent wilh the results of dredge and bottom photography data indicating that the flanks are covered with fragments of broken pillows and flows. Intact flows have been observed near the base of the volcano usually near tha deep portion of the soulh rift zone: few evenls were situated in this region.

 An additional facet to this experiment was the recording of several Kilauea events by both the Loihi and Hawaii Volcano Observatory (HVO) arrays These events, together wllh Loihi events recorded by HVO were relocated using a joint hypocentral determination technique yielding better than usual depth resolution. Therefore, in addition to valuable data pertaining to magma transport and edifice building at Loihi itself, permanent monitoring of Loihi Seamount would enable better resolulion of both southflank and Loihi Seamounl seismicity.

 This experiment although limited in time extent has shown us that (1) Loihi seismicity is sufficient to warrant permanent monitoring and (2) HVO station corrections for a comhined HVO/Loihi array would yield better depth control for all south flank events.



Cox, D.C., 1980, Source of the tsunami associated with the Kalapana (Hawaii) earthquake of November 1975: Hawaii Institute of Geophysics, HIG-80-8, Dec., 46 p. 



 The travel times of the tsunami generated on 29 November 1975 off the Kau-Puna coast of Hawaii to the tide gages at Hilo, Kahului, Honolulu, and Nawiliwili have been calculated from the arrival times indicated on the tide-gage records, applying gage-time corrections, assuming that the tsunami was generated at the time of the earthquake it accompanied. Travel times have also been calculated similarly to other places on the coast of Hawaii where arrival times of the tsunami were reported, and to Johnston Atoll. Inverse tsunami refraction diagrams have been constructed by graphical means for the path of the tsunami between the vicinity of its source and the places of known arrival times.

 The isochrones of the refraction diagrams corresponding to the respective calculated travel times for the tsunami front have been used to define the boundary of the area of upward seafloor displacement from which the tsunami propagated. This area is about 15 or 20 miles long (parallel to the southeast coast of Hawaii) and on the order of 14 or 15 miles wide, considerably smaller than the area earlier considered the tsunami source. Coastal subsidence measured soon after the earthquake indicates that the area of initial upward displacement was separated from the coast by a narrow belt of downward displacement.

 Comparisons between the crest arrival times and the travel times indicated by the inverse infraction diagrams indicate a lag of about four minutes between the time of the earthquake and the accomplishment of the maximum upward displacement. Accuracies of estimation are insufficient to determine whether the maximum upward displacement occurred within the area of initial displacement or seaward of it within a distance of about 15 miles.

 Displacement resulting from a mega-landslide cannot be distinguished from strictly tectonic displacement by the comparison of arrival times and travel times.



Cox, D.C., 1985, Approximate relationship of intensity to magnitude and hypocentral distance for Hawaiian earthquakes: Honolulu, University of Hawaii Environmental Center, 23 p. 



 Formulas relating the intensities of earthquakes to various functions of distances from the sources of the earthquakes and of their source strengths, tested by Howell and Schultz for earthquakes in the contiguous United States, are combined and modified to produce a formula relating the intensity of an earthquake in a continuous-valued equivalent of the Modified Mercalli scale to the magnitude of the earthquake and its hypocentral distance:

 

 ln (I'-0.5) = ln (M-1) + a - b ln r - cr



 where I' = continuous-valued intensity such that

 I' - 0.5  I  I' + 0.5

 

 I = conventional (integer valued) MM intensity,

		M = Richter magnitude,

		 r = hypocentral distance.



By applying the formula to selected records of Hawaiian earthquakes, the coefficients in it have been assigned the following values:

		 a = 0.877

		 b = 0.144 per ln km.

		 c = 0.00053 per km.



Recommendations are made for more thorough investigation of the relation between intensity to magnitude and hypocentral distance for Hawaiian earthquakes.



Cox, D.C., 1985, The Lanai earthquake of February 1871: Honolulu, University of Hawaii Environmental Center, 50 p. 



 From an extensive compilation of the reported effects of the large Hawaiian earthquake of February 1871, it is concluded that the earthquake occurred at 22:11 on 19 February Honolulu local time (08:42.5 on 20 February Greenwich time); that its epicenter was probably south of Lanai within 60 km of 20.8 N, 157.0 W; and that it had a Richter magnitude of 7.0  0.5. Considering its probable epicentral location, it seems appropriately referred to as the Lanai earthquake.

 Probable average intensities of the earthquake on the Modified Mercalli scale are estimated at IX on Lanai, VII to IX on East Molokai, XI to VIII on Maui; IV to VI on Hawaii; VI to VII on Oahu; V on Kauai; and IV on Niihau



Cox, D.C., 1986, The Oahu earthquake of June 1948, associated shocks, and the hypothetical Diamond Head fault: Honolulu, University of Hawaii Environmental Center, 32 p. 



 Contemporary and later reports on the Hawaiian earthquakes of late June 1948 indicate that the most significant earthquake of the period occurred at 10:41 (HST, equivalent to 11:41 GMT) on 28 June. The highest intensities of this earthquake were on Oahu--those at Honolulu averaging VI on the modified Mercalli scale and reaching VII on Tantalus and in Iwilei. Its intensity distribution suggests that the earthquake had a Richter magnitude of 4.80.5, an epicenter within 50 km of 21.2 N, 157.90 W (just offshore from Honolulu), and a focal depth of less than 20 km and probably only about 5 km. Considering its intensity distribution and probable epicentral location, it is appropriately identified as the Oahu earthquake of 1948.

 The earthquake may have been preceded by an unfelt foreshock at about 01:33 and followed by an aftershock felt in Honolulu at about 01.51. A quake felt on Oahu at 19:32 on 17 January 1948 may have been an additional foreshock.

 The estimated epicenter of the principal shock falls on the trend of the hypothetical Diamond Head fault, whose existence was originally suggested on the basis of the alignment of seven earthquakes occurring during the period from 1962 through 1977. Two more earthquakes occurring in 1981 had epicenters on the fault line; and two occurring in 1976 probably did. As many as 31 earthquakes felt on Oahu in the period from 1859 through 1983, including the June 1948 earthquake and its possible January foreshock and June aftershock, originated, or night have originated, on the hypothetical fault.

 Although there is clearly a preferential distribution of earthquake epicenters along the hypothetical fault zone, the preference is no greater than that along some other zones in the general area that have not been identified as faults; there is no other geological or geophysical evidence of the existence of the fault, and only very slight bathymetric evidence. Neither the frequency distribution or the magnitudes of the earthquakes that originated or might have originated on the trend of the hypothetical fault nor the frequency distribution of the Honolulu intensities of those earthquakes suggest the existence of a seismic gap along that trend.

 

 CONTENTS

 

Introduction

 Impetus to study	1

 Sources of Information an the 1948 earthquake	1

 Earthquake intensities	2

 Places	2

Background information on the 1948 earthquake and associated

 shocks	5

 Number, dates, and times of shocks	5

 Shocks of 26-28 June	5

 Possible foreshock of 17 January	5

 Estimated epicentral and Oahu intensity of principal shock	5

Effects of the 1948 earthquake and associated shocks	8

 Possible January foreshock	8

 Principal shock	9

 In Honolulu	9

 Elsewhere on Oahu	10

 On other islands	10

 Aftershock	10

Estimated intensities of the 1948 earthquake and associated

 shocks	13

 January foreshock	13

 Principal shock	13

 In Honolulu	13

 Elsewhere on Oahu	13

 On other islands	13

 Aftershock	14

 Summary	14

Intensity distribution and source of the 1948 earthquake	15

The hypothetical Diamond Head fault	17

 Earthquakes originating or possibly originating along the fault	17

 Critique of evidences for the existence of the fault	17

 Seismological evidence	17

 Other geophysical, geological, and bathymetric evidence	21

 Summary	24

 Frequency distributions of earthquakes originating along the possible fault	24

 Frequency distribution of magnitudes	24

 Frequency distribution of Honolulu intensities	27

Acknowledgments	29

References	31



Cox, D.C., 1986, Earthquakes felt on Oahu, Hawaii and their intensities: Honolulu, University of Hawaii Environmental Center, 120 p. 



 Evidences have been found, mainly in newspaper accounts, confirming the non-instrumental observation on Oahu of 113 natural earthquakes out of a total of 139 events occurring from 1859 through 1983 that have been reported as if earthquakes felt on the island. Modified Mercalli (MM) intensities at Honolulu have been estimated for the 113 earthquakes from observations of their effects, and the intensities at one or more other places on Oahu have been estimated similarly for 40 of the quakes.

 Descriptions of the Oahu effects of the 113 natural felt earthquakes and their intensities in both the conventional discrete-valued MM scale and a continuous-scale equivalent are presented in this report.

 The dates and sources of and the intensities estimated for earthquakes with Honolulu intensities equal to or greater than the middle part of the range of MMV are:

 	Date Source	 Intensity



	1861 Dec 5 Molokai-Lanai vic. (?)	 V

	1871 Feb 19 South coast of Lanai	 Between VI and VII

	1895 Dec 8 Oahu (?)	 V

	1929 Oct 5 West of Hawaii	 V

	1938 Jan 22 North of Maui	 Between V and VI

	1948 Jan 28 South coast of Oahu	 VI

	1973 Apr 26 Hamakua coast, Hawaii	 V

	1981 Mar 5 Kalohi Channel	 V



Crosson, R.S., and Endo, E.T., 1980, The effect of structure models on focal mechanisms of earthquakes related to the November 29, 1975 Kalapana, Hawaii earthquake [abs.]: Eos, Transactions, American Geophysical Union, v. 61, no. 10, p. 109. [AGU fall meeting, San Francisco, CA, Dec. 3-7, 1979, late abstract] 



 Initial focal mechanism determinations for the November 29, 1975 Kalapana, Hawaii earthquake indicated discrepancy between the mechanism determined from teleseismic data by Ando and the mechanism determined using data from the local USGS network surrounding the epicenter region. The resolution of this difference is crucial to correct understanding of this earthquake as well as understanding of the tectonics in general of the south flank of Kilauea Volcano. The discrepancy vanishes when a model with a low velocity layer (LVL) at the base of the crust is used for projection back to the focal sphere in deriving the local network mechanisms. To further investigate this result, focal mechanisms were determined for a number of well recorded, felt earthquakes in 1974 using several contrasting models. A large number of these 1974 earthquakes have mechanisms nearly identical to that of the main shock when the LVL model is used. Dispersion of P and T axes is also minimized for events throughout the south flank of Kilauea when the LVL model is used. The low angle slip direction, favored for the main shock, exhibits remarkable stability normal to the east rift zone of Kilauea. The existence of a LVL at the base of the crust is indirectly supported by these results and the general nature of Ando's proposed mechanism for the main shock and model for south flank tectonics is also supported.



Crosson, R.S., and Endo, E.T., 1981, Focal mechanisms of earthquakes related to the 29 November 1975 Kalapana, Hawaii, earthquakes: the effect of structure models: Bulletin of the Seismological Society of America, v. 71, no. 3, p. 713-729. 



 Initial focal mechanism determinations for the 29 November 1975 Kalapana, Hawaii, earthquake indicated discrepancy between the mechanism determined from teleseismic data by Ando and the mechanism determined using data from the local U.S. Geological Survey network surrounding the epicenter region. The resolution of this difference is crucial to correctly understand this earthquake, as well as to understand the tectonics of the south flank of Kilauea volcano. When a model with a low-velocity layer at the base of the crust is used for projection back to the focal sphere for the local network mechanisms, the discrepancy vanishes. To further investigate this result, focal mechanisms were determined using several contrasting models for a set of well-recorded earthquakes. A large number of these earthquakes have mechanisms identical to the main shock when the low-velocity layer model is used. Dispersion of P and T axes is also minimized by use of this model. A low-angle slip direction, favored for the main shock and typical of most other solutions, exhibits remarkable stability normal to the east rift zone of Kilauea. Our results suggest a tectonic model, similar in nature to that proposed by Ando, in which the south flank of Kilauea consists of a mobile block of crust which is relatively free to move laterally on a low-strength zone at about 10 km depth. Forceful injection of magma along the rift zones provides the loading stress which is released by catastrophic failure in the weak, horizontal layer in a cycle of perhaps 100 yr.



Crosson, R.S., and Endo, E.T., 1982, Focal mechanisms and locations of earthquakes in the vicinity of the 1975 Kalapana earthquake aftershock zone 1970-1979: implications for tectonics of the south flank of Kilauea Volcano, Island of Hawaii: Tectonics, v. 1, p. 495-542. 



 The November 29, 1975 Kalapana earthquake of magnitude 7.1 on the south flank of Kilauea Volcano, Hawaii, represents a major rift tectonic event. It is generally understood that the earthquake resulted from movement on a nearly horizontal fault plane, with the crustal block south of Kilauea's east rift zone moving south southeastward up to several meters. Well-recorded earthquakes on the south flank of Kilauea from 1970 to 1979 were analyzed and focal mechanisms determined to obtain a better understanding of the details of south flank tectonics. Included are a large number of earthquakes from the aftershock sequence of the 1975 earthquake. Hypocenters are distributed in a sub-planar zone that dips 2 to 3 to the west at a depth of about 8-9 km depth. We interpret this pattern to coincide with a portion of the slip plane of the Kalapana earthquake and to be consistent with the notion of the slip plane occurring in a weak layer at the top of the old oceanic crust. Focal mechanisms are remarkably constant throughout this time period, both before and after the 1975 event, and closely agree with the mainshock mechanism. P axis azimuths and slip vectors for the low-angle fault planes are normal to the middle and lower east rift zones of Kilauea. There is suggestion of a change in the orientation of P axes from shallower to steeper plunge at the time of the Kalapana earthquake. Such a change is consistent with a general reduction in the horizontal compressional stress normal to the rift zone at the time of the large earthquake. No other evidence of precursory reorientation of the stress field was found and the precise predictability of this event remains in doubt. However, a general model of the tectonics of the volcanic rift system is now available that satisfies a number of geological and geophysical observations.



Crosson, R.S., and Endo, E.T., 1985, Focal mechanism and locations of earthquakes in the vicinity of the 1975 Kalapana earthquake aftershock zone 1970-1979: implications for tectonics of the south flank of Kilauea Volcano, Island of Hawaii [Crosson and Endo, 1982]; reply to Udias and Buforn (1984): Tectonics, v. 4, no. 2, p. 247-250. 



 We appreciate the comments of Udias and Buforn [this issue]. The situation was changing rapidly at the time our paper was written, and our remarks reflected our perception of the status at that time rather than the one today. If we were starting this project now, no doubt we would attempt to utilize automated analysis. Clearly, Udias and Buforn and their colleagues have made significant progress in the difficult task of automated statistical analysis of focal mechanism data. It would, of course, be quite useful to apply their programs to the Kalapana earthquake data set, but this effort is a large undertaking and will perforce be the subject of future work.

 We wish to emphasize that no analysis program will provide results that are better than the data that are fed to it, and it is always necessary carefully to monitor data quality and possible interactions between assumptions and data. In the case of focal mechanisms, we were able to do this quite effectively for the hand constructed solutions which we used in our paper. For example, focal mechanism results may be highly dependent on the structure model used (the structure model is an assumption), and naturally, any focal mechanism fitting program may produce incorrect results if the model assumption is in error. In the case of the Hawaii data, we pointed out [Crosson and Endo, 1981] some of the difficulties associated with the possible existence of a low velocity channel beneath the Island. This experience guided us in the main analysis, and we encountered many cases where careful judgment allowed us to satisfactorily interpret initially rather inconsistent polarity distributions. Certainly, for large quantities of data such as we were dealing with, automated procedures should now provide more efficient, consistent and, hopefully, satisfactory analysis of the data.



Cuff, K.E., and Thomas, D.M., 1985, Soil gas radon changes at Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 66, no. 18, p. 417. [AGU spring meeting, Baltimore, MD, May 27-29, 1985, Program and abstracts] 



 The results of a five-year study of radon activities in soil gas at Kilauea volcano have shown that substantial changes in soil gas radon activities are associated with both tectonic and volcanic events. Long-term changes in the focus of eruptive and intrusive activity on the Kilauea shield were accompanied by statistically significant (at >99% confidence level) changes in both the magnitude and variability of soil gas radon concentrations. Changes in radon levels were also observed at least three weeks prior to one major earthquake of m = 6.6 and several minor events were preceded by radon variations several weeks prior to the earthquakes. A major magmatic intrusion generated substantial changes in radon activities at eight of nine monitoring stations at distances of up to 35 km from the intrusion. The observed changes in radon activity for the major events showed a decline in magnitude with increasing distance between the events and the monitoring location and were significantly affected by major structural features. The results obtained from this study suggest that the observed changes in radon activity in soil gases result from the stress induced release of radon gas from subsurface rocks.



Dana, J.D., 1887, Eruption of Mauna Loa, Hawaii, in January: American Journal of Science, 3rd ser., v. 33, p. 310-311. 



 Dana describes the early stages of the eruption of Mauna Loa in 1887 and the earthquake swarm preceding it, quoting from contemporary Honolulu newspaper accounts. The earthquake swarm began in December 1886. The initial outbreak on January 16 at Mauna Loa summit died within a few hours. The earthquake swarm increased in intensity just before 7:00 a.m. [p.m. in other accounts], January 18, when a flank eruption broke out at an elevation of 6,500 ft. 

 "On the 23d, earthquakes began again and continued through the 24th. They were heavy enough at Kahuku to throw over walls and destroy or move some houses. Damage was also done at other places and to some extent at Hilo, where a heavy shock was felt near noon on the 23d and many others, but lighter, on that day and the next.

 The oscillations at Hilo are stated to have been from S.S.E. to N.N.W. According to Mr. F.L. Clarke, of the Government Survey, the walls that fell in Kau had a northeast and southwest direction and were thrown to the southeast, and the houses (light wooden buildings) were moved 8 to 10 inches in the same direction or down the slopes."



Dana, J.D., 1888, History of the changes in the Mt. Loa craters, on Hawaii: American Journal of Science, 3rd ser., v. 35, p. 15-34, 213-228, 282-289 [includes maps]; v. 36, p. 14-32, 81-112, 167-175 [includes maps]. 



 This series of articles continues Dana's observations on Kilauea, followed by his observations on Mauna Loa, and concludes with a summary of his ideas regarding volcanic action in Hawaii. Dana estimates the mean rise of Kilauea crater floor as 10-100 ft/yr. He provides a summary cross section showing the filling of Kilauea caldera. He provides a careful and critical evaluation of earlier maps; the result of his evaluation is a substantial revision of Wilkes' (1845) original map of Kilauea. He also reconciles earlier maps to make a consistent history of filling and collapse. He summarizes the periodicity of discharges, hypothesizing that the earlier collapses were larger, due either to increased strength of the crater fill (making it more resistant to collapse), or to greater force of volcanic action. [Dana favors the latter.] Dana considers normal volcanic action to be a function of fusibility, which he says does not depend on silica content or basicity. He also postulates that more heat is needed to melt rhyolite than is needed to melt basalt. [Dana is incorrect on both counts.] He discusses the origin of central craters in terms of activity over an initial fissure. He holds to his earlier view that H2O is the dominant vapor associated with volcanic eruption and is derived from the atmosphere. He guesses that vesiculation does not occur at depths greater than 200 ft. He describes the origin of Pele's hair and gives a detailed description of thread-lace scoria. He postulates thermal erosion as a means to widen the conduit. Dana follows his section on Kilauea with an equally valuable chronology of Mauna Loa activity between 1832 and 1887. This section is concerned less with volcanic process, presumably because he did not directly observe Mauna Loa activity. Dana concludes this series of articles with the following inferences on the mechanics of volcanic action. 1. Volcanic periodicity is ascribed to seasonal (rainfall) effects, in agreement with Coan. 2. All magmatic vapor is derived from surface water. 3. Earthquakes are not a cause of volcanic activity, but incidental, being the means of opening the volcano so that lava can come out. Dana correctly identifies the 1868 earthquake as a Mauna Loa event; he considers eruption at Kilauea as an accident, triggered only because of the wide area over which the earthquake was felt. Dana notes further that the 1868 earthquake was local to Mauna Loa because of little disturbance on Oahu. [These are insights that stand up to current understanding of Kilauea and Mauna Loa.] Dana raises questions with regard to reconciling flow rates observed in lava tubes compared with those observed at the flow front, and with regard to the formation of underground lava channels. He discusses the origin of aa and its distinction from pahoehoe. He concludes that conditions must be such as to reflect the region being flowed over and to allow simultaneous formation of fluid pahoehoe and pasty aa. The aa stream must have been subjected to deep cooling to make the crust equal to the thickness of the blocks. Cooling of aa must be from the base up, not from the top down, as in pahoehoe. He suggests that aa requires moist ground to satisfy all of the above facts. Dana describes littoral cones as "lateral" cones, inferring [incorrectly] that a primary fissure must exist beneath them analogous to normal cinder/spatter cones. Dana discusses explosive eruptions, comparing Kilauea's 1790 eruption with those of Krakatoa (Indonesia) and Tarawera (New Zealand). He correctly infers that explosive eruptions require that the cooling agent (ground water) gain access to the interior of the magma conduit. He describes the formation of stalactites as a metamorphic process. He explains the shape of Mauna Loa as a consequence of its eruptive style: short summit overflows broaden the summit, and voluminous flank flows broaden the lower slopes. He describes the order of extinction of Hawaiian volcanoes. He describes the "Kea" and "Loa" lines of volcanoes, notes that Kilauea and Mauna Loa lie on separate trends, and concludes from this that Kilauea is later and independent of Mauna Loa. He reiterates his earlier conclusion that volcanoes are not "safety valves," but are places of danger. "The safe place is somewhere else." He compares Vesuvius with Hawaiian volcanoes, finding more similarities than differences, particularly in eruption mechanism. The cycle of Kilauea is repeated as a rise in level of the liquid lava and the bottom of the crater, a discharge of the accumulated lava down to some level in the conduit determined by the elevation of the point of outbreak, and a subsidence of the floor over the region drained by the discharge. He closes with a discussion of volcanic mechanism and the influence of volatiles. The higher lava fountains of Mauna Loa are attributed to greater gas content.

 [These two references stand as a monument to the care with which early observations of Hawaiian volcanoes were made; their contribution to our current understanding of volcanic process is significant. The summary of Kilauea chronology from 1789 to 1887 is particularly good, providing an essential reference to put the many individual visits to Kilauea and Mauna Loa in a single context. Dana provides an essentially objective synthesis of the reported data, adding little interpretation beyond what is warranted by direct observation.]



Davies, 1926, Martinson sees large crater: Honolulu Advertiser, 04/14, p. 1. 



 Hilo, April 13.--A report from Waiohinu that Puu Keokeo is active, with a large crater formed inside, and fire visible at about the 5000-foot level.



Davies, 1926, Latest Mauna lava flow continues active at source; Speed decreases: Honolulu Advertiser, 04/23, p. 1. 



 [subheads: Lava stream halts as it nears road; McWayne losses will mount up should flow continue; Quake precedes volcanic glow; New activity starts half mile beyond 1916 outbreak]

Hilo, April 22--A report that the Mauna Loa eruption was still active at its source.

 "Severe earth tremors were felt in Hilo this morning, while preceding them by an hour unusual glows over the source of the flow were seen. Kau also felt the quakes."



Davies, 1927, Halemaumau lava flow starts: Honolulu Advertiser, 07/07, p. 1. 



 The article recounts the return of lava to Halemaumau.

 "The outbreak was first seen . . . at one o'clock this morning.

 . . . .

 . . . . One earthquake about midnight shook the vicinity of the volcano. also one at Hilo at 3:25 a.m. Both were light. . . .

 The return . . . did not come entirely unexpected as the staff at the volcano observatory were warned early this month by the apparent widening of one of the great cracks found about the pit of Halemaumau.

 This crack which extends about 1500 feet along the edge and about 50 feet back from it, just to the north and east was first noticed about two weeks ago but little attention was paid to it until just a few days ago when it appeared to be considerably larger.



Davies, 1927, Volcano in full eruption: Honolulu Advertiser, 07/08, p. 1, 2. 



 [subheads: Fire pit filling up with streams of lava gushing in from great fountains; Geysers hurl blazing lava 300 feet into air with thousands of spectators celebrating return of Madame Pele to her fiery home]

The article recounts the continuation of the 1927 return of lava to Halemaumau, closing with the following:

 "Honokaa residents reported two of the heaviest earthquakes they have ever experienced between 3 and 4 o'clock this morning."



Davis, A.S., and Clague, D.A., 1998, Changes in the hydrothermal system at Loihi Seamount after the formation of Pele's pit in 1996: Geology, v. 26, no. 5, p. 399-402. 



 Sulfide and sulfate minerals recovered from Loihi Seamount during PISCES V submersible dives in October 1996 are the first occurrence of high-temperature hydrothermal mineralization documented for ocean island volcanoes. Millimeter- to centimeter-sized particles recovered in talus deposits on the north rim of the newly formed Pele's pit consist of aggregates of pyrite, marcasite (?), pyrrhotite, wurtzite, and barite. The barite occurs as single, clear, euhedral crystals or as acicular, radial crystal clusters on sulfide or rock fragments. The mineral assemblage and the composition of the sulfide phases are similar to those of hydrothermal sulfide from mid-ocean spreading centers. The sulfide assemblage confirms the presence of high-temperature fluids (>250C) in the Loihi hydrothermal system. The sulfide samples are not pieces of broken chimney or basal mound structures, or stockwork from lower levels in the hydrothermal system. The euhedral crystals and homogeneous compositions suggest rapid precipitation from a high-temperature plume injected into cold seawater along fractures and fissures that define the north wall of the new pit crater formed during the seismic swarm in July and August 1996.



Dawson, P., Chouet, B., Ohminato, T., and Saccorotti, G., 1997, Wavefield and source properties of a long-period event and tremor episode recorded on January 20, 1996, at Kilauea Volcano, Hawaii [abs.]: Seismological Research Letters, v. 68, no. 2, p. 317. [Seismological Society of America, 92nd annual meeting, Honolulu, HI, Apr. 9-11, 1997 [Abstracts)] 



 We use a combination of dense small-aperture and disperse large-aperture arrays of three-component sensors deployed around the summit caldera of Kilauea Volcano to investigate the wavefield properties of a long-period (LP) event and tremor episode originating beneath the caldera. Measurements of slowness and azimuth as a function of time show waves propagating from a source located beneath the Halemaumau pit at a depth shallower than 2 km, and backscattering waves propagating from a direction opposite the source. The backscattered field is attributed to strong lateral velocity contrasts possibly associated with the ring fracture system surrounding the caldera. Polarization vector directions measured during the first 3 s of the LP event and for the 3 s spanning the maximum event amplitude depict a complicated pattern of body waves suggesting that ground motion is strongly affected by topographic and structural complexities in the vicinity of the caldera. The spectra of the LP event are marked by narrowband peaks that are common to all components and receiver sites, indicating those features represent a source effect. The persistence of the same spectral peaks in the LP event and tremor preceding and following the LP event lends strong support to the hypothesis that the two phenomena share the same source but represent different excitations of this source. This interpretation is further buttressed by the lack of significant changes observed in both ray parameter and azimuth at the onset of the LP event.



De Carlo, E.H., Resing, J.A., Wen, X.Y., and Cowen, J.P., 1996, Rare earth elements in hydrothermally altered water collected over Loihi Seamount during the August 1996 seismic event [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F398. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 Beginning in mid-July 1996 a large swarm of earthquakes was detected from Loihi Seamount, located offshore and to the south east of the island of Hawaii. Several thousand earthquakes, including more than 40 with magnitudes between 4 and 5, were recorded by the Hawaiian Volcano observatory. Highly altered hydrothermal plume samples were recovered during a "rapid response cruise", including submersible dives, conducted August 5-9. Eight hydrocasts recovered water and associated suspended material from the water column overlying and within a collapse pit crater that was previously the locus of Pele's Vents. Fluids within the pit crater are characterized by large temperature anomalies, high suspended particle concentrations, high alkalinities, an absence of O2, elevated CO2, and low pH. Dissolved Mn and Fe concentrations exceeding 5 mM and 100 mM, respectively, were observed in samples collected near 1200 m depth within the pit crater. Suspended particle loads in the same samples reached 250 mg/L, whereas background water column values near Loihi are approximately 0.2 mg/L. The mineralogy of particles suspended in the highly hydrothermally altered water was determined by X-ray diffraction spectrometry. Particles consist of a mixture of amorphous matter, smectite, and primary volcanic minerals.

 We will discuss the distribution and abundance of rare earth elements (REE) in the water column and associated particles from two hydrocasts which sampled the pit crater. REE determinations were carried out by flow injection-inductively coupled plasma mass spectrometery (FIA-ICP-MS) to measure dissolved and particulate REE concentrations. Weak acid leach and total digestion procedures were utilized to help evaluate phase associations of particulate REE.



de Montessus de Ballore, F., 1924, Mauna Loa (Hawai), mars et avril 1868, in La Geologie Sismologique: Paris, Librairie Armand Colin, p. 239-248. 



 The author describes the events of 1868, quoting from others. He comments favorably on H.O. Woods' (1914b) hypothesis that the earthquake of 1868 was a tectonic, rather than a volcanic, event and closes by noting the similiarity of the 1868 earthquake to an earthquake in Achaie on December 28, 1861



de Varigny, C.V., 1873, Voyage aux Iles Sandwich: Paris, Hachette and Co., 350 p. [Originally published as a special issue of the magazine Le Tour du Monde. Translated from the French by Alfons L. Korn. Reprinted in 1981 with an introduction by Korn as Fourteen Years in the Sandwich Islands, 1855-1868, by The University Press of Hawaii and the Hawaiian Historical Society, Honolulu; p. 70-77, 209-241 cover the material abstracted.] 



 This popular account of Hawaii in the 1860s contains many inaccuracies. Kilauea is confused with Mauna Loa in headings; the 1855 and 1859 eruptions of Mauna Loa are combined as one. Dates of journal entries are wrong, the 1859 eruption of Mauna Loa being described under an 1857 date. [The confusion regarding dates is explained in a footnote to an earlier chapter. Apparently, a single date was arbitrarily given to journal entries, even though they cover a long period of time.] The author gives a valuable first-hand description of damage following the earthquake on April 2, 1868.



de vis Norton, L.W., 1916, For science, promotion and the best interests of the Territory; Strong appeal is made for funds to install museum on brink of firepit of Kilauea volcano: Hilo Tribune, 04/18, p. 6. [HVO weekly report is given on p. 7] 



 A letter to the editor in support of the establishment of a volcanological museum on the rim of Kilauea crater. Donations to the Hawaii Volcano Research Association are requested.

 [The museum was established at Uwekahuna bluff, run by the National Park Service, the forerunner to the Jaggar museum built in 1986]



de Vis-Norton, L.W., 1924, Kilauea Volcano during 1924: Hawaiian Annual for 1925, p. 110-112. [See also Pele activities, p. 123-124] 



 The author summarizes conditions at Kilauea during 1924. East rift earthquakes began in the latter half of February, following the draining of Halemaumau lava lake. On April 7, HVO issued a warning of possible earthquakes in Puna, shortly before heavy shocks began in that area. The crisis in Puna was accompanied by subsidence and ground-cracking and was over by April 29. Earthquakes at Kilauea summit began May 6, followed on May 11 by the first explosion accompanying further collapse and enlargement of Halemaumau. The earthquake crisis and explosive activity reached a maximum on May 18 and was essentially over by May 24. The author discusses the difference in seismic signatures between earthquakes accompanying explosions and ordinary earthquakes, and notes that no juvenile material was thrown out during the 1924 collapse. At the end of the activity, Halemaumau had enlarged long and short diameters of 3,400 and 3,000 ft and was 1,330 ft deep. There was a small earthquake swarm on June 8-15. Lava returned to Halemaumau on July 19 and disappeared again on July 31. Mokuaweoweo was inactive during 1924.

 

Decker, R.W., and Decker, B., 1980, Volcano Watching: Hawaii Volcanoes National Park, HI, Hawaii Natural History Association, 80 p. 



 4 PREFACE

7 SECTION ONE HOW VOLCANOES WORK

8 CONTINENTAL DRIFT FORMS VOLCANOES

11 HOT SPOTS

13 FORECASTING VOLCANIC ERUPTIONS

17 TILT!

19 VOLCANOES AND EARTHQUAKES

20 EXPLOSIVE VS. QUIET ERUPTIONS

22 VOLCANOESDEAD OR ALIVE

25 VOLCANIC LANDSCAPES

26 LAVA, ASH AND BOMBS

28 VOLCANOES AND CLIMATE

30 ORIGIN OF THE SEA AND AIR

33 HOW HOT IS LAVA?

35 THE HEAT SOURCE OF VOLCANOES

36 GEOTHERMAL POWER

39 SECTION TWO VOLCANOES IN HAWAII

40 HOW OLD ARE THE HAWAIIAN ISLANDS?

43 LIFE STAGES OF HAWAIIAN VOLCANOES

44 PAHOEHOE AND AA

47 LAVA TUBES

48 IS HAWAII SINKING?

51 GEOTHERMAL POWER IN HAWAII

52 REGROWTH OF PLANTS AFTER VOLCANIC ERUPTIONS

55 MAUNA LOA'S 19TH CENTURY THREAT TO HILO

56 HOW ARE THINGS ON MAUNA LOA?

58 MAUNA KEA'S GLACIER

60 THE KALAPANA EARTHQUAKENOVEMBER 29, 1975

63 TODAY AT THE VOLCANO OBSERVATORY

64 SECTION THREE VOLCANOES AROUND THE UNIVERSE

66 PARICUTINMEXICO'S YOUNGEST MOUNTAIN

69 MEXICO'S VOLCANO ARTIST

71 THE VOLCANIC COLLAPSE OF ATLANTIS?

72 THE FLIGHT FROM ATLANTIS

74 MAUNA LOA'S MARTIAN RELATIVES

76 VOLCANOES AROUND THE UNIVERSE

80 SUGGESTED ADDITIONAL READING

80 PHOTO CREDITS



Decker, R.W., 1984, Hawaii earthquake of November 16, 1983: Earthquake Information Bulletin, v. 16, no. 1, p. 4-9. 



 At 06:13:01 HST, November 16, 1983, a magnitude 6.6 earthquake struck Hawaii, causing substantial damage in the southern parts of the island. Maximum intensity was estimated to be at least VIII on the Modified Mercalli Intensity Scale in parts of Kapapala, Volcano, Hawaii Volcanoes National Park, Kau and Puna districts, and Hilo. Structural damage was estimated to he in excess of $6 million.

 The earthquake was located in the Kaoiki region, an area of persistently high seismicity, between the centers of Hawaii's active volcanoes Mauna Loa and Kilauea. several tens of earthquakes are commonly recorded each day by nearby seismic stations of the Hawaiian Volcano Observatory's 48-station island-wide network. Over the past three decades, about 35 earthquakes have ocurred that were equal to or greater than magnitude 4.0. Two of the largest of these events that caused damage were on June 27, 1962, a magnitude 6.1, and on November 30, 1974, a magnitude 5.5. The recent magnitude 6.1 earthquake was, nevertheless, the greatest in magnitude. structural damage, and ground breakage.

 The earthquake was about 7 miles deep, and a preliminary first motion analysis of local seismic data indicates a strike-slip mechanism. The faulting was a probable result of compressional stresses within the crust induced by magmatic activity, which generated lateral tensions from Mauna Loa and Kilauea.

 In the 8 days following the main shock, more than 9,000 earthquakes have been detected at stations a few miles from the aftershock zone. Over 800 of these, which ranged in magnitude from about 1.0 to 4.3, were selected for computer processing for location and magnitude. About 50 aftershocks were greater than magnitude 3.0, and 3 were over magnitude 4.0. Preliminary determination of hypocenters from data collected during the initial 10 hours of aftershock activity indicates an epicentral zone about 12 miles in diameter centered between the summit areas of Mauna Loa and Kilauea. Focal depths are concentrated at about 6 miles.



Delaney, P.T., Johnson, D.J., Kauahikaua, J.P., Okamura, A.T., Sako, M.K., Wright, T.L., Fiske, R.S., and Gushiken, H., 1988, Recovery of coseismic subsidence by uplift of the south flank of Kilauea Volcano, Hawaii, since the 1975 Kalapana M=7.2 earthquake [abs.]: Seismological Research Letters, v. 59, no. 1, p. 35. 



 The M7.2 Kalapana earthquake of November 29, 1975, was the largest local event ever instrumentally recorded in Hawaii. Along the seacoast south of Kilauea Volcano horizontal seaward displacements were as great as 8 m; in the same area, subsidence exceeded 3 m. Farther east, in the epicentral region of the 10-km-deep thrust-type event, co-seismic subsidence was generally less than 1 m. This earthquake is a crucial factor in ascertaining the deep rifting structure of Kilauea and the role of the south-flank normal faults in accommodating high-level summit and rift-zone extension. We have used leveling and high-precision gravity surveys, spirit-level tilt measurements, and tide-gauge and water-well data to monitor post-earthquake vertical movements of the south flank. Tide-gauge and water-well data at Apua Point, Royal Gardens, and Kalapana indicate that uplift began soon after the earthquake and is continuing at a constant rate. Leveling, gravity, and tilt data show that the uplift is greatest a few kilometers inland from the seacoast south of Kilauea's summit; from there, it decays in magnitude eastward past Kalapana. South of Kilauea's summit, where slumping along normal faults contributed to the co-seismic deformation, postearthquake uplift rates of 4-5 cm/yr amount to 15-20% recovery of subsidence in the slumped hanging-wall block of the normal-fault system and as much as 70-80% recovery in the footwall block. Farther eastward, south of the east rift, uplift rates of ~1.5-3.5 cm/yr amount to 30-60% recovery. We are unable to forecast a recurrence of Kalapana-type events on the basis of these data because the 14 years of south flank tide-gauge records preceding the 1975 earthquake do not reveal significant vertical deformation along the seacoast.



Delaney, P.T., Miklius, A., Okamura, A.T., Sako, M.K., and Fiske, R.S., 1989, Continuous rifting and subsidence of Kilauea Volcano's summit and rift zones, and uplift of its south flank since the 1975 M=7.2 earthquake [abs.], in Continental Magmatism, International Association of Volcanology and Chemistry of the Earth's Interior, General Assembly, Santa Fe, NM, June 25-July 1, 1989, Abstracts: New Mexico Bureau of Mines & Mineral Resources Bulletin 131, p. 71. 



 A ML7.2 earthquake originated at 9-10 km depth beneath the south flank of Kilauea Volcano, Hawaii, about 25 km southeast of its summit, on November 29, 1975. This earthquake triggered a brief summit eruption and caused ~1.0-1.5 m of summit subsidence. Concurrently, there was ~0.5-0.8 m of rift-zone subsidence and up to ~1 m or more of rift-zone extension. Most of Kilauea's south flank subsided ~1-3.5 m and moved seaward, 3-8 m, causing a moderate local tsunami. Although there was up to 1.5 m of normal-fault ground rupture along a 25 km zone, the earthquake probably originated from thrust motion on the shallowly dipping contact between the volcanic pile and the underlying oceanic sediments. The focal depth and widespread deformation associated with this earthquake demonstrated that some of Kilauea's fundamental tectonic structures are deeper and more extensive than had been envisioned on the basis of observed shallow magmatic events.

 Geodetic data spanning the 13 years following the earthquake confirm this finding. Since 1975, the summit and rift zones of Kilauea Volcano have been extending and subsiding, establishing a pattern that began with the co-seismic deformation. Total extension across the summit has been ~2.25 m, averaging 26 cm/yr until 1983 and 5 cm/yr since. Post-1975 summit subsidence locally exceeds 1.5 m. Subsidence of the middle southwest rift zone has been in excess of 0.75 m and the upper east rift near Mauna Ulu has subsided more than 0.5 m. The lower east rift has subsided 0.2 m, even at the farthest landward extent of Kilauea, more than 50 km from the summit. Concurrently, distances measured northward from cinder cones in the lower east rift show extensions along the length of the rift zone that average from 3.0 cm/yr to 1.5 cm/yr. Distances measured southward show contractions that are typically ~0.5 cm/yr. For the past 13 years, Kilauea's south flank has been rising, reversing the abrupt co-seismic subsidence of 1975. A tide gauge situated south of Kilauea's summit reveals more than 0.5 m of uplift; a water well situated over the epicenter of the 1975 event reveals an uplift of ~0.4 m. Leveling from the Hilo tidal datum to benchmarks south of Kilauea's summit reveals an uplift of more the 0.6 m. The greatest south-flank uplift is south of the region of geodetic control. Although the summit and south flank deformations have been decelerating since the 1975 earthquake, deformation of the lower east rift continues unabated.

 The motions reported here are only partly caused by the frequent but sporadic intrusions that originate at the shallow magma reservoir system beneath Kilauea's summit and often propagate along its rifts. The most frequently measured data sets are well characterized by least-squares fits to first- and second-order polynomial functions, implying that the motions result from a relatively continuous, and partially aseismic, deformation of the volcanic pile. These motions affect about 1000 km2, spanning most of the subaerial exposure of Kilauea; the extent of motions of its submarine surface are unknown but probably appreciable. Thus, Kilauea appears to possess a deformation source deep within the rift zones and/or along the base of the volcanic pile. Although Kilauea deformation is typically interpreted on the basis of known shallow magmatic events, much, if not most, of the post-1975 motions are attributable to this deeper source. Based upon these results, the total magma supply rate to Kilauea is probably greater than has been estimated on the basis of observed shallow magmatic activity.



Delaney, P.T., Miklius, A., Okamura, A.T., and Sako, M.K., 1989, Deformation due to the June 25th, 1989, M=6.1 Kilauea, Hawaii, south-flank earthquake [abs.]: Eos, Transactions, American Geophysical Union supp., v. 70, no. 43, p. 1410. [AGU fall meeting, San Francisco, CA, Dec. 4-8, 1989, Program and abstracts] 



 Although level and distance measurements are still being made to determine the extent and magnitude of coseismic motions, data gathered to date reveal a deformation pattern consistent with the source inferred from focal mechanism solutions: seaward slip on a low-angle fault deep below the eastern section of Kilauea's south flank. Leveling is complete along a road crossing the east rift zone of Kilauea, approximately parallel to the direction of coseismic slip, about 15 km east of the epicenter. Comparison of benchmark elevations for March 1988 and July 1989 shows a maximum subsidence of about 22 cm located just south of the rift-zone axis. The subsidence extends more than 10 km northward from the rift zone, where displacement gradients are negligible. Southward from the rift-zone, displacement gradients are steep, about 5 cm/km, giving 5 cm of uplift at the coastal village of Kaimu, where the level line turns westward and crosses a zone of coseismic ground cracks. Level lines crossing the east rift zone about 25 and 30 km east of the epicenter show about 5 and 1 cm of maximum subsidence, respectively; the latter amount is less then the random survey error. Distance measurements show that baseline extensions of up to 35 cm occur between stations north of the lower east rift zone and those on the rift zone. Baselines between stations on the rift zone and those along the coast to the south contracted up to 14 cm, except those crossing the zone of ground breakage near Kaimu. The magnitude of extensions decreases rapidly eastward, away from the epicenter. Tilt at Kilauea summit was relatively unaffected by the earthquake, and baselines across Kilauea's summit area suffered minor extension; baselines across the upper east rift zone and central south flank also experienced minor changes. The 1989 earthquake originated near the focus of the 1975 M=7.2 event. Unlike the 1975 event, however, there is an apparent lack of coupling between slip on the south-flank fault system and the configuration and behavior of Kilauea's magmatic system.



Delaney, P.T., Fiske, R.S., Miklius, A., Okamura, A.T., and Sako, M.K., 1990, Deep magma body beneath the summit and rift zones of Kilauea Volcano, Hawaii: Science, v. 247, March 16, p. 1311-1316. 



 A magnitude 7.2 earthquake in 1975 caused the south flank of Kilauea Volcano, Hawaii, to move seaward in response to slippage along a deep fault. Since then, a large part of the volcano's edifice has been adjusting to this perturbation. The summit of Kilauea extended at a rate of 0.26 meter per year until 1983, the south flank uplifted more than 0.5 meter, and the axes of both the volcano's rift zones extended and subsided; the summit continues to subside. These ground-surface motions have been remarkably steady and much more widespread than those caused by either recurrent inflation and deflation of the summit magma chamber or the episodic propagation of dikes into the rift zones. Kilauea's magmatic system is, therefore, probably deeper and more extensive than previously thought; the summit and both rift zones may be underlain by a thick, near vertical dike-like magma system at a depth of 3 to 9 kilometers.



Delaney, P.T., Wyss, M., Lipman, P.W., and Okamura, A., 1992, Comment on "Precursors to the Kalapana M - 7.2 earthquake" by Max Wyss, F.W. Klein, and Arch C. Johnston: Journal of Geophysical Research, v. 97, no. B4, p. 4839-4841. 



 The M7.2 Kalapana earthquake of 1975 is the largest instrumentally recorded event to have struck the island of Hawaii and among the largest earthquakes to occur in a volcanic setting during the twentieth century. This earthquake caused up to 1.5 m of normal-fault ground rupture along 25 km of the Hilina Pali fault system (Figure 1a) and up to 3.5 m of subsidence along the south coast of Kilauea Volcano. Overall, the subaerial surface of the volcanic edifice extended and moved seaward about 8 m; the summit area subsided about 1.5 m and the two rift zones subsided by lesser amounts. The extensive deformation accompanying the earthquake triggered a brief eruption at Kilauea summit, about 25 km from the epicenter. Despite the normal-fault ground breakage and proximity of the hypocenter to the large south facing scarps of the Hilina Pali, Ando [1979], Furumoto and Kovach [1979], and Crosson and Endo [1981] conclude that the event was initiated along a low-angle fault at about 9-10 km depth; Eissler and Kanamori [1987] find that the long-period seismic radiation is best explained by movement of a landslide block.

 In a study of precursors to the 1975 earthquake, Wyss et al. [1981] use triangulation, trilateration, and other laser-ranging measurements to argue that baselines spanning the Hilina Pali fault system had extended during the 1-4 years before the earthquake, reversing a pattern of twentieth century contraction. Unfortunately, a datum of the most important baseline (Goat-Apua, Figure 1a) was incorrectly plotted in a report (Figure 2b of Lipman et al. [1985]) used by Wyss et al. [1981]. After correction, the amount of preseismic extension is much reduced, possibly to zero, and the last pair of measurements taken prior to the earthquake indicate contraction. Furthermore, the sequence was actually constructed from measurements taken along two nearby baselines (Goat-Apua and Goat2-Apua2 in Figure 1b) that lack redundant comeasurements, and not all of the data needed to compare the two baselines have been published. The purposes of this comment, therefore. are to present the complete and correct data set and to reassess the geodetic precursor identified by Wyss et al [1981]. In Figure 2a, we show the previously published construction of these data (labelled Goat-Apua), linked with a dashed line; the correct construction is shown with data linked by a solid line. Data for each baseline used in the construction are shown in Figure 2b.



Delaney, P.T., 1992, Motion of Kilauea Volcano during sustained eruption from the Puu Oo and Kupaianaha vents, 1983-1991 [abs.]: Eos, Transactions, American Geophysical Union supp., v. 73, no. 43, p. 506. [AGU fall meeting, San Francisco, CA, Dec. 7-11, 1992, Program and abstracts] 



 Kilauea remained in near-continuous eruption from January 1983 through 1991, providing an opportunity to examine its behavior in the absence of the two most common sources of deformation, magma-reservoir inflation beneath the summit and dike propagation along the rift zones. During this period, 10-11-cm/yr subsidence of the ground surface above the summit magma reservoir was accompanied by 4-8-cm/yr subsidence along the upper southwest and east rift zones. Baselines on Kilauea summit contracted, up to 6-7 cm/yr, while lines with an end station on the nearby slopes of Mauna Loa Volcano extended, up to 6-7 cm/yr. The, summit moved -3 cm/yr away from Mauna Loa, suggesting that it was slipping from the larger volcano upon which it has grown.

 The largest sudden disturbance on Kilauea was the M6.1 south flank earthquake of 26 June 1989, which produced 25-40 cm of seaward displacement of stations along the middle and lower east rift zone and eastern south flank. It also produced ~25 cm of subsidence a few kilometers south of the rift-zone axis 15 km downrift of the epicenter. Preseismic seaward migration along the eastern south flank occurred at rates probably less than ~5 cm/yr. Subsidence along the middle and lower east rift zone continued through 1991 at rates that probably did not exceed a few centimeters per year. The section of the south flank south of the summit migrated seaward, relative to the summit, at ~3 cm/yr and rose at minimum rates of 2-5 cm/yr, continuing a pattern of extensive south flank uplift that began after the M7.2 earthquake of 1975.

 The pattern, extent. and steadiness of the motions and the apparent lack of a precursor to the 1989 earthquake suggest that poorly resolved structures and processes were active within the volcanic edifice. In this regard, we note that the geodetic networks spanning Kilauea summit are probably too geographically limited to easily resolve the source of deformation that acted beneath it between 1983 and 1991. Nonetheless, seaward migration of the volcanic edifice is broadly consistent with low angle faulting near its base, generating subsidence along the rift zones and summit behind the mid plane of faulting and producing local uplift of the south flank in front.



Delaney, P.T., Miklius, A., Arnadottir, T., Okamura, A.T., and Sako, M.K., 1993, Motion of Kilauea Volcano during sustained eruption from the Puu Oo and Kupaianaha vents, 1983-1991: Journal of Geophysical Research, v. 98, no. B10, p. 17,801-17,820. [See Delaney and others, 1993, [same article title]: Appendices for microfiche: Washington, D.C., American Geophysical Union (24 p.)] 



 Kilauea erupted almost continuously from January 1983 through 1991. Although the summit began subsiding during the rift zone dike intrusion that initiated this eruption, remarkably steady ground surface motions began in late 1983 after a magnitude 6.6 earthquake beneath the slopes of nearby Mauna Loa volcano and continued until the onset of brief upper east rift zone earthquake swarms in late 1990. During these 7 years the summit and upper rift zones subsided up to 10-11 and 4-8 cm yr-1, respectively, and summit baselines contracted up to 6 cm yr-1. Baselines directed northward from the summit to stations on Mauna Loa extended at rates up to 7 cm yr-1, and a baseline from south of the summit to Mauna Loa extended 4 cm yr-l. Much of this extension is inconsistent with deformation caused solely by summit magma reservoir collapse and more likely reflects rifting as the south Rank of the volcano moved seaward from the summit and rift zones. Farther from the summit, baselines crossing the south flank extended up to 2 cm yr-1, and a south flank tide gauge rose 2 cm yr-l; the lower east rift zone, 40-50 km from the summit, subsided about 2 cm yr-1. Motion on Kilauea, then, is broadly consistent with slip along low-angle south flank faults, generating subsidence that is focused at the summit and along the rift system behind the faulting and uplift along the coastal south flank ahead of it. Dislocation models that combine these elements show that much of Kilauea's edifice migrated seaward, producing ground surface motions along the south flank of up to about 6 cm yr-1. The magnitude 6.1 earthquake of 1989 punctuated these motions along the eastern south flank, producing more than 25 cm of seaward displacement and, 15 km east of the epicenter, up to 24 cm of subsidence south of the lower east rift zone. Unlike the magnitude 7.2 south flank earthquake of 1975, the 1989 event was preceded neither by summit magma reservoir inflation nor by rift zone dike intrusions and accompanying compression of the south flank. Deformation was probably caused by the weight of the volcanic overburden and by ongoing dilation and slip within the rift system.



Delaney, P.T., 1996, Forty years of geodetic monitoring at Kilauea Volcano [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F138. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 Geodetic measurement at Kilauea Volcano has played a crucial role in appraisal of volcano-related hazards since the initiation of systematic monitoring in the second decade of this century. Its usefulness, however, was greatly increased in the 1950's by development of improved measurement of ground-surface tilt and by more frequent reoccupation of level networks. By the early 1970's, a program of repeated trilateration and installation of telemetered electronic tilt devices completed the installation of methodologies only now being supplanted by GPS.

 These measurements record remarkable deformations. Swelling of the summit, for instance, often amounts to about half a meter of uplift, or more, which is rapidly lost during subsequent dike intrusion or eruption. Edifice motions are also apparent, although not so well constrained because of poor network configuration. Uplift of the summit and upper rift zones from 1970 to 1975 proceeded at rates up to about 20 cm/yr. The summit subsided about 1.5 m and extended about .75 m during the 1975 earthquake. Subsequently, the summit extended at about 25 cm/yr and has, since 1976, subsided almost 2 m. Overall, extension of Kilauea's edifice has amount to about 12 m since 1970.

 These data record several types of events that may not be measured by GPS for at least several decades. Cycles of inflation, dike intrusion, and eruption may not soon recommence, as many eruptions have lasted for decades and several, during the past 700-800 years, have lasted for perhaps a century. Also, large decollement earthquakes recur over time scales of a century. Accordingly, older terrestrial geodetic data will continue to play an important role in testing new ideas of volcano deformation; improved analysis methods will likely lead to new insights into the functioning of this and other active volcanoes. Attractive lines of inquiry include better characterizations of magma-reservoir configuration and interactions of magma reservoirs with nearby faults.



Delaney, P.T., Denlinger, R.P., Lisowski, M., Miklius, A., Okubo, P.G., Okamura, A.T., and Sako, M.K., 1998, Volcanic spreading at Kilauea, 1976-1996: Journal of Geophysical Research, v. 103, no. B8, p. 18,003-18,023. 



 The rift system traversing about 80 km of the subaerial surface of Kilauea volcano has extended continuously since the M7.2 flank earthquake of November 1975. Widening across the summit has amounted to more than 250 cm, decelerating after 1975 from about 25 to 4 cm yr-1 since 1983. Concurrently, the summit has subsided more than 200 cm, even as the adjacent south flank has risen more than 50 cm. The axes of the upper zones, about 10 km from the summit, subsided before 1983 at average rates of 9 and 4 cm yr-1, respectively, and at rates of 4 and 3 cm yr-1 since. The middle southwest rift zone is also subsiding and, at the other end of Kilauea's subaerial rift system, subsidence along the lower east rift zone has averaged 1-2 cm yr-1. Deformation of Kilauea's south flank has been continuous, although subject as well to displacements caused by major rift zone seismic swarms. Whereas horizontal strains across the subaerial south flank seem to have been generally compressive after 1975, they have been extensional since about 1980 or 1981, interrupted only by the east rift zone dike intrusion of 1983. Because the magnitudes of these contractions and extensions are much less than the extension across the rift system, the subaerial south flank is apparently sliding seaward on its basal decollement more than it is accumulating horizontal strains within the overlying volcanic pile. Kilauea suffers from gravitational spreading made even more unstable by accumulation of magma along the rift system at depths in excess of about 4-5 km in the presence [of] hot rock incapable of withstanding deviatoric stresses. This seismic[al]ly quiescent zone decouples the south flank from the rest of Hawaii's volcanic edifice; the rift zones at lesser depths exhibit a more brittle and, therefore, sporadic extensional behavior. Judging from the modern extension record of the summit, which both predates the M7.2 earthquake of 1975 and has outlived its 10-year period of aftershocks, Kilauea will continue to spread along its rift system as its south flank slips seaward to accommodate the accretion of magma and its relatively dense olivine-rich differentiate.



Dermengian, J.M., and Langston, C.A., 1979, Focal mechanism of the Ms 7.2 November 29, 1975, Kalapana earthquake from a wave form correlation technique [abs.]: Eos, Transactions, American Geophysical Union, v. 60, no. 46, p. 894. [AGU fall meeting, San Francisco, CA, Dec. 3-7, 1979, Program and abstracts] 



 Ambiguous P wave first motions are often a serious problem in focal mechanism studies because of source complexities and/or seismic noise. Wave form modeling techniques minimize this problem by utilizing shape and later wave form amplitude information which are also a function of radiation pattern at the source. Long period teleseismic body wave forms generally change slowly with azimuth, except near radiation nodes, and display symmetry properties which depend on source orientation. This suggests a method where unambiguous first motions are used in conjunction with wave form correlations between adjacent and separated stations on the focal sphere. Used in conjunction with synthetic seismograms to test various hypotheses on orientation, fields of similar wave forms, symmetry between fields, and wave form changes can all be utilized to determine usual orientation parameters. This technique was applied to a foreshock and the main event in the 1975 Kalapana, Hawaii, earthquake sequence. Long period WWSSN P wave forms for the main event, although plentiful, exhibit emergent first arrival and large secondary phases within the first two minutes of the P arrival suggesting a complicated source time function or series of multiple events. The mechanism obtained for the main event has a well constrained nodal plane striking N52E and dipping 88 to the NW. The rake is less well constrained as shown by the auxiliary plane which may dip 50 to the NE or SW. Fault slip is down towards the NW. The foreshock mechanism is identical and both mechanisms are qualitatively consistent with previous work.



Dermengian, J.M., 1981, On the application of teleseismic body wave modeling to study the source characteristics and tectonic implications of the Kalapana, Hawaii foreshock mainshock sequence of 11/29/75: University Park, PA, The Pennsylvania State University, M.S. thesis, 131 p. 



 Teleseismic long-period body waves and surface wave radiation have been studied to estimate source characteristics of the November 29, 1975 Kalapana, Hawaii tsunamigenic earthquake (Ms ~ 7.2) and its principle foreshock (ML = 5.7) on the south flank of Kilauea volcano. Focal mechanisms for each event are similar consisting of a tightly-constrained, near-vertical nodal plane striking N52E and dipping 88 to the NW and an auxiliary plane gently dipping 2 to the SSE. The resulting solution is a dip-slip mechanism on either a steep fault plane or a shallow dipping fault plane. The strike of the steep nodal plane coincides with the strike of the well-defined band-like aftershock zone extending to 9 km beneath the island of Hawaii. These results agree quantitatively and qualitatively with the 1954 Kalapana foreshock-mainshock sequence. The depths of the 1975 foreshock and mainshock are shallow, less than 8 km, as determined from short-period pP, relative hypocenter relocation, and wave form modeling. Long-period P-waves from the foreshock and mainshock are also similar within the first l5-20 seconds after onset, however, the foreshock P-waves exhibit shorter pulse width, shorter duration, and simpler wave shape. Mainshock P-waves generally display emergent first motions followed by large amplitude radiation 45 seconds into the earthquake suggesting unusual complexity and long duration of the source process. The P wave forms were stacked to obtain composite wave forms in order to minimize noise and extract more useful information about the seismic source beyond first motion polarity. Preliminary synthetic seismograms were computed for the foreshock and mainshock using a general vertical dip-slip model and a near-horizontal dipslip model. Under the assumption of a single point, double couple source, the resulting P and SH wave forms for such a source distributed on either a nearly-vertical nodal plane or a nearly-horizontal nodal plane generally satisfy the observed wave form polarities. In order for the actual slip surface to be consistent with the equivalent forces for a double-couple and with the observed fault displacements, the preferred fault plane is the shallow dipping one. Rayleigh wave and Love wave radiation patterns provide further support for the choice of this slip surface. These results agree qualitatively with previous studies not incorporating body wave forms from the Kalapana mainshock. In this study a mainshock source model, which is consistent with the dynamic behavior of the tectonically complex south flank, is proposed. This model envisions the mainshock as a low strength gravity slide on the unstable portion of the south flank. Fault morphology, inefficient short-period body wave radiation, and low ground acceleration levels provide support for the model. A low static-stress drop, 0.7 bar, estimated for the mainshock, may be principally due to the gravitational body force; if true, the slip surface is always near failure and large earthquakes on the south flank can occur more frequently than the previously suggested 100 year return period. In addition, the lack of a space-time correlation of major eruptive episodes at Kilauea and large earthquakes on the south flank indicates that such events are not intimately related.



Dibble, S., 1839, History and general views of the Sandwich Islands' mission: Lahaina-luna, T.H., Mission Seminary, 464 p. [Simultaneously published in New York by Taylor & Dodd; p. 14-56 of the New York edition cover the material abstracted] 



 Dibble describes the Hawaiian Islands as being entirely of volcanic origin (p. 14-15). He describes an earthquake swarm felt in Hilo, including one strong shock, accompanied by an eruption lighting the heavens (p. 49-52). The eruption continued for one night and part of the next day. Dibble visited the crater on the following day: "When we arrived within several miles of the volcano we found the earth broken into deep chasms; and when we came within a half mile perhaps of the crater we found that the earth for that distance around had sunk about 18 in, and from there on to the crater's edge the ground was so rent into chasms as to be almost impassable." In the crater he found "this tremendous depth (of 800 or 1,000 ft) an immense area had been filled with boiling lava; that in the rollings and tossings of the mighty convulsion, the lava had been thrown out in huge waves on every side, until, by some shock, a chasm was rent in one side of the crater, through which an immense mass had disgorged itself into the ocean. The almost fathomless abyss was now empty, presenting only a raging lake of fire at the very bottom." [Although no date is given, this vivid description fits other accounts of the Kilauea eruption of 1832. Dibble recognizes the likelihood of a submarine eruption or intrusion into the southwest rift zone of Kilauea.]



Dieterich, J.H., 1983, The mechanism and precursors of the 1975 Kalapana, Hawaii earthquake: U.S. Geological Survey Open-File Report 83-0174, p. 23-26. [Hill, David P., and Nishimura, Keiji, UJNR Panel on Earthquake Prediction Technology, 3rd Joint Meeting, Tsukuba, Japan, Sept. 20-22, 1982, Proceedings] 



 The magnitude 7.2 1975 Kalapana, Hawaii earthquake resulted in up to 8 m of horizontal displacement and 3 m of subsidence along 50 km of the southern coast of the island of Hawaii. This region experienced an earthquake of comparable magnitude and apparently similar mechanism in 1868. The region affected by this earthquake has particularly good geodetic and seismic data prior to and following 1975. The data suggest a pattern of pre-seismic and postseismic phenomena similar to some other earthquakes and analogous to processes observed in laboratory experiments and numerical simulations.

 The Kalapana earthquake occurred on the south flank of Kilauea volcano and apparently owes its origin to processes related to the volcano. The driving force for the earthquake appears to have derived from semi-continuous injection of magma from the summit region of the volcano into the southwest and east rift zones of the volcano that resulted in rift zone spreading at an average rate of 5.5 cm/year for at least 79 years prior to the earthquake. Analysis of old triangulation data and recent trilateration surveys for the east rift zone for the period 1896-1970 by Swanson et al. (1979) show a continuous and consistent pattern of: a) horizontal extension across the rift zone and b) crustal shortening in a direction roughly perpendicular to the rift in the eventual source region of the earthquake in the region south of the rift. The patterns of deformation are consistent with forceful expansion of the shallow rifts by continuous addition of magma into the rifts an interpretation that is supported by several other lines of evidence. Aftershocks, first motion solutions, and dislocation models (Crosson and Endo, 1981; Ando, 1979) and finite element modeling conducted for this report indicate that the earthquake originated by slip along a shallow approximately horizontal fault. The fault plane apparently intersects the base of the rift zones and extends southward from the rift zones. The earthquake is interpreted to be the mechanism of accommodation to the strain induced by the shallow, forceful spreading of the rift zones. Finite element modeling of the coseismic horizontal and vertical displacements of the south flank of Kilauea indicate that passive extension of the rifts contributed significantly to the coseismic deformation.

 Based upon evidence from a single geodimeter line that showed reversal from contraction to extension, Swanson et al. (1976) suggested that the south flank of Kilauea may have accumulated the maximum possible strain due to rift expansion and could experience a major earthquake in the near future (the paper was in press prior to the 1975 earthquake). Review of a more extensive data set by the present author indicates a clear pattern of strain reversal beginning from six months to five years before the earthquake depending on location. The region affected by the strain reversal is within the region of maximum coseismic strain change and is roughly 300 km2 compared to the earthquake source area of 1000 km2. Various explanations for the reversal of the pattern of strain accumulation have been considered including premonitory fault slip, contraction of the rifts due to removal of magma and local intrusion of magma. Only the fault slip explanation is supported by the data. The magnitude of the strain changes indicate that the premonitory fault displacements were up to 30 cm. The pattern of the strain reversals in space and time resembles in addition the pattern obtained in laboratory fault simulation experiments where large amounts of stable slip are sometimes observed prior to slip instability. In addition to the strain precursors other premonitory effects for the 1975 earthquake include P-wave velocity changes (Wyss, et al., 1981), and a short-lived foreshock sequence. The foreshocks and the velocity anomaly occurred within the region of the strain anomalies.

 Following the earthquake, the south flank of Kilauea volcano experienced a prolonged period of afterslip. On the south flank the afterslip can be detected in the deformation data for an interval of six months while at the summit caldera the geodetic measurements indicate that afterslip continued for at least five years and may be continuing at present. The summit caldera was displaced southward 1.2 m by the earthquake and has been displaced at least 0.70 m subsequent to the 1975 earthquake apparently by afterslip.



Dieterich, J.H., and Okamura, A., 1984, Modeling surface deformations due to coupled interactions between magma bodies and fault slip [abs.], in Measurement and Modeling, American Geophysical Union Chapman Conference on Vertical Crustal Motion, Harpers Ferry, WV, October 22-26, 1984, Program and abstracts: American Geophysical Union Chapman Conference on Vertical Crustal Motion, Program and Abstracts, [unpag.]. 



 Many deformation events on active volcanoes are associated with fault slip in addition to the effects of magma injection and withdrawal. The abundance of fault structures within volcanoes and the common association of large earthquakes with volcanic centers attest to the importance of faulting in controlling volcano deformation. Surface deformations due to coupled interactions between magma bodies and fault slip have been examined using finite element models. The 1975 magnitude 7.2 Kalapana, Hawaii, earthquake is a possible example of coupled interactions between a magma body and faulting. The earthquake resulted in up to 8 m of horizontal displacement and 3 m of subsidence of the south flank of Kilauea volcano. The deformation data suggest slip on a nearly horizontal thrust fault with patterns of pre-seismic and post-seismic fault creep similar to some tectonic earthquakes. Following previous studies, we interpret the driving force for the earthquake to be repeated injections of magma from the summit region of Kilauea into the southwest and east rift zones of Kilauea. Vertical deformation data indicate significant coseismic subsidence over the rift zones, suggesting interaction between intrusive bodies and the thrust fault.



Dieterich, J.H., 1995, Coupling of magmatic processes, flank expansion and earthquakes at Kilauea Volcano, Hawaii [abs.], in, Geophysics and the environment, International Union of Geodesy and Geophysics (IUGG), 21st General Assembly, Boulder, CO, July 2-14, 1995, Abstracts, Week A: [s.l.], [s.n.], p. A454. 



 Major volcanic episodes are generally accompanied by significant earthquake activity and occasionally gross failure of a volcanic edifice. A model is proposed in which interactions among magmatic injection, yielding by fault slip and gravity determine structural stability and persistence of intrusion processes during the growth of a volcano. At Kilauea volcano, Hawaii, these interactions result in seaward spreading of the volcano flank by slip on sub-horizontal faults, possibly in the sea floor sediments at the base of volcano. Basal fault slip permits long-term persistence and continuing magmatic expansion of the volcano rift zones. The earthquake of June 26, 1989 (M 6.1) apparently represents recurrence of slip on a portion of the Kalapana, Hawaii November 29, 1972 (M 7.2) fault surface. Portions 1989 earthquake slip zone also slipped in several moderate earthquakes (M4.8-M5.5) between 1975 and 1989. In the regions of overlap, the seismic moment release rate since 1975 is consistent with the inferred continuing rates of basal fault slip (6 cm/yr - 25 cm/yr, depending on the time interval, assumptions and data employed). Elsewhere, seismic moment release is too small and aseismic yielding must be the current dominant mechanism of flank slip. A constitutive formulation for rate of earthquake activity [Dieterich, 1994, J. Geophys. Res. 99, 2601-2618] has been employed to quantitatively examine the relation between changes of seismic activity and changes in the stress state at Kilauea. Intrusion events into the East Rift Zone of Kilauea in 1977 and 1983 were accompanied by significant changes in flank seismic activity. Inversions of the seismic activity data indicate step-like increase of stress in the flank and are consistent with stress changes expected from elastic crack models of the intrusions.



Dougherty, H.E., 1926, Volcano conditions hint '68 quake: Honolulu Advertiser, 04/14, p. 1. 



 [subheads: Finch sees similarity to those preceding fatal sixty-foot tidal wave; Blue fumes rise from Halemaumau and watch is kept for outburst believed to be imminent; Alika flow crater reported smoking]

Volcano House, Hawaii, April 13.--One hundred and fifty earthquakes, 12 of them noticeable and 6 of them severe, were recorded today on the Kilauea observatory seismograph.

 Roy [sic-Ruy] Finch, assistant volcanologist, says present conditions are similar in many respects to those of 1868 when a great earthquake rocked Hawaii and a 60-foot tidal wave wrecked villages on the Kona coast preceding a second outbreak of Mauna Loa.

 Kilauea is under constant observance. Blue fume smoke was today ascending from the crater floor. Finch interprets this sign as forecasting early activity at Halemaumau.

 The rest of the article mainly talks of the weather, noting that smoke was possibly seen from the Alika cone [source of 1919 eruption on Mauna Loa's southwest rift zone].



Dougherty, H.E., 1926, Flow partly destroys town; Wharf wrecked as river of fire reaches sea; Greater havoc is threatened: Honolulu Advertiser, 04/19, p. 1. 



 [subheads: Big Island staggers from explosions of Mauna Loa's wrath; Hoopuloa is scene of indescribably magnificent display when molten mass thousand feet wide cascades into ocean]

Volcano House, April 18, 7:30 p.m.--Three severe earthquakes following in quick succession at 2:05 this afternoon rocked the Kilauea district and were felt in Hilo. Dishes fell from the shelves, doors slammed and chandeliers were set swinging.

 Great avalanches fell into the pit of Halemaumau.

 . . . .

 A following article describes in some detail the entry of lava into the sea at Hoopuloa, where it destroyed the village.



Dougherty, H.E., 1926, Terrific earthquakes disturb Kilauea area; Jaggar awaits outbreak there: Honolulu Advertiser, 04/21, p. 1. 



 [subheads: Mauna Loa continues eruptions but flows, short, quickly cool; Volcanologist reiterates activity waning at one source but warns of Halemaumau outbreaks]

Volcano House (Kilauea), April 20.--Terrific earthquakes shook the Kilauea section at 5:05 o'clock this afternoon, causing enormous avalanches in Halemaumau pit and frightening considerably guests of the Volcano House.

 Professor Jaggar says the tilt of the quakes indicates a movement of lava near the pit.

 The remainder of the article reports the waning of activity on Mauna Loa's southwest rift zone.



Doyle, E.L., 1832, [no title], in Makua Laiana, 1945, 259 p.: Honolulu, HI, Honolulu Star Bulletin, p. 93. [Emma Doyle's entry of July 9, 1832, from Kona] 



 We hear of the breaking out of a new volcano near the center of the island, this was followed by a shock of earthquake.



Du, Y., Segall, P., and Gao, H., 1994, Crustal deformation modeling in three-dimensional inhomogeneous half-space [abs.]: Eos, Transactions, American Geophysical Union supp., v. 75, no. 44, p. 177. [AGU fall meeting, San Francisco, CA, Dec. 5-9, 1994, Program and abstracts] 



 Elastic dislocations in homogeneous half-space are commonly used to model crustal deformation measurements. Recently, we have applied a moduli perturbations method to compute the slip Green's functions in inhomogenoeous media and presented some two-dimensional solutions (Du et al., J. Geophys. Res., 1994). We now extend the moduli perturbation method to the three-dimensional half-space. In the perturbation procedure, a homogeneous half-space is chosen to obtain the zeroth-order solution. For the medium with only piecewise constant variations in shear modulous, the displacements in a homogeneous half-space, and the Green's function for the homogenous half-space.

 As an example, we investigate the effect of material inhomogeneity on the location of fault plane for the 1989 Kalapana, Hawaii, earthquake by applying the moduli perturbation method and a linearized inversion scheme. Shallow basalt lavas with low seismic velocities are represented by a compliant horizontal layer (m1) overlaying a stiffer horizontal lower layer (m2). The thickness of the complaint surface layer is 5 km. The east rift zone has high densities and velocities, and is represented by a stiff vertical layer (m3). The material contrasts are m1/m2=0.33 and m1/m3=0.2, respectively. It is found that leveling data can be reasonably fit by a flat-lying dislocation at a depth of 71 km. This is more consistent with the depths of aftershocks (6-9 km) than the depth determined from an inversion in a homogeneous half space (4 km) by Arnadottir et al (Geophys. Res. Lett, 1991). We conclude that inclusion of both vertical and lateral variations in material properties can resolve most, if not all, of the discrepancy between geodetic and seismic fault depths for the 1989 Kalapana, Hawaii, earthquake.



Duennebier, F., Malahoff, A., Harris, D., and Hahn, B., 1992, HUGO: the Hawaii Undersea Geo-Observatory; a progress report [abs.]: Eos, Transactions, American Geophysical Union supp., v. 73, no. 14, p. 314. [AGU spring meeting, Montreal, Canada, May 12-16, 1992, Program and abstracts] 



 The first phase of a permanent ocean bottom observatory is due to be installed on Loihi seamount within the next several months. This observatory has the capacity to support more than 90 experiments that will monitor the activity of this active underwater volcano located about 35 km southeast of the Island of Hawaii. The initial phase involves the installation of an electro-optical cable (donated by AT&T) from shore to the summit of Loihi at a depth of 1 Km. The cable will be capable of transmitting up to 5 kW of electrical power to experiments on the seamount, and several megabytes of data back to shore. A small experiment package containing three orthogonal geophones, a high-rate hydrophone (32 KHz), a pressure gauge, and temperature sensor will be installed as part of the first phase

 Experiments and multiplexing nodes will be installed by submersible during the expansion phase of the project. Underwater connectors are being designed to allow power and optical fibers to be connected by the submersible in a single action. Individual experiments will obtain power and have the ability to accept commands from the recording station, and will send data to the recording station at a rate of 2000 samples per second. Investigators are invited to design and build experiments for installation in HUGO, with the only requirements being conformation to system specifications and adequate funding.

 Loihi seamount is one of the best studied submarine volcanoes in the world, and it is the only known active submarine volcano in U.S. territorial waters. The seismic array operated by the Hawaiian Volcano Observatory often records seismic swarms from Loihi, the last two occurring in March, 1990 and December, 1991.

Submersible dives have observed warm water, chimneys, algal mats, and water rich in CO2. The HUGO system provides an excellent opportunity for study of these phenomena over an extended period of time.



Duennebier, F.K., 1996, Loihi and HUGO: the Hawaii Undersea Geo-Observatory [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F398. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 Recent activity at Loihi seamount, the future site of the HUGO Observatory, has increased both the interest in and the apparent risks of the HUGO Project. Had HUGO been emplaced in February, 1996, as originally planned, it is quite likely that the system would have been destroyed during the July, 1996 activity. The purpose of HUGO is to provide observatory infrastructure-power, a real-time data link, and command capability-from Loihi seamount to shore for over 60 experiments studying tectonics, earthquakes, volcanic processes, chemistry, ocean currents, and biology. The "backbone" of HUGO is a 45 km electro-optical cable donated by AT&T to be installed in February/March, 1997. The cable will be terminated at a Junction Box at the Loihi summit. Experiments supplied by the marine science community will be installed by submersible. Indications from PISCES V submersible dives and from noise heard on sonobuoys during the August, 1996, Rapid Response cruise suggest that surface activity was occurring just north of a pit crater on the east side of the Loihi summit (18 55.12'N, 155 14.95'W), near the target site for the HUGO Junction Box. Turbid water and black sand were observed from the submersible down-current from this area, and triangulation on an acoustic transient noise source observed from sonobuoys indicates that either a surface flow or strong hydrothermal venting was active at that time. Surveying and dives planned for late September should further delineate the activity and may locate a new site for studies of recent volcanic and hydrothermal activity on the ocean floor. In addition, these studies should make it possible to locate a safe cable route and new site for the HUGO Junction Box.



Duffield, W.A., Jackson, D.B., and Swanson, D.A., 1974, The shallow, forceful intrusion of magma and related ground deformation at Kilauea Volcano, May 15-16, 1970, in Gonzales-Ferran, O., ed(s)., Symposium on Andean and Antarctic Volcanology Problems, Santiago, Chile, Sept. 9-14, 1974, Proceedings: International Association of Volcanology and Chemistry of the Earth's Interior, Special Series, p. 577-597. 



 On May 15-16, 1970, a shallow, forceful intrusion of magma beneath Kilauea Caldera was accompanied by hundreds of earthquakes and substantial tumescence. The earthquakes occurred in the south and east parts of the caldera and in the adjacent part of the uppermost east rift zone at depths ranging from 5 to less than 1 km. Tumescence was localized in the south and east parts of the caldera and amounted to as much as several centimetres of both vertical and horizontal ground displacement.

 Daily and biweekly measurements of ground tilt indicate that the May 15-16 intrusion was preceded by a four-month period of inflation centered in the south part of the caldera. During intrusion, additional domal uplift occurred about 1 km to the southeast of the earlier center, and two ridges grew on the northeast flank of the new dome. Maximum net ground displacements resulting from the intrusion and the preceding inflation were 19 cm vertically and 29 cm horizontally.

 The dome and ridges that grew during the intrusion were localized within a one-kilometer-wide, northeast-trending zone of caldera faults. The ridges may have resulted from slight offset triggered on preexisting faults by the nearby shallow emplacement of magma beneath the dome. Alternatively, comparison of the cross sectional profile of the ridges with those computed from model studies suggests that the ridges may have grown over an almost vertically dipping dike that intruded to within about 340 metres of the surface.

 Horizontal displacements south of the area of intrusion are roughly twice those at comparable distances north of the intrusion. Many of the southern stations are in or adjacent to the Koae fault system, a zone of numerous N. 75 E.-trending open ground cracks, and tape measurements across some of these cracks indicate that the large southerly displacements were accommodated mainly be closing of many of the cracks. the resulting dilatational strain within the fault system was on the order of 10-5. Some of this southerly-directed was transmitted as much as 15-20 km to the south, resulting in NNW-SSE directed contractile horizontal strain there on the order of 5 x 10-6.



The May 15-16, 1970 intrusion is unique to the recorded history of Kilauea Caldera because it is the most thoroughly documented and the first to be recognized at such apparently shallow depths beneath the caldera itself.



Dutton, C.E., 1887, The eruption of 1868: Hawaiian Gazette, 02/08, p. 3. 



 An excerpt from Dutton (1884) describing the events of 1868.



Dvorak, J.J., and Okamura, A.T., 1984, Vertical ground movement associated with volcanism in Hawaii [abs.], in Measurement and Modeling, American Geophysical Union Chapman Conference on Vertical Crustal Motion, Harpers Ferry, WV, October 22-26, 1984, Program and abstracts: American Geophysical Union Chapman Conference on Vertical Crustal Motion, Program and Abstracts, [unpag.]. 



 Repeated level surveys in Hawaii are used to monitor ground movement associated with active volcanism. In the summit regions of the two most active Hawaiian volcanoes, Kilauea and Mauna Loa, vertical changes of 0.5 m are recorded over periods of several years. These changes are related to temporary magma storage in reservoirs 2 to 4 km beneath the surface. Some summit stored magma migrates horizontally into radial rift zones. Level surveys along the rift zones indicate that magma, emplaced as vertical dikes, may reach within 500 m of the surface without erupting.

 The accumulation of magma in the summit region and rift zones builds up compressive strain along the flanks of the volcano. The compressive strain is partially released by strike-slip earthquakes that occur between Kilauea and Mauna Loa (e.g., 6.6 M, 16 Nov. 1983) and by horizontal, seaward faulting along the coast (e.g., 7.2 M, 19 Nov. 1975). Level surveys conducted along the flanks of the volcano are used to estimate the extent of subsurface rupture related to these earthquakes.



Dvorak, J.J., and Tanigawa, W.R., 1985, Generation of earthquake swarms along the south flank of Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 66, no. 46, p. 851-852. [AGU fall meeting, San Francisco, CA, Dec. 8-13, 1985, Program and abstracts] 



 Persistent earthquake activity along the south flank of Kilauea volcano, Hawaii, is related to seaward displacement of the flank caused by forceful intrusion of magma into the rift system. Earthquake swarms along the south flank occur either as an aftershock sequence following a large south flank earthquake or as a response to a major rift intrusion. The depth of south flank earthquakes range from about 5 to 13 km. We have investigated whether there is a significant difference between the earthquake swarms along the same part of the south flank produced by these two very different events. We have examined the aftershock sequences which followed the 29 November 1975 magnitude 7.1 and the 21 September 1979 magnitude 5.4 south flank earthquakes. The time histories of aftershocks follow an exponential decay with time constants of 14 days for the 1979 earthquake and 0.3 days for the 1979 earthquake. The time histories of the earthquake swarms produced by the September 1977 and the January 1983 east rift intrusions also follow an exponential decay with a similar range of time constants: 3 days in 1977 and 12 days in 1983. The b-values for the aftershock sequences and for the earthquake swarms produced by the rift intrusions were all about 0.8. Geodetic measurements indicate that forceful intrusion of magma into the rift system results in compression of the south flank. This compression is relieved by large south flank earthquakes. Although rift intrusions and large south flank earthquakes result in different strain conditions along the south flank, the increased earthquake activity generated by either type of event appears to be identical. The time history and the size distribution of these earthquake swarms are apparently controlled by the mechanical properties of the south flank and are independent of the source.



Dvorak, J.J., 1990, Activity along the rift zones of Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 71, no. 43, p. 1601. [AGU fall meeting, San Francisco, CA, Dec. 3-7, 1990, Program and abstracts] 



 The two rift zones and summit caldera of Kilauea Volcano, Hawaii, form a 150-km-long feature that divides the volcano nearly in half. This is an extensional feature whose surface expression is identified by a narrow zone of eruptive vents, normal faults, and pit craters. The driving mechanism responsible for the growth of Hawaiian rift zones is controlled ultimately by a nearly continuous supply of magma that wedges open the volcano. Though this is unlike the remote horizontal stress responsible for extension along the mid-oceanic ridge, some aspects of activity along Hawaiian rift zones may also occur along segments of the mid-oceanic ridge.

 Activity along a rift zone of Kilauea probably originates from one of the magma bodies that lies beneath the rift zone and reaches to within a few kilometers of the surface. The start of activity is often heralded by a dramatic increase in shallow earthquakes and rate of ground movement. For example, a few hundred earthquakes greater than magnitude 1.5 were recorded during the 24-hour period that preceded the 3 Jan. 1983 eruption along the east rift zone. The epicentral locations of these earthquakes migrated a horizontal distance of 10 km at an average rate of about 700 m/hr. During this same 24-hour period. a small network of tiltmeters located along the length of the east rift zone recorded the growth of the fissure. The fissure grew horizontally at nearly 700 m/hr and vertically at about 75 m/hr. The net result was the formation of a 15-km-long fissure that rose from a depth of 2 to 3 km to the surface. The average amount of opening perpendicular to the axis of the east rift zone was 3.5 m. About 100 million cubic meters of magma were involved in the growth of this fissure and the subsequent 10-day-long eruption. The rate of earthquakes and ground movement dropped sharply after the outbreak of the eruption. Harmonic tremor has been recorded at various levels since 3 Jan 1983, dramatically increasing in amplitude during the most vigorous eruptive phases.

 The 3 Jan. 1983 event is one example of the wide spectrum of activity that has been recorded along the rift zones of Kilauea During the past 150 years, one of the largest events occurred over a 25-day period in May-June 1840 and formed a discontinuous line of eruptive fissures along 40 km of the east rift zone. The smallest event recognized was the movement of about 50,000 cubic meters of magma from the summit to the east rift zone on I5 Jul. 1982, accompanied by about a dozen earthquakes recorded by a seismometer located within 1 km of the epicentral area. Tiltmeters have also recorded the aseismic movement of magma from the summit to the rift zones. The operation of a network of seismometers and tiltmeters along the rift zones has been a key element in recognizing the occurrence and recording the characteristics of activity along the rift zones.



Dvorak, J., and Okamura, A.T., 1991, Ground movement associated with the M-6.1 26 June 1989 earthquake on the south flank of Kilauea Volcano, Hawaii: results using the satellite Global Positioning System [abs.], in Towards the Pacific Century: The Challenge of Change, Pacific Science Congress, 17th, Honolulu, May 27-June 1991, Proceedings: Pacific Science Congress, 17th, Proceedings, p. 31. 



 The Global Positioning System (GPS) is a satellite-based system that can be used to determine relative positions to within an accuracy of a few centimeters over distances of hundreds of kilometers. This system has been used in Hawaii to record the patterns of ground movement associated with (1) magma transport inside the volcanoes and (2) large earthquakes. A station in Kawaihae, located in the northwestern part of the island 90 km from Hilo was used as the reference station for the Hawaii GPS network.

 The largest movements recorded since measurements were begun in April 1987 were associated with an M=6.1 earthquake at 3:27 GMT on 26 June 1989 beneath the south flank of Kilauea. Horizontal displacements at stations located over the aftershock zone indicated seaward movement of the south flank of as much as 300 mm Vertical displacements indicated subsidence of as much as 250 mm near the edges of the aftershock zone.

 The ground displacements are modeled as a planar rectangular sheet, with constant displacement across the sheet. To fit the measured pattern and magnitudes of ground movements, this sheet must be horizontal and located partly within and tended seaward from the earthquake aftershock zone at a depth of about 6 km. This sheet has dimensions of 27 by 12 km; its long axis is oriented N65E, parallel to the east rift zone and the coastline. Displacement on the sheet is 1.2 m seaward and perpendicular to the east rift zone. Using a shear modulus of 5x1011 dyne/cm2, as determined from seismic-refraction surveys of the Island of Hawaii, these dimensions and displacement yield a geodetic moment of 2x1026 dyne-cm This value is a factor of four greater than the seismic moment, which was 5x1025 dyne-cm, suggesting that a significant amount of the ground movement was aseismic.



Dvorak, J.J., Okamura, A.T., Lisowski, M., Prescott, W., and Svarc, J., 1992, GPS measurements on the island of Hawaii: 1987 to 1990 [abs.]: Eos, Transactions, American Geophysical Union supp., v. 73, no. 43, p. 118. [AGU fall meeting, San Francisco, CA, Dec. 7-11, 1992, Program and abstracts] 



 T14100 receivers were used to conduct GPS surveys on the island of Hawaii in April 1987, August 1988, August 1989, and August 1990.

 Approximately 40 ground stations were occupied during each survey, mostly on Kilauea volcano, though stations also were occupied in the summit area of Mauna Loa and along the Kealakekua fault system on the west coast of Hawaii. All measurements were processed using the Bernese software package and satellite positions computed from orbits provided by the U.S. Naval Surface Weapons Center (NSWC).

 Our GPS measurements show that the summit area of Kilauea subsided at least 0.2 m between April 1987 and August 1990. The subsidence, also indicated by repeated leveling surveys conducted during the same time period, was probably caused by the net removal of 0.03 cubic kilometers of magma from a shallow magma reservoir. This can account for only ten percent of the volume of the magma erupted during the four years. The other 90 per cent was supplied by a deeper source that had no significant influence on GPS or other geodetic measurements.

 The largest ground movements recorded in Hawaii by GPS were associated with a 6.1-magnitude earthquake beneath the south flank of Kilauea on 26 June 1989 (GMT). Horizontal displacements at stations located over the aftershock zone showed seaward movement of the south flank of as much as 0.3 m and subsidence of as much as 0.25 m near the eastern edge of the aftershock zone.

 GPS measurements have been made in the summit area of Mauna Loa volcano since 1988. Measured horizontal positions have varied less than 20 mm, consistent with results of trilateration measurements between 1988 and 1990.

 GPS measurements also have been made at three stations along the Kealakekua fault system on the west flank of Mauna Loa since 1988. These stations may have moved seaward at rates of 20 to 28 mm/yr. Seaward movement is consistent with westward slip indicated by earthquake focal mechanisms beneath the west flank. The annual seaward rates are a quarter to a half of the rate of seaward movement along the south flank of Kilauea. Additional measurements are needed to confirm or refute the apparent seaward movement of the west flank of Mauna Loa.



Dvorak, J.J., Klein, F.W., and Swanson, D.A., 1994, Relaxation of the south flank after the 7.2-magnitude Kalapana earthquake, Kilauea Volcano, Hawaii: Bulletin of the Seismological Society of America, v. 84, no. 1, p. 133-141. 



 An M = 7.2 earthquake on 29 November 1975 caused the south flank of Kilauea Volcano, Hawaii, to move seaward several meters: a catastrophic release of compression of the south flank caused by earlier injections of magma into the adjacent segment of a rift zone. The focal mechanisms of the mainshock, the largest foreshock, and the largest aftershock suggest seaward movement of the upper block. The rate of aftershocks decreased in a familiar hyperbolic decay, reaching the pre-1975 rate of seismicity by the mid-1980s. Repeated rift-zone intrusions and eruptions after 1975, which occurred within 25 km of the summit area, compressed the adjacent portion of the south flank, apparently masking continued seaward displacement of the south flank. This is evident along a trilateration line that continued to extend, suggesting seaward displacement, immediately after the M = 7.2 earthquake, but then was compressed during a series of intrusions and eruptions that began in September 1977. Farther to the east, trilateration measurements show that the portion of the south flank above the aftershock zone, but beyond the area of compression caused by the rift-zone intrusions and eruptions, continued to move seaward at a decreasing rate until the mid-1980s, mimicking the decay in aftershock rate. Along the same portion of the south flank, the pattern of vertical surface displacements can be explained by continued seaward movement of the south flank and development of two eruptive fissures along the east rift zone, each of which extended from a depth of ~3 km to the surface. The aftershock rate and continued seaward movement of the south flank are reminiscent of crustal response to other large earthquakes, such as the 1966 M = 6 Parkfield earthquake and the 1983 M = 6.5 Coalinga earthquake.



Dvorak, J., 1994, An earthquake cycle along the south flank of Kilauea Volcano, Hawaii: Journal of Geophysical Research, v. 99, no. B5, p. 9533-9541. 



 The intrusion of magma that led to the beginning of the January 3, 1983, eruption along the middle east rift zone of Kilauea Volcano, Hawaii, resulted in widening of the rift zone and compression of the adjacent portion of the south flank of the volcanic edifice. An earlier rift zone event, and subsequent eruption, on September 12, 1977, probably had a similar effect on the south flank. The compression built up since 1977 was relieved by a M = 6.1 earthquake on June 26, 1989. Horizontal displacements associated with the earthquake, determined by using the Global Positioning System (GPS), indicated seaward movement of the south flank of as much as 300 mm. Vertical displacements, measured by a conventional leveling technique and by GPS, indicated subsidence of as much as 250 mm near the east edge of the aftershock zone. These ground displacements can be modeled by horizontal slip of 1.2 m at an average depth of 6 km. The geodetic moment was 1 x 1026 dyn cm, a factor of 2 greater than the seismic moment, indicating a significant amount of ground movement was aseismic. The geodetic moment associated with the 1977 and 1983 rift zone events was about 0.8 x 1026 dyn cm, nearly equal to the geodetic moment of the 1989 south flank earthquake. The 6-km depth of average slip during the earthquake was well above the 9-km depth of the base of the volcano, which indicates the average depth where strain was released by the 1989 earthquake was well within the volcanic edifice. The strain released by the earthquake, and the initial compression caused by rift zone intrusions, occurred over a range of depths, indicating the south flank behaves more as a large elastic spring coupled to a sliding mass rather than a rigid block sliding along the base of the volcano.



Dvorak, J.J., and Dzurisin, D., 1997, Volcano geodesy: the search for magma reservoirs and the formation of eruptive vents: Reviews of Geophysics, v. 35, no. 3, p. 343-384. 



 Routine geodetic measurements are made at only a few dozen of the world's 600 or so active volcanoes, even though these measurements have proven to be a reliable precursor of eruptions. The pattern and rate of surface displacement reveal the depth and rate of pressure increase within shallow magma reservoirs. This process has been demonstrated clearly at Kilauea and Mauna Loa, Hawaii; Long Valley caldera, California; Campi Flegrei caldera, Italy; Rabaul caldera, Papua New Guinea; and Aira caldera and nearby Sakurajima, Japan. Slower and lesser amounts of surface displacement at Yellowstone caldera, Wyoming, are attributed to changes in a hydrothermal system that overlies a crustal magma body. The vertical and horizontal dimensions of eruptive fissures, as well as the amount of widening, have been determined at Kilauea, Hawaii; Etna, Italy; Tolbachik, Kamchatka; Krafla, Iceland; and Asal-Ghoubbet, Djibouti, the last a segment of the East Africa Rift Zone. Continuously recording instruments, such as tiltmeters, extensometers, and dilatometers, have recorded horizontal and upward growth of eruptive fissures, which grew at rates of hundreds of meters per hour, at Kilauea; Izu-Oshima, Japan; Teishi Knoll seamount, Japan; and Piton de la Fournaise, Reunion Island. In addition, such instruments have recorded the hour or less of slight ground movement that preceded small explosive eruptions at Sakurajima and presumed sudden gas emissions at Galeras, Colombia. The use of satellite geodesy, in particular the Global Positioning System, offers the possibility of revealing changes in surface strain both local to a volcano and over a broad region that includes the volcano.

Introduction 343

Volcanoes as dynamic landscapes 344

 Magma mixing

 Development of large intrusions

 Geophysical evidence of shallow magma

 Hydrothermal systems

 Sills, laccoliths, plugs, and dikes

 Linear dike swarms

How far and how fast 350

 Long-term displacements

 Sakurajima

 Campi Flegrei

 Long Valley

 Kilauea

 Development of fissures

 Development of central vents

Visualizing the source of ground movement 359

 Point source of dilation

 Plane strain

 Three-dimensional sheet models

Watching volcanoes grow 365

 Shallow basaltic reservoirs

 Rate of magma movement

 Resurgent domes

 Long-term subsidence of calderas

 Growth of eruptive fissures

 Explosive eruptions

 Predicting volcanic activity

The coming revolution 375

Acknowledgments 377

References 378



Dziak, R.P., Fox, C.G., and Schreiner, A.E., 1995, The June-July 1993 seismo-acoustic event at CoAxial Segment, Juan de Fuca Ridge: evidence for a lateral dike injection: Geophysical Research Letters, v. 22, no. 2, p. 135-138. [NOAA, Pacific Marine Environmental Laboratory Contrib. No. 1527.] 



 The CoAxial segment (Juan de Fuca Ridge) was the site of an intense swarm of earthquakes that began at 21:43 GMT on June 26, 1993 (Julian Day 177). The swarm started near 4615'N and migrated northward over the next 40 hours to ~4636'N, where the majority of 676 events occurred during the following 3 weeks of activity. The earthquakes propagated NNE at a velocity of 0.3  0.1 m s-l from the southern to northern swarm sites. The activity went undetected by land-based seismic networks along the Oregon and Washington coasts, suggesting that the earthquakes were all M 4.0. The character of this earthquake swarm is very similar to dike injections observed at Krafla and Kilauea Volcanoes. The earthquake activity and subsequent migration probably represent a lateral dike injection into faults and fissures comprising the CoAxial segment. The reservoir acting as the dike's source likely resides beneath, or to the south of, the initial southern swarm of earthquakes. The large magma supply at Axial Volcano cannot be ruled out as the source for the CoAxial dike, even though Axial Volcano exhibited no earthquake activity related to the CoAxial swarm. The T-wave earthquake swarm reported here is the first deep-ocean observation of volcanic seismicity associated with what most likely was a mid-ocean ridge dike injection event.



Dzurisin, D., Anderson, L.A., Eaton, G.P., Koyanagi, R.Y., Lipman, P.W., Lockwood, J.P., Okamura, R.T., Puniwai, G.S., Sako, M.K., and Yamashita, K.M., 1978, Analysis of the magma budget at Kilauea Volcano: November 1975-September 1977 [abs.]: Eos, Transactions, American Geophysical Union, v. 59, no. 12, p. 1213. [AGU fall meeting, San Francisco, CA, Dec. 4-8, 1978, Program and abstracts] 



 Following a 22-month hiatus in eruptive activity, Kilauea Volcano on the island of Hawaii extruded roughly 35 x 106 m3 of tholeiitic basalt from vents along her middle East Rift Zone from 13 September to 1 October 1977. The lengthy preclude to this latest eruption began with a magnitude 7.2 earthquake in November 1975, and included rapid summit deflation episodes in June 1976, July 1976, August 1976, and February 1977. Synthesis of seismic, geodetic, gravimetric, and electrical self-potential observations leads to the following model of this atypical Kilauea eruptive cycle.

 Simultaneous leveling and micro-gravity observations suggest that 40-80 x 106 m3 of microfractures were emptied or created within Kilauea's summit magma chamber as a result of the November 1975 earthquake. If these fractures were filled by magma from depth before the East Rift intrusive event of June 1976, the average rate of supply was 6-12 x 106 m3/month.

 Seaward movement of Kilauea's south flank during and immediately after the November 1975 earthquake caused significant dilation of the volcano's upper and middle East Rift Zone. A rough estimate of the net volume change implied by observed surface extensions across the rift is 150 x 106 m3. At the rate of magma supply calculated above, 12-24 months would be required to fill this newly-created volume. The September 1977 eruption occurred 15 months after the first East Rift intrusive event, and roughly 3-6 months' supply was extruded. Although complications will likely arise, these results suggest that quantitative modelling of the magma budget at Kilauea may now be feasible.



Dzurisin, D., Anderson, L.A., Eaton, G.P., Koyanagi, R.Y., Lipman, P.W., Lockwood, J.P., Okamura, R.T., Puniwai, G.S., Sako, M.K., and Yamashita, K.M., 1980, Geophysical observations of Kilauea Volcano, Hawaii, 2. Constraints on the magma supply during November 1975-September 1977, in McBirney, A.R., ed(s)., Gordon A. Macdonald Memorial Volume (special issue): Journal of Volcanology and Geothermal Research, v. 7, no. 3/4, p. 241-269. 



 Following a 22-month hiatus in eruptive activity, Kilauea volcano extruded roughly 35 x 106 m3 of tholeiitic basalt from vents along its middle east rift zone during 13 September 1 October, 1977. The lengthy prelude to this eruption began with a magnitude 7.2 earthquake on 29 November, 1975, and included rapid summit deflation episodes in June, July, and August 1976 and February 1977. Synthesis of seismic, geodetic, gravimetric, and electrical self-potential observations suggests the following model for this atypical Kilauea eruptive cycle.

 Rapid summit deflation initiated by the November 1975 earthquake reflected substantial migration of magma from beneath the summit region of Kilauea into the east and southwest rift zones. Simultaneous leveling and microgravity observations suggest that 40-90 x 106 m3 of void space was created within the summit magma chamber as a result of the earthquake. If this volume was filled by magma from depth before the east rift zone intrusive event of June 1976, the average rate of supply was 6-13 x 106 m3/month, a rate that is consistent with the value of 9 x 106 m3/month suggested from observations of long-duration Kilauea eruptions.

 Essentially zero net vertical change was recorded at the summit during the 15-month period beginning with the June 1976 intrusion and ending with the September 1977 eruption. This fact suggests that most magma supplied from depth during this interval was eventually delivered to the east rift zone, at least in part during four rapid summit deflation episodes. Microearthquake epicenters migrated downrift to the middle east rift zone for the first time during the later stages of the February 1977 intrusion, an occurrence presumably reflecting movement of magma into the eventual eruptive zone. This observation was confirmed by tilt. surveys in May 1977 that revealed a major inflation center roughly 30 km east of the summit in an area of anomalous steaming and forest kill first noted in March 1976.

 Seaward movement of the south flank of the volcano during and immediately after the November 1975 earthquake caused significant dilation of the upper and middle east rift zone. A rough upper estimate of the net volume change implied by observed surface extensions across the rift is 100 X 106 m3. At the rate of magma supply calculated from summit leveling and gravity data, 8-18 months would be required to fill this newly created volume. The September, 1977 eruption occurred 15 months after the first intrusive event, and roughly 3 months supply of magma was extruded. In addition to the magma that presumably filled newly created space within the east rift zone, an unknown volume of newly delivered magma was responsible for net uplift of the eruptive zone during the September 1977 eruption. We therefore propose that the total volume of magma supplied to Kilauea volcano from its mantle source during the period November 1975-September 1977 (130-280 X 106 m3) was partitioned as follows: (1) 40-90 X 106 m3 to refill newly created void space within the summit magma chamber, (2) 100 X 106 m3 to occupy new volume within the east rift zone, (3) 35 X 106 m3 extruded, and (4) 0-55 x 106 m3 responsible for net uplift of the eruptive zone. Although complications will likely arise, these values suggest that quantitative modeling of the magma supply at Kilauea may now be feasible, given adequate geophysical surveillance of the summit region and rift zones.



Dzurisin, D., and Koyanagi, R.Y., 1981, Changed magma budget since 1975 at Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 62, no. 45, p. 1071. [AGU fall meeting, San Francisco, CA, Dec. 7-11, 1981, Program and abstracts] 



 A new method of estimating the magma supply to Kilauea Volcano, based on summit deformation as recorded by a 3 m water-tube tiltmeter in Uwekahuna vault on the northwest caldera rim, gives results that compare favorably with estimates for specific intervals by other workers. Our calculations suggest that the apparent magma supply to Kilauea decreased from roughly 8 x 106 m3/mo during 1956-75 to roughly 5 x 106 m3/mo during 1976-80. This decrease may reflect disruption of Kilauea's magma plumbing system by a magnitude of 7.2 earthquake in November 1975, most notably through increased leakage from a summit magma reservoir into the volcano's rift zones. The historical pattern of antithetic behavior of Kilauea and neighboring Mauna Loa suggests that reawakening of Mauna Loa in 1975 after 25 years of quiescence may also have affected the magma supply to Kilauea in some unknown way. In either case, we suspect that the next few years at Kilauea will extend the period of relative quiescence prevalent since 1975. Frequent shallow intrusions into the rift zones most often will not culminate in surface eruptions until the volcano's adjustment to the 1975 earthquake is more nearly complete.



Eaton, J.P., 1957, Seismometric results from recent Hawaiian earthquakes [abs.]: Geological Society of America Bulletin, v. 68, no. 12, pt. 2, p. 1853. 



 Travel-time studies of some recent Hawaiian earthquakes indicate that the M discontinuity lies as shallow as 15 km below sea level under the island of Hawaii. Velocities of P and S below this discontinuity are about 8.25 km/sec and 4.75 km/sec, respectively.

 Earthquakes of moderate size originate at depths of at least 30 km, well below the M discontinuity. One such earthquake stemming from a focus about 30 km deep and 10 km south of Kilauea caldera on August 14, 1955, awakened people in Honolulu 350 km from the epicenter and was felt on the island of Kauai 500 km from the epicenter; yet it caused no significant damage to structures in the epicentral area. The deepest earthquakes recorded during the last 2 years have been small. Several swarms of tiny earthquakes accompanying "spasmodic tremor" originated at depths approaching 60 km in the vicinity of Kilauea caldera.



Eaton, J.P., 1957, Earthquakes accompanying the 1955 eruption of Kilauea [abs.]: Geological Society of America Bulletin, v. 68, no. 12, pt. 2, p. 1853. 



 The 1955 eruption of Kilauea was attended by two remarkable series of earthquakes The first series originated along the east rift zone of Kilauea where the volcano split open and poured out the lava of the 1955 eruption. These earthquakes appear to have been closely related to the actual splitting open of the fissures that led the eruption. The second series originated in and around Kilauea caldera in response to the subsidence of the crown of the volcano which accompanied the outpouring of lava along the east rift zone.

 Both of these groups were characterized by large numbers of very small earthquakes punctuated at intervals by earthquakes of moderate size. Between February 23 and March 26 about 7500 earthquakes stemmed from the east rift zone eruption area. Between March 6 and April 16 about 11,000 earthquakes, on the average a little smaller than the east rift zone earthquakes, originated in or near Kilauea caldera.

 Harmonic tremor of two distinct origins was recorded during the eruption. Rather long period (0.8 to 1.0 sec ) harmonic tremor was generated in the eruption area while lava was being extruded at the surface. From March 7 to March 19 minute, short-period (0.3 to 0.5 sec ) harmonic tremor originated, apparently at a depth of 15 to 30 km, in the vicinity of Kilauea caldera. During the first 5 days of this short-period tremor no lava emerged at the surface.



Eaton, J.P., and Fraser, G.D., 1957, Hawaiian Volcano Observatory summary 7--July-September 1957: U.S. Geological Survey Administrative Report, 8 p. 



 A summary of the volcanic conditions, seismicity, and seismographic tilt during the quarter.



Eaton, J.P., and Murata, K.J., 1960, How volcanoes grow: Science, v. 132, no. 3432, p. 925-938. 



 "Summarizing the state of volcanological knowledge in 1952, Howel Williams observed: "Much has been learned about the distribution, internal structure, and products of volcanoes, but pitifully little about the causes and mechanism of eruption." To remedy this deficiency he called for more intensive, continuous observations of well-chosen active volcanoes, with geophysics and geochemistry supplementing the traditional tools of geology. Current investigations of the U.S. Geological Survey's Hawaiian Volcano Observatory are much like those envisaged by Williams, and they are yielding an exciting new insight into the internal workings of volcanoes.

 No volcano has influenced our conception of the vital processes of active volcanism more than Kilauea. Geologists drawn to Hawaii by travelers' accounts of fantastic activity at this volcano were so impressed by what they saw that they framed whole theories of volcanic action around it. Even though its prime attraction, the renowned lava lake that circulated almost continuously within its great summit caldera for at least a century, was destroyed in 1924, Kilauea and its giant neighbor, Mauna Loa, have remained very active, one or the other having erupted about once in two years since that date. The comparative simplicity, the large size, and the frequent, voluminous, nonviolent eruptions of Hawaiian volcanoes make them ideally suited to illustrate the fundamental processes of volcanism. Here these processes can be studied safely and conveniently, in isolation from the great complications of structure and contaminating rocks that render most volcanoes so baffling."



Eaton, J.P., 1962, Crustal structure and volcanism in Hawaii, in Crust of the Pacific Basin: American Geophysical Union Geophysical Monograph 6, p. 13-29. [National Academy of Science, National Research Council Publication 1035] 



 Earthquakes in Hawaii are byproducts of volcanism; almost all of them occur beneath or near the island of Hawaii and its active volcanoes. Travel times of longitudinal waves indicate that the Mohorovicic discontinuity is depressed only a few kilometers beneath the Hawaiian Ridge, where it lies about 15 km below sea level. The pattern of ground deformation around the summit of Kilauea Volcano suggests that magma rising from a deep source accumulates slowly in a reservoir a few kilometers beneath the caldera and then is discharged rapidly during an eruption. This reservoir is the principal immediate source of lava discharged through a rift zone during a flank eruption. Periodic swarms of deep earthquakes from a zone in the mantle about 60 km beneath the summit of Kilauea outline a possible source of magma for the volcano. Swarms of small shallow earthquakes herald the opening of fissures within the volcano and provide short-term warnings of impending eruptions. More persistent swarms of somewhat larger, shallow earthquakes stem from widespread failure in rocks surrounding the summit reservoir during severe downwarping of the summit when the reservoir is deflated by an important flank eruption.



Eaton, G.P., and Lipman, P.W., 1977, Changes in deformation mode of Kilauea Volcano [abs.], in International Association of Volcanology and Chemistry of the Earth's Interior meeting, Durham, NC, Abstracts: International Association of Volcanology and Chemistry of the Earth's Interior, Abstracts, p. 235. 



 The 1975 M=7.2 earthquake on Kilauea's south flank has notably modified deformation patterns on the volcano. Rates of horizontal and vertical deformation at the summit have been very high (several mm/day) in the 20th century, mainly reflecting inflation-deflation cycles related to eruptive activity as magma accumulated in or was withdrawn from a 2-3 km deep magma reservoir centered near the summit. The 1975 earthquake, on the seaward flank of Kilauea, involved major slumping of the entire south flank--a deformation pattern that geologic features suggest has occurred periodically in the past. Maximum vertical and horizontal changes (3.5 and 7-9 meters, respectively) occurred along the coast, but the entire volcano underwent major changes. Since the earthquake, deformation patterns have been complex. The volcano has been unable to maintain sustained inflation cycles similar to those of the recent past, and the dominant deformation pattern continues to be sizable southward displacement of the flank, presumably continued adjustment to effects of the 1975 earthquake. There has been no eruption at Kilauea during this interval, the longest period of inactivity in more than 10 years. Precise gravity and self-potential measurements, recently added to the surveillance network, have also aided the interpretation of important changes in the shallow subsurface region of the volcano.



Eissler, H., and Kanamori, H., 1985, A single-force source model for the 1975 Kalapana, Hawaii earthquake [abs.]: Eos, Transactions, American Geophysical Union, v. 66, no. 18, p. 307. [AGU spring meeting, Baltimore, MD, May 27-29, 1985, Program and abstracts] 



 Reassessment of long-period surface waves from the 1975 Ms =7.1 Kalapana, Hawaii, earthquake from the WWSSN, HGLP, and IDA networks shows that the event's long-period source can be best represented by a single force. The earthquake involved slumping of a large area of the south flank of Kilauea volcano. The azimuthal radiation pattern of 100 s spectral amplitudes of C2 Love waves observed at 17 WWSSN and HGLP stations is clearly two-lobed, as opposed to the four-lobed pattern expected for the double couple earthquake source. The Love wave spectral amplitudes reach a maximum of 2.7 cm s at an azimuth of N60E. Both the observed Love wave radiation pattern and long-period R2 and R3 Rayleigh waves, recorded at IDA stations, can be modeled with a single force source of magnitude lxl020 dynes, oriented N30W with a dip angle of -5, and a one-cycle sine wave time dependence of 180s duration. A single force mechanism, interpreted as the seismic signature of a landslide, was invoked by Kanamori and Given (1982) to explain the long-period radiation from the Mt. St. Helens eruption sequence. The Kalapana source is roughly two orders of magnitude larger than Mt. St. Helens in terms of peak force, and has about the same time duration. Local P-wave first motion data from the HVO network indicate that the Kalapana event began as a small double couple source. Our interpretation is that as the event progressed, the upper slide block became increasingly decoupled from the earth. On-land subsidence, though large, cannot explain the long time constant; we propose that progressive slumping of the undersea south flank extended tens of kilometers beneath the ocean.



Eissler, H.K., and Kanamori, H., 1986, Depth estimates of large earthquakes on the island of Hawaii: Journal of Geophysical Research, v. 91, no. B2, p. 2063-2076. 



 Although hypocenters of earthquakes on the island of Hawaii are now routinely assigned to within 5 km, depth was a poorly determined parameter until the early 1960's. However, the 1950-1960 period was very active both in volcanic eruptions and large earthquakes. Source depths for the 12 largest Hawaiian earthquakes (magnitude 6 or greater) since 1940 are estimated from the ratios of body and surface wave amplitudes recorded at Pasadena, California. Excitation functions for Rayleigh waves are calculated as a function of source depth for the two dominant periods in the Pasadena records, 8 s and 20 s. Theoretical body wave amplitudes are determined from synthetic seismograms. Calculated ratios are very sensitive to source depth, for example, amplitudes of 8-s Rayleigh waves diminish by a factor of 300 between depths of 10 km and 50 km. This is a much larger effect than the fault geometry, which we estimate to be a factor of 4 between representative focal mechanisms. Estimated depths for post-1960 earthquakes agree fairly well with the instrumental depths. In general, large earthquakes near the volcanic flanks and fault systems are shallow ( 20 km). Two earthquakes of magnitude 6 occurred under the volcanoes Mauna Loa (in 1950) and Kilauea (in 1951); they preceded major eruptions by 3 days and 14 months, respectively, and had the largest depth estimates at 40-55 km and 35-50 km. Ms values assigned from global amplitudes are compared with those assigned from Pasadena amplitudes alone. for 70 events in 1973-1974 with 5.1 Ms6.0. The global values are only slightly larger (0.05 magnitude units) than the Pasadena values, indicating that Pasadena amplitudes are on the average representative of the event magnitude.



Eissler, H.K., 1986, Investigations of earthquakes and other seismic sources in regions of volcanism: Pasadena, CA, California Institute of Technology, Ph.D. dissertation, 179 p. 



 Outline

Acknowledgments		ii

Abstract		iii

 Source properties of earthquakes in Hawaii and seismological aspects of explosive volcanic eruptions are examined in three chapters. In Chapter 1, source depths are estimated for all earthquakes larger than magnitude 6 on the island of Hawaii since 1940 by comparing relative amplitudes of short-period surface waves to body waves. Rayleigh wave excitation functions are calculated versus source depth, and the calculation is compared with observed data and calibrated using known depths of recent earthquakes. In general, results show that large earthquakes near the volcanic flanks and fault systems are shallow ( 20 km), but those near active volcanic centers can be deeper (~ 50 km). Two earthquakes with the largest depth estimates (40-55 km and 35-50 km) occurred under the active volcanoes Mauna Loa and Kilauea, preceding eruptions by three days and 14 months respectively. As a check on the data set, which consisted of Pasadena seismograms alone, Ms values assigned from many global amplitude readings were compared with those from Pasadena amplitudes for worldwide earthquakes. Global Ms values on the average are 0.05 magnitude units larger than Ms values from Pasadena amplitudes.

 In Chapter 2, the horizontal single-force source used to model seismic radiation from the Mt. St. Helens landslide is investigated as the source of the Ms = 7.1 Kalapana, Hawaii earthquake. The azimuthal radiation pattern of 100 s Love waves is two-lobed, consistent with a horizontal single-force source. The observed surface deformation is also more consistent with the single force than the conventional double-couple shear dislocation source. The single force is a crude representation of motion of a large slide mass that is partially decoupled from the Earth. The interpretation is that the bulk of seismic radiation from the Kalapana earthquake was produced by large-scale slumping of the south flank of Kilauea volcano. The peak amplitude f0 of the force time function is estimated at 1 x 1020 dyne from Love and Rayleigh surface waves. The peak acceleration inferred from the seismic force is l0-100 cm s-2, comparable to that of gravity on a gently inclined plane.

 In Chapter 3, far-field seismograms were searched for signals associated with recent large volcanic eruptions to examine whether models of the volcano as a seismic source derived for Mt. St. Helens are applicable to other explosive volcanoes. The 1982 eruption of El Chichon in Mexico produced Rayleigh waves and body waves that were marginally recorded at IDA and SRO stations less than 40 away; still, several characteristics of the eruption can be inferred from the seismic waves. Near-field seismograms of smaller eruptions at Mt. Asama, Japan, were found to be comparable in size to smaller secondary eruptions of Mt. St. Helens, and appear to have a more complicated source. Atmospheric pressure waves recorded on barographic instruments from several large explosive eruptions are compared and show differences in signal duration, amplitude, and characteristic period that are indicative of the overall size of the eruption.Introduction		1

Chapter 1: Depth Estimates of Large Earthquakes on the Island of Hawaii Since 1940

 1. Introduction 	6

 2. Earthquake Data 		7

 3. Analysis		20

 4. Discussion		38

 5. Conclusions 		43

 6. References		45

Chapter 2: A Single-Force Model for the 1975 Kalapana, Hawaii Earthquake

 A single force mechanism is investigated as the source of long-period seismic radiation from the 1975 Kalapana, Hawaii earthquake (Ms = 7.1). The observed Love wave radiation pattern determined from the spectra of WWSSN and HGLP records at 100 s is two-lobed with azimuth, consistent with a near-horizontal (dip ~ 10) single force acting opposite (strike

330 ) to the observed displacement direction of the earthquake; this pattern is inconsistent with the expected double-couple pattern. Assuming a form of the force time history of a one-cycle sinusoid, the total duration of the event estimated from Rayleigh waves at two IDA stations is approximately 180 s. The peak amplitude f0 of the time function is 1 x 1020 dyne from amplitudes of Love and Rayleigh waves. The interpretation is that the bulk of the seismic radiation was produced by large-scale slumping of a large area of the south flank of Kilauea volcano. The single force is a crude representation of motion of a large slide mass that is partially decoupled from the Earth. Using the mass estimated from the tsunami generation area (1018- 1019 grams), the peak acceleration of the slide block (10 - 100 cm s-2) inferred from the seismic force is comparable with the acceleration due to gravity on a gently inclined plane. The slump model for the Kalapana earthquake is also more qualitatively consistent with the large horizontal deformation (8 m on land) and tsunami associated with the earthquake, which are difficult to explain with the conventional double-couple source model. The single force source has been used previously to model the long-period seismic waves from the landslide accompanying the eruption of Mt. St. Helens volcano, and may explain other anomalous seismic events where the predominant mechanism is massive slumping of sediments or unconsolidated material and not elastic dislocation planes, eventually disintegrating into a massive rubble slide or flow to produce a complex and sustained seismic event.

 1. Introduction		52

 2. Long-Period Love Wave Radiation Pattern		65

 3. Rayleigh Wave Analysis		73

 4. Discussion		82

 5. Conclusions 		89

 6. References		92

Chapter 3: Investigation of Global Seismic and Atmospheric Signals Associated

 with Explosive Volcanic Eruptions

 1. Introduction		98

 2. Proposed Source of Seismic Radiation		102

 3. Summary of Results from Mt. St. Helens		108

	4. Seismic Observations of El Chichon, Chiapas, Mexico	114

	5. Lamb Pulses from Mt. Asama, Japan	143

	6. Atmospheric Waves Observed from Large Explosive Eruptions	153

	7. Conclusions	167

	8. References 	169



Eissler, H.K., and Kanamori, H., 1987, A single-force model for the 1975 Kalapana, Hawaii earthquake [abs.], in Decker, R.W., Halbig, J.B., Hazlett, R.W., Okamura, R., and Wright, T.L., ed(s)., Hawaii Symposium on How Volcanoes Work, Hilo, HI, January 19-25, 1987, Abstract volume: Honolulu, University of Hawaii, Hawaii Institute of Geophysics, p. 62. 



 We investigate a single-force mechanism as the source of the long-period seismic radiation from the 1975 Kalapana, Hawaii earthquake (Ms = 7.1). This is the same force system used to successfully explain the long-period seismic waves from the May 18, 1980 eruption sequence of Mt. St. Helens; in that case, the single force was interpreted as the counter force on the Earth produced by motion of part of the volcanic slope as it failed in a massive landslide. The observed Love wave radiation pattern from the Kalapana earthquake determined from the spectra of WWSSN and HGLP records at 100 s is two-lobed with azimuth, consistent with a near-horizontal single force acting opposite (azimuth  330) to the observed displacement direction of the earthquake. This pattern is inconsistent with the expected double-couple pattern, which is four-lobed. Assuming a one-cycle sinusoid for the time history of the force, the total duration of the event estimated from Rayleigh wave forms at 2 IDA stations is approximately 180 s, with an acceleration phase and a deceleration phase. The long inferred duration is consistent with the large tsunami associated with the event. The peak amplitude fo of the force time function is estimated from the amplitude of Love and Rayleigh waves to be l x 1020 dyne, two orders of magnitude larger than the peak force of the Mt. St. Helens landslide. Our estimate of the mass of the displaced block in the Kalapana earthquake (from the tsunami generation area and hypocenter) is 1018- 1019 grams, compared with 5 x 1015 grams for the Mt. St. Helens landslide.

 We interpret the single-force source of the Kalapana earthquake as the expression of the motion of a large block of the south flank of Kilauea volcano that is essentially decoupled from the Earth. Decoupling of the upper block; is necessary for the source to approach a single force, as opposed to the usual double couple. The relative amplitude of Love to Rayleigh waves constrains the force to be near horizontal (10 updip or downdip). The single force model is consistent with both types of models that have been proposed for the Kalapana earthquake: a passive magmatic process where the south flank slumps due to gravitational instability, creating "room" for magma to move into the East Rift Zone of Kilauea volcano, or an active magmatic process where magma injection into the East Rift Zone forces seaward displacement of the south flank of the volcano.



Eissler, H.K., and Kanamori, H., 1987, A single-force model for the 1975 Kalapana, Hawaii earthquake: Journal of Geophysical Research, v. 92, no. B6, p. 4827-4836. 



 A single force mechanism is investigated as the source of long-period seismic radiation from the 1975 Kalapana, Hawaii, earthquake (Ms = 7.1). The observed Love wave radiation pattern determined from the spectra of World-Wide Standard Seismograph Network and High Gain Long Period records at 100 s is two-lobed with azimuth, consistent with a near-horizontal single force acting opposite (strike ~330) to the observed displacement direction of the earthquake; this pattern is inconsistent with the expected double-couple pattern. Assuming a form of the force time history of a one-cycle sinusoid, the total duration of the event estimated from Rayleigh waves at two International Deployment of Accelerometers stations is approximately 180 s. The peak amplitude fo of the time function is 1 x 1015 N from amplitudes of Love and Rayleigh waves. The interpretation is that the bulk of the seismic radiation was produced by large-scale slumping of a large area of the south flank of Kilauea volcano. The single force is a crude representation of the effect on the earth of the motion of a partially decoupled large slide mass. Using the mass estimated from the tsunami generation area (~ 1015-1Ol6 kg), the peak acceleration of the slide block (0.1-1 m s-2) inferred from the seismic force is comparable with the acceleration due to gravity on a gently inclined plane. The slump model for the Kalapana earthquake is also more qualitatively consistent with the large horizontal deformation (8 m on land) and tsunami associated with the earthquake, which are difficult to explain with the conventional double-couple source model. The single-force source has been used previously to model the long-period seismic waves from the landslide accompanying the eruption of Mount St. Helens volcano, and may explain other anomalous seismic events as being due to massive slumping of sediments or unconsolidated material and not to elastic dislocation.



Eissler, H.K., and Kanamori, H., 1988, Reply to comment on "A single-force model for the 1975 Kalapana, Hawaii, earthquake" by Wyss, M. and Kovach, R.L.: Journal of Geophysical Research, v. 93, no. B7, p. 8083-8084. 



 "As we discussed above, we believe that the two-lobed Love wave radiation pattern is real and can be best explained by a single-force model. Obviously, the actual source process is likely to be more complex than one that can be represented by a simple single force. However, more complicated kinematic source models were not warranted because of the limited quality and quantity of the data available to us. The interpretation of the data from the Kalapana earthquake is not as clear as for the classic landslide associated with the eruption of Mount St. Helens, discussed by Kanamori and Given [1982]. Improvement of the source model may be possible in the future; for example, Kawakatsu [1987] has used digital HGLP data from the Kalapana earthquake at a few stations only recently compiled by the U.S. Geological Survey. These data are probably better than the analog records used by Eissler and Kanamori [1987]. Further analysis of the improved data set may be able to resolve more details of the source process associated with the 1975 Kalapana earthquake, but we believe that our primary conclusion that the long-period Love wave radiation pattern can be best explained by the single force will remain unchanged. We thank Wyss and Kovach for this opportunity to clarify our results."



Ellis, W., 1825, Narrative of a tour through Hawaii, or, Owhyhee: London, H. Fisher, Son, and P. Jackson, 264 p. [Simultaneously published in Boston by Crocker & Brewster. Reprinted 1826, 1827 in London by Fisher and Jackson; reprinted 1917 by the Hawaiian Gazette Co., Ltd., Honolulu; 1827 London ed. reprinted 1963 as Journal of William Ellis by the Advertiser Publishing Co., Ltd., Honolulu, 342 p.] 



 A description of a trip through the island of Hawaii in 1823 and of many of the physical features encountered. This is the earliest visit to Kilauea by persons other than Hawaiians or seamen. It is also the first detailed description of the geology and the eruptive activity. Ellis describes the island of Hawaii: "Perforated with innumerable apertures in the form of craters, the island forms a hollow cone over one vast furnace, situated in the heart of a stupendous submarine mountain rising from the bottom of the sea. . . ." He briefly describes an eruption of Hualalai, said to have occurred about 1800; he visited the source vents which were still fuming. On July 31, Ellis, on his way to the summit of Kilauea, visited Ponahohoa chasms on Kilauea's southwest rift zone. There he found a graben of recent origin. Two large open chasms were said to have formed 11 months before, and the graben, 2 months before, his arrival. The area was hot and fuming at the time; farther downrift Ellis saw recently-erupted lava associated with fractures in the graben. Ellis describes this lava, stating that the eruption had occurred 3 weeks before his visit. [The feature labeled Ponohohoa chasms on current maps cannot be what Ellis saw, as it is an area of older lava well uprift from the source of the 1823 eruption.] Ellis continued his journey, reaching the summit of Kilauea in July 1823, and described the appearance of Kilauea caldera. The "black ledge" was about 400 ft below the rim, and an active lava lake 300 or 400 ft lower still. [Ellis correctly realizes that the black ledge is visible because lava has drained away from the summit to feed the flank eruption of 1823.] Later in his trip, he stops at several places on the Puna coast, where he is treated to the following native accounts of a major earthquake that had been felt in Kaimu about two months before and which formed a crack one foot wide. 

"GREAT EARTHQUAKE AT KAIMU IN 1823

 We also examined the effects of an earthquake experienced in this place about two months before. We were informed that it took place about ten o'clock in the evening. The ground, after being agitated some minutes with a violent tremulous motion, suddenly burst open, for several miles in extent, in a direction from north by east, to south by west, and emitted, in various places at the same instant, a considerable quantity of smoke and luminous vapour, but none of the people were injured by it.

 A stone wall, four feet thick and six feet high, enclosing a garden at the north end of the village, was thrown down.

 A chasm about a foot wide marked distinctly its course; this was generally open, though in some places it seemed as if the earth had closed up again.

AN EARTHQUAKE CHASM.

 We entered a house, sixteen feet by twelve in the inside, through which it had passed. Ten persons, viz. one man, six women, and three children, were asleep here at the time it occurred. They were lying on both sides of the house, with their heads towards the centre; some of them every near the place where the ground was rent open. The trembling of the ground, they said, awoke them, but before they could think what it was that had disturbed them, the earth opened with a violent percussion; a quantity of sand and dust was thrown up with violence, and smoke and steam were at the same time emitted.

 After a short interval, a second percussion was felt, vapour again arose, and at the opposite end of the house to that in which they were lying, they saw a light blue flame, which almost instantly disappeared.

 We asked them if they were not alarmed? They said they were at first, but after remaining awake some time, and finding the shock was not repeated, they lay down and slept till morning, when they filled up the fissure with grass and earth!

 We examined the aperture, that still remained open at one end of the house, and found its sides perpendicular, and its breadth one foot and eleven inches. The north-west corner of the house was broken by the shock.

TRACING THE EARTHQUAKE CRACK.

 We next traced its course through the fields of potatoes. In some places the ground seemed hardly disturbed, yet it sunk six or eight inches beneath our tread. At other places we saw apertures upwards of two feet wide. The potatoes that were growing immediately in the direction of the fissure, were all spoiled. Several roots of considerable size were thrown out of the ground, and, according to the representations of the natives, appeared as if they had been scorched.

 At the south end of the village, it had passed through a small well, in which originally there was seldom more than eighteen inches' depth of water, though since that period there has been upwards of three feet.

 The crack was about ten inches wide, running from north to south across the bottom of the well. The water has not only increased in quantity, but suffered a great deterioration in quality, being now very salt; and its rising and falling with the ebbing and flowing of the tide, indicates its connexion with the waters of the ocean, from which it is distant about 300 yards."

 No mention is made of a tsunami. [This was probably the earthquake responsible for the Ponahohoa graben.] Ellis describes traditional Hawaiian interpetations of Kilauea's volcanic activity, including recognition that lava could move underground from Kilauea summit and emerge as a flow close to the sea. He also summarizes native accounts of the past activity of Kilauea; he mentions an eruption in 1789 that destroyed part of Keoua's army, an eruption in Puna about 30 years prior to that event, as well as eruptions from Keanakakoi in the reign of Liloa, about 14 generations before. Ellis describes aa lava and accretionary lava balls, and recognizes how lava tubes originate. He also gives an excellent description and accurate interpretation of a lava cascade on the Kona coast [probably at Hookena beach]. He characterizes littoral cones as piles of cinder that have never been craters, describes and interprets the formation of Pele's hair, and describes olivine crystals and porphyritic lava with olivine and feldspar. He accurately interprets lava sequences with intercalated soil [saprolitic horizons], as marking a time of weathering between eruptions. He identifies the Kahuku Pali as a fault with the Kona side downdropped. Ellis speculates on volcanic plumbing, indicating that the volcanic furnace lies within the volcanic edifice, perhaps below the ocean floor. He has brief descriptions of Mauna Loa and Mauna Kea from Cook's voyage, and he recapitulates Goodrich's trip up Mauna Kea. [This book is a valuable resource for information on the early history of Kilauea. Ellis is a keen observer and listener, and his interpretations show great insight into volcanic processes, derived in part from his conversations with native Hawaiians.]



Ellsworth, W.L., 1976, Preliminary evaluation of teleseismic travel time residuals preceding the Hawaiian earthquake of 29 November 1975 [abs.]: Eos, Transactions, American Geophysical Union, v. 57, no. 4, p. 288-289. [AGU spring meeting, Washington, D.C., Apr. 12-15, 1976, Program and abstracts] 



 Mean teleseismic travel time residual data collected from a dense network of seismograph stations located atop the focal region of the shallow (depth = 5 km) MS = 7 Hawaiian earthquake of 29 November 1975 fail to show premonitory variations in travel time during the period 1970-1975. Relative residual values at all stations including one located 2.5 km from the epicenter fall within an absolute bound of 0.5 sec. Much of the scatter at these stations can be attributed to local heterogeneities in crust and mantle structure. Inversion of the residual data for a three-dimensional crust and mantle model allows no regional velocity fluctuations exceeding 2% in the six years preceding the earthquake. Comparison of crustal structure obtained from the inversion with results of refraction profiles conducted in 1964 imply a much longer term stability of the velocity. Saturation of the highly porous (10-20%) crustal rocks in the hypocentral zone with ground water offers a possible explanation for these negative findings. If dilatant cracks are assumed to have opened prior to failure, they would fill with water immediately, leaving the velocity unaffected by their presence.



Ely, J., 1825, [no title], in Missionary Letters, 8 v: Honolulu, HI, Hawaiian Mission Children's Society, v. 2, p. 686-688. [Letter to Jeremiah Evarts dated Kaawaloa, Kona, November 5, 1827] 



 [p. 686] . . . "Last night we were awakened from our quiet slumbers by the shock of an earthquake. It was much lighter than what is often expressed in this island though it shook our house very sensibly."

[p. 686-687] . . . "On the 6th of Jan. 1825 at half past eleven P. M. we experienced a heavy shock of an earthquake at the village of Kaawaloa. It was preceded by a rumbling noise and its motion was so rapid that it woke us from sleep and shook us violently. People who were standing were thrown suddenly to the earth and those who lay at full length were tossed from side to side. Many rocks and stone fell from the precipice with a tremendous crash which added not a little to the horror of the scene. At the hours of 2 and 3 of the same night two others were experienced much lighter than the one before described. The vibrations of the earth were from the N. E. to the S. W. terminating suddenly like the motion of a carriage slipping on a pavement."



Endo, E.T., 1971, Focal mechanisms for the May 15-18, 1970 shallow Kilauea earthquake swarm: San Jose State College, master's thesis, 164 p. 



 Since the origin of the Hawaiian Volcano Observatory in 1912, many earthquake swarms have been recorded at Kilauea Volcano. Among the most spectacular were the earthquake swarms that occurred during May 1938, August 1938, and December 1950. In these three cases earthquake activity was accompanied by extensive ground cracking on the upper east rift of Kilauea.

 From 1961 to 1969, 14 additional swarms of similar character have been described by various investigators. In each case seismic events had some relationship to volcanic inflations and eruptions on the east rift of Kilauea. During May 1970, the Hawaiian Volcano Observatory seismograph net recorded 4000 earthquakes from an area 1 to 6 kilometers east and southeast of Halemaumau Crater. For a sequence of earthquakes this first well recorded earthquake swarm produced 268 events that gave hypocenter solutions that are the best determined to date. Earthquake hypocenter depths ranged from near surface to depths approaching 6 kilometers. A migration of epicenters away from Kilauea Caldera on the east rift after the first hour of the earthquake swarm suggested the intrusion of magma along the east rift from the east edge of Kilauea Caldera. Of the located events, 50 gave quadrant distributions for the first motions of P. Fault plane solutions derived from equal area projections of P phases to various stations showed a systematic distribution of nodal planes that corresponds to observed geologic structure. In addition, inferred stress axes derived from the same equal area projection show a distribution expected for a zone close to the center of a volcano. A majority inferred maximum stress axes for events were found to parallel the trend of the east rift. The least stress axes were oriented perpendicular to the trend of the east rift. The focal mechanisms that we determined were consistent with movement observed on faults and cracks by previous investigators. Most of the events show a right lateral component of slip. The poles of the complementary nodal plane, which indicated the direction of slip, are generally horizontal or show up to 20 degrees of dip to the east.



Endo, E.T., Koyanagi, R.Y., and Okamura, A.T., 1972, Hawaiian Volcano Observatory summary 57--January, February, and March 1970: U.S. Geological Survey Administrative Report, 54 p. 



 A summary of the volcanic conditions, seismicity, and tilt during the quarter.



Endo, E.T., 1972, Focal mechanisms for the May 15-18, 1970, shallow Kilauea earthquake swarm [abs.]: Geological Society of America Abstracts with Programs, v. 4, no. 3, p. 155-156. [Geological Society of America, Cordilleran Section, 68th annual meeting, Honolulu, HI, Mar. 29-Apr. 1, 1972] 



 During May 1970, the Hawaiian Volcano Observatory seismograph net recorded 4,0O0 earthquakes from an area 1 to 6 km east and southeast of Halemaumau Crater. This well-recorded earthquake swarm produced 268 events that gave the best-determined hypocenter solutions to date for Kilauea. Earthquake hypocenter depths ranged from near surface to depths approaching 6 km. A migration of epicenters away from Kilauea Caldera on the east rift, after the first hour of the earthquake swarm, suggests the intrusion of magma along the east rift from the east edge of Kilauea Caldera. Fifty of the located events gave quadrant distributions for the first motions of P. Fault-plane solutions derived from equal-area projections of P phases to various stations showed a systematic distribution of nodal planes that corresponds to observed geologic structure. A majority or inferred maximum stress axes for events were found to be parallel to the trend of the east rift. The least stress axes were oriented perpendicular to the trend of the east rift. The focal mechanisms were consistent with movement observed on faults and cracks by previous investigators. Most of the events show a right-lateral component of slip.



Endo, E.T., Ward, P.L., Harlow, D.H., Allen, R.V., and Eaton, J.P., 1975, A prototype global volcano surveillance system monitoring seismic activity and tilt: Bulletin Volcanologique, v. 38, no. 2, p. 315-344. 



 The Earth Resources Technology Satellite makes it feasible for the first time to monitor the level of activity at widely separated volcanoes and to relay these data almost instantaneously to one central office, This capability opens a new era in volcanology where the hundreds of normally quiescent but potentially dangerous volcanoes near populated regions around the world can be economically and reliably monitored, A prototype global volcano surveillance system has been established beginning in the fall of 1972 with the help of local scientists on 15 volcanoes in Alaska, Hawaii, Washington, California, Iceland, Guatemala, El Salvador, and Nicaragua, Data on earthquake activity and ground tilt are received 6 to 10 times daily in Menlo Park, California, within 90 minutes of transmission from the sites, Seismic events counters were installed at 19 locations with biaxial borehole tiltmeters with 1 microradian sensitivity installed at seven sites, Direct comparison of seismic events that are counted with records from nearby seismic stations show the event counters work quite reliably, An order of magnitude increase in seismic events was observed prior to the eruption of Volcan Fuego in Guatemala in February, 1973, Significant changes in tilt were observed on volcanoes Kilauea, Fuego, and Pacaya, This study demonstrates the technological and economic feasibility of utilizing such a volcano surveillance system throughout the world.



Endo, E.T., Koyanagi, R.Y., and Klein, F.W., 1978, Geologic and seismic evidence for strike-slip faulting between Kilauea and Mauna Loa Volcanoes, Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 59, no. 12, p. 1207. [AGU fall meeting, San Francisco, CA, Dec. 5-9, 1977, Program and abstracts] 



 A recently discovered zone of cracks on the southeast slope of Mauna Loa confirms right-lateral strike-slip faulting suggested by seismic data. The zone lies at 1610 m elevation and is approximately 8 km northwest of a topographically prominent but inactive step fault that strikes N 43 E. The cracks trend east-west and show northeast-southwest opening. A few cracks have more than 0.2 m gaps and one fissure was traced for more than 100 m. Some vertical offset was observed, but may be local to a few cracks. Compression ridges trending north-south were also observed. The cracks appear to form a zone of en echelon tension fissures. The offset to the left is consistent with right-lateral shear suggested by focal mechanism studies of a 1974 magnitude-5.5 earthquake that was located less than 2 km north of the crack zone. The cracks are located in the aftershock region of the earthquake which is nearly equidistant between the two active volcanoes Mauna Loa and Kilauea. Inferred maximum (compression) axes for the mainshock and aftershocks parallel a line joining the two volcanoes.



Endo, E., 1978, Focal mechanisms of large magnitude earthquakes associated with a magma intrusion into a rift system of Kilauea [abs.], in, Workshop on Active and Passive Seismic Methods Applied to Geothermal Systems (APSMAGS), Taos, N.M., Oct. 1-5, 1978, [Abstracts]: Taos, NM, Ft. Burgwin Research Center, p. 60. 



 For a well documented eruption and magma intrusion into the southwest rift system of Kilauea, earthquake focal mechanisms suggest strike-slip faulting as the dominant type of faulting associated with the intrusion process. During a ten day period, extending from 4 hours after the cessation, of eruptive activity of the December 31, 1974 eruption, 42 earthquakes with body wave magnitudes ranging from 3.5 to 5.3 were recorded by the observatory network. Thirty two events gave well constrained focal mechanism solutions. The orientation of inferred maximum and least stress axes for the events were consistent with the trend of the southwest rift zone of Kilauea. Maximum stress axes (pressure) were oriented parallel to the rift system and least stress axes ( tension) were oriented perpendicular to the rift. A 20 degree mean dip for the least stress axes point out the possibility of a 70 to 80 degree dip of the rift to the east. The trend of epicenter locations and a current understanding of Kilauea suggest a preferred nodal plane which strikes N171 with a dip of 80 degrees to the east. Right lateral strike-slip motion on this plane is consistent with other studies of Kilauea which indicate that the south flank of Kilauea is moving to the south in response to forceful intrusion into the rift systems.



Endo, E.T., 1985, Seismotectonic framework for the southeast flank of Mauna Loa Volcano, Hawaii: Seattle, University of Washington, Ph.D. dissertation, 349 p. 



 This dissertation places available geologic and seismic evidence for the southeast flank of Mauna Loa volcano into a framework that is consistent with the lateral growth of the volcanic edifice. The southeast flank of Mauna Loa is characterized by two seismically active areas: 1) the Kaoiki located between the active summit calderas of Mauna Loa and Kilauea volcanoes, 2) the Hilea area located approximately 10 km to the SE of the bend in the southwest rift of Mauna Loa. While low-angle faulting to the SE is common to both areas, the Kaoiki is dominated by right-lateral strike-slip faulting to the SW. Six of 8 earthquakes with local magnitudes ranging from 4.8 to 6.6 located within the Kaoiki from 1959 to 1983 were strike-slip events. The 7th was a normal faulting earthquake and the 8th mechanism is undetermined.

 Surface breaks associated with 1974 and 1983 earthquakes confirm NE-SW right-lateral strike-slip faulting. En echelon and offset to the left vertical extension cracks oriented E-W and connecting N-S compression rock bridges support the interpretation of earthquake fault plane solutions that indicate right-lateral shear on a NE-SW plane. Within the uncertainties of the respective techniques, fault plane orientation and pressure axes directions inferred from fractures agree with earthquake mechanism data. The surface breaks documented in this dissertation are the first to be discovered in Hawaii that provide clear geologic evidence for right-lateral strike-slip faulting. The validation of the simplest type of earthquake focal mechanism provides confidence in low-angle faulting mechanisms and their interpreted relationship to the lateral growth of Mauna Loa.

 Within the Hilea area, low-angle thrust mechanisms were the only earthquake types from 1959 to 1983. Low-angle faulting and slip to the SE in both the Kaoiki and Hilea areas is a direct response to extension owing to dike emplacement from either the northeast rift or southwest rift of Mauna Loa and/or inflation of the summit magma reservoir. As in the case of the south flank of Kilauea, the oceanic crust-volcano interface is the primary zone of weakness along which slip occurs. A dilating magma chamber at the summit of Mauna Loa appears to be the principal cause for compressive stress within the Kaoiki that results in strike-slip faulting.

 

 TABLE OF CONTENTS

List of Figures vi

List of Plates xiii

List of Tables xv

Chapter 1. Introduction 1

 1.1. Objective 1

 1.2. The area of study 4

 1.3. Method and scope of study 6

 1.4. Terminology 10

 1.5. Subaerial Geology 11

 1.6. Principal Structural Features of Kilauea's South Flank 14

 1.7. Tectonics 17

 1.8. Historical seismicity 20

 1.8.1. The great earthquake of 1868 20

Chapter 2. Surface deformation 26

 2.1. Previous studies 26

 2.2. Summary of previous studies 36

 2.3. Tectonic geomorphology, 1978-1979 field work 39

 2.3.1. Mapping technique 40

 2.3.2. Features mapped 41

 2.3.2.1. En echelon extension cracks 41

 2.3.2.2. Popups 47

 2.3.2.3. Thrust faults 51

 2.3.2.4. Mole tracks 55

 2.3.2.5. Summary of fracture geometry 55

 2.4. November 1983 reconnaissance work 57

 2.4.1. Traverse 1 57

 2.4.2. Traverse 2 59

 2.4.3. Traverse 3 63

 2.4.4. Traverse 4 63

 2.4.5. Traverse 5 66

 2.4.6. Traverse 6 69

 2.4.7. Traverse 7 72

 2.4.8. Summary of 1983 field observations 72

Chapter 3. Seismicity 76

 3.1. Earthquake data

 3.2. Earthquake locations 79

 3.2.1. Velocity model

 3.2.2. Earthquake location procedure 81

 3.2.2.1. Experiments to improve relative hypocenter locations 82

 3.3. Earthquake focal mechanism studies 92

 3.3.1. Event Selection 92

 3.3.2. Earthquake focal mechanisms 101

 3.4. Interpretation of large magnitude earthquake focal mechanism solutions from 1959 to 1982 108

 3.4.1. Example fault plane solutions 108

 3.4.2. Spatial and temporal distribution of hypocenters for large magnitude earthquakes in the Kaoiki-Hilea region 108

 3.4.2.1. Strike-slip earthquakes 112

 3.4.2.2. Low angle faultlng earthquakes.120

 3.4.3. Temporal distribution of mechanism parameters 124

 3.4.3.1. Strike-slip earthquakes 124

 3.4.3.2. Low angle faulting events 133

 3.5. Kaoiki crustal earthquakes 1959 to 1984 143

 3.5.1. 1962-63 earthquakes 143

 3.5.2. 1974 earthquakes 150

 3.5.3. 1983 earthquakes 174

 3.6. Hilea crustal earthquakes from 1959 to 1982 204

 3.7. Relationship of earthquakes to mapped surface fractures 208

Chapter 4. Discussion and conclusions 211

 4.1. Summary of observations 211

 4.2. Summary of fault parameters 215

 4.2.1. Strike-slip faulting 215

 4.2.2. Low angle (thrust) faulting 216

 4.3. Proposed tectonic model 218

 4.3.1. Principal structural features 219

 4.4. Speculations 227

 4.4.1. The West flank of Mauna Loa 227

 4.4.2. Preferential direction of rift spreading 229

 4.4.3. The Ninole hills and the change in direction of the southwest rift of Mauna Loa 230

 4.5. Comments 230

List of References 234

Appendix A Extension fracture measurements 243

Appendlx B Seismic station parameters 247

Appendix C Large magnitude 1959-1982 earthquake focal mechanism solutions 257

Appendix D List of events for specific geographic groups of earthquakes relocated 326

Appendix E Upper mantle earthquake focal mechanism solutions 331

Appendix F Polarity reversal history 344

Pocket Material: Kaoiki Fracture Map



English, T.T., Koyanagi, R.Y., and Nakata, J.S., 1983, Automatic earthquake picker used to monitor the seismic swarm related to the 1983 eruption of Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 64, no. 45, p. 905. [AGU fall meeting, San Francisco, CA, Dec. 5-9, 1983, Program and abstracts] 



 An earthquake P-picker was installed in August 1982 at the Hawaiian Volcano Observatory (HVO). The system was designed and built by the U.S. Geological Survey to time P-wave arrivals and to determine preliminary epicenters of earthquakes. A program was prepared at the HVO to pass the picker output to a computer system running a more detailed algorithm, to improve hypocentral locations. Near-real-time processing of machine-picked output enabled us to track the progress of the earthquake swarm that preceded the major eruption of Kilauea in January 1983 faster and more completely than had previously been possible with manual picks. At 00:31 (H.S.T.) January 2, 1983 a seismic swarm began near Mauna Ulu on Kilauea's east rift. Shallow earthquakes migrated downrift at an average rate of 0.7 km/h over the next 12 hours. From about 13:00 January 2 until 00:31 January 3, earthquakes occurred along a 3-km-long zone between Napau Crater and Pu'u Kamoamoa, and culminated in a lava outbreak at Napau. More than 250 earthquakes were located during the pre-eruption swarm in sequential time increments based on changes in seismic pattern. This information, relayed by radio, kept field observers constantly alerted on the probable location of the impending eruption. On January 7, the seismic activity increased and migrated farther downrift. Field crews, alerted to this activity, later observed extensive ground cracking in the seismic area, where, at 09:57 January 7, a new series of vents opened. The earthquake swarm that set the stage for the 1983 major flank eruption of Kilauea was essentially over by January 8.



Eppley, R.A., 1965, Hawaii, in Earthquake history of the United States, pt. 1. Stronger earthquakes of the United States (exclusive of California and Western Nevada): U.S. Coast and Geodetic Survey Special Publication 41-1, p. 100-105. [Revised edition through 1963] 



 Seismic activity in the islands centers on the Island of Hawaii. Much of this activity is directly associated with volcanic processes since this is an active volcanic region. However, the stronger shocks that are sometimes felt over all the islands are of tectonic origin. The greatest known earthquake occurred in 1868 and was extremely violent and destructive, considering the sparsely settled nature of the island. Shocks north of Hawaii are often felt strongly on Maui, Lanai and Molokai.

 [Earthquakes between 1834 and 1963 are tabulated with date, time, locality, latitude, longitude, area, intensity, authority, and brief account of damage sustained. The 1868 earthquake is listed as "Major" with a somewhat fuller description.]



Estill, R., and Odegard, M., 1977, Seismicity and velocity structure of the Hawaiian Ridge [abs.]: Eos, Transactions, American Geophysical Union, v. 58, no. 12, p. 1185. [AGU fall meeting, San Francisco, CA, Dec. 5-9, 1977, Program and abstracts] 



 A study of seismic events recorded by the Makapuu Ocean-Bottom Seismograph for the period 30 July 1976 to 30 March 1977 is reported. Preliminary epicenter locations indicate most events recorded are due to Hawaii (Big Island) activity, however many events unrelated to volcanic activity occur in areas near the Hawaiian Ridge including an unexpected local event at the northwest end of the major island chain near Niihau (mag 4.5) on 22 January 1977. These events are probably related to the interaction of the Molokai fracture zone and Hawaiian ridge systems and many have been detected solely by the Makapuu 0cean-Bottom Seismograph. Tau Inversion and the Minimum Apparent Velocity method (MAV) of Matumoto et al. (BSSA, 1977) are used to determine velocity structure along the Hawaiian Ridge from earthquake travel times. Results indicate a velocity-depth function of 5.9 km/sec at 2 km depth monotonically increasing to 8.05 km/sec at the Moho (15 km).



Fagerlund, G.O., 1942, Mauna Loa eruption--1942 edition: Paradise of the Pacific, v. 54, July, p. 6-8, 30. 



 Fagerlund gives a popular eyewitness account of the eruption of Mauna Loa, which began on April 28, 1942, at 10,200 ft on the northeast rift. The author describes intense local earthquakes with nearly vertical acceleration associated with the source of eruption. The paper contains excellent photographs of the rarely-witnessed early "curtain of fire" phase of Mauna Loa eruptions which precedes the more commonly-observed cone-building stage of restricted lava fountains.

 

Finch, R.H., 1925, The earthquakes at Kapoho, island of Hawaii, April 1924: Bulletin of the Seismological Society of America, v. 15, p. 122-127. 



 Finch describes the mild but numerous earthquakes in eastern Puna which preceded the explosive Kilauean eruption of 1924 and the faulting which accompanied the earthquakes. He describes a progressive increase in the distance of earthquake epicenters from Kilauea summit during the March earthquake swarm that followed disappearance of lava from Halemaumau in February. The Kapoho earthquake swarm began about April 17, reaching a maximum intensity on April 23. Subsidence accompanying the earthquakes was gradual, amounting to a maximum of 8 ft at the ocean end of the Kapoho graben.



Finch, R.H., 1926, Twelve years record of earthquakes: The Volcano Letter, no. 54, p. 1. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 "From the time that seismographic records were first kept at Hawaiian Volcano observatory the summer of 1913, to the close of 1925, 12,264 local earthquakes were registered. The yearly totals are shown in the following table:

 Year	Number of earthquakes	Year	Number of earthquakes

1913	 167*	 1920	 211

1914	 274	 1921	 279

1915	 456	 1922	 921

1916	 1319	 1923	 650

1917	 207	 1924	 5877

1918	 281	 1925	 922

1919	 700	*For last 6 mos. of year only	

The yearly average for the 12 complete years, 1914 to 1925 inclusive, is 1022. This value is over twice that for Italian earthquakes (Volcano Letter No. 42, 1925).

 The majority of the earthquakes occurred in swarms at times of crises, such as outbreaks of Mauna Loa, movements along one of the Kilauea rifts, of collapses in Halemaumau. In 1922, for instance, about 645 of the 921 earthquakes for that year were due to a collapse of Halemaumau and the opening of the northeastern rift of Kilauea. It appropriate deductions for such swarms are made from the total number of earthquakes for years with molten lava in the pit the yearly average becomes about 230. The years 1917, 1920, and 1921, during which molten lava was continuously present, were without great crises and it will be noted that the 230 is comparable to their totals, 207, 211, and 279 respectively. The average per month for quiet times with lava in the pit is then about 19. 1925 furnishes a year for giving the monthly average for quiet times without molten lava and gives 77, of about the same as when all earthquakes are counted.

 The greatest total for any month for the 12 years is 5313 for May. The May total is swelled by great swarms of earthquakes in three different years. Aside from the June total of 1680 which was affected by the swarms beginning in May, April furnished the next monthly total with 672 shakes. The least of the monthly totals is 285 for February."



Finch, R.H., 1943, The seismic prelude to the 1942 eruption of Mauna Loa: Bulletin of the Seismological Society of America, v. 33, p. 237-241. 



 According to Finch, "This paper may be considered a sequel to one . . . by H.O. Wood for the 1914 eruption of Mauna Loa" [H.O. Wood, 1915b] Precursory signs of the flank eruption of Mauna Loa which began on April 26, 1942, were (1) the summit activity of 1940; (2) progression of epicenters along the northeast rift of Mauna Loa, starting near Hilo on February 8, 1942; (3) a swarm of earthquakes on the northeast rift on February 21, with epicenters at 9,000 ft elevation; (4) the large number of additional Mauna Loa earthquakes in February and March, greatly exceeding those of Kilauean origin; (5) easterly tilt in February and March indicating impending Mauna Loa activity; and (6) large fluctuations in March of the east-west tilt, indicating that molten lava was approaching the surface. Finch also makes brief reference to earthquakes in 1935 and 1941.



Finch, R.H., 1943, Activity at Mauna Loa in November 1943: The Volcano Letter, no. 482, p. 1. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 Seismicity and tilt recorded at HVO indicate a sustained and fairly high pressure under the Kilauea-Mauna Loa volcanic system for several months. Observation of harmonic tremor on the HVO seismographs, combined with observation of intermittent fuming and glow from Mokuaweoweo, suggest that a small amount of lava may have reached the surface. [This was not confirmed.] He speculates that there may have been previously undetected Mauna Loa summit eruptions, citing as evidence descriptions of Mauna Loa summit eruptions that lacked high fountains and therefore may not have been visible outside of the crater. He also describes atmospheric conditions that might give a false impression of fountaining.



Finch, R.H., 1945, On the depth of foci of earthquakes on the island of Hawaii: The Volcano Letter, no. 490, p. 1-2. [See Fiske and others, 1987] 



 Finch describes Hawaiian earthquakes as originating in (1) the principal rift along which the Hawaiian islands were formed, (2) superficial faults within the volcanic edifice, and (3) within volcanic conduits. He applies this classification to earthquakes that occurred on April 2, 1868, December 27, 1944, and May 19, 1945, all of which he locates along "the fundamental rift of Mauna Loa." [This appears to refer to what we now call the Kaoiki and Hilea fault zones.] These earthquakes were distinguished by widespread damage and were felt at least as far as Oahu. [Finch's discussion is severly compromised by the lack of a true seismic network in which earthquakes could be accurately located.]



Finch, R.H., 1950, The December 1950 subsidence at Kilauea: The Volcano Letter, no. 510, p. 1-3. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 An earthquake swarm beginning at noon on December 8 at Kokoolau crater on Kilauea's east rift zone extended over the next four days across the Koae fault zone to the Kamakaia Hills. The depths ranged from 6 to 8 km and the total number of quakes exceeded 656. A fault near Kokoolau showed a few mm of displacement down toward Kilauea caldera. A sharp deflation of Kilauea's summit accompanied the earthquakes, as recorded by tilt deflections in the Whitney vault. Tilting, earthquakes, and ground cracks suggest that a triangular block bounded by the east and southwest rifts and a line from Kokoolau crater to the upper end of the 1823 flow subsided more than adjacent areas. Short periods of harmonic tremor suggest that the earthquake swarm was accompanied by underground movement of magma. [This fits the typical "Koae event", an earthquake swarm accompanying deflation of Kilauea's summit and intrusion beneath the rift zone (s).]



Finch, R.H., and Macdonald, G.A., 1953, Hawaiian volcanoes during 1950: U.S. Geological Survey Bulletin 996-B, p. 27-89. 



 This is the second in a series of USGS bulletins covering the work of the Hawaiian Volcano Observatory and the activity of Hawaiian volcanoes during the year. Others are 1948-49 (Finch and Macdonald, 1951), 1951 (Macdonald and Wentworth, 1954), 1952 (Macdonald, 1955d), 1953 (Macdonald and Eaton, 1955), 1954 (Macdonald and Eaton, 1957), and 1955 (Macdonald and Eaton, 1964). Each bulletin describes the physical plant of the Hawaiian Volcano Observatory and summarizes eruptive activity, seismicity, ground deformation, crack measurements, fumarole temperatures, rainfall, and special studies conducted during the year.

 Abstract 27

The activities of the Hawaiian Volcano Observatory during the calendar year 1950 are briefly described. Statistics on local and distant earthquakes recorded during the year, tilting of the ground surface, crack measurements, monthly rainfall statistics, and temperature measurements are presented and briefly discussed. Occurrences of warm water at several localities on the rift zones of Kilauea volcano are described. The warm water apparently results from heating of ground water by either contact with hot intrusive rock or rising hot gases.

 An eruption of Mauna Loa began on the evening of June 1, and continued until June 23. Fissures opened along the southwest rift zone of Mauna Loa for a distance of more than 12 miles. At 9:04 p.m. a fissure 1.5 miles long opened between 11,000 and 12,000 feet altitude. Floods of very liquid lava poured out, and a cloud of fume rose two miles in the air, brightly illuminated by the red glare of the liquid lava beneath. This activity lasted only about four hours. At 10:15 p.m. a new series of fissures started to open lower on the rift, between 8,500 and 10,500 feet altitude. Activity along the upper portion of the lower group of fissures lasted about a week, but the lower portion remained active for more than three weeks. A total of seven large lava flows poured out, both southeastward and westward. Three of the western flows entered the ocean, the first advancing down slope at an average rate of 5.8 miles an hour. The total volume of lava extruded is estimated to have been more than 600 million cubic yards. In terms of estimated volumes of lava extruded, the eruption was the largest since 1859

Temperatures measured ranged from 1,080 C. at the source fountains and 1,110 in the glowing throat of a spatter cone, to 840 in the lava river 10 miles from the vents. Lava at 675 C. had become immobile.

 Harmonic tremor accompanying the eruption was recorded on the Bosch-Omori seismograph at Kilauea caldera. During the first part of the eruption the tremor was continuous, but during later stages it became intermittent, fluctuations apparently correlating with variations in the amount of lava being extruded. A large number of earthquakes accompanied and directly followed the outbreak.

 No surface eruptive activity occurred at Kilauea volcano during the year. Moderately strong northward tilting of the ground at the northeasterly edge of Kilauea caldera preceded the Mauna Loa outbreak, and the beginning of the Mauna Loa eruption was followed by rapid southward tilting. This appears to indicate an increase of volcanic pressure under Kilauea, followed by a sudden decrease at the time of the Mauna Loa eruption.

 The end of the Mauna Loa eruption was followed by a period of northward tilting at the northeastern edge of Kilauea caldera, apparently caused by resumption of pressure increase. In early December very rapid southward tilting of the ground was accompanied by more than 650 earthquakes as the entire top of Kilauea volcano subsided. The amount of sinking was more than one foot in the vicinity of Halemaumau. The subsidence is interpreted as resulting from decrease of volcanic pressure and withdrawal of the Kilauean magma column.

 Introduction 28

 Acknowledgments 28

Seismographs and tiltmeters 29

Records and investigations 31

 Earthquakes 31

 Tilting of the ground 41

 Crack measurements 43

 Geomagnetic observations 45

 Temperature measurements 45

 Thermal water on Kilauea volcano 46

 Rainfall records 48

 Volcanic conditions during 1950 48

The 1950 eruption of Mauna Loa 49

 Narrative of the eruption 50

 Lava flows 72

 Temperature measurements 73

 The authors describe temperature measurements made on the active flows and inactive vents using an optical pyrometer. [As in all recent studies, the measured temperatures are lower by several tens of degrees than the temperature estimated from geothermometry of rapidly quenched glass.] 

 Radiation studies 76

 Tilting of the ground 76

 Harmonic tremor 77

 Earthquakes 78

 Littoral explosions 81

 The absence of large, littoral explosions where the lava entered the ocean is noted as unusual.

 The December 1950 subsidence at Kilauea 82

 The authors also describe an earthquake swarm at Kilauea in December 1950, which had epicenters spanning the Koae fault zone from Kokoolau Crater to the Kamakaia Hills. The earthquake swarm was accompanied by a sharp deflation of Kilauea summit, inferred to be associated with intrusion of magma into the rift. A map shows the new cracks formed during the intrusion.

 Literature cited 87

Index 89



Fiske, R.S., and Koyanagi, R.Y., 1968, The December 1965 eruption of Kilauea Volcano, Hawaii: U.S. Geological Survey Professional Paper 607, 21 p. 



 More than 1 million cubic yards of tholeiitic basalt was erupted from the upper east rift zone of Kilauea Volcano during a brief 6-hour period on December 24 and 25,1965. The eruptive fissures opened in an en echelon zone about 2 miles long, from Aloi crater eastward to Kane Nui o Hamo. The vigorous early stage of the eruption formed a 47-foot-deep lava lake in Aloi Crater and flooded about 160 acres of forest to the east. At a later stage, withdrawal of magma into the source fissures and other cracks drained the lava lake in Aloi Crater and considerably reduced the volume of lava in the flows remaining on the surface.

 Measurements of ground tilt show that Kilauea summit inflated before the eruption, and that it abruptly deflated just before and during the eruption. Significantly, the summit continued to deflate for an additional 10-hour period after the eruption had ended. Precise leveling suggests that the summit of the volcano did not collapse simply, and that small subsidiary areas of collapse lay about 1.6 km north and 2 km southeast of Halemaumau.

 The eruption marked only the beginning of a major seismic crisis that lasted for more than a week. Thousands of earthquakes were recorded, and preliminary results indicate that most of the epicenters lay in a narrow area extending from the upper east rift zone westward along the Koae fault zone into the Kau Desert. Hundreds of ground cracks and faults opened in this area, and precise leveling has shown that the area of cracking locally subsided nearly 6 feet.

 The eruption ended as the tempo of ground cracking and earthquakes was just reaching a maximum. The rift zone is interpreted to have substantially dilated at this time, perhaps by seaward movement of the entire south flank of the volcano; this dilation created additional underground space in the rift system at a greater rate than magma was fed into it from the summit reservoir. Eruption of lava to the surface could no longer be maintained, and, moreover, much of the lava that had previously been erupted began to drain back into the rift zone. Tremor, earthquakes, ground cracking, and summit collapse continued vigorously for 10 hours after the eruption had ended, indicating that magma continued to move from the summit reservoir into the east rift zone. Apparently all this magma was accommodated underground in intrusive bodies.



Fiske, R.S., Simkin, T., and Nielsen, E.A., ed(s)., 1987, The Volcano Letter: Washington, DC, Smithsonian Institution Press, 539 p. [Compiled and reprinted; originally published, 1925-1955, by the Hawaiian Volcano Observatory] 



 The Volcano Letter, no. 1-530, covering the years 1925-1955, describes volcanic and seismic activity in Hawaii, and, through special reports, at many other places in the world. The volume has a comprehensive subject index. [This reprinting, combined with the reprinting of The Early Serial Publications of the Hawaiian Volcano Observatory (Bevens and others, 1988), constitute the definitive information on Hawaiian volcanic and seismic activity in the period 1909-1955.]



Fiske, R.S., Duffield, W.A., and Swanson, D.A., 1987, The magnitude-7.2. earthquake November 1975 and the structure of the south flank of Kilauea [abs.], in Decker, R.W., Halbig, J.B., Hazlett, R.W., Okamura, R., and Wright, T.L., ed(s)., Hawaii Symposium on How Volcanoes Work, Hilo, HI, January 19-25, 1987, Abstract volume: Honolulu, University of Hawaii, Hawaii Institute of Geophysics, p. 77. 



 Ground displacements associated with the M-7.2 earthquake of November 1975 not only affected Kilauea's mobile south flank, but they also deformed the volcano's summit, its north flank, and parts of adjacent Mauna Loa as well (Lipman and others, 1985). These displacements and other events associated with this earthquake can be interpreted as follows within the structural model proposed by Swanson, Duffield, and Fiske (1976):

 1) The mobile south flank of Kilauea, the region south of the east and southwest rifts and the Koae Fault System, was stressed by the repeated forceful injection of magma into the rift zones since 1868.

 2) These stresses ultimately led to the M-7.2 earthquake, but instead of directly triggering slumping motion of the blocks of the Hilina Fault System, the initial failure took place along a low angle fault 8-10 km beneath the south coast of the island (Ando, 1979; Crosson and Endo, 1982). This failure produced part of the measured seaward displacement of Kilauea's mobile south flank.

 3) Strong ground motion associated with this earthquake jostled the blocks of the Hilina Fault system, which had already been made unstable by the accumulated strain within Kilauea's south flank. Some of these blocks were dislodged and slumped downward and seaward. These motions triggered a submarine landslide, as indicated by a large single-force seismic event (Eissler, 1986). The motion of these fault blocks and associated submarine landslide are interpreted to be relatively shallow, second order phenomena with respect to the earthquake-triggered displacement of the volcano's mobile south flank.

 4) The seaward motion of the fault blocks of the Hilina Fault System and related submarine landslide, combined with the more widespread motion of the mobile south flank that was triggered by the M-7.2 earthquake itself, perturbed the gravitational stresses within adjacent parts of the volcanic edifice. Adjusting to the new set of boundary conditions caused by the seaward and downward motion of the lower south flank, the remainder of the volcano, and part of adjacent Mauna Loa as well, sagged slightly downward and seaward. It is noteworthy that the sagging motion north of Kilauea's summit and rifts was accompanied by minimal seismicity.

 5) The resulting strains of 10-3 to 10-4 in the main body of Kilauea resulted in minor cracking in the Koae Fault System and in dilation of the summit reservoir and rift zones. This dilation triggered a brief eruption characterized by vigorous gas emission (Tilling and others, 1976), probably reflecting a pressure drop and resulting vesiculation at depth.

 6) In the weeks and months that followed the earthquake, the dilated plumbing system accommodated large volumes of magma underground, without normal cycles of inflation and deflation. Some injections in the upper east rift in late 1975 and 1976 renewed the southward shouldering of at least part of Kilauea's mobile south flank, as shown by seaward and upward motion of the region just south of the Koae Fault System (Lipman and others, 1985).

 The ground motions associated with items 2, 3, and 4 above combined to produce the overall horizontal and vertical displacements that were measured in the absence of real-time deformation data, it is difficult to separate the effects of each of these three contributing processes. It is likely, however, that most of the large displacements within the Hilina Fault System were due to landsliding. If a sole fault exists at the base of Kilauea's mobile south flank, this fault need extend no farther to the north than the steeply dipping structural boundary formed by the rift zones and the Koae Fault System. (The extension of such a fault farther to the north, as shown in Fig. 20 of Lipman and others (1985) was unintentional and was the result of a drafting error). The events of 1975 demonstrate that the gravitational stresses within Kilauea and adjacent Mauna Loa are in delicate balance and can readily be perturbed by volcano/tectonic and landsliding events on the lower south flank. At this point, we have no way of knowing whether the next large south flank event will occur in 100 years, 10 years, or even sooner. This uncertainty poses important research challenges for the years ahead.



Forbes, C., 1841, [no title], in The journals of Cochran Forbes, 1984, 207 p.: Honolulu, HI, Hawaiian Mission Children's Society, p. 93. [Forbes entry of March 12, 1841 from Kaawaloa, Kona] 



 Today at a little past noon had a very severe shock of an earthquake, so severe that we all instinctively left the house fearing the result. In a short time afterward followed 3 others, at short intervals.



Fu, Z., 1992, Focal mechanism of small quakes before and after the Kaoiki, Hawaii, earthquake (Ms = 6.6) of November 16, 1983: Acta Seismologica Sinica, v. 5, no. 2, p. 225-235. 



 The Kaoiki, Hawaii, earthquake with magnitude 6.6 of November 16, 1983 was a strike-slip faulting event on a fault with large dip angle The results for mechanisms of smaller events before and after the Kaoiki mainshock show that there were two kinds of mechanisms; (1) strike-slip on the fault with large dip angle; (2) slip on the crustal discontinuity plane with smaller dip angle, and systematic and alternative changes in the mechanisms were observed.



Furumoto, A.S., 1966, Seismicity of the island of Hawaii [abs.]: Geological Society of America Abstracts for 1965, GSA Special Paper 87, p. 331. [Geological Society of America and Associated Societies, annual meeting, St. Louis, MO, Apr. 12-14, 1965] 



 A study of the seismicity of the island of Hawaii has been done by reviewing historical references and by statistical analysis of data published by the Hawaii Volcano Observatory. It was found that a major earthquake of magnitude 7.75 had occurred on the island in the year 1868. Analyses of recent data on number and magnitude of earthquakes showed that the well known empirical formula log N = AbM fits Hawaiian data well. The conclusion is drawn that the seismicity of the island is comparable to that of areas considered to be seismically active. Strain release on the island is consistent with the pattern of worldwide strain release.



Furumoto, A.S., Nielsen, N.N., and Phillips, W.R., 1972, A study of past earthquakes, isoseismic zones of intensity, and recommended zones for structural design for Hawaii: Engineering Bulletin (University of Hawaii), PACE 72033, 53 p. [Joint report with the Center for Engineering Research, with minor corrections (notably Tables 1 and 2, and Figures 3 and 6) and additions to the text (two appendices); originally issued by the Center for Engineering Research, University of Hawaii, as Engineering Bulletin, PACE 72033, June 15, 1972, under the same authorship] 



 Summary and Conclusions

"In order to assess the seismic risk problem for the Hawaiian Islands, all available seismic data have been tabulated. We have found that it is not sufficient to rely only upon the technical literature in order to assess damage from past earthquakes. Considerable information can be obtained by scanning newspaper archives, history books, private diaries, etc.

 From damage descriptions and geographical distributions of past earthquakes, we conclude that the seismic risk for Oahu, Maui, Molokai, Lanai and Kahoolawe should be determined from the major earthquakes that have occurred close to the Molokai Fracture Zone, and not from earthquakes that have their epicenters close to the very seismically active areas close to the island of Hawaii. By investigating and rating damage descriptions from past earthquakes, we conclude that the seismic risks are presently underestimated for the islands of Oahu, Molokai, Maui, Lanai and Kahoolawe. A new seismic zoning map for the Hawaiian Islands is proposed. Details are given in Chapter VIII and the proposed zoning map is shown in Figure 8.

 Hawaii presently has an excellent network of seismograph stations. Unfortunately, instruments capable of measuring the strong ground motion are completely lacking. It is proposed that a network of about twelve strong-motion accelerographs be installed in the Islands, in addition to a larger number of less expensive seismoscopes. This is important for two reasons; first, in order to obtain a better picture of what ground motions can be expected in the Islands, and second , in anticipation that building codes in the future will base their seismic requirements upon actual recorded ground accelerations. Presently, in case a dynamic analysis were to be used in design of structures, we would have to rely upon strong ground motion measurements as for instance, those recorded in California. It is quite possible that the characteristics of the strong ground motion would be different for the various islands as compared to typical records obtained in California."



Furumoto, A.S., Nielsen, N.N., and Phillips, W.R., 1973, A study of past earthquakes, isoseismic zones of intensity, and recommended zones for structural design for Hawaii: Hawaii Institute of Geophysics, HIG-73-4, Mar., 50 p. [Joint report with the Center for Engineering Research, with minor corrections (notably Tables 1 and 2, and Figures 3 and 6) and additions to the text (two appendices) originally issued by the Center for Engineering Research, University of Hawaii, as Engineering Bulletin, PACE 72033, June 15, 1972, under the same authorship] 



 Summary and Conclusions

"In order to assess the seismic risk problem for the Hawaiian Islands, all available seismic data have been tabulated. We have found that it is not sufficient to rely only upon the technical literature in order to assess damage from past earthquakes. Considerable information can be obtained by scanning newspaper archives, history books, private diaries, etc.

 From damage descriptions and geographical distributions of past earthquakes, we conclude that the seismic risk for Oahu, Maui, Molokai, Lanai and Kahoolawe should be determined from the major earthquakes that have occurred close to the Molokai Fracture Zone, and not from earthquakes that have their epicenters close to the very seismically active areas close to the island of Hawaii. By investigating and rating damage descriptions from past earthquakes, we conclude that the seismic risks are presently underestimated for the islands of Oahu, Molokai, Maui, Lanai and Kahoolawe. A new seismic zoning map for the Hawaiian Islands is proposed. Details are given in Chapter VIII and the proposed zoning map is shown in Figure 8.

 Hawaii presently has an excellent network of seismograph stations. Unfortunately, instruments capable of measuring the strong ground motion are completely lacking. It is proposed that a network of about twelve strong-motion accelerographs be installed in the Islands, in addition to a larger number of less expensive seismoscopes. This is important for two reasons; first, in order to obtain a better picture of what ground motions can be expected in the Islands, and second , in anticipation that building codes in the future will base their seismic requirements upon actual recorded ground accelerations. Presently, in case a dynamic analysis were to be used in design of structures, we would have to rely upon strong ground motion measurements as for instance, those recorded in California. It is quite possible that the characteristics of the strong ground motion would be different for the various islands as compared to typical records obtained in California."



Furumoto, A.S., and Kovach, R.L., 1979, The Kalapana earthquake of November 29, 1975: an intraplate earthquake and its relation to geothermal processes: Physics of the Earth and Planetary Interiors, no. 18, p. 197-208. 



 By use of teleseismic and local data, the P-wave source mechanism of the Kalapana, Hawaii, earthquake of November 29, 1975 was found to have a common strike of N64E for the two nodal planes. One plane dipped 4 to the NW; the other dipped 86 to the SE. After consulting subsurface geological data obtained by the recent Hawaii geothermal exploration program, it was decided that the plane dipping to the NW at 4 was the preferred solution.

 Seismic moment obtained from body-wave data and surface-wave data averaged 1.2 x 1027 dyn cm. Fault area from P-wave, surface wave and tsunami data amounted to about 2200 km2. Stress drop was on the order of tens of bars.

 The earthquake appears to be of volcanic origin. When magma pressure in the dike complex of the east rift of Kilauea exceeded the fracture point, the southern flank of the east rift was pushed across the ancient sea floor upon which the volcanic edifice rests. The result was a low-angle overthrust, which also produced a tsunami. The hypothesis of forceful intrusion of magma into the east rift is consistent with the mechanism of the earthquake.

 The low stress drop (in relation to other intra-plate earthquakes) is probably due to the occurrence of the earthquake in a hot-rock regime.



Furumoto, A.S., Herrero-Bervera, E., and Adams, W.M., 1990, Earthquake risk and hazard potential of the Hawaiian islands: Honolulu, Hawaii Institute of Geophysics, July, 37 p. 



 Introduction

"In this monograph, we bring together relevant information to discuss in technical terms the earthquake risk and potential seismic hazards of the Hawaiian Islands. The purpose of the monograph is to stimulate mitigation measures where earthquake risk does exist and where adequate mitigation measures are not in place because the risk is not perceived.

 In discussing the earthquake risk for the Hawaiian Islands, we divide the major islands into three regions (Figure 1). The southwestern region consists of the island of Hawaii by itself; the central region Consists of the islands of Maui, Kahoolawe, Lanai, Molokai and Oahu; the northwestern region includes the islands of Kauai and Niihau. Of these, the southwestern region with the island of Hawaii is by far the most active seismically, then comes the central region, and finally the least active is the northwestern region.

 In the most active region, the island of Hawaii, earthquakes occur often, and the residents and the civil authorities are well aware of earthquake risk. Mitigation measures in terms of proper building codes and disaster preparedness are in place. Nevertheless past earthquake history will be recalled in this monograph to draw attention to the Kau-Puna area, which is highly prone to earthquake damage, even by world standards.

 In the northwestern region with the islands of Kauai and Niihau, the historical record shows hardly any earthquake damage, and mitigation measures for earthquake disaster need not be of much concern.

 The region that needs attention is the central region, the Maui-Oahu region. Although damaging earthquakes have occurred in historical times in the region, because they have recurred at rather protracted intervals, most residents in the region are unaware that they live in an earthquake zone. Hence this monograph will primarily discuss the central region. The intent is to awaken attention to earthquake risk for this region by assembling historical earthquake data of the region, analyzing the data, and attempting to estimate the probability of a damaging earthquake in the next twenty years."



Furumoto, A.S., 1991, Seismic risk of the summit area of Haleakala Volcano; an internal report submitted to the Solar Group Institute for Astronomy: Hawaii Institute of Geophysics, School of Ocean and Earth Sciences and Technology, Oct., 23 p. 



 This report has been prepared at the request Mr. Wayne Loo, Assistant Director of Haleakala Observatory, to evaluate the earthquake risk of the summit area of Haleakala Volcano. The request has been made because a new round of buildings will be constructed in the summit area and because no such evaluation for the island of Maui has been done. A seismicity study of the region around Maui has been done as part of a study covering all Hawaiian Islands (Furumoto 1990), but to be useful for engineering and planning purposes, the seismicity study must be further enhanced to include the probability of occurrence of earthquakes within a meaningful time frame and the expected vibration levels.

 A seismicity study uses historical and instrumental data to estimate how often earthquakes of large magnitudes occur in the region that is being studied. This is fine for the seismologist. But the engineer or architect must also consider whether earthquakes occurring in neighboring seismic source regions will send over damaging vibrations. To illustrate this concern in practical terms, the seismic risk study for Haleakala on Maui must consider the recurrence of large earthquakes around Maui and also the recurrence of large earthquakes on the Big Island because some of the earthquakes on the Big Island that occurred within historical times were large enough as to cause damage in Maui.

 This study is based on instrumentally recorded data and documented information on earthquake which occurred within historical times. Instrumentally recorded data are available in the Summary Series published by the Hawaii Volcano Observatory, whose network of seismographs effectively cover the islands from the Big Island to Oahu. As for historical documents, detailed descriptions of damage caused by major destructive earthquakes in the Hawaiian Islands have been published over the years. In this study we shall first define and explain some of the fundamental concepts of seismology, especially the concepts of intensity and magnitude, as these terms are often confusing to the non-seismologist. As these concepts are the necessary ingredients for estimating the seismic risk of a region, they must be clearly understood by those who intend to implement into practice the results of an earthquake risk study.

 The contents of this report were discussed with members of the Earthquake Preparedness Committee, which advises the Office of the Director of Civil Defense, State of Hawaii, on matters concerning earthquakes in Hawaii, at the bimonthly committee meeting on September 23, 1991. Among the thirteen members were seismologists from the University of Hawaii at Manoa, University of Hawaii at Hilo, Hawaii Volcano Observatory and the private industry sector of Hawaii. The discussions were often very pointed and the opinions set forth at the meeting have been incorporated into this report.

VI. Conclusions

 Construction at Haleakala should proceed with the recurrence of magnitude 7 earthquakes in the Molokai Seismic Zone in mind. Such an earthquake will subject East Maui to intensity VIII or an acceleration of 0.3 g. For Haleakala summit as a safety factor due to height amplification, an acceleration of 0.4 g. should be considered. The recurrence of an earthquake is in the not too distant future because the last destructive earthquake was in 1938 and the average return period is 40 years.

 If planning takes into consideration hazards from earthquakes in the Molokai Seismic Zone, danger from Big Island earthquakes will be automatically taken care of.

 The probability of volcanic eruption along the Southwest Rift in the next hundred years is very small.



Ganse, R.A., and Nelson, J.B., 1981, Catalog of significant earthquakes 2000 B.C.-1979: Boulder, CO, World Data Center A for Solid Earth Geophysics; U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Report SE-27, 154 p. 



 A summary giving depth, magnitude, intensity, deaths, damage and location of the largest earthquakes for which records are available. Hawaii earthquakes are reported on p. 127.



Gaspari, M.A., Thomas, D.M., and Koyanagi, R.Y., 1989, Soil gas radon anomolies associated with a M=6.2 earthquake on the Kilauea east rift zone [abs.]: Eos, Transactions, American Geophysical Union supp., v. 70, no. 43, p. 1194. [AGU fall meeting, San Francisco, CA, Dec. 4-8, 1989, Program and abstracts] 



 An investigation of soil gas radon activities at the summit of Kilauea has monitored changes in shallow (1 to 2 meters) radon concentrations over integration intervals of less than one hour to as long as one week. Observations to date show that radon levels are highly variable both temporally and spatially and that substantial variations in radon activity occur that cannot be accounted for by meteorological influences. During the course of this investigation one station showed an increase in radon activity by a factor of approximately three prior to a magnitude 4.8 earthquake located at a distance of about 60 km from the station and an increase by a factor of 4 prior to a magnitude 6.2 earthquake at a distance of 30 km. This station was paired with a second instrument located within 20 meters of the primary device which also showed a coincident anomaly. The anomalies that were observed showed substantial radon increases above relatively flat baseline levels and began several days to a few weeks prior to the earthquakes with which they were associated. In the first instance, the radon levels returned to near the prior baseline within about two weeks after the events but, in the second, activities have remained well above baseline for a period of more than a month. Other stations distributed over the summit of Kilauea also showed anomalous behavior prior to the M - 6.2 event; one station located on the East Rift Zone (the structure most immediately affected by the earthquake) showed an increase in radon by a factor of fifty whereas others showed smaller changes in their normal pattern of radon variations. We suggest that the observed radon variations are produced by small-scale deformation that is occurring on the summit and flanks of Kilauea in response to stress changes that ultimately lead to the earthquake events.



Gharib, J., and Resing, J.A., 1996, Dissolved concentrations of Co, Ni, and Al in water column samples taken during Loihi Seamount's seismic event [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F398. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 Starting 16 July 1996, an intense seismic swarm was recorded at Loihi Seamount; investigators visited Loihi from 5-9 August to observe and sample this event. Water column samples were collected in six vertical casts and two tow-yos during this cruise. These samples will be analyzed for the concentrations of dissolved and total cobalt, nickel, and aluminum. Cobalt and nickel concentrations will be compared to the concentrations obtained for normal hydrothermal activity on Loihi when not undergoing eruptive behavior (Sakai, et al., 1987), wherein the maximum concentrations in the water column were reported to be approximately 4 nM for cobalt and 1300 nM for nickel. The aluminum concentrations will be compared to those from Macdonald Seamount and also previous Loihi measurements to test the hypothesis that aluminum can be used as an indicator for volcanic activity. Analysis of the samples will be conducted on the ICP-MS for cobalt and nickel, and also flow-injection analysis for cobalt and aluminum.

 Preliminary observations from this cruise imply that multiple water masses of differing natures were sampled during the casts. CTD data show both positive and negative salinity anomalies, and temperature anomalies greater than 3 C. Measurements of pH were as low as 5.6, and very large concentrations of iron, manganese, and methane indicated intense hydrothermal activity at this location.



Gill, L.T., 1923, Tidal waves of bygone days recalled; eighteen known to historians: Honolulu Advertiser, 02/11, p. 1, 10. 



 "Eighteen tidal waves, large and small, disastrous and harmless, have visited the Hawaiian Islands since their history emerged from its legendary past. Yet there are no traditions of any waves of cataclysmic force and destructiveness and scientists maintain that Hawaii has no reason to fear a gigantic sea convulsion.

 "It has been said that the main reason for our safety from the onrush of such mountainous bodies of water as have, from time to time, swept the coast of South America and other shores of the world, is the vent afforded by the active volcano. It carries off the gases and steam which, otherwise, might cause terrific explosions in the ocean bed.

 "The modern theory of the cause of tidal waves is that sea water, sweeping into the recesses of the earth, causes compression and a chemical reaction which forms molten pockets. At these points there are volcanic areas. Earthquakes are their vibrations, and then the surface of the water is disturbed by giant ripples."

 [This fanciful explanation obviously predates the recognition that tidal waves are triggered by earthquakes that occur near coastal areas, of large enough magnitude to produce a "T-phase," or surface wave transmitted through the water.]

 The article continues with descriptions of the tsunami known to have affected the Hawaiian Islands. A detailed description is given of damage caused by the great tsunami of Nov. 7,1837. Others described are 1819, May 17, 1841, Dec. 1860, Apr. 2, 1868, Aug. 13-15, 1868, May 10, 1877, Jun. 15, 1896, Aug. 14, 1901, May, June and July, 1902, Sept. 2, 1902, Nov. 29, 1903, Jan. 31, 1906, Aug. 15, 1906, Dec. 16, 1921, and Nov. 11, 1922.



Gillard, D., Wyss, M., and Nakata, J.S., 1992, A seismotectonic model for western Hawaii based on stress tensor inversion from fault plane solutions: Journal of Geophysical Research, v. 97, no. B5, p. 6629-6641. 



 For 57 fault plane solutions of earthquakes with magnitude ML > 3.0 located west of the southwest rift zone of Mauna Loa volcano in Hawaii, which occurred between 1972 and 1988, the dominant focal mechanisms (44 events) are decollement type with one nodal plane nearly horizontal (dip < 30). The average slip vector of the upper crust on the decollement plane points in an azimuth of 260 toward the ocean, away from Mauna Loa's southwest rift zone at an angle of about 150 with respect to the NE-SW oriented rift. Two other types of focal mechanisms are present: normal faults (four events) and strike-slip faults with normal component (nine events). The orientation of the principal stresses was derived by minimizing the sum of the misfits between the theoretical and observed fault geometry for each focal mechanism. After subdividing the data set into three different regions we found that the stress tensor is not homogeneous in west Hawaii. The orientation for the stress tensor is best resolved in the area located between latitudes 19.27N and 19.4N and longitudes 155.7 and 155.9 W where the greatest principal stress directions within the 95% confidence limits are nearly vertical with some spreading to the west. Their plunge varies between 53 and 85. The intermediate and least principal stresses are mostly horizontal and have similar magnitudes. Their plunge varies between 1 and 36. The area between latitudes 19.4 and 19.6N and longitudes 155.7 and 156W is characterized partly by near-vertical and partly by east-west oriented greatest principal stresses. The least principal stresses are approximately horizontal and have magnitudes similar to the intermediate principal stresses. In the two areas where the stress tensor was well resolved, the principal strain directions differed from the principal stress directions by 30 in the plunge, suggesting that the faulting in western Hawaii takes place on a weak plane, but this result could not be established at the 95% confidence level. The tectonic model proposed for west Hawaii is similar to the model for the Kalapana region. The strain is accumulated through magmatic intrusions in the southwest rift zone of Mauna Loa, and the earthquakes occur along a zone of weakness composed of oceanic sediment at about 10 km depth. The west flank of Mauna Loa slips in the direction away from the rift.



Gillard, D., Wyss, M., and Okubo, P., 1992, Stress-tensor orientation in the south flank of Kilauea, Hawaii, estimated from fault plane solutions [abs.]: Eos, Transactions, American Geophysical Union supp., v. 73, no. 43, p. 506. [AGU fall meeting, San Francisco, CA, Dec. 7-11, 1992, Program and abstracts] 



 Fault plane solutions of 827 earthquakes with magnitude ML  2.5 which occurred between 1972 and 1992 on the south flank of the Kilauea volcano in Hawaii were determined using P-wave first motion polarities. More than 90% of these earthquakes are located south of the Kilauea east rift zone between longitudes 154 58'W and 155 16 W and at a depth of about 9  2 km. The dominant focal mechanisms (67%) are decollement type with one nodal plane nearly horizontal (dip  30). Reverse faults and normal faults compose the rest of the fault plane solutions with 20% and 13% respectively. The average slip vectors for each of the three types of focal mechanisms are parallel to each other as well as to the direction of maximum geodetic strain. They indicate a southeast, seaward motion of Kilauea's south flank.

 The types of fault plane solutions vary as a function of time and space. The normal faults occur mainly during the aftershock period of the 1975 Kalapana earthquake, while none were observed before it, and they decrease after 1979. The number of reverse faults is high before 1975 and drops significantly after 1983. The decollement type mechanisms are always present with a significant increase in number after the 1975 Kalapana earthquake. The normal faults are located slightly north of the reverse faults. Inverting for the stress orientation for different sub-volumes and periods, we found that the greatest and least principal stresses (s1 and s3) are most frequently and overall oriented perpendicular to the rift with a plunge of 45 (s1 to the SE). This stress orientation explains the simultaneous occurrence of the three types of focal mechanisms. However, differences in the orientation of s1 and s3 as a function of time and space exist, indicating that the stress tensor is not homogeneous in the south flank. During limited periods, s1 or s3 can locally be rotated giving rise to slip parallel to the rift. We interpret this type of faulting and the presence of fault planes striking perpendicular to the rift as caused by local block rotations due to different amount of slip of parts of the south flank in the overall SE direction. We conclude that the source of stress is a combination of gravitational load and magma pressure, which, if vectorially added, could explain the 45 plunge of the greatest principal stress.



Gillard, D., Rubin, A.M., and Okubo, P., 1994, Characteristics of earthquakes accompanying dike intrusion [abs.]: Eos, Transactions, American Geophysical Union, v. 75, no. 16, p. 345. [AGU spring meeting, Baltimore, MD, May 23-27, 1994, Program and abstracts] 



 Earthquakes from recent intrusions in Hawaii were examined in light of predictions of an elastic/fluid mechanical model of dike propagation. These predictions include: (1) the stress perturbation due to intrusion is insufficient to produce shear failure of intact rock but can induce slip along existing fractures; (2) fault slip is most likely to occur very near the dike perimeter; (3) if the dike is intruded perpendicular to the least compressive stress, this stress remains perpendicular to the dike in regions undergoing failure; and (4) despite the stress concentration at the dike tip, earthquakes large enough to be detected require a substantial contribution from the ambient deviatoric stress, so their focal mechanisms should be consistent with the ambient stress field.

 We extracted from the catalog of earthquakes of the Hawaiian Volcano Observatory (HVO), 222 events associated with the 10-km-long 1983 dike intrusion at Kilauea, Hawaii. Earthquake magnitudes range from 0 to 3, implying fault dimensions on the order of meters to hundreds of meters. The width of the seismic zone from the HVO catalog is approximately 2 km. A preliminary event relocation using a joint hypocenter determination technique (Pujol, 1988) did not significantly improve the location of these events, due possibly to lack of station coverage or reading errors. Some of the first arrival times will be reread to check the latter possibility. Nevertheless, the best located events from this intrusion (rms <=0.09) and smaller intrusions in 1982 (rms<=0.04) (Karpin and Thurber, 1986) are consistent with the hypothesis that the earthquakes are occurring essentially on the dike plane and that the great majority occur at the propagating tip. This observation will be further tested with the 1993 intrusion at Kilauea, Hawaii, for which better station coverage exists. Faulting will be studied for both intrusions by computing focal mechanisms from first motion polarities. Preliminary results indicate that a mixture of normal, reverse and strike-slip faults characterizes the faulting associated with the 1983 intrusion. Normal and strike-slip faulting are favored by the stress perturbation due to intrusion; however, reverse slip along faults striking perpendicular to the dike is possible if the ambient stress is very favorable.



Gillard, D., Rubin, A.M., and Got, J.-L., 1994, Precise relocations and focal mechanisms of earthquakes accompanying dike intrusions in Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 75, no. 44, p. 715. [AGU fall meeting, San Francisco, CA, Dec. 5-9, 1994, Program and abstracts] 



 We searched for similar events in a data set of 407 earthquakes associated with the 1983 dike intrusion along Kilauea's middle east rift zone, by requiring that pairs of events have similar waveforms (coherency > = 90%) for a one second window centered around the first P arrival at 4 stations. We found 9 distinct groups (multiplets) containing at least 5 events similar to each other. The largest multiplet contained 11 events. The average distance between multiplets measured along the rift is about 700 m and each multiplet was contained within a volume of one km**3. Within each multiplet, the time delays between pair of events at each station are measured using a cross-spectrum technique. These precise time delays are used to relocate the events relative to the barycentre of the multiplets following Got et al. (1994). We measured time delays with a precision of 7 ms on average. The median spatial extent of the multiplets perpendicular to the dike trend was reduced from about 500 m prior to relocation, to less than 200 m after. The relative location uncertainty is estimated to be about 100 m. For each multiplet, we computed composite focal mechanism from first motion polarities. We used a stacking procedure to enhance the signal of the first P arrival at some stations. Thus far a mixture of oblique normal fault and strike slip with fault planes striking parallel to perpendicular to the dike trend have been found. Further results will allow us to compare these focal mechanisms to those obtained for earthquakes in the years preceding the intrusion.



Gillard, D., Rubin, A., and Okubo, P., 1996, A new view of shallow rift seismicity at Kilauea [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F812. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 We present a new interpretation of shallow seismicity within Kilauea's East Rift based on the precise relative relocation of microearthquakes. Unlike the diffuse cloud of seismicity observed previously, relocated earthquakes from the Upper East Rift from 1991 and 92 define vertical strike-slip faults at about 3 km depth that extend 2.5 km along the rift but less than 100 to 200 m vertically. We find that this ribbon of seismicity can be explained as a manifestation of the stress concentration above Kilauea's inferred deep rift, which is believed to extend down to the old seafloor. The observed earthquake depths, left-lateral focal mechanisms, limited vertical extent, and increasing moment release rate since 1983 are in quantitative agreement with an elastic model in which left-lateral motion of the deep rift following dike intrusion in 1982 loads the shallow portion of the rift. These results show that shallow background seismicity within Kilauea's rifts can be tied to large-scale motions within the volcano, and need not be interpreted as resulting from magma flow or pressure changes within a shallow conduit system. Relocated events associated with the 1983 East Rift intrusion also show tight clustering at 3 to 4 km depth. By analogy with the Upper East Rift events, and based on elastic calculations suggesting that a significant ambient differential stress is required for dikes to produce detectable earthquakes, we infer that these events are also produced in the stress concentration overlying the deep rift. The seismicity may directly overlie the inferred shallow magma conduit at Kilauea, which in turn may overlie the deep rift body. We will extend our data set by adding earthquakes from years with high concentration of events (1987 and 1988), in order to present a high resolution image of rift zone seismicity that extends from within Kilauea caldera to over 20 km downrift.



Glennon, M.A., Chen, W.-P., and Nabelek, J., 1989, Source processes of three large Hawaiian earthquakes [abs.]: Eos, Transactions, American Geophysical Union, v. 70, no. 15, p. 397. [AGU-MSA spring meeting, Baltimore, MD, May 7-12, 1989, Program and abstracts] 



 We determined the source parameters of Hawaii's three largest earthquakes within the past 25 years by inverting teleseismic P and SH waves as recorded on the long-period instruments of the World-Wide Standardized Seismograph Network and the Global Digital Seismograph Network.

 The 1973 Hilo event (Ms = 6.2) beneath the volcano Mauna Kea has an unusually large focal depth of about 40-50 km. The depth of the source makes this event ideally suited for investigating whether or not a component of nondouble-couple source was present due to magmatic activities. Comparing the results of inversion for an unconstrained moment tensor and for a pure double-couple point source indicates that there is no resolvable nondouble-couple component associated with this event of oblique strike-slip faulting.

 Preliminary modeling of the P and SH waves of the 1975 Kalapana earthquake indicates a complicated source time function with the most prominent phase arriving about 40 s after the first arrival. The first 60 s of both P and SH waves can be adequately explained by a series of at least four subevents. Each subevent is a pure double-couple point source of no longer than 15 s in duration. The total scaler seismic moment release of these subevents is about 1x1020 N-m. The subevents have essentially the same mechanism as the largest foreshock with one nearly horizontal nodal plane and a vertical plane trending approximately east-northeast. Our results, which are based on body waves in the period range of 5-20 seconds, complement the study of Eissler and Kanamori (JGR, 92, 1987) who investigated only long-period (> 100 s) Love and Rayleigh waves. Their source mechanism is represented by a single-force couple with a total duration of three minutes. Our results indicate that there were significant double-couple moment releases during the Kalapana event. If one were to accept that the long-period radiation of the Kalapana event is associated with a slow, massive landslide, the subevents can be interpreted as a sequence of elastic dislocations which may be caused by breakage of large asperities during the landslide.

 The 1983 Kaoiki earthquake (Mo ~1x1017 N-m) can be explained by oblique strike-slip faulting with a simple source time function of a few s in duration.



Goodhue, E.S., 1907, Rivers of fire flowing down mountain side make a scene of truly awesome splendor: Honolulu Evening Bulletin, 01/18, p. 1, 3. 



 [Subheads: Described by Bulletin writer; camp made beside heated a-a and many get close view of volcanic grandeur]

 Extensive description of the eruption from Mauna Loa's southwest rift zone.

 . . .

 "There was quite a shock on Saturday [Jan. 12] felt at Holualoa."



Goodrich, J., 1831, [no title], in Missionary Letters, 8 v: Honolulu, HI, Hawaiian Mission Children's Society, v. 6, p. 1572-1582. [Joseph Goodrich's Journal] 



 [p. 1575-1576] . . . : standing on the verge of the crater we looked down 1200 or 1400 feet & almost directly under us . . . saw a river of liquid fire rolling its firey billows from shore to shore in a most terrific manner, the river was about 6/4ths of a mile long from 6 to 8 rods wide in some places the lava was thrown up a great distance & with the utmost violence scattering it out in every direction; at one end of it was a cataract of liquid lava precipitating its firey bellows surges down an awful precipice into the yawning gulf below . . .

 . . . It is not now so deep by 600 feet as it was on our first visit [in 1823, with Ellis]. . . .



Gordon-Cumming, C.F., 1883, Fire fountains, 2 v.: Edinburgh, William Blackwood and Sons, v. 1, 297 p.; v. 2, 279 p. [Volume 1, p. 65-90, 121-244, and v. 2, p. 235-279 cover the material abstracted] 



 Volume 1 contains a description of Kilauea caldera from October 29 to November 2, 1879 (p. 155-197), a brief description of changes at Kilauea from 1789 to 1878 (p. 209-223), descriptions of the Mauna Loa eruptions of 1843, 1851, 1852, 1855, 1859, 1868, and 1877 (p. 223-244), and accounts of the tsunamis of 1837 and 1872. Lady Gordon-Cumming gives a vividly written lay account of the appearance of the volcanoes and their lava surfaces and activity. She expands her account of Kilauea activity in 1879 (Gordon-Cumming, 1881) and mentions Turnbull's description of the 1801 Hualalai eruption. [This doesn't jibe with Turnbull {1805}. She might have confused Turnbull with the person living in Kona who was Ellis' informant regarding the 1801 eruption.]



Gower, M.M., 1886, [Notes of] A voyage from Boston to california and the Sandwich Islands via Cape Horn, in the years 1858 and 1859: Honolulu, Hawaiian Historical Society Library, Unpublished manuscript, p. 80-111. [Paper delivered to New Haven Colony Historical Society in 1886. (See letter to W.D. Alexander, 1894, HHS correspondence.) The manuscript was typed for Hawaiian Historical Society in 1894 and was apparently never printed.] 



 A diary kept in 1859 contains a brief eyewitness account of flows from the 1859 Mauna Loa eruption. Gower summarizes accounts of previous eruptions from Mauna Loa and Kilauea, including quoted eyewitness accounts of the 1868 earthquakes, tsunami, coastal subsidence and Mauna Loa eruption, and the following summary of the 1832 eruption of Mauna Loa: "In 1832 there was an eruption both of Kilauea and the summit of Mauna Loa. The latter occurred on June 20th and the lava flowed from several vents on the side of the mountain to the North West for two or three weeks and probably flowed into Kawaihae Bay." [Modern mapping has never identified with certainty lava from this eruption.] Gower also gives accounts from friends of the 1868 Mauna Loa eruption, the great earthquake, and the tsunami. He gives the height of the tsunami as 60 ft and coastal subsidence ranging from 18 in to 2 ft. He briefly mentions other tsunami in 1877 and 1867. He describes the 1886 draining of Halemaumau and gives an account of Hilo residents visiting the 1855 flow and having the ground rise under them, the lava having entered an underground tube.

 Gower closes by quoting some fanciful theories regarding the cause of volcanic action.



Green, I.S., and Dibble, S., 1833, Extracts from a letter: Missionary Herald, Feb., p. 57-60. 



 A description of Kilauea caldera in January 1832. The elevated plain separating Kilauea caldera from Kilauea Iki Crater had been fissured during a strong earthquake about 11:00 a.m. on January 10, and lava flowed from the fissure into both Kilauea and Kilauea Iki. The authors also mention a trip to the south coast over chasms made by the recent earthquake.

 

Green, J.S., 1834, [no title], in Missionary Letters, 8 v: Honolulu, HI, Hawaiian Mission Children's Society, v. 6, p. 1730-1736. [Letter to Rev. R. Anderson, dated Wailuku, Maui, November 12, 1834] 



 [p. 1733] . . . So dreadful have been the shocks [his underline] to which the land has been subjected during the last two years, that it is a matter of surmize that our congregations have not all been shaken to pieces! . . .



Green, W.L., 1886, Is Kilauea becoming extinct: Hawaiian Gazette, 03/23. 



 Green comments that the March 1886 collapse is a repetitive phenomenon at Kilauea and that lava will almost certainly return. He also describes native reports of chasms opening in Puna with some evidence of associated heat. [This is not mentioned in any other description of the 1886 collapse; it suggests that, following the summit collapse, magma intruded into the east rift zone or, as in 1924, went past Puna to erupt on the submarine portion of the rift.]



Green, W.L., 1887, Vestiges of the molten globe, pt. 2. The Earth's surface features: Honolulu, Hawaiian Gazette Publishing Co., 337 p. [Folded map, The Hawaiian Islands and craters, by F.S. Dodge, scale 1:1,200,000. Material pertinent to Hawaii on p. 131-180, 270-337] 



 Green argues for the absence of magmatic H2O in Hawaiian eruptions; he considers vapor given off by lava streams and fountains to be anhydrous, and the total amount of liberated vapors very small. He believes in gravitative settling of olivines, but considers the action of H2O in altering certain minerals, such as olivine and augite, to be the prime cause of the differences between basaltic and more feldspathic rocks. The cause of the rise of magma at vents is believed to be the weight of the surrounding crust on an underlying fluid basalt layer. He repeats his earlier observations (Green, 1877) on orientation and spacing of Hawaiian volcanoes. He attributes tuff cones on Oahu and cones on Mauna Kea to accidental contact of molten lava with water. Green agrees with Dutton in considering Kilauea as a volcanic edifice independent of Mauna Loa, although he considers that both volcanoes are related to a common liquid substrate, producing some sympathy of action. Later in the paper, he says that simultaneous eruption at Kilauea and Mauna Loa is not evidence of a deep-seated direct connection. He describes from personal observations the Mauna Loa lava flow of 1859, lava fountain activity in Mokuaweoweo in 1873, and activity at Kilauea in 1860, 1867, and 1873. He compiled notes on many of the eruptions on the island of Hawaii from 1823 to 1887, and presents a tabular summary of them. He quotes at length newspaper accounts of the earthquake, tsunami, landslide, and Mauna Loa eruption of 1868, quotes as fact the account of a submarine eruption off Kau [see annotation to Coan, 1868a], and discusses subsidence of Kilauea in 1886, quoting from other sources. He mentions correlation of eruptions with rainy seasons but does not consider climatic factors to be a primary cause of eruption. [Green is referred to by many later writers as a major source of ideas regarding volcanic mechanism, and his quotations of others are very useful. However, he tends to force observations to fit his own theories, with the result that many volcanic phenomena, beautifully described elsewhere, are here misinterpreted. For example, he writes that aa produces an arched, solidified crust over a molten interior; in fact, it is tube-fed pahoehoe that commonly exhibits this behavior.]

 Section 10 of Chapter Vl is entitled "On the evidence of upheaval and subsidence on the Hawaiian group, and their bearing on Darwin's theory of coral reefs and subsidence." Green summarizes evidence of many kinds for subsidence of different parts of the island chain, including subsidence associated with the 1868 earthquake, subsidence associated with the Kahuku Pali (fault), and the discovery of coral reef deposits in drill holes on Oahu. He also summarizes Darwin's (1837) theory of subsidence and the objections raised thereto. Green interprets the island chain as subsiding more to the northwest along a stationary axis situated under the island of Hawaii, which is not subsiding. Irregular uplift of the islands occurs on the same axis. [This idea is rendered obsolete by plate tectonics and modern observation of ongoing subsidence of the island of Hawaii.]



Gripp, A.E., and Thurber, C.H., 1986, Seismicity of the Koae fault zone, Kilauea Volcano, Hawaii during the early 1980s [abs.]: Eos, Transactions, American Geophysical Union, v. 67, no. 44, p. 1085. [AGU fall meeting, San Francisco, CA, Dec. 8-12, 1986, Program and abstracts] 



 The seismicity distribution and focal mechanism solutions of the ENE-trending Koae fault zone and environs show the western and eastern halves of the Koae behaved fundamentally different during the early 1980's. Eastern Koae and environs seismicity was relatively constant in time regardless of volcanic activity and almost exclusively restricted to depths between 5 and 10 km. Its focal mechanism solutions are all reverse with NE-striking nodal planes which dip at roughly 10 and 80. The shallowly-dipping plane generally dips NW, subparallel to the seismicity of the south flank of Kilauea. The eastern Koae and environs seismicity is probably related to displacement at 8-10 km along a decollment on the ocean floor, along which the south flank of Kilauea is pushed south by intrusions along the rift zones. The lack of seismicity in the eastern Koae proper is similar to the "seismic gap" present before the 1965 Christmas swarm.

 The western Koae and environs only produced seismicity contemporaneous to or in the months following intrusive activity along the southwest rift zone or at the summit caldera. Double-couple focal mechanism solutions for these events are variable and often unsolvable. Because somewhat remote volcanic events caused seismicity in the western Koae, the block north of the Koae may be behaving rigidly and transmitting stress from intrusions to at least the western Koae, where it is released by earthquakes.



Gulick, O.H., 1865, The late earthquake as felt near the crater: Pacific Commercial Advertiser, 03/18, p. 2. [Letter from Waiohinu, Kau, Hawaii dated March 6, 1865] 



 At 1 A.M. Friday, March 3, we were awakened from sleep by the most severe earthquake that we have ever experienced. The shock was accompanied by a heavy rumbling sound, which with the violent rattling of every door and window in the house, startled from their slumber twenty-four out of twenty-six inmates of our house.

 The first and most violent shock seemed to continue with a quick rumbling motion for half a minute after we were fairly awake. A few minutes later two slight shocks were noticed. A band-box which fell from a shelf, was the only article which was displaced in our house, by mother Earth's short spasm. A few persons ran out of their houses, but the most lay quietly in bed waiting to see what would come next. The dogs of the village set of a most vigorous barking at the unwonted sounds and motions.

 The shock we learn was felt in Kona, and we shall be interested to know whether it was noticed throughout the island, and whether it was felt on any other island of the group.

 It was much more violent at Mr. F.S. Lyman's at Keaiwa; a point but twenty miles from the volcano, than here. A letter just received from there states that "old Jacob," an intelligent native, who has resided in Keaiwa for seventy years, says that this is the most violent earthquake that he has ever experienced. He was up with a neighbor, at the time, (one o'clock at night) reading the news in the Kuokoa, and was therefore a better judge of the character of the convulsion than those who were startled from their slumbers by it. The letter says:

 "Jacob and his friend heard a loud report, and thought it was thunder; then came slight shocks of the earthquake which increased in severity every shock for a minute or so, then passed off as it came, with slight shocks. He thinks it was three or four minutes. I thought it must have been three minutes that we felt it; shock after shock shaking the house as if it would tear it from its foundation. Windows and doors rattling, and bottles falling. There seemed to be great convulsions and noises in the earth right under our house. It was awful! after the hard shocks, it passed off gradually. Shortly after, we heard a report as if something had come bounding up against the side of the mountain from the inside; then it came rumbling down till it reached us as another shock, but it did not continue very long. We felt as many as five more slight shocks before morning!

 "Our stone walls are tumbled down in six different places. Doors that were swollen with the rain and were shut as tight as could be, were opened; and the safe door which was fastened with a button that fits tight was unfastened, and the door open. All over the house we find things thrown down and tipped over. It seemed as if a little more would have demolished us entirely.

 Are we to have another eruption of Mauna Loa. Who knows?



Gutenberg, B., and Richter, C.F., 1941, Seismicity of the Earth: Geological Society of America Special Paper 34, p. 82-85. 



 Although many of the earthquakes on the island of Hawaii are direct results of volcanic processes, other larger shocks are tectonic in origin. That of April 2, 1868, and the Hualalai earthquake swarm of September 1929 are so considered. The big shock of September 26, 1929, was recorded in western Europe. Hawaiian earthquakes produce seismograms usual for shallow earthquakes. Strong shocks occurred on January 23, 1938, at 21 N. 156 W.; and on June 17, 1940, at 20.5 N. 155.25 W. Honolulu was shaken by earthquakes in 1871 and 1881, which were weaker in other parts of the island chain.



Gutenberg, B., and Richter, C.F., 1945, Seismicity of the Earth: Geological Society of America Bulletin, v. 56 supp., p. 644-645. 



 The authors briefly discuss earthquakes in the Hawaiian region. They give epicenters for six earthquakes, large enough to permit the use of data from distant stations. The located earthquakes occurred on January 23, 1938; September 2, June 17, and July 16, 1940; October 5, 1929; and September 25, 1941. Three of these had instrumental magnitudes between 6.0 and 6.9; the other three between 5.3 and 5.9. These shocks are presumed to be tectonic, as distinguished from the numerous small shocks directly associated with the volcanoes.



Gutenberg, B., and Richter, C.F., 1954, Seismicity of the Earth (2nd ed.): Princeton, NJ, Princeton University Press. 



 Pages 79-80 cover briefly the seismicity of the Hawaiian Islands. Table 17 (p. 225-226; 244) gives dates, times and magnitudes for earthquakes in the Hawaiian Islands under Section 39 (Pacific Basin).



Hall Wallace, M., and Delaney, P.T., 1994, Rift-zone and south flank motions of Kilauea Volcano during 1982 [abs.]: Geological Society of America Abstracts with Programs, v. 26, no. 7, p. A-220. [Geological Society of America, 1994 annual meeting, Seattle, WA, Oct. 24-27, 1994] 



 A major change in the style of magmatism and deformation of Kilauea volcano occurred during 1982 and early 1983. After the 1975 M7.2 Kalapana earthquake, and prior to 1983, magmatism was dominated by intrusions and deformation by rapid extension of the summit and seaward movement of the south flank. This behavior changed to nearly continuous eruption and slower deformation of the volcanic edifice in January 1983, a pattern that continues today. We examine the interval January 1982 - October 1982 for mechanisms of deformation of the volcano and focus on a large earthquake swarm in the southwest rift zone that occurred in June 1982. We define possible sources of surface displacements using a least-squares non-linear inversion technique and planar dislocations. Models are constrained with measured changes in line-length and ground-surface tilt. Deformation related to the June earthquake swarm is best modeled as a steeply dipping dike, ~1-2 m wide, emplaced at about 2 to 11 km depth in the upper and middle southwest rift zone. Tilt measurements gathered in May 1982 and repeated in August 1982 record a small deflation of Kilauea summit related to the earthquake swarm. However, trilateration measurements gathered between January 1982 and October 1982 indicate the summit was rapidly extending. Dislocation models of the trilateration data predict the south flank moved seaward on a low-angle basal thrust fault. Residual errors for all models indicate that substantial data are unexplained. Seaward motions of the south flank during 1982 are not well modeled by simple dikes and summit deflations; however, attempts to constrain a low angle fault in the south flank were only partly successful due to the limited extent of the geodetic networks. Geodetic measurements indicate the south flank has continued to slip seaward, although at lower rates, since the initiation of the eruptive sequence in the east rift zone during January 1983. We suggest a mechanism of deformation whereby seaward slip along low angle faults near the base of the volcanic edifice causes continuous extension of the summit and rift zones and allows slow intrusions and gradual summit deflations. Further, it is the accumulation of magma deep within the edifice that drives the extension.



Hall Wallace, M., and Delaney, P.T., 1995, Deformation of Kilauea Volcano during 1982 and 1983: a transition period: Journal of Geophysical Research, v. 100, no. B5, p. 8201-8219. 



 A major transition in the style of deformation of Kilauea volcano occurred during the period January 1982 through November 1983. Prior to 1983, the deformation was dominated by magma intrusions, rapid extension of the summit, and seaward movement of the south flank. The pattern of activity changed to magma eruption and slowed deformation of the volcanic edifice in January 1983. An earthquake swarm in the southwest rift zone in June 1982 and an intrusion of a large dike in the east rift zone in January 1983 prepared the volcano for the eruptive sequences that continue today. We estimate the sources of surface displacements associated with these events using a least squares nonlinear inversion technique and planar dislocations. The models are constrained with measurements of line length changes and of surface height changes from tide gauges, water wells, and spirit-level tilt data. Deformation associated with the 1982 earthquake swarm is best modeled as the emplacement of a steeply dipping dike in the upper and middle southwest rift zone extending from 2-3 km to 10-11 km depth with a width of ~1-2 m. Tilt measurements gathered at the time of the earthquake swarm record a small deflation of Kilauea's summit; however, trilateration data indicate the summit was rapidly extending in 1982. The extension and our models are consistent with seaward slip of the south flank on a low-angle basal thrust fault. Dislocation models of the January 1983 dike intrusion yield a 14- to 15-km-long dike along the zone of observed ground rupture. The dike extends from just below the surface to the region of the most intense rift zone seismicity at 4-5 km depth. A strong nonlinear relationship among height, dip, and width results in a suite of models that explain the data equally well. Tests of parameter sensitivity indicate that the dike width and height are the least constrained parameters; the best fit average width ranges from 1.7 to 2.8 m. Our models also include a source of contraction at ~5 km depth that produces 40 cm of ground subsidence near Makaopuhi, the point of initiation of the intrusion. This location is consistent with geochemical and seismic evidence that indicate magma is stored in the rift zone. Residual errors for all models indicate that substantial line-length changes are unexplained. Seaward motions of the south flank during 1982 and 1983 are not well modeled by simple dikes and summit deflations; however, attempts to constrain low-angle faults in the south flank were only partly successful due to the limited extent of the geodetic networks.



Hanatani, R.Y., 1987, Permanent-glass EDM measurements on Kilauea, Hawaii, from June 6, 1979, to September 23, 1987: U.S. Geological Survey Open-File Report 87-202, 97 p. 



 Purpose and Scope of Report

This purpose of this report is to present the results of permanent-glass EDM measurements on Kilauea from the time the first lines were measured on June 6, 1979 to September 23,1987. We report data for all permanent-glass EDM lines ever measured on Kilauea, but discuss in more detail those monitors that were set up to track ground deformation with frequent measurements over a long period of time. Data reported here are preliminary and subject to revision as refinements are made to data reduction procedures. Also included in this report are station descriptions with location maps, and documentation of equipment and measurement procedures.

 

Table Of Contents



Introduction 	1

Background 	1

Purpose and Scope of Report 	2

Acknowledgment 	2

Equipment 	2

Measurement Procedure 	3

Kilauea Permanent-Glass EDM Network 	4

Summit Cross-Caldera Monitor 	5

Summit Quadrilateral Monitor 	5

Upper Southwest Rift Zone Monitor 	5

Upper East Rift Zone Monitor 	6

South Flank Hilina Pali Monitor 	6

South Flank Holei Pali Monitor 	6

South Flank Kalapana Monitor 	6

Results	7

References 	7

Figure 1. Kilauea Permanent-Glass EDM Network 	8

Figure 2. Kilauea Summit Cross-Caldera Permanent-Glass EDM Monitor 	9

Figure 3. Kilauea Summit Quadrilateral Permanent-Glass EDM Monitor 	10

Figure 4. Kilauea Upper Southwest Rift Zone Permanent-Glass

 EDM Monitor 	11

Figure 5. Kilauea Upper East Rift Zone And South Flank (Hilina & Holei)

 Permanent-Glass EDM Monitor 	12

Figure 6. Kilauea South Flank Kalapana Permanent-Glass EDM Monitor 	13

Time Series Plots of the Summit Cross-Caldera Monitor 	14

Time Series Plots of the Summit Quadrilateral Monitor 	23

Time Series Plots of the Upper Southwest Rift Zone Monitor 	29

Time Series Plots of the Upper East Rift Zone Monitor 	39

Time Series Plots of the South Flank Hilina Pali Monitor 	43

Time Series Plots of the South Flank Holei Pali Monitor 	48

Time Series Plots of the South Flank Kalapana Monitor 	53

Table 1. Summit Cross-Caldera Monitor Line Length Measurements 	57

Table 2. Summit Quadrilateral Monitor Line Length Measurements 	67

Table 3. Upper Southwest Rift Zone Monitor Line Length Measurements 	69

Table 4. Upper East Rift Zone Monitor Line Length Measurements 	74

Table 5. South Flank Hilina Pali Monitor Line Length Measurements 	76

Table 6. South Flank Holei Pali Monitor Line Length Measurements 	78

Table 7. South Flank Kalapana Monitor Line Length Measurements 	79

Table 8. Inactive or Seldom Measured Line Length Measurements 	81

Appendix I Description of Kilauea permanent-glass EDM stations 	89

Appendix II Coordinates for Actively Measured Kilauea

 Permanent-glass EDM stations 	97



Handy, E.S.C., and Handy, E.G., 1972, The cataclysm of 1868, in Native planters in old Hawaii; their life, lore, and environment: Benice P. Bishop Museum Bulletin 233, p. 566-568. [with the collaboration of Mary Kawena Pukui (Hawaiian translator). The abstracted account, written by C.J. Waialoha, was published in Ka Nupepa Ku'oko'a, April 11 and 18, 1868.] 



 A vivid account of the events associated with the 1868 earthquake swarm, tsunami, mudflow [landslide], and eruption at Mauna Loa. The article descibes some of the damage and gives a complete accounting of the number of persons and animals killed and number of dwellings destroyed.



Hart, R.S., and Butler, R., 1977, S wave travel times and lower mantle shear velocity from waveform correlations [abs.]: Eos, Transactions, American Geophysical Union, v. 58, no. 12, p. 1186. [AGU fall meeting, San Francisco, CA, Dec. 5-9, 1977, Program and abstracts] 



 The waveform correlation technique for obtaining reliable shear wave travel-times, applied first by Hart (1975) to several large nuclear explosions, has been employed in the analysis of seismograms from two recent large earthquakes. These earthquakes, the 1968 Borrego Mountain, California event and the 1973 Hawaiian earthquake, have been carefully modelled by Burdick and Mellman (1976) and Butler (1977) respectively. The detailed source mechanisms thus obtained allow waveform analyses to be applied with confidence. Moreover, since earthquakes are vastly more efficient S wave sources than explosions, the S waves have large amplitudes throughout the range of 30-95, which in turn yields more reliable travel-time estimates particularly at the far end of the distance range. Over 80 travel-times have been obtained from these two earthquake sources. In addition to an overall trend, relative to the Jeffreys-Bullen tables varying with distance in both slope and amplitude, several regional variations in upper mantle structure are apparent. These observed travel times have also been inverted to investigate the implications for the lower mantle shear velocity gradient. Some additional structure in that gradient is required.



Hart, R.S., and Butler, R., 1978, Shear-wave travel times and amplitudes for two well-constrained earthquakes: Bulletin of the Seismological Society of America, v. 68, no. 4, p. 973-985. 



 The wave-form correlation technique (Hart, 1975) for determining precise teleseismic shear-wave travel times is extended to two large earthquakes with well-constrained source mechanisms, the 1968 Borrego Mountain, California earthquake and the 1973 Hawaii earthquake. A total of 87 SH travel times in the distance range of 30 to 92 were obtained through analysis of WWSSN and Canadian Network seismograms from these two events. Major features of the travel-time data include a trend toward faster travel times at a distance of about 40 (previously noted by Ibrahim and Nuttli, 1967; Hart, 1975); another somewhat less pronounced trend toward faster times at about 75; a +6 sec base line shift, with respect to the Jeffreys-Bullen Table, for the Borrego Mountain data; and large azimuthally-dependent scatter for the Hawaiian data, probably reflecting dramatic lateral variations in the near-source region. When azimuthal variations in the Hawaii data are removed, the travel times from both events show very low scatter. The correlations were also used to investigate SH amplitudes for possible distance dependence in the data and variations in tb*.

 The Borrego Mountain data show very low scatter and no discernible distance dependence. All of the data are compatible with a value of tb* = 5.2 + 0.5. The amplitudes from the Hawaii earthquake show the same azimuthal variations found in the travel-time data. When those effects are removed, the Hawaii data satisfies a value of tb* equal to 4.0 + 0.5 and, as with the other data set, no distance dependence is apparent.



Harvey, D., and Wyss, M., 1986, Comparisons of a complex rupture model with the precursor asperities of the 1975 Hawaii Ms = 7.2 earthquake: Pure and Applied Geophysics, v. 124, no. 4/5, p. 957-973. 



 A simplified multiple source model was constructed for the 1975 Hawaii Ms = 7.2 earthquake by matching synthetic signals with three component accelerograms at two stations located approximately 45 km from the epicenter. Six major subevents were identified and located approximately. The signals of these are larger by factors of 1.4 to 3.2 than that of the M, = 5.9 foreshock which occurred 70 minutes before the main rupture and also triggered the SAM-1 recorders at the two stations. Dividing the rupture length (40 km) by the duration of strong ground shaking ( 50 sec) an average rupture velocity of 0.8 km/sec (about 25% of S-velocity) is obtained. Thus it is likely that the rupture stopped between subevents. The approximate epicenters of the 6 major subevents, and of the foreshock, support the hypothesis that they were located in high stress asperities which rupture during the main shock, except for the last events which is interpreted as a stopping phase generated at a barrier. These asperities have been previously defined on the basis of differences in the precursor pattern before the mainshock. Thus, it appears that both the details of the precursors and of the main rupture depended critically on the heterogeneous stress distribution in the source volume. This suggests that main rupture initiation points and locations of high rupture accelerations may be identified before the mainshock occurs, based on precursor anomaly patterns. A satisfactory match of synthetic signals with the observations could be obtained only if the azimuth of the fault plane of subevents was rotated from N60E to N90E and back to N30E. These orientations are approximately parallel to the nearest Kilauea rift segments. Hence the slip directions and greatest principal stresses were oriented perpendicular to the rifts everywhere. From this analysis and other work, it is concluded that this fault surface consisted of three types of segments with different strength: Hard asperities (radius ~ 5 km), soft but 'brittle' segments between the asperities (radius ~ 5 km), and a 'viscous' half (10 x 40 km) which slipped during the mainshock, but where microearthquakes and aftershocks are not common.



Hatori, T., 1976, Wave source of the Hawaii tsunami in 1975 and the tsunami behavior in Japan: Journal of the Seismological Society of Japan, v. 29, no. 4, p. 355-363. [Zisin; paper in Japanese with English abstract] 



 The Kalapana tsunami was generated off the south coast of Hawaii Island, accompanying the earthquake of magnitude Ms=7.2 (NOAA), at 14h 48m (GMT), Nov. 29, 1975. Some features of this tsunami are investigated on the basis of tide gauge records of NOAA and Japan, adding the reports of the US field investigation.

 Tsunami magnitude of the Imamura-Iida scale is decided as m=2, judging from the tsunami heights observed near and distant fields. The initial motion of the tsunami waves was in an upward direction at the whole Hawaiian stations, suggesting the uplift of the sea-bottom in the tsunami source area. The source dimension of tsunami is inferred to be 70 km along the south coast of Hawaii Island, and the area is 2.2xl03km2. By applying the corrections for the refraction and shoaling from the inundation heights at the Hawaii Island, the average vertical displacement of 1.2 m would be occurred in the source area. The tsunami energy of approximately is 1.6x1020 ergs. According to statistical relation, the present tsunami is large compared with the earthquake magnitude.

 The tsunami fronts arrived in NE Japan at about 7h 40m after the occurrence of the earthquake. The maximum double amplitude is 20-30 cm with the period of about l5 min and the amplitude is relatively higher than that in SW Japan. It is noticed that the wave rays emitting the tsunami source concentrate in the Kuril Islands.



Hazard, D.L., 1916, Earthquakes, in Results of observations made at the Coast and Geodetic Survey magnetic observatory near Honolulu, Hawaii, 1913 and 1914: Washington, DC, Department of Commerce and Labor, Coast and Geodetic Survey, Serial No. 21, p. 98-104. [See abstract for Hazard, 1910] 



 A register of the earthquakes recorded at the Honolulu Magnetic Observatory



Hazard, D.L., 1918, Earthquakes, in Results of observations made at the Coast and Geodetic Survey magnetic observatory near Honolulu, Hawaii, 1915 and 1916: Washington, DC, Department of Commerce and Labor, Coast and Geodetic Survey, Serial No. 86, p. 95-100. [See abstract for Hazard, 1910] 



 A register of the earthquakes recorded at the Honolulu Magnetic Observatory



Hazard, D.L., 1920, Earthquakes, in Results of observations made at the Coast and Geodetic Survey magnetic observatory near Honolulu, Hawaii, 1917 and 1918: Washington, DC, Department of Commerce and Labor, Coast and Geodetic Survey, Serial No. 133, p. 97-103. [See abstract for Hazard, 1910] 



 A register of the earthquakes recorded at the Honolulu Magnetic Observatory



Hazard, D.L., 1922, Earthquakes, in Results of observations made at the Coast and Geodetic Survey magnetic observatory near Honolulu, Hawaii, 1919 and 1920: Washington, DC, Department of Commerce and Labor, Coast and Geodetic Survey, Serial No. 200, p. 91-96. [See abstract for Hazard, 1910] 



 A register of the earthquakes recorded at the Honolulu Magnetic Observatory



Hazard, D.L., 1924, Earthquakes, in Results of observations made at the Coast and Geodetic Survey magnetic observatory near Honolulu, Hawaii, 1921 and 1922: Washington, DC, Department of Commerce and Labor, Coast and Geodetic Survey, Serial No. 276, p. 93-104. 



 A register of the earthquakes recorded at the Honolulu Magnetic Observatory

 "In February, 1921 [the Milne seismograph] was replaced by a Milne-Shaw seismograph. It consists of two horizontal pendulums, one recording east-west motion (E) and the other recording north-south motion (N). Because of the large magnification (150), microseisms are continuously present on the seismograms, with amplitudes ranging from 0.5 mm to 2.0 mm and predominant periods of 4 and 8 seconds, the larger amplitudes usually accompanying the longer period. Preliminary phases of small amplitude are difficult to separate from the microseisms. The amplitudes have been computed on the basis of the constants given below. Where the periods of the waves could not be determined, the trace amplitude has been divided by 100. These values are indicated by asterisks.

 Period of pendulums, 12 sec

 Damping ratio, about 20:1

 Multiplication, 150

 Sensitivity, 25-30 mm



Heck, N.H., and Bodle, R.R., 1931, Hawaiian Islands, in United States earthquakes, 1929: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial no. 511, p. 16. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Heliker, C.C., 1988, Volcanic hazards and eruption forecasting in Hawaii, in, Kagoshima International Conference on Volcanoes, Kagoshima, Japan, July 19-23, 1988, Proceedings: Kagoshima, Japan, Kagoshima Prefectural Government, p. 598-601. 



 In recent years, eruptions of Kilauea and Mauna Loa Volcanoes on the Island of Hawaii have repeatedly threatened populated areas. One of the primary goals of the Hawaiian Volcano Observatory (HVO) is to forecast the onset and location of eruptions and to evaluate the hazard posed by lava flows to inhabited areas.

 The most reliable precursors of Hawaiian eruptions are seismicity and ground deformation, which provide a basis for both short-term predictions (hours to days) and long-term predictions (weeks to years). A successful long-term prediction was made of the 1984 Mauna Loa eruption, which lasted for 3 weeks and threatened the town of Hilo. A year before this eruption occurred, HVO forecast an increased probability of a Mauna Loa eruption within the next 2 yrs, mainly on the basis of the increasing frequency of shallow- and intermediate-depth earthquakes. Short-term prediction of the eruption was not successful; no recognized precursors signaled the actual onset of the eruption.

 The beginning of the current eruption series on Kilauea's east rift zone in January 1983 was heralded by a seismic swarm that migrated 17 km downrift ahead of the intruding dike. The swarm began 24 hrs before magma reached the surface, allowing short-term prediction of both the onset and the location of the activity. During other eruptions, however, magma has moved almost aseismically into the rift zone, precluding an accurate prediction.

 From June 1983 to July 1986, Kilauea's eruption established a cycle of episodic activity, with eruptive episodes occurring on the average every 23 days and lasting about 10 hrs. Short-term predictions of eruptive episodes were based on the daily counts of summit earthquakes and on the amount of inflation of Kilauea's summit magma reservoir, measured by electronic tiltmeters.

 In July 1986, the site of the eruption shifted 3 km downrift. Since then, continuous lava extrusion from the new vent, at a rate of approximately 0.5 million cubic meters per day, has built a lava shield and a system of lava tubes that has repeatedly delivered flows to the populated coastal plain 10 km to the SE. Our hazard evaluations are now focused on predicting in which direction and how fast the tube-fed pahoehoe flows will travel. HVO's evaluations are passed on to the Hawaii County Civil Defense and Hawaii Volcanoes National Park; these agencies make decisions regarding road closures, evacuations, and fire control.

 Volcanic eruptions are a part of Hawaii's cultural history and are familiar to long-term residents. However, as the population of the island grows, many newcomers build homes and businesses in areas of high volcanic hazard without any knowledge of the risk to their property. Effective land-use planning and public response in times of emergency depend on scientists and public officials increasing their efforts to educate the public about volcanic hazards.



Hill, D.P., 1977, A model for earthquake swarms: Journal of Geophysical Research, v. 82, no. 8, p. 1347-1531. 



 A model for earthquake swarms in volcanic regions consists of the following concepts: (1) clusters of magma-filled dikes exist within brittle volumes of the crust, (2) dikes within a cluster are systematically oriented with their long dimension in the direction of the regional greatest principal stress, and (3) a sequence of shear failures (an earthquake swarm) occurs along a system of conjugate fault planes joining en echelon offset dike tips at oblique angles. This model accounts for commonly observed geometric relations between surface faulting patterns, the hypocentral distribution of swarm earthquakes, and fault plane solutions in a variety of situations. Swarm areas dominated by strike-slip faulting, however, provide the most compelling examples of the utility of the model. Specific examples considered here include a swarm on the east rift zone of Kilauea volcano, Hawaii, and swarms in the Imperial Valley, California, and the Reykjanes Peninsula, Iceland, which represent transitional zones between spreading centers and transform faults.



Hillebrand, W., 1868, [On the eruptions of 1868]: Hawaiian Gazette, 05/06, p. 2. [Excerpted in American Journal of Science, 2nd ser., v. 46, p. 115-121] 



 Hillebrand describes the effects of the eruptions of Kilauea and Mauna Loa and the great earthquakes of 1868. In spite of ground-cracking around Kilauea, "the Volcano House has not suffered nor is the ground surrounding it broken in the least." [This has also been true for more recent large earthquakes.] On April 18 there was no lava active in Kilauea caldera, and the south lake was 500 ft deep. More than two-thirds of the caldera floor of Kilauea had collapsed and lay 100-300 ft below the remaining floor. The collapse extended to the western edge and was greater at the northern end than at the southern end. Hillebrand quotes the following chronology of events from Kaina, a guide who was residing at the Volcano House.

	January 20-March 29		Caldera generally active

	March 27			First felt earthquake

	April 2, 4:00 p.m.		Great earthquake

	April 2			Lava confined to lakes

	April 4			Lava confined to South Lake only

	April 5			Lava gone from the caldera

He gives a good description of the mudflow triggered by the 1868 earthquake. He makes no mention of activity in Kilauea Iki. This reference is followed by an excerpt from Anonymous (1868f) and additional remarks by J.D. Dana on the 1868 events.



Hitchcock, D.H., 1887, [On the earthquake swarm and eruption of 1887]: Hawaiian Gazette, 02/01, p. 8. [Letter no. 08. Excerpted in American Journal of Science, 3rd series, v. 33, p. 310-311] 



 Subheads over letters from correspondents, signed and unsigned:

The latest from Kau!; great damage to property!; continued earthquakes



Hilo, Jan. 27, 1887-- . . .

 Ever since early in December last, there has been a steady increase in the number and heaviness of the earthquake shocks. About the 12th of January, they had increased to an average of about three a day and on the 14th, 15th and 16th, shocks were heavier and heavier, until on Saturday, the 16th, about midnight, came the heaviest shock yet felt. The motion was long and wavy from a little west of south to the east of north. That night the summit crater of Mauna Loa blazed forth for a few hours and disappeared, and not long after the heavens were lighted with a brilliant reflection from the lava as it ran down the Kau side of the mountain. . . .

 We were however greatly astonished when on Sunday last the earth again became nervous, and when shock after shock came sabbath eve, each harder and more violent than the last, Hiloans began to think that the "shake" of 1868 was again to be enacted, and numbers availed themselves of their lanais in order to be ready for "the next one". In twenty minutes nine shocks were felt, two of them being violent enough to shake down dishes, stop clocks, upset stoves, and set chandeliers to swinging. The one in my dining room had a swing of fifteen inches from the perpendicular and for two hours there were shocks heavy enough to keep it swinging. . . . Last night [Jan 26] was the first that I've not felt a shock since Saturday night.

 . . . .

 From a party who were camping above the woods on Mauna Kea, I hear that from Monday morning to Tuesday morning, the earth there was in a continued state of vibration, over twenty-five distinct shocks being counted. They must have been very nearly over the line of greatest displacement [i.e., the epicenter].



Hitchcock, D.H., 1887, [On the earthquake swarm and eruption of 1887]: Hawaiian Gazette, 02/08, p. 5. [Reprinted in Hawaiian Gazette, Feb. 15 supp., p. 1] 



 Earthquakes felt at Hilo continued at least to February 2, 1887.



Hitchcock, C.H., 1909, Hawaii and its volcanoes: Honolulu, Hawaiian Gazette Co., 314 p. [2nd ed., with supp., 1911, 314 p.] 



 Contents

Part 1. Physiography of the Hawaiian Archipelago 1

The Hawaiian Archipelago, "the loveliest fleet of islands anchored in any ocean," is usually described as consisting of eight high inhabited islands with a N.W., S.E. trend. The nautical charts, however, show a dozen smaller low islands and shoals situated to the northwest of the more important part of the group, over which the authority of the territorial government is now extended. The archipelago extends over twenty-five degrees of longitude, or about I,800 miles. The following table presents their names, order, areas and extreme altitudes:

 LOW ISLANDS AND REEFS.

 Ocean Islands 10 feet

 Midway Islands 57 feet

 Gambia Shoal 

 Pearl and Hermes Reefs 

 Lisiansky Island . 50 feet

 Laysan Island 25 feet

 Maro Reef 

 Dowsett's Reef 

THE LOWEST OF THE HIGH ISLANDS.

 Gardiner Island 170 feet

 French Frigate Shoal 120 feet

 Necker Island 300 feet

 Frost Shoal 

 Nihoa or Bird Island 903 feet

 HIGH INHABITED ISLANDS.

Name Altitude Area in Square Miles

Niihau 1,300 feet 97

Cinder cones adjoining, named Kaula and Lehua.

Kauai Waialeale 5,250 feet

Oahu Kaala 4,030 feet

Molokai Komokoa 4,958 feet

Lanai 3,400 feet

Maui. Haleakala 10,032 feet

Kahoolawe Moaula Hill 1,472 feet

Hawaii Mauna Kea 13,825 feet

Part 2. The History of the Exploration of Mauna Loa 56

Part 3. The History of the Exploration of Kilauea 160

Part 4. The Hawaiian Type of Volcanic Action. 262

APPENDIX.

A. Earthquakes in Hawaii 290

B. The Place of Origin of the Moon 296

C. Use of the Spectroscope 297

D. Analyses of Hawaiian Igneous Rocks 298

E. Biographical Notes 301

This is C.H. Hitchcock's major work, primarily a descriptive chronology of the eruptions of Kilauea and of Mauna Loa, and, like Brigham (1909) and Dana (1891a), he summarizes all that is known about Hawaiian volcanoes. Hitchcock includes more unpublished material (including many letters written to him) and places more emphasis on the Hawaiian accounts of eruptive activity before the arrival of the missionaries.

 Hitchcock provides a systematic description of the Hawaiian Islands from Midway to Hawaii and briefly describes the geology of the principal Hawaiian Islands. He includes notes (previously unpublished) of his ascent of Mauna Kea in 1886. He resolves map discrepancies mentioned in earlier references (Hitchcock, 1900, 1906), and identifies the upper part of a flow erroneously plotted as 1823 as the Keamoku flow of prehistoric age. Hitchcock provides an excellent summary of the history of exploration of Mauna Loa, beginning with the voyage of Captain Cook. He presents Archibald Menzies' unpublished journal [reprinted in part as Menzies, 1920] of the first ascent of Mauna Loa and first observation of Mokuaweoweo in 1793. Menzies determined the elevation of Mauna Loa to be 13,564 ft. Hitchcock identifies eyewitnesses for each eruption and quotes from them. He summarizes an ascent made by himself in 1883 and an unpublished account of an ascent by Professor Willis T. Pope in July 1905; Mokuaweoweo was inactive both years. He describes and illustrates lava tree molds and repeats observations on Mohokea caldera and ash deposits. He speculates briefly on the origin of calderas and briefly describes the geology of Hualalai.

 Following the material on Mauna Loa, Hitchcock gives an equally good chronology of observations on Kilauea, using the Volcano House Register (Bevens, 1988) to fill in chronology for years in which nothing else was published. He correctly infers a young, prehistoric age for lava between Keaau and Pahoa. [Modern mapping and radiocarbon dating show this lava to be about 350 years old.] He summarizes the early history of Kilauea gleaned from Hawaiian accounts. Kilauea was apparently active in 190 A.D., 1090, and in every king's reign since. The Pele legend originated after an eruption around 1175 and Keanakakoi erupted in 1420. The age of Kapoho cone is estimated at 1340-80, an eruption at Kaimu occurred in the period 1730-54, and there was another Puna eruption in 1788. He describes the 1790 explosive summit eruption, disputing Dana's inference that all of the ash deposits in the south caldera and Kau Desert date from 1790. Hitchcock believes they are too widespread for one eruption and infers an extensive prehistoric explosive history for Kilauea. [Modern mapping and study confirm Dana's view that all but a small part of what is now called Keanakakoi ash originated in 1790.] Hitchcock discovered Yellow Cone on Kilauea's southwest rift zone and thought it could be part of a series of yellow cones, now buried on Kilauea from Puu Kapukapu to lower Kau, that provided a source for the Pahala ash. He quotes from an unpublished letter of E.D. Baldwin regarding the 1868 eruption on Kilauea southwest rift. He shows sections across Halemaumau from 1886-92 covering two collapses, and again describes Kilauea as quiet after 1894. [This is confusing because he also quotes from the Volcano House Register to show that Kilauea was active for short periods, separated by longer periods when no lava was visible.]

The last section of the paper describes the Hawaiian type of volcanic action. Hitchcock provides a good discussion of ideas regarding the relation of Kilauea to Mauna Loa, including a table of eruption dates highlighting times when both volcanoes were active. He concludes that Kilauea and Mauna Loa are separate volcanoes, possibly connected at depth. He gives a chronology of Kilauea eruptions (1790-1908) and tabulates the levels of lava in Halemaumau relative to the elevation of Volcano House, both before and after major collapses [which he calls eruptions, following Dana's terminology]. He also gives a chronology and tabulates fountain heights for Mauna Loa eruptions (1852-1907). He summarizes ideas on the origin of aa and pahoehoe; he questions Dana's conclusions with regard to their origin but makes no concusion of his own. He infers from historic lava coverage that many millions of years were necessary to build Mauna Loa. [This is probably too high. Present estimates are less than l my.] He repeats published claims that rhyolite and trachyte are fusible at 2,700-3,100F, whereas basalt is fusible at 2,250F. [Hitchcock perpetrates the confusion regarding a comparison of liquidus temperatures and a comparison of the temperatures at which rhyolite and basalt would have equal viscosity.] He discusses W.H. Pickering's (1906) paper comparing lunar and Hawaiian features.

Hitchcock covers additional topics in an appendix. He discusses earthquakes in Hawaii with reference to the Lyman diary [see S.J. Lyman, 1859; Wyss and Koyanagi, in press], and earthquake-induced tsunami in 1837, 1868, and 1877. He gives a few analyses from Washington's tables (Washington, 1917b) and repeats his plea for more spectroscopic measurement at Kilauea. The appendix concludes with biographical notes on Titus Coan, Sereno Bishop, W.T. Brigham, C.E. Dutton, J.D. Dana, and W.L. Green. A supplement, added to later editions of the book, gives additional information on chronology of events in 1868. [This is a rather confusing account in which Hitchcock now associates the earthquake with Kilauea rather than Mauna Loa.] He includes comments and corrections by L.A. Thurston to the first edition of the book and concludes with a review of Brigham's book published in the same year (Brigham, 1909). He discusses Brigham's error in quoting the maximum height of lava lake as 75 ft below Volcano House in 1894. [Confusion arose from ambiguous cross sections drawn by F.S. Dodge in the Volcano House Register and was cleared up by later comments entered in the Register.] He corrects one final error. Brigham cites "110 cones over 50 to 75 feet high;" Hitchcock points out that 110 is actually a mistranscription of "no."

[This is an excellent sourcebook for the chronology of Kilauea and Mauna Loa activity, particularly adding in the inferences for the prehistoric period. His interpretation sections are somewhat scattered, mostly reciting the ideas of others, rather than attempting any synthesis of his own.]



Hitchcock, C.H., 1910, The volcanoes of Hawaii in 1868: Honolulu Advertiser, 10/09, p. 3. 



 Hitchcock reviews the events of 1868. He interprets them with the aid of maps to suggest that the earthquakes were volcanic rather than tectonic, that all volcanic and seismic activity originated at Kilauea, and that the 1868 eruption at Kahuku was a sympathetic response of Mauna Loa to the events at Kilauea. [Hitchcock is incorrect in many of his facts as well as in his conclusions. He claims that Titus Coan overlooked the 1868 lava erupted from Kilauea's southwest rift zone and that E.D. Baldwin first discovered it in 1907. In fact, Coan (1869) accurately described the 1868 Kilauea lavas. The map of Baldwin's is in error, showing a reversal of the true position of the 1823 and 1868 eruptions and in showing the 1868 lavas extending to the ocean. The first accurate map was that of Stearns and Clark (1930). Modern interpretation would make the 1868 earthquake a tectonic event associated with instability of the south flank of Mauna Loa, not Kilauea, triggered indirectly by magmatic injection associated with Mauna Loa's rift zone. Hitchcock's errors regarding the 1868 activity were perpetuated for many years after publication of this article.]



Holman, C.W., 1982, Seismicity, crustal deformation, and seismic risk from earthquakes on Maui, Molokai, and Lanai: Honolulu, University of Hawaii, M.S. thesis, 148 p. [In Hawaii reference collection] 



 Four seismometers have been installed on Maui by the Hawaii Institute of Geophysics to monitor local seismicity and crustal deformation. During the monitoring period from mid-May 1980 until mid-August 1981, this array detected one hundred twenty-four local events. Twenty-six of these were quarry blasts. Twenty-five of the earthquakes yielded reliable hypocentral locations with residuals less than 0.50 seconds and standard deviations less than twenty kilometers. The locations indicate that there are two main areas of seismicity near Maui: beneath Haleakala Volcano and between Molokai and Lanai. Seismic activity was also detected between Maui and the island of Hawaii, north of Maui, and north of Molokai. Most seismic activity seems to be related to the loading of the crust. The Molokai Fracture Zone does not appear to be seismically active. The seismicity study results, as well as data obtained from a geodetic network established by the Hawaii Institute of Geophysics, suggest that seismic crustal deformation is not geodetically measurable in the Maui-Molokai-Lanai region. Current and historical seismicity are analyzed to determine the seismic risk from earthquakes with source locations near Maui, Molokai, and Lanai. The 6 3/4 magnitude 1938 Maui earthquake has been relocated to 21.02 N. and 156.09 W., just 0.2 south of its 1938 location. Magnitudes of 6.8 and 6.9 were calculated. The revised depth estimate (about 20 km based upon P and pP wave arrivals) is considerably less than the 1938 estimate of 65 miles. For the Gutenberg-Richter relation (Log N = A - bM) the respective A and b values obtained are 4.28 and 0.50 for the monitoring period and 4.31 and 0.67 for the past twenty year period. The b values for the recent seismic study and the past twenty years are significantly lower than known Hawaiian Island b values, suggesting that the Maui-Molokai-Lanai region is under stress. Strain release data for the last twenty years show that the Maui region releases strain with earthquakes of magnitude 3 to 5 every 2 to 5 years. This result may be of use in predicting the possible magnitude of future earthquakes. Earthquake recurrence rates are calculated for the monitoring period and the past twenty years. Recurrence rates for the monitoring period are unreliable due to a strong dependence on the March 5, 1981 magnitude 5.0 Molokai earthquake and its aftershocks. The recurrence rates for the past twenty years indicate a magnitude 7 earthquake could occur once every 250 years. Evaluation of the 1938 Maui earthquake and the magnitude 7.1 1871 Molokai earthquake indicate that seismic risk for Maui, Molokai, Lanai, and Oahu has been underestimated. Maui, Molokai, and Lanai should be within seismic risk Zone 3 and Oahu within Zone 2.

 

ACKNOWLEDGEMENTS.....................................................iii

ABSTRACT............................................................. 	iv

LIST OF ILLUSTRATIONS.............................	viii

LIST OF TABLES....................................................... 	xi

CHAPTER I INTRODUCTION.....................................1

CHAPTER II HYPO71 AND THE CRUSTAL MODEL

 FOR EARTHQUAKE LOCATION............................... 	11

 The Operation of the Earthquake Location

 Program HYPO71................................... 	11

 The Tectonic Setting and

 Geology of Maui.................................. 	13

 Geophysical Studies on Maui..................... 	18

 Quarry Blasts and the Crustal Model.............. 	26

CHAPTER III CURRENT SEISMICITY NEAR

 MAUI, MOLOKAI, AND LANAI............................. 	35

 Data Acquisition ant Reduction................... 	35

 Earthquake Location Study........................ 	38

 Hypocenters from the Maui Network............... 	41

 Possible Earthquake Mechanisms

 in the Maui-Molokai-Lanai Region................. 	49

CHAPTER IV CRUSTAL DEFORMATION NEAR

 MAUI, MOLOKAI, AND LANAI................................ 	58

 A Brief History of the Lunar Ranging

 Experiment and the Maui Crustal

 Deformation Project, 1976-1981................... 	58

 Measurable Crustal Deformation

 Detected by Seismic Means........................ 	50

 Comparison of Measurable Crustal

 Deformation Detected by

 Seismic and Geodetic Means....................... 	63

CHAPTER V THE RELOCATION OF THE 1938 MAUI EARTHQUAKE............ 	72

 Description of the 1938 Maui Earthquake.......... 	72

 Data Acquisition and Reduction...................	76

 Discussion.........................	80

CHAPTER VI EARTHQUAKE FREQUENCY, STRESS, AND

 SEISMIC RISK FROM EARTHQUAKES NEAR

 MAUI, MOLOKAI, AND LANAI.............................. 	87

 b values and Regional Stress..................... 	87

 The Time Distribution of Earthquakes

 in the Maui-Molokai-Lanai Region................ 	93

 Seismic Risk Zoning for Earthquakes

 from Maui, Molokai, and Lanai....................	102

SUMMARY....................................	109

SUGGESTIONS FOR FUTURE STUDY........................................	111

APPENDIX 1 MODIFIED MERCALLI INTENSITY SCALE,

 1956 REVISED VERSION.........	113

APPENDIX 2 THE ARRIVAL TIME DIFFERENCE METHOD....................	l16

	 The Arrival Time Difference Model................	116

	 The Relocation Model................	117

APPENDIX 3 THE .METHOD OF SINGULAR VALUE DECOMPOSITION AND

 NOTES ON THE COMPUTER PROGRAM 'DECOM'................	120

APPENDIX 4 THE COMPUTER PROGRAM 'DECOM'................	126

REFERENCES................................	142



Huang, Z., 1986, Coda Q before the 1983 Hawaii earthquake [abs.]: Eos, Transactions, American Geophysical Union, v. 67, no. 16, p. 315. [AGU spring meeting, Baltimore, MD, May 19-22, 1986, Program and abstracts] 



 Apparent Q values were derived from the S wave coda of more than 300 microearthquakes, that occurred in a five year period before the Nov. 16, 1983 Kaoiki, Hawaii, earthquake (Ms=6.6). The microearthquakes took place within a 15x12 km rectangular region surrounding the mainshock, and were recorded on three stations. The epicentral distances were from O to 18 km. The digital seismograms were narrow band-pass-filtered with center frequencies from 4.5 to 27 Hz. Apparent Q was calculated from the amplitude decay rate for each frequency band. The area studied was divided into a southeast and a northwest subregion. Average Q for the NW region is about 10% higher than that of the SE region, where seismicity was five times higher. Both regions show the same frequency dependence of Q: Q=65xf0 44 for SE region, and Q=72xf0 46 for NW region. No significant temporal change in average Q was observed during the five to six years before the mainshock.



Huang, Z.-X., and Wyss, M., 1988, Coda Q before the 1983 Hawaii (Ms = 6.6) earthquake: Bulletin of the Seismological Society of America, v. 78, no. 3, p. 1279-1296. 



 Coda Q values were derived for more than 300 microearthquakes that occurred in a 6-yr period before the 16 November 1983 Kaoiki, Hawaii, earthquake (Ms = 6.6). The sources were located within a 14 x 16 km rectangular region surrounding the main shock epicenter, and most of them occurred at depths between 5 and 10 km. Digital recordings from three stations at epicentral distances ranging from 0 to 18 km were used. Coda Q was calculated from the amplitude decay rate of the S wave coda in nine frequency bands from 4.5 to 27 Hz. The average Q of the NW part of the studied area is about 15 per cent higher than that of the SE part. These two subregions also showed differences in seismicity, b value, and microearthquake source mechanisms. In the high-Q volume, the b value was 1.0, and the rate of earthquakes per unit volume was about 50 per cent of the rate in the low-Q volume where b = 1.3. One interpretation of these observations Is that more extensive faulting in the SE Kaoiki fault zone leads to lower O, higher b value, and a higher seismicity rate. During the 5 to 6 yr before the mainshock, the 1-yr average Q values were stable. No significant Q change could be identified as a precursor to the main shock.



Hubbard, F., 1952, Quakes off Puna recall 1868 Kau wave disaster: Hilo Tribune-Herald, 03/27, p. 1. [Fran Hubbard is the wife of the Chief Naturalist, Hawaii National Park] 



 The author recounts the devastating tsunami and other consequences associated with an earthquake swarm in 1868. The following paragraph is of interest with regard to tectonic changes associated with the ongoing offshore seismic swarm:

 "Observers in the Kalapana area have reported that rocks are visible which have never been in evidence before."



Hubbard, F., 1952, Undersea temblors continue; 'strong' quake felt in Kau: Hilo Tribune-Herald, 03/28, p. 1. [Fran Hubbard is the wife of the Chief Naturalist, Hawaii National Park] 



 . . . .

 Temblors in the 24 hours up to 8 a.m. yesterday numbered about 187, as against 168 the previous 24 hours and 132 in the 24-hour period preceding that. . . .

 The grand total of the quakes since 6 a.m. March 16 now is more than 2,400.

 Of the tremors in the last 24 hours one was in the "moderate" class. It occurred at 10:43 last night and was also reported by Myrtle Hansen, Tribune-Herald correspondent in Naalehu, as being felt "quite strong." It was felt rather longer than usual, she told Dr. Macdonald.

 The article continues, discussing the likelihood of the tremors continuing and the unlikely prospect of eruption. Macdonald also discusses the lack of correspondence between quake epicenters and undersea mountains off the south coast.



Hubbard, F., 1952, Kilauea quakes are continuing: Hilo Tribune-Herald, 04/08, p. 1. [Fran Hubbard is the wife of the Chief Naturalist, Hawaii National Park] 



 . . . .

 The series of earthquakes, all slight and nearly all of shallow origin, is continuing. In the last 24 hours, only one could be classified as "moderate," Dr. Macdonald said. This came at 12:54 p.m. Monday and was felt lightly in the National Park area.

 The quakes are coming from three sources, Dr. Macdonald said. These sources are beneath the Kilauea crater, from the east rift zone of Kilauea 10 to 12 miles east of the crater, and from off the southern coast of the island where a disturbance of some kind beneath the floor of the ocean has been in progress for three weeks. the quakes from the offshore area, however, have slackened off greatly.



Ihnen, S., and Wyss, M., 1978, Crustal stress changes precursory to the 1975 Hawaii M=7.2 earthquake [abs.]: Earthquake Notes, v. 49, no. 4, p. 60-61. 



 The state of stress in a portion of the south flank of Kilauea volcano, Hawaii, has been examined as part of a search for precursors to the 1975 Kalapana Earthquake (Ms=7.2). Geodetic, geological and seismological data have been combined to derive information on the state of stress in the south flank during the last 100 years.

 Triangulation and trilateration surveys indicate that the south flank has separated from the rest of the island along Kilauea's rifts by several meters since the turn of the century. Measured displacements of points within the south flank show stress accumulations of 100-200 bars between 1896 and 1970. Geologic evidence suggests that this separation is due to forcible injection of magma into the rift zones which open against the least horizontal principal stress and whose strike reflects the direction of maximum compressive stress, which we therefore deduce to be oriented in the NE direction in the hypocentral volume.

 Focal mechanism studies of more than 100 earthquakes in the source area of the Kalapana earthquake confirm that the prevailing direction of compressive stress is parallel to the rift. In late 1972, three years prior to the Kalapana earthquake, the P-axis direction of events near the future epicenter was observed to change from about N60E to approximately S60E. It appears that this rotation and the change from stress accumulation to stress release, as evidenced by preliminary geodetic data, were precursors to the Kalapana earthquake.



Ingalls, A.B., 1895, Vibrations of earthquake: Pacific Commercial Advertiser, 12/10, p. 5. [A letter to the editor] 



 The earthquake of 11:04 p.m. yesterday threw from the shelves of the Bishop Hall of Science several tall glass cylinders. . . . the vibrations proceeded from a point about 10 to 12 north of east.



Jachens, R.C., and Eaton, G.P., 1980, Geophysical observations of Kilauea Volcano, Hawaii, l. Temporal gravity variations related to the 29 November, 1975, M=7.2 earthquake and associated summit collapse [abs.], in McBirney, A.R., ed(s)., Gordon A. Macdonald Memorial Volume (special issue), no. 3/4: Journal of Volcanology and Geothermal Research, v. 7, p. 225 -240. 



 Repeated high-precision gravity measurements made near the summit of Kilauea volcano, Hawaii, have revealed systematic temporal variations in the gravity field associated with a major deflation of the volcano that followed the 29 November, 1975, earthquake and eruption. Changes in the gravity field with respect to a stable reference station on the south flank of neighboring Mauna Loa volcano were measured at 18 sites in the summit region of Kilauea and at 4 sites far removed from its summit. The original survey, conducted 10-23 November, 1975, was repeated during a two-week period after the earthquake. The results indicate that sometime between the first survey and the latter part of the second survey the gravity field at sites near the summit increased with respect to that at sites far removed from the summit. The pattern of gravity increase is essentially radially symmetrical, with a half-width slightly less than 3 km, about the point of maximum change 1.5 km southeast of Halemaumau pit crater. Gravity changes at sites near the summit correlate closely with elevation decreases that occurred sometime between leveling surveys conducted in late September 1975 and early January 1976. The systematic relation between gravity and elevation change (-1.71  0.05 (s.e.) ugal/cm) shows that deflation was accompanied by a loss of mass from beneath the summit region. Mass balance calculations indicate that for all reasonable magma densities, the volume of magma withdrawn from beneath the summit region exceeded the volume of summit collapse. Analysis suggests that magma drained from at least two distinct areas south of Kilauea caldera that coincide roughly with two reservoir areas active during inflation before the 1967-68 Kilauea eruption.



Jackson, D.B., Swanson, D.A., Koyanagi, R.Y., and Wright, T.L., 1975, The August and October 1968 east rift eruptions of Kilauea Volcano, Hawaii: U.S. Geological Survey Professional Paper 890, 33 p. 



 The eruption of August 22 26, 1968, began in Hiiaka Crater, on Kilauea's east rift zone. In 3 days, the activity migrated 20 km down the northern margin of the active part of the rift zone, venting in six different places. A 27-m-deep pool containing 8.9 x l04 m3 of lava formed in Hiiaka; only about 3.5 x 103 m3 remained after drainback into the eruptive fissure. The total volume of lava remaining on the surface, about 13.5 x 103 m3, is the smallest net output of lava in a historic Kilauea eruption. The August lava is the chemical equivalent of one of the early variants of the 1969-71 eruption mixed with a lesser amount of 1967-68 summit lava and olivine. Systematic enrichment in phenocrysts of plagioclase and clinopyroxene downrift suggests the lava cooled about 65C during shallow underground transport.

 Following 6 weeks of rapid reinflation of the summit area, another east rift eruption began on October 7 along a more or less continuous, 6.5-km-long line of vents northeast of Makaopuhi Crater. The eruption lasted until at least October 22, and spattering of uncertain origin was observed as late as November 11. Napau Crater was flooded by a lava lake 5 m deep and 6.3 x 105 m2 in area. The net volume of lava remaining above ground, about 7 .5  2.2 x 106 m3, is perhaps 25 percent less than the total volume of erupted lava, because of voluminous drainback. Some of the October lava is a differentiate, chemically equivalent to 1961 summit lava from which some olivine, clinopyroxene, and plagioclase have been removed. Other October lava can be explained as a mixture of 1 part differentiate and 3 parts lava of 1967-68 summit composition.

 The August and October eruptions were accompanied by severe ground deformation at the summit and along the rift zone near the sites of eruption. The summit region subsided, tilted inward, and contracted as magma was withdrawn from a reservoir and moved into the rift zone. Maximum vertical displacement at the summit was about 20 cm, maximum measured horizontal displacement about 16.l cm. Frequent tilt measurements made during the eruptions indicate multiple centers of deformation that shifted location with time. The center of net deformation for both eruptions, as defined by vertical and horizontal displacements, ground tilt, and dilatational strain, was about 1.5 km southeast of Halemaumau Crater. By using a point-source elastic model, the vertical displacement and tilt data give the best solutions for a focal depth of 3.2 km for the August eruption. The October deformation data are inadequate for modeling purposes.

 Parts of the east rift zone adjacent to the eruptive fissures were uplifted during eruptions, at least 35 cm in August and 20 cm in October. A subsidence trough, probably a keystone graben, formed along the August fissures. Trilateration stations on the rift zone were displaced as much as 63 cm away from the new fissures. Finite element modeling and geologic evidence suggest that the August dikes are vertical or dip steeply southward.

 Seismicity was concentrated in the summit and eruption areas during each eruption. Earthquakes and harmonic tremor at the summit were probably related both to the mechanics of subsidence and the transfer of magma. Earthquakes in the eruption area were mainly associated with ground rupture as magma forced its way to the surface, once dikes were emplaced, earthquakes gave way to tremor, caused by both subsurface transfer of magma and surface fountaining.

 The presence of a magma reservoir on the east rift zone in the vicinity of Makaopuhi Crater is inferred from seismic, petrographic, and chemical evidence.



Jackson, M.D., Delaney, P.T., and Endo, E.T., 1988, Ground rupture from the 1983 Kaoiki earthquake, Mauna Loa Volcano, Hawaii [abs.]: Seismological Research Letters, v. 59, no. 1, p. 30. 



 On November 16, 1983, rock fracture associated with the M6.6 Kaoiki earthquake generated a zone of ground cracking that extends for at least 5 km on the southeast flank of Mauna Loa Volcano. Unlike many other earthquakes, the Kaoiki event apparently created a new rupture, at least in its surface expression, rather than following the trace of an older fault. The general trend of the zone of ground cracks, 45, parallels a nodal plane of the main shock's focal mechanism, indicating right lateral shear. Left-stepping echelon opening-mode cracks within the zone of surface rupture strike east-west, 45 clockwise from the overall trend of the zone. These cracks are consistent with right-lateral shear and strike parallel to a transect joining the summit magma reservoirs of Mauna Loa and Kilauea Volcanoes. The cracks are as much as 50 m in length and have jagged walls, with opening-mode displacements of as much as ~0.5 m. Shear displacements on the cracks are virtually absent. Some echelon crack tips curve toward one another; elsewhere, closely grouped cracks parallel to their neighbors for much of their outcrop length. Our mapping indicates that, over a distance of 0.8 km, the northeast end of the ground-rupture zone narrows and turns 20 to a trend of 65; there, the cracks strike 110, maintaining a 45 angle with the trend of the zone. It is well documented that many laboratory shear and extension fractures propagate by the coalescence of opening-mode microcracks created in the crack-tip region, or fracture-process zone, of the primary, or parent, crack. By analogy, we suggest that stresses generated by the propagating Kaoiki rupture caused tensile failure of the near-surface rocks. If the rupture had continued to propagate upward, we hypothesize that these opening-mode cracks would have coalesced to form a continuous zone of strike-slip ground breakage.



Jackson, M.D., and Endo, E.T., 1989, Genesis of a strike-slip fault zone: the 1974 and 1983 Kaoiki ground ruptures, Mauna Loa Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 70, no. 43, p. 1409. [AGU fall meeting, San Francisco, CA, Dec. 4-8, 1989, Program and abstracts] 



 The Kaoiki seismic system, a young tectonic feature of Mauna Loa Volcano, Hawaii, is the site of recurrent moderate- to large- magnitude earthquakes that propagate new ruptures. The 1983 ML=6.6 event, the 1974 ML=5.5 event, and a much older undated event produced ground rupture zones that trend N48-55E, a direction nearly parallel to nodal planes of the main shocks' right-lateral focal mechanisms. Future earthquake ground ruptures should be expected to merge eventually into a strike-slip fault zone. Individual ruptures consist of left-stepping, en echelon cracks up to 20 m long, mostly with opening displacements (up to 1 m in 1983), and strike roughly E-W, about 30-50 clockwise from the overall trend of the zones. The cracks apparently represent breakdown zones above the parent faults. With depth, individual crack segments coalesce to form progressively longer, left-stepping arrays of twisted surfaces that become progressively more parallel to the overall trend of the rupture zone. The geometry of the 1983 rupture appears to confirm the self-similarity of earthquake-produced fractures in the hierarchial arrays that range in length from several kilometers to a few meters. At lengths of less than a few meters, self-similarity is destroyed by the cracks' jagged walls. Although most en echelon segments within the 1983 rupture step to the left with little overlap, some segments are linked by zones of rubble breccia and have small (<15 cm) right-lateral displacements. In contrast, the 1974 cracks have greater components of right-lateral slip, and crack segments are commonly linked by zones of uplift. These features indicate coalescence at depth. They may result from reactivation of yet another zone of cracks, perhaps associated with a 1962 ML=6.2 event, or they may be a result of the 1974 event's shallower hypocenter, 4 to 5 km deep (compared with 9 to 10 km depth in 1983), that allowed the tip of the underlying parent crack to propagate closer to the earth's surface and form a more continuous zone of strike-slip ground breakage.



Jackson, M.D., Endo, E.T., Delaney, P.T., Arnadottir, T., and Rubin, A.M., 1992, Ground ruptures of the 1974 and 1983 Kaoiki earthquakes, Mauna Loa Volcano, Hawaii: Journal of Geophysical Research, v. 97, no. B6, p. 8775-8796. 



 The November 30, 1974. ML = 5.5 and November 16, 1983, ML = 6.6 earthquakes generated left-stepping, en echelon ground cracks within the Kaoiki seismic zone, on the southeast flank of Mauna Loa volcano, Hawaii. The general trend of the ruptures, N48-55E, parallels a nodal plane of the main shocks' focal mechanisms. The ruptures themselves consist of short, predominantly extension cracks, which are up to 20 m long and strike roughly E-W, 30-50 clockwise from the overall trend of the zones. Some of the cracks are linked by secondary fractures and rubble breccia to form left-stepping crack arrays, which are themselves linked to form longer en echelon systems of ground rupture. Geologic maps and field observations indicate that these features emerge from an underlying strike-slip fault, and they form a "fracture-process zone" above its tip. The maximum displacement measured across cracks in the 1983 rupture zone is 0.5 m. Trilateration data, however, suggests that the overall shear displacement was about 1.5 m at depth. Elastic solutions indicate that a region of significant tensile stress can exist above buried strike-slip faults. We suggest that these stresses generated the extensional ground cracks and that shear displacements were transmitted to the Earth's surface by subsequent growth and linkage of these cracks into the observed arrays. We infer that the crack arrays accommodate increased displacement with depth and they merge downward into the "parent'' strike-slip fault at an estimated 1-2 km depth, where strike-slip displacement was probably more or less continuous along the ~7 km length of the rupture. In the Kaoiki region, only three major ground ruptures traverse a series of basaltic lava flows that date back 1500 years. This suggests that the recent ~10-year periodicity of moderate-magnitude Kaoiki strike-slip events may not have extended far into the past. The tectonic significance of strike-slip faulting on Mauna Loa volcano remains enigmatic.



Jaggar, T.A., 1909, Should record volcanic action; so said Prof. T.A. Jaggar, speaking before the University Club: Pacific Commercial Advertiser, 04/15, p. 1. 



 Jaggar states that there is no place better place to establish a station for volcanic research than in the Hawaiian islands and close to the crater of Kilauea. He lists goals for a worldwide network of observatories as: 1. prediction of earthquakes; 2. prediction of volcanic eruptions; 3. engineering and construction in volcanic and seismic lands [building codes]. He further discusses the usefulness to populations living in volcanic and seismic areas of such observatories and closes by crediting Frank Perret with pioneering good records of volcanic activity.



Jaggar, T.A., 1909, Observatory at Kilauea brink; Prof. Jaggar points out the unique possibility for science: Pacific Commercial Advertiser, 06/11, p. 1, 5. 



 Jaggar's address to the Hawaii Chamber of Commerce cites the advantages of siting an observatory at Kilauea, with an emphasis on prediction of volcanic and seismic events. 

 Following Jaggar's address, L.A. Thurston emphasized the commercial advantages to siting an observatory at Kilauea and the Chairman of the Chamber of Commerce named a committee of three, including Thurston, to canvas funds for the maintenance of the proposed observatory.

 The proposal by M.I.T. to establish such and observatory, including a detailed list of research goals and logistical requirements, was circulated. The last paragraph of the article announces that $2500 a year had already been subscribed for maintenance of the observatory, about half of the minimum amount required.



Jaggar, T.A., 1909, Hawaii soon center of volcanic study: Pacific Commercial Advertiser, 08/09, p. 1. 



 [From an interview with R.A. Daly]

"R.A. Daly, the assistant to Prof. Jaggar of the Massachusetts Institute of Technology, who will organize the volcano observatory on Kilauea, is very enthusiastic over his work, . . .

 "Mr. Daly is taking great interest in the work, . . . and believes that with the observatory completed, Hawaii will become the world's distributing center of volcanic lore. He is certainly a man well fitted to carry on the work outlined by Prof. Jaggar, for in addition to his enthusiasm, he has his full share of energy." 

[A confusing article that makes it sound as if Daly, rather than Jaggar, was going to organize the new observatory]



Jaggar, T.A., 1912, Severe earthquake felt last week; tremor alarms new comers---mules, horses and roosters show fear--little damage done: Hilo tribune, 05/28, p. 1. [Repeated, almost verbatim, in the Pacific Commercial Advertiser of May 27.] 



 At eleven o'clock on last Wednesday night, a severe shock of earthquake was felt in Hilo . The tremor seemed to travel from West to East and, while it lasted, the rumbling was most uncanny. The shake lasted some seven seconds and, in town, many people were much alarmed. Very little damage was said to have been done by the quake, and the articles broken were confined to bottles and glasses, that were left standing too near the edge of tables and shelves.

 There was little or no warning before the big shake struck Hilo. The first indication was a faint rumbling that could be heard a long way off. It seemed something like a shower of rain falling on tin roofs, and only old-time residents knew what was coming.

 As the rumbling noise approached, mules and horses, confined in stables, began to bray and neigh. Roosters also started to crow and there was a noticeable noise all around. The first tremors were very faint, but the main shake soon came along. Then there was a straining and groaning of wooden houses, and everything swayed back and forth.

 The hard part of the shake did not last long, however, and things soon resumed their normal quiet Hilo way. The rumbling of the quake could be heard going away in the distance, and that finished the shake.

 Many newcomers, who are not used to small earthquakes, were very scared, and a great desire for company was expressed by several persons who, while declaring that they were not frightened, seemed anxious not to be left alone for the rest of the night.



Jaggar, T.A., 1912, Jaggar reports on volcanic activity; several earthquakes lend probability to theory that vibrations result from local volcanic activity: Hilo tribune, 09/24, p. 4. [Repeated in Jaggar, 1947?] 



 Technology Station, Sept. 19, 1912

Most of the report discusses the condition of Halemaumau lava lake during the week ending Sept. 18. Information of seismic interest is as follows:

 "The work of the seismographs has been interrupted during the past week. The major tromometer had been gradually tuned and adjusted to have a period of practically 20 seconds with a factor of magnification of 200, constants within the ordinary range of such a mechanism, but conferring on it a high degree of sensitiveness. Our experience with this adjustment demonstrated that this was too sensitive for the place--in particular with regard to the slow diurnal wave as encountered here--so that, as the surface tilted with the swelling of the wave, the writing index swung far too widely to one side and the other of its equilibrium position to yield serviceable seismogram, free from confused interscoring among neighboring hour lines. Apparently this diurnal wave is greater here than at most stations, the majority of which are situated on continents."

 Jaggar continues by mentioning problems caused by dust and air movements during high winds.

 "So the operation of the instruments was suspended to permit re-adjustment in magnification, briefly resumed to test the change, and then discontinued to permit battening and sealing the room against dust and air.

 "This interruption in the registration has resulted, so far, in the failure to register at least one local earthquake, felt by several persons, a feeble shock with motion apparently in a SW-NE direction as note by Director Jaggar at the Volcano House. By others at the volcano House the shock was not felt. Its intensity here was, therefore, II R-F. It occurred at about 8:30 p.m. in the evening of Sept. 16."

 Four very feeble earthquakes of local origin were registered by the major tromometer on Sept. 12, 1912. None of these was strong enough to start the ordinary seismograph. Hence all must be classified under grade I, R-F scale, though they were by no means equally energetic. All were distinctly registered. The approximate times are given here:

 September 12, 1912, 10:50 a.m., feeble; 11:09 a.m., feeble; 4:03 p.m., very feeble; 8:04 p.m., feeble.

 "A shock somewhat stronger than these but still only grade I, R-F scale, was registered about 11:20 p.m. on Sept. 13, 1912."



Jaggar, T.A., 1912, Daring scientists again brave Madam Pele and descend deep into fiery depths of Halemaumau; With rope ladders they climb down four hundred feet and cross hot lavas to secure gas samples: Hawaiian Gazette, 12/10, p. 1. 



 An account of the first attempts to collect gas samples from the active lava lake.

Technology Station, December 5

 An account of fluctuations in the Halemaumau lake level and of the earthquakes recorded at Kilauea.



Jaggar, T.A., 1913, Great seismic activity noted; Old bench at crater below rest house falls in accordance to prediction made by scientists: Hilo Tribune, 04/01, p. 4. 



 Now began a series of shocks, occurring in rapid succession, quite without precedent at this Observatory. None of these were felt here, though at least one was so strong that it should have been distinctly perceptible. . . . in Hilo tremors were perceptible for a period of about ten minutes without cessation. Continuous vibration from shock to shock, though far too feeble to be perceptible, was registered for several minutes here at the edge of the main crater. Nearly all of these shocks originated at distances approximating to twenty miles, presumably in the Hilo direction.



Jaggar, T.A., 1914, Kilauea lava pit does some weird and vivid stunts: Pacific Commercial Advertiser, 11/23, p. 1, 2, 4. 



 [subheads: During violent internal activity there have been many small local earthquakes; All cones develop unusual phenomenon; Great change takes place in lake and operations are remarkable]

Technology station, November 19, for the week of Nov. 12-18 inclusive.--A description of Halemaumau lava lake. Small local earthquakes accompanied enlargement of the active lake surface and increased activity in the lake.



Jaggar, T.A., Jr., 1915, The outbreak of Mauna Loa, Hawaii, 1914: American Journal of Science, 4th ser., v. 39, p. 167-172. 



 Shortly before 4:00 p.m. on November 25, 1914, a column of white vapor suddenly rose at the summit of Mauna Loa. Registration of 55 local earthquakes in the preceding 21 days constituted a definite seismic prelude to the eruption. However, no change was observable at the summit 1 week before the eruption. On November 27, eight main lava fountains were playing in Mokuaweoweo; on December 3, four fountains were active. Jaggar reproduces a sketch map of Mokuaweoweo on November 27 by L.C. Palmer and an interesting moonlit photo of Kilauea and Mauna Loa in simultaneous eruption. [Jaggar's prediction {Jaggar, 1912c} was realized.]



Jaggar, T.A., 1916, Professor Jaggar reports eruptions; Story of Mauna Loa told by expert; Lava flows scientifically described: Pacific Commercial Advertiser, 06/05, p. 9. 



 Jaggar's official scientific report covering the May 1916 eruption of Mauna Loa.

 Mauna Loa outbreak

 In Jaggar's address to the HVRA on March 10, 1915, it "was pointed out that there should be yet to come (1) a low level in Kilauea, (2) a short-lived summit outbreak of Mauna Loa in June or December within four years from the beginning of 1915, and (3) a lava flow from Mauna Loa. By analogy with the lava flows of 1899 and 1907 and some others during the previous thirty years, therefore was not expected quite so soon as the present date, and it was not expected on the south side of the mountain."

 Habit of volcano changes

 "The occurrence of two Kahuku flows within ten years is contrary to the habit of the volcanoes since 1868. It was expected, however, that the next flow ion the south side should come from a vent higher than 1907, and this has happened. It was further expected from the experience of the past that the next south flow, like former ones, would be accompanied by many earthquakes in Kau; and this has also happened in the present instance.

 "The attempt at forecast, therefore, made by the writer as far back as 1911 and published in 1912, has been verified in the Mokuaweoweo outbreak of November 23, 1914, in the interval of eighteen months of quiet following it, in the high gaseous explosion of Mauna Loa , May 19, 1916, and in the relatively quiet outburst of flowing lava at a lower point forty hours later, this point being somewhat higher than the place of last eruption on that side of the mountain; and in the occurrence of all these happenings at dates near the solstice."

 Alternate eruptions

 Eruptive episode summarized

 Faint glow over Kahuku

 Main fume column extends

 Flow heads for houses

 Front of flow motionless

 South-east flow revives

 Lava advances in billows

 Carbon gas only odor [sic-sulphur?-carbon gases are odorless]

 Under-flow in two lobes

 Noise is not great

 Smoke and bright flames

 New flows are located

 Procession of large blocks

 Fumes and glow dwindle

 Activity of Kilauea

 Lava in crater rises

 Rampart of broken crusts

 Tremendous overflowing

 Islands shift positions

 Fresh flows everywhere

 Lake brims with overflows

 Many grottoes form

 "At 6:30 p.m. on this date [May 24] rapid subsidence began. . . . [this was a preliminary subsidence to the main subsidence on June 5-6, 1916]

 Big lake again sinks

 Pit quiet and smoky



Jaggar, T.A., 1916, Walls of Kilauea cave as lava sinks rapidly; Spectacular phenomenon at raging crater: Pacific Commercial Advertiser, 06/06, p. 1. 



 Photographs of the sinking lava lake.



Jaggar, T.A., 1916, Floor of Kilauea is still falling; Crowds see lava drop to 1,000-foot depth, greatest recession in years: Pacific Commercial Advertiser, 06/07, p. 9. 



 Hilo, Hawaii, June 6.--The floor of the Halemaumau pit in the crater of Kilauea is still falling.

 In a burst of unparalleled activity, the bottom fell to a depth of 650 feet last night . . .

 The lava then began to rise slowly, reaching within 500 feet of the top. The floor, after remaining at this point for several hours, today dropped again, falling until it reached a depth of about 1000 feet, the greatest it has reached in recent years.

 . . . .

 Prof. O.H. [sic-H.O.] Wood reports a great 'flock' of minor earthquakes, none of which, however, have done any damage.



Jaggar, T.A., Jr., and Finch, R.H., 1924, The explosive eruption of Kilauea in Hawaii, 1924: American Journal of Science, 5th ser., v. 8, p. 353-374. 



 Lava in Halemaumau gradually drained 370 ft in February, disappearing from sight before the end of the month. An earthquake swarm began on the east rift in March; distance of earthquakes from Kilauea summit increased through time and led to a correct forecast that earthquakes would occur in Puna by April. Earthquakes increased in number and intensity during April; ground cracking in Puna began April 23, accompanied by subsidence, as much as 8-12 ft south of a reactivated fault scarp. The crisis was over by April 27. Subsidence of Halemaumau began on April 29, with increase in seismic activity. Explosions began May 13, culminating on May 18; the last rock-throwing explosion was on May 24. The earthquake swarm at Kilauea summit continued at a diminishing rate until about June 24. Glowing intrusive bodies were exposed in the newly-collapsed Halemaumau, now 3,400 ft by 3,000 ft, with a depth of 1,335 ft. The paper contains good photographs of the eruption cloud and boulders thrown out.



Jaggar, T.A., Jr., 1929, [The earthquake swarm at Hualalai]: The Volcano Letter, no. 248, p. 1; 249, p. 1; 250, p. 1; 251, p.1. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 Jaggar describes the earthquake swarm between September 19, 1929 and October 20, when numbers of events declined to near-background levels. He tabulates shocks per day; the number peaked on October 2, and a strong earthquake occurred on October 5. He infers that magma has intruded to near the surface and that a lava outbreak is expected. [Eruption never came.]



Jaggar, T.A., Jr., 1930, Hawaiian volcanoes in 1929: The Volcano Letter, no. 263, p. 3. [See Fiske and others, 1987] 



 Jaggar briefly summarizes the Halemaumau eruptions of February and July, and the seismic crisis at Hualalai.



Jaggar, T.A., Jr., 1930, The Hualalai earthquake crisis of 1929: The Volcano Letter, no. 309, p. 1-2; no. 310, p. 1-4. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 Jaggar summarizes information on the earthquake swarm at Hualalai, repeating information reported in Volcano Letters 248-251 (Jaggar, 1929i). He describes and illustrates with photographs damage from the two largest quakes (intensity IX on the Rossi-Forel scale). He notes that "a modern car is an admirable earthquake-proof building," citing the experience of persons who slept comfortably in their cars while homes next to them were rattling with aftershocks. He notes the absence of preliminary tremor characteristic of normal earthquakes--each station on the island experienced the earthquake as if it was directly over the epicenter--, attributing that to the presence of magma beneath Kilauea, Mauna Loa, and Hualalai. [The description is confusing in light of modern experience. It is possible that, because these larger shocks were embedded in an ongoing earthquake swarm, that the preliminary motions mentioned by Jaggar were obscured.] He attributes the swarm to an intrusion beneath the Hualalai rift. [This accords with modern thinking.]



Jaggar, T.A., Jr., 1930, The Hualalai earthquake crisis of 1929 [abs.], in Hawaiian Academy of Sciences, 5th annual meeting, Honolulu, HI, May 1-3, 1930, Proceedings for 1930: Bernice P. Bishop Museum Special Publication 16, p. 8-9. 



 A major swarm of earthquakes centering about Hualalai began suddenly on September 19 and continued for a month. During the 26 days following Sept. 21, instruments registered 6,211 shocks. Large earthquakes on September 25 and October 5 showed no preliminary tremor at Hilo, Kealakekua, or Kilauea, and were inferred to be deep.



Jaggar, T.A., Jr., 1931, When the pit lava sinks: The Volcano Letter, no. 324, p. 1-3. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 Jaggar attributes lowering of the lake level in Halemaumau to three processes: (1) gradual sinking due to loss of gas, (2) rapid lowering due to breaking open of the mountain elsewhere, and (3) periodic fluctuation due to tidal controls. He notes the similarity of collapses at Halemaumau following the end of Mauna Loa flank eruptions with that accompanying Kilauea east rift eruptions in 1922 and 1923, as establishing a direct connection between Kilauea and Mauna Loa. He also remarks on the association of earthquake swarms with rapid lowering of the magma column.



Jaggar, T.A., Jr., 1931, Twenty years of Hawaiian eruptions: The Volcano Letter, no. 319, p. 1-4; no. 320, p. 1-4. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 Jaggar briefly reviews activity of Kilauea (1909-1913, 1914-1916, 1916-1918, 1919-1920, 1921, 1922, 1923, 1923-1924, 1924, 1927, 1928, 1929, and 1930), eruptions at Mauna Loa (1914, 1916, 1919, and 1926), and the Hualalai earthquake swarm of 1929.



Jaggar, T.A., Jr., 1931, The great eruption of Kilauea in 1924: The Volcano Letter, no. 328, p. 1-4. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 Volcano letters 328-332 review aspects of lava lake activity from 1912 to the great collapse of 1924. Information is mainly taken from Weekly and Monthly Bulletins of the Hawaiian Volcano Observatory (Bevens and others, 1988). Each article is permeated with Jaggar's ideas regarding eruption cycles and the relationship between Mauna Loa eruptions and the lowering of the lake level in Halemaumau.

In this article Jaggar reviews events of 1924, the end of his 134-year cycle. The sequence of events in 1924 was like what had happened In May 1922, when there had been: 

 (1) Sinking of the lava column.

 (2) Great enlargement of Halemaumau pit with avalanches.

 (3) Cracking open of the Puna rift to the east.

 (4) Southerly tilt and many earthquakes at Kilauea.

 (5) Cauliflower dust clouds rising.

The summary of the 1924 sequence was then as follows: 

 (1) Sinking of the lava column in March.

 (2) Cracking open of the Puna rift far to the east April 22.

 (3) Subsidence of a fault block at Kapoho in Puna.

 (4) Southerly tilt and increasing earthquakes at Kilauea.

 (5) Great enlargement of Halemaumau pit in May.

 (6) Avalanches at Halemaumau making cauliflower clouds.

 (7) Same cauliflower clouds containing steam blasts upward, May 11.

 (8) Engulfment of pit walls in May.

 (9) Steam-blast spasms two hours apart May 13, thereafter less often.

 (10) Ejection of stones, maximum May 19.

 (11) Duration explosive spasms, maximum seven. hours May 19.

 (12) electric storms maximum May 17-19.

 (13) Felt earthquakes maximum May 22.

 (14) Total earthquake frequency maximum May 24.

 (15) Cessation of steam-blast phase May 28.

 (16) Glowing intrusive body exposed in pit wall June 12.

 (17) Adustment of pit walls June-July.

 (18) Liquid lava in pit bottom July 19-31.

Included is a daily plot, from May 10 to 28, of earthquakes, explosions, electrical storms, and observed rock falls.



Jaggar, T.A., Jr., 1931, Review of Hawaiian earthquakes 1929-1930: The Volcano Letter, no. 358, p. 1-4. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 Jaggar reviews the earthquake swarm beneath Hualalai in September-October 1929, noting that the seismic sequence peaked early and tapered off, opposite to the 1924 sequence at Kilauea, where seismicity peaked near the end of the eruptive period. Submarine eruption was suspected at Kilauea, leading Jaggar to infer that magma moved upward rather than outward at Hualalai.



Jaggar, T.A., Jr., 1935, Mauna Loa observations [eruption of 1935]: The Volcano Letter, no. 429, p. 3-6. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 Jaggar gives an account of the beginning and subsequent activity of the Mauna Loa northeast rift eruption of 1935. A felt earthquake was recorded 5 hours before vents opened at 11,500 ft and a small earthquake swarm immediately preceded the eruption. Jaggar describes a new flow (named the Humuula flow) that began quietly at an elevation of 9,000 ft; this was apparently fed through a lava tube buried below the rift.



Jaggar, T.A., Jr., 1938, The Maui earthquake of January 22, 1938: The Volcano Letter, no. 457, p. 1-7. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 On the evening of January 22, 1938 at about 10:03 a moderate to strong earthquake dismantled all seismographs on the island of Hawaii with the exception of a low-magnification [strong-motion] instrument at HVO. It was felt throughout the Hawaiian Archipelago and was registered on sesimographs as far away as New York City. The final location was offshore 18 miles north of the east point of Maui, in approximate agreement with estimates made from arrivals at stations on the island of Hawaii. Most of the article discusses damage reports from the several Hawaiian islands, describes how the epicenter was determined, and reviews the occurrence of earthquakes at distances of 150-500 km recorded at HVO betweeen 1912 and 1938. He closes with a plea to take seriously the possibility of earthquakes in Hawaii at locations other than below the island of Hawaii.



Jaggar, T.A., Jr., 1945, Volcanoes declare war: Honolulu, Paradise of the Pacific, Ltd., 166 p. 



 A popular book that discusses the entire circum-Pacific belt of volcanoes. Jaggar describes the Kilauea eruption of 1924, including the draining of Halemaumau and rift eruptions in 1922-23 leading up to it, and inference of undersea eruption accompanying the 1924 collapse. He describes the eruption of 1934, including a diagram showing the filling of Halemaumau from 1924 to 1934. He also describes (p. 12-16) the Mauna Loa eruption of 1935, including bombing of the 1935 lava flow. Aerial bombing of the flow is believed to have stopped the eruption. He assesses the cost/benefit as being $25,000 for the bombing operation vs. over $51,000,000 for the value of Hilo. [Whether the bombing contributed to the end of the eruption is debatable. Evidence that the bombing did "disrupt the forward movement" is indisputable.] The book contains a large section of photos, showing good views of Halemaumau lava lake, some lava forms, the effects of the earthquake swarm in Puna, the 1924 eruption, and various Mauna Loa subjects, including aerial and ground views of 1926 lava destroying Hoopuloa village. Included also are contemporary newspaper cartoons of the Jaggar expedition to Halemaumau in 1917 to measure temperature. Jaggar includes a diagram, covering the years 1790-1942, showing the height of the Halemaumau lava column, Mauna Loa eruptions, and sunspot maxima and minima. He concludes with a [poor] review of volcano science and theories of volcanic action.



Jaggar, T.A., Jr., 1949, Revised history of Mauna Loa: Paradise of the Pacific, v. 61, May, p. 3-7. 



 Jaggar discusses the chronology of Mauna Loa eruptions. Flank eruptions are almost always preceded by an eruption in Mokuaweoweo, e.g., the 1916 eruption on Mauna Loa's southwest rift zone, which succeeded the summit eruption of 1914. The southwest rift zone eruptions of 1919 and 1926 are noted as exceptions in that they directly followed rift activity without an intervening summit eruption. [The 1916-1919-1926 eruptions broke the pattern that obtained through 1907 in which flank eruptions alternated between the two rift zones.] Most flank activity is on the northeast or southwest rifts, although exceptions occurred in 1859 (northwest flank) and 1877 (a submarine eruption in Kealakekua Bay). Jaggar relates the Hualalai eruption of 1800-01 and earthquake crisis of 1929 to Mauna Loa activity. [There is no apparent basis for this in modern thinking.] He remarks on the increasing altitude of initial outbreaks on the southwest rift zone from 5,600 ft in 1868 to 13,300 ft in 1933. [The location of the principal vents for each eruption also show this pattern. The pattern continued in 1950, as the main outbreak was higher than any of the previous historic eruptions on Mauna Loa's south rift zone.] Jaggar points out that eruptions do not occupy previous fissures, although they may be quite close. [This observation has modern confirmation at Kilauea.] He reconfirms Green's ideas regarding sympathetic behavior of Kilauea and Mauna Loa. Jaggar concludes by forecasting an eruption in 1951, most likely on the northeast rift. [The actual eruption was on the southwest rift in 1950.]

 

Jarves, J.J., 1840, Gleanings from the editor's notebook--Hawaii. No. 6: The Polynesian, v. 1, no. 12, 08/29, p. 45-46. 



 Jarves recounts an expedition, accompanied by Rev. Mr. Lyman, beginning August 8, 1840, to explore the site of the recent eruption [May-June 1840 on Kilauea's east rift zone]. He describes the lava as still being hot to the feet, strewn with the smoking remains of fallen trees adjacent to tree molds. He describes gurgling and cracking sounds beneath, indicating lava was still flowing. The lava was uniform in appearance, "full of glittering crystals of pyroxine [sic; probably altered olivine] and olivine." Crevices in the lava were lined with multicolored deposits of sulfur and salts. He describes the entry of lava into the see at Nanawale, pushing more than 1500 feet into the sea, "forming three bold promontories, or crater-shaped hills, parallel to each other, and a few hundred feet apart. Between these the lava had flowed a short distance beyond. These hills were formed of scoriae, sand and ashes, precipitous toward the sea, and sloping gradually inland." These hills were still fuming at their summits, were hot enough to form steam with each new wave, and the sulfurous gases in the vicinity were choking.

 Jarves quotes Mr. Castle, "an intelligent mechanic residing in Hilo, who, at the first appearance, hastened to the spot, and was enabled accurately to observe its progress." The eruption began about 2 o'clock on Sunday May 31. The light was so bright that fine newsprint could be read 30 miles away for a period of two weeks. [The actual distance from Hilo to the lava stream is about 18 miles]. Lava reached the sea on Thursday, four days from the beginning. Flow velocities were irregular, with maximum rates of 4-5 miles per hour over short distances. At times the lava burrowed beneath the adjacent soil, "presenting the singular appearance of earth, rocks and trees in motion like the swell of the ocean. Mr. C. was standing near the stream and watching its progress, when the land beneath him began to rise, and in a few minutes he was ten feet above his companions, who were but a short distance from him. He had barely time to leave this dangerous situation, when the earth opened, and lava gushed out. He describes the entry into the sea; on the next day (June 5) fish floated dead as far as Keaau, 15 miles distant, where the water was hot to the touch.

 He says that no one has yet examined the original outbreak, but that the natives say it is only a few miles east of Kilauea [caldera]. He notes that the eruption must have been fed from Kilauea, as the summit lava lake drained several hundred feet. Jarves corrects earlier rumors of lives lost to indicate that "upon careful inquiry we could learn of no one who perished." However, several houses, hogs and poultry were destroyed.

 Jarves concludes his narrative with comments on the eruptive process as it relates to earthquakes, and the first appearance of the sand hills. "It is singular that an eruption of this magnitude should occur without the slightest shock of an earthquake, at least none was noticed if any happened, which proves that this was the effect of no sudden, violent action, but one of long and gradual preparation. On Wednesday, June 3rd, three new hills, of a mile in length and of seven hundred to eight hundred feet elevation, were seen from Hilo, in the direction of the first outbreak. Thursday was rainy, and they were not visible, and on Friday they had entirely disappeared. No earthquake was perceived, though the natives report that a slight shock took place at the time.

 Three years since, smoke and steam were seen issuing from near where the present eruption commenced, and two years ago great rent was made in the ground, and all the springs in the vicinity dried up."



Jarves, J.J., 1843, History of the Hawaiian or Sandwich Islands (1st ed.): London, Edward Moxon, 407 p. [Pages 17-21, 131-132 cover the material abstracted. Published simultaneously in Boston by Tappan and Dennett. 2nd ed., 1844, J. Munro, Boston; 3rd ed., 1847, C.E. Hitchcock, Honolulu, 240 p; 4th ed., 1872, Henry M. Whitney, Honolulu] 



 The author describes earthquakes of November 1838 and March 1841, felt in Kailua, Kona, one on Maui in April 1841, felt in Hilo, and the tsunamis of November 1837 and May 1841. He briefly recounts the destruction of part of Keoua's army by the explosive eruption of Kilauea in 1790.



Jimenez, E., Cara, M., Rouland, D., and Okal, E.A., 1989, Fault-plane solution from single station surface-wave data [abs.]: Eos, Transactions, American Geophysical Union, v. 70, no. 15, p. 397. [AGU-MSA spring meeting, Baltimore, MD, May 7-12, 1989, Program and abstracts] 



 A method for determining the seismic moment tensor from single-station Love and Rayleigh wave records was proposed a few years ago by Ekstrom et al [1986] for large events and at very long periods. We propose to extend their method to intermediate-size earthquakes and regional data surface waves observed in the period range 20-100 seconds.

 The main difficulty when applying such a method is to properly correct the Fourier spectrum of the records for the propagation terms, which are expected to exhibit significant regional variation due to lateral heterogeneity. With a few simple assumptions on the source spectrum. it is possible to estimate the phase velocity curves from the integration of the apparent group-velocity curves, as determined from the records themselves, and assuming a low-frequency value of the phase velocity is known. Once the phase delay curves are estimated, the source spectrum is inverted in terms of the seismic moment tensor components, and an eigenvector decomposition used to extract the main double-couple solution, and its fault plane representation.

 This method is applied to intermediate-size earthquakes recorded on a limited number of stations, such as the June 10, 1987 Southern Illinois earthquake (mb, = 4.9), and the September 22, 1988 Tern Island (Hawaiian Chain) event (mb = 5.5). The method clearly has considerable potential in the study of historical records, of which an example is also given.



Johnson, R.K., ed(s)., 1976, Kukini 'aha'ilono [Carry on the news]; over a century of native Hawaiian life and thought from the Hawaiian language newspapers of 1834 to 1948, published in honor of the bicentennial: Honolulu, Topgallant Publishing Co., xiv, p. 140-145, 302-305. 



 From Table of contents:

 O Hawaii, he aina Pele (Hawaii, a volcanic island); a report of all of the major volcanic eruptions on the island of Hawaii from 1789-1855; eyewitness descriptions; Ptr. Malcolm Chun--p. 140-145.

 Ka hu ana o ka Pele, na olai a me ka kaihoee ka hu mua ana (Lava eruption, earthquakes, and tsunami in the beginning on the island of Hawaii, 1868; Ptr. Erin Casey--p. 302-305



Johnson, C.E., and Koyanagi, R.Y., 1988, A Monte-Carlo approach applied to the estimation of seismic hazard for the State of Hawaii [abs.]: Seismological Research Letters, v. 59, no. 1, p. 18. 



 A synthetic risk method has been developed and applied to the problem of evaluating seismic hazard for the state of Hawaii. This method directly relates the statistics describing the distribution of potentially damaging earthquakes to acceleration exceedance contours for arbitrary return periods using a direct Monte-Carlo simulation. This technique avoids the mathematical complexity of other current approaches which require the spatial integration of the transfer function relating peak acceleration with magnitude over simplified potential source regions. Three different seismogenic regimes were considered. The first, comprising small (ML <3.0) magma driven sequences occurring within the volcanic edifice, are generally benign. Basal events, such as the 1975 Kalapana earthquake, make up a second group. With magnitudes approaching 7.5, these events are capable of causing considerable damage in the immediate vicinity of the island of Hawaii. A third class includes lithospheric events with depths ranging from 20 to 60 km. Related to the bending stresses associated with regional volcanic loading of the Hawaiian archipelago, these events can effect seismic risk throughout much of the state. The 1973 Honomu event (Mb = 6.2, z = 40 km) is typical of this group. Results generally agree with those obtained from a consideration of historical intensities.



Johnson, D.J., 1995, Molten core model for Hawaiian rift zones: Journal of Volcanology and Geothermal Research, v. 66, no. 1-4, p. 27-35. 



 Kilauea volcano's East Rift Zone (ERZ) is extraordinary in that abundant lateral dike intrusions and rift zone widening associated with seaward slip of the south flank over a basal fault may have allowed an extensive molten core to develop. The rift zones of Mauna Loa and the Southwest Rift Zone (SWRZ) of Kilauea do not appear to have such extensive molten cores, perhaps because of a diminished role of flank slip. A molten core may efficiently convey pressure and transport magma to distant sites along the rift zone. This concept helps to explain the long, low profile of Kilauea as viewed along the axis of the ERZ. The combined influence of a molten core and flank slip helps to explain the varied repertoire of magmatic events at Kilauea. I propose that the 1975 M 7.2 earthquake marked a fundamental change of activity at Kilauea, from shallow dike injection above the molten core and largely effusive edifice growth to chiefly endogenous growth by deep dike intrusion below the molten core. Dike intrusion slowed during the 1983-1991 Pu'u O'o eruption sequence, because inflation of the magmatic system--the engine of intrusion and flank slip processes--was retarded by continuous magma loss via the molten ERZ core to a low-elevation vent site.



Johnston, A.C., 1978, Localized compressional velocity decrease precursory to the Kalapana, Hawaii, earthquake: Science, v. 199, p. 882-885. 



 A delay in the arrival times of compressional or P waves of 015 to 0 2 second from deep distant earthquakes has been detected at the closest seismograph station to the 20 November 1975 earthquake at Kalapana, Hawaii (surface-wave magnitude Ms = 7 2) This delay appeared approximately 3 5 years prior to the quake, and travel times returned to normal several months before it The P-wave arrival times at other nearby stations remained constant during this period, an indication that the decreased velocity implied by the delay in travel time was associated with this normal-faulting earthquake and was confined to distances less than 20 kilometers from the epicenter



Johnston, A.C., 1978, A systematic study of temporal P-velocity variation in Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 59, no. 4, p. 328-329. [AGU spring meeting, Miami Beach, FL, Apr. 17-21, 1978, Program and abstracts] 



 Recently, evidence has accumulated that crustal seismic velocities can change in response to stress changes associated with tectonic activity. It is therefore of interest to test the long-term stability of the travel times of seismic waves in a tectonically active area so that the significance of any temporal changes may be assessed. This was done in Hawaii where a large seismic array has monitored a region of intense seismic and volcanic activity for more than a decade. Work using teleseismic sources for a vertical crustal sample has been completed; work with local source events yielding a horizontal crustal sample is in progress.

 The only significant travel time change detected during the period 1967-1977 was at station WHA, 4 Ku from the epicenter of the Nov., 1975 (M - 7.2) Kalapana earthquake (A.C. Johnston, Science, in press, 1978). The 0.2 sec delay began in 1972, and returned to normal in early 1975. It was not observed at other stations of the Hawaii network. If this one example is excluded, arrival times at all stations are constant in time to within the reading accuracy (.05-.1 sec). In addition, no detectable changes occurred that correlate with any volcanic activity, although absolute travel time baselines are early for summit stations and late for flank stations.

 This temporal stability of arrival times recorded by the Hawaii network (except WHA) provides support for a causal relationship between the WHA delay and the preparatory phase of the Kalapana earthquake. This was Hawaii's largest earthquake in this century - it appears that any changes associated with smaller scale activity could not be resolved by this technique.



Johnston, A.C., 1978, The south flank of Kilauea Volcano, Hawaii: P-velocity variations associated with earthquakes and volcanic activity [abs.]: Earthquake Notes, v. 49, no. 4, p. 60. 



 The south flank of Kilauea volcano, Hawaii, is characterized by high rates of seismicity and horizontal strain. Most of the area was included in the aftershock zone of the 29 November 1975 Kalapana earthquake (Ms = 7.2; depth = 9 km). As a rule crustal P-velocities inferred from relative teleseismic P-residuals for all permanent seismic stations on the south flank remain surprisingly stable to within .1 sec during 1967-1978. There are two prominent exceptions to this: (1) residuals decrease (velocity increases) during crack closure on the Koae fault zone during the 1970-1971 intrusive and extrusive episodes on the Kilauea summit and the southwest rift zone; (2) teleseismic residuals increase 31/2 years prior to the Kalapana earthquake but only at station WHA, 31/2 km from the epicenter. Residuals from local earthquakes beneath Kilauea do not exhibit any increase at WHA suggesting that the zone of reduced P-velocity was less than 10 km in horizontal dimension and did not extend to the surface.



Johnston, A.C., 1979, An investigation of temporal P-velocity variation using travel time residuals at Hawaii and selected Circum-Pacific sites: Boulder, CO, University of Colorado, Ph.D. dissertation, 258 p. 



 Microcracking begins in stressed laboratory rock samples at about one-half of the fracture strength of the rock. The stress levels in the earth associated with earthquakes may be sufficient to initiate similar microcracking; if so, P-velocities in the cracked material will be slowed (unless the cracks immediately saturate with fluid). The search for evidence of such slowdowns by means of timing seismic signals through suspected earthquake preparatory zones is currently a very active research field in seismology and is the topic of this thesis.

 One objective of this research was to demonstrate reliable techniques of sufficient sensitivity to resolve 0.1-0.2 second travel time changes in the earth because this is the likely magnitude for an earthquake precursor. A series of studies of sources of P-residual scatter and effective methods to minimize it was conducted to meet this objective. Evidence was found for a probable velocity change prior to the Gisborne, New Zealand earthquake but, this result was compromised by the inability to identify all sources of scatter. The method of computing teleseismic relative P-residuals for waveform-correlated signals from a small source region was developed at seismograph networks in the Aleutian Islands. It yielded very low levels of data scatter, capable of resolving expected P-velocity precursors to earthquakes.

 The relative residual technique was applied at a seismic network within and close to the aftershock region of the November, 1975 Kalapana, Hawaii earthquake (Ms= 7.2). A 0.2 second travel time increase at the station nearest to the epicenter (3.5 km) occurred in 1972 and lasted until mid-1975. Other Hawaiian stations were not affected. Analysis of source dependencies and instrumental effects established that neither could account for the travel time delay.

 A decrease in background seismicity synchronous with the travel time change strengthens the argument for a crustal velocity decrease in a small volume about the hypocenter. P-residual data from local earthquake sources indicate that the anomalous zone did not extend into the upper crust of the south flank.

 The identification of the P-velocity decrease that preceded the Kalapana earthquake is the most important result of this thesis. With the possible exception of results from China and Japan, this earthquake is the largest event to date for which a velocity anomaly has been found. The localized extent of the low velocity zone is a new result. If the evidence from Hawaii can be extrapolated to other seismic regions, velocity precursors may be much harder to detect than laboratory results and proposed earthquake preparatory models have suggested.



Johnston, A.C., Wyss, M., Habermann, R.E., and Koyanagi, R., 1981, Stability and change of P-wave travel times in the crust [abs.]: Eos, Transactions, American Geophysical Union, v. 62, no. 45, p. 964. [AGU fall meeting, San Francisco, CA, Dec. 7-11, 1981, Program and abstracts] 



 A five-year study of P-wave velocities using data gathered by the Hawaii Volcano Observatory (HVO) seismic network has produced strong evidence that P-velocities are significantly affected by rapidly changing crustal tectonic processes P-wave travel times to six seismic stations within the rupture zone of the 1975 Ms7.2 Hawaii earthquake plus three other nearby stations were studied by means of relative residuals from deep Tonga teleseismic sources, Novaya Zemlya nuclear explosions and absolute residuals from local sources restricted to small volumes. Travel times for up to eight years before the main shock remained remarkably stable (within 0.06 sec) at all stations with two well-defined exceptions. (1) In the Koae fault zone where closure of crustal cracks in response to volcanic activity was documented geodetically, station AHU recorded a P-residual decrease (velocity increase) of 0.13 s. (2) The relative residuals at station WHA, within 4 km of the main shock epicenter, increased by nearly 0.2 sec in early 1972 signaling a P-velocity decrease. Both travel time anomalies were localized at single stations; neither was detected using residuals from local sources. We conclude from the AHU data that P-velocities are responsive to the opening and closing of cracks at upper-to-mid-crustal depths. For the case of WHA opening microcracks caused the velocity decrease that was precursory (i.e., causally related) to the impending Hawaii earthquake, but confined to a localized volume (<6 km radius) about the hypocenter.



Johnston, A.C., Wyss, M., Koyanagi, R.Y., and Habermann, R.E., 1982, P Wave travel times: stability and change within the source volume of a M = 7.2 earthquake: Journal of Geophysical Research, v. 87, no. B8, p. 6889-6905. 



 The dense seismograph network on the south flank of Kilauea afforded a unique opportunity to study travel time changes as a function of space and time within the source volume of the Hawaii earthquake (Ms=7.2) of 1975. Careful analysis of more than 600 teleseismic P arrivals from deep Fiji-Tonga earthquakes revealed the following: out of eight stations studied, six showed constant travel times to within +0.03 s for up to 10 years with the exception of some small changes of about 0.03 s at the time of the main shock. One station, AHU, showed a highly significant and unique travel time decrease by 0.13 s during 1971/1972. At the beginning of this velocity anomaly a southwest rift intrusion caused closure of surface cracks associated with normal faults located near the station AHU. Also, geodetic measurements revealed that between August and October 1971 compressive strain of 4 x 10-5 was accumulated perpendicular to the southwest rift in the area of AHU. We conclude that these data show for the first time that in situ velocity increases occur due to the closure of cracks by tectonic forces. The AHU residuals returned to normal approximately at the time of a major earthquake swarm on the fault zone near AHU, during which surface cracks were observed to have opened again. This travel time decrease was corroborated by residuals from Novaya Zemlya explosions, but high frequency local signals did not show it. Assuming that the stress sensitivity of the velocity was similar to that found by Reasenberg and Aki (1974), we have interpreted the teleseismic residual change at AHU as due to a P velocity increase of about 10% in the top 3.5 1.5-km of the crust. The only station, WHA, which showed a large (0.2 s) and extended (1972 to 1975) travel time increase was located only 4-km from the main shock epicenter. We interpret this velocity decrease as a precursor to the 1975 main shock, and we hypothesize that a process reverse from that at AHU caused this anomaly by first opening and then closing cracks in the crust below WHA. Both of these velocity anomalies were extremely localized in crustal volumes of dimensions of about 53-km.



Jones, G., 1887, Eruption of Mauna Loa with frequent earthquakes: The Friend, 02, p. 13-14. 



 "Sunday January 16, 1887, fire was noticed on the summit of Mauna Loa, near Mokuaweoweo. It was seen first about 8 pm, but died out in a couple of hours. 

 On January 17, an earthquake swarm began with three quite severe earthquake shocks between 2 and 3 am, the first that have been felt for some time. A number more were noticed during the morning, and in the afternoon they increased rapidly. Up to 7 pm 100 were counted. From that hour until midnight there was often not one minute's interval between them, and at 4 am of the 18th, 314 distinct shocks had been recorded. They continued, although fewer in number, until midnight. 

 At 7 pm the eruption began in good earnest. The starting point is on the slope of Mauna Loa, about a mile to the north and a little above the well know extinct crater called Halepohaha. . . . The new crater is perhaps twenty miles from the sea and about ten north-west and above the fissure from which poured out the lava flow of 1868. . . . at daylight of the 19th [the lava flow] had crossed the government road . . . . At 11:30 a.m. one of the streams reached the sea between the South Point and Ka Puuo Pele . . . .

 . . . At 9:15 am [Jan. 22] had a peculiar earthquake. All of the others have been from a northerly to a southerly direction and without noise. This was apparently from east to west, and although the jar was light, it was accompanied by a rattle similar to that produced by running a stick along a picket fence.

 . . . .

 Reports from Pahala, Punaluu and Naalehu also show the earthquakes to have been numerous and severe, especially the one of Sunday night, January 23rd, at 11:30, that was experienced in this city [Honolulu]. The steamer W.G. Hall, at anchor off Punaluu at the time, was so shaken that Captain Bates prudently steamed seaward several miles lest a tidal wave would follow as it had in 1868. Four or five buildings are reported thrown down, cisterns broken, and the boilers at Pahala displaced."

 The eruption was still in progress, as of January 30.

 

Jones, G., 1887, Eruption of Mauna Loa with frequent earthquakes: The Friend, Feb., p. 13-14. 



 "Sunday January 16, 1887, fire was noticed on the summit of Mauna Loa, near Mokuaweoweo. It was seen first about 8 pm, but died out in a couple of hours. 

 On the 17, between 2 and 3 a.m., there were three quite severe shocks of earthquake, the first that have been felt for some time. A number more were noticed during the morning, and in the afternoon they increased rapidly. Up to 7 p.m. 100 were counted. From that hour until midnight there was often not one minute's interval between them, and at 4 am of the 18th, 374 distinct shocks had been recorded. They continued, although fewer in number, until midnight. 

 At 7 pm the eruption began in good earnest. The starting point is on the slope of Mauna Loa, about a mile to the north and a little above the well know extinct crater called Halepohaha. . . . The new crater is perhaps twenty miles from the sea and about ten north-west and above the fissure from which poured out the lava flow of 1868. . . . at daylight of the 19th [the lava flow] had crossed the government road . . . . At 11:30 a.m. one of the streams reached the sea between the South Point and Ka Puuo Pele . . . .

 . . . The main flow reached the sea at 7:30 p.m. [Jan. 20], a few miles to the westward of the terminus of that of 1868. . . .

 . . . At 9:15 am [Jan. 22] had a peculiar earthquake. All of the others have been from a northerly to a southerly direction and without noise. This was apparently from east to west, and although the jar was light, it was accompanied by a rattle similar to that produced by running a stick along a picket fence.

 . . . .

 Reports from Pahala, Punaluu and Naalehu also show the earthquakes to have been numerous and severe, especially the one of Sunday night, January 23rd, at 11:30, that was experienced in this city [Honolulu]. The steamer W.G. Hall, at anchor off Punaluu at the time, was so shaken that Captain Bates prudently steamed seaward several miles lest a tidal wave would follow as it had in 1868. Four or five buildings are reported thrown down, cisterns broken, and the boilers at Pahala displaced."

 The eruption was still in progress, as of January 30.

 

Jones, G., 1887, [On the Mauna Loa eruption and earthquake swarm of 1887]: Hawaiian Gazette, 02/01, p. 1. [Letter no. 02. Excerpted in American Journal of Science, 3rd ser., v. 33, p. 310-311] 



 Subheads over letters from correspondents, signed and unsigned:

Mauna Loa!; Hawaii's great volcano; twenty miles of liquid fire in motion!; Madam Pele on the rampage!; continuous earthquake shocks!; description of the flow!; notes and incidents



Kahuku Ranch, January 21st, 1887--"The earthquake shocks began at 2:12 a.m. of the 17th, and up to 7 p.m. we had 100.--As I knew that they indicated an eruption, I sat up all night taking a record of the shocks, and squints of the mountain side. At 4:00 a.m. of the 18th, my count had reached 314, and during the day and until 12 midnight 67 were added. On the 19th we had but two and no more since. This was a total of 383 well defined shocks, strong enough to make an open door tap, tap, tap against a partition. There were probably as many more slight tremors and jars, many of which were noticed, but which I did not register, as I preferred to hear the tapping of the door indicate the shock as of some force. At 7 p.m. of the 18th . . . the lava burst out about ten miles N.N.W. of my ranch buildings, and has been running ever since. The point would be about twenty miles from the sea, and the first stream reached there about noon of the 19th. The main flow has passed about two miles to the westward of my buildings and reached the sea last evening. . . ."

[This paper is followed by Martin,1887]



Jones, A.E., 1932, A chart of Kilauea seismicity: The Volcano Letter, no. 371, p. 1-4. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p. The article is followed by a discussion by Jaggar (p. 3-4)] 



 Jones attempts to quantify the descriptions of earthquakes recorded at Kilauea by assigning numerical weights to different descriptive classifications (e.g., "feeble" is assigned a weight of 1, "strong" a weight of 4, 1 minute of tremor is assigned a weight of 0.25). He then plots cumulative weekly totals (earthquakes and tremor, expressed as a log value) for the years 1928-1931. Most peaks correspond to Halemaumau eruptions. One peak corresponds to the Hualalai earthquake swarm of October 1929. Two additional peaks (January and March 1929) that flank the Halemaumau eruption of February 1929 are unexplained. Jaggar comments on the possible correlation of the seismic data with lunar cycles.



Jones, A.E., 1934, Earthquakes associated with the 1933 eruption of Mauna Loa, Hawaii: Journal of the Washington Academy of Sciences, v. 24, p. 413-418. 



 Jones lists the times of earthquakes that occurred during 1933 and plots their epicenters on a map. [There are a surprising number of earthquakes located away from the active volcanoes.] A swarm of earthquakes in October preceded the eruption by 6 weeks, and 13 earthquakes accompanied the outbreak. The author notes a slight tendency for the earthquakes to get progressively shallower up to the time of the eruption.



Jones, A.E., 1935, A seismologic study of the Kilauea eruption, 1931-1932: University of Hawaii Research Publication 9, 60 p. 



 Jones constructs a seismicity curve for a year preceding and following the Kilauea eruption of 1931-32. High areas on the curve correspond with periods of eruption. He tabulates epicenters and plots them on maps. The earthquake foci are located by use of newly-developed travel-time and S-P curves for Hawaii. Most Kilauea earthquakes fall on the circumferential fault planes which enclose Kilauea caldera. Premonitory earthquakes and harmonic tremor occurred in October 1931, 2 months before eruption, and again just prior to and during eruption. Another caldera swarm occurred in March 1932 about 2 months after euption. It is not known whether the latter swarm was related to the preceding eruption. [The exposition is confusing with regard to which earthquakes are actually associated with eruption.]



Karpin, T., and Thurber, C.H., 1985, Earthquake swarms and magma transport within Kilauea Volcano [abs.]: Eos, Transactions, American Geophysical Union, v. 66, no. 46, p. 958. [AGU fall meeting, San Francisco, CA, Dec. 8-13, 1985, Program and abstracts] 



 Distributions of earthquake swarms have proved to be an accurate documentation of the passage of magma through the summit and rift zones of Kilauea volcano. With the use of a fairly realistic three-dimensional velocity model, well constrained hypocentral locations and relatively consistent and unambiguous fault plane solutions are attainable. These locations and solutions are important for discerning the nature of earthquake swarms in relation to magma transport. In this study, earthquake swarms emanating from the summit region towards both the southwest and east rift zones were relocated and their fault plane solutions constructed. Hypocenters for the Jan. 20, 1981 southwest rift zone earthquake swarm roughly define an eastward dipping plane 2 km long by 1 km high with a basal depth 2 km below sea level Hypocenters for the Dec. 9, 1982 east rift zone earthquake swarm roughly define a vertical plane 3 km long by 3 km high with a basal depth 4 km below sea level. This significant difference in maximum swarm depth suggests that the summit magma complex contains distinct magmatic bodies that supply each individual rift zone. Construction of fault plane solutions for events from both intrusive episodes shows predominantly strike-slip faulting with a P-axis direction parallel to the rift zone. This produces an en-echelon fault plane pattern, each plane striking about 45 degrees from the strike of the earthquake swarm. No observed events for both intrusive episodes showed any evidence of a compensated linear-vector dipole (CLVD) type first motion pattern. Rather than being due directly to magma intrusion, we propose these earthquakes represent the failure of overlying and adjacent country rock as dikes intrude and propagate towards the surface.



Karpin, T.L., and Thurber, C.H., 1987, The relationship between earthquake swarms and magma transport: Kilauea Volcano, Hawaii: Pure and Applied Geophysics, v. 125, no. 6, p. 971-991. 



 A detailed investigation of earthquake locations and focal mechanisms for swarms associated with intrusive events at Kilauea volcano, Hawaii, further illuminates the relationships among stress state, faulting, and magma transport. We determine the earthquake locations and mechanisms using a three-dimensional crustal model to improve their accuracy and consistency. Swarms in Kilauea's upper east and southwest rift zones, from the years 1980 through 1982, provide clear evidence for the propagation and/or dilation of dikes. Focal mechanisms are predominantly strike-slip, and the faulting and inferred dike orientations can be interpreted quite consistently in terms of the model of HILL (1977). Stresses induced by the summit magma reservoir system strongly control faulting and magma transport in the rift zones close to the summit.



Kawakatsu, H., 1987, Centroid single force inversion of seismic waves generated by land slides [abs.]: Eos, Transactions, American Geophysical Union, v. 68, no. 44, p. 1353. [AGU fall meeting, San Francisco, CA, Dec. 6-11, 1987, Program and abstracts] 



 The Centroid Moment Tensor (CMT) waveform inversion method of Dziewonski et al. (1981) is modified to analyze long period seismic waves generated by the "single force" events studied by Kanamori and others, in the hope of settling some controversy associated with the 1975 Kalapana, Hawaii event. Eissler and Kanamori (1987) proposed a single force model for the Kalapana event, but whether this event is an earthquake or a land slide is still unresolved.

 As a source function for the Centroid Single Force (CSF) inversion, we use the negative of the momentum of inertia or a sliding object, which is the integral of "effective force" acting on the earth during a land slide. It is convenient to introduce this source function because it is a one sided function during the event, and is zero before and after the event when the system is static, as in the case of moment rate for the CMT inversion. As a result of inversion we obtain the spatio-temporal centroid and three components of a vector we call the "Centroid Single Force" vector. This vector is equal to (Mass) x (Distance) of a land slide.

 We first apply this method to the long period surface waves generated by the 1980 Mt. St. Helens event. There are records from 11 GDSN and 9 IDA stations available. The solution obtained from all the records is CSF=l.5x1021 g.cm. The CSF azimuth (6  3 SW) is consistent with the earlier observation of force azimuth by Kanamori and Given (1982). The CSF plunge (5.2  1.8 upward) agrees remarkably well with the 6 grade of the land slide. Single station solutions, using three components of data from 11 CDSN stations fall within 10 of the full-data solution. This suggests that the CSF solution is stable and that the single station analysis may be useful. The CMT inversion applied for the whole data set does not converge to a proper solution.

 For the Kalapana event the preliminary analysis of the long period data from two IDA (NNA,.CAN) and one SRO (ANMO) stations suggests either model can be possible. The CSF solution is CSF=2.6x1022 g cm, azimuth=34 NW, plunge=29, which agrees with the Eissler & Kanamori's model in general. Analysis of High Gain Long Period (HGLP) digital data will be presented.



Kawakatsu, H., 1989, Centroid single force inversion of seismic waves generated by landslides: Journal of Geophysical Research, v. 94, no. B9, p. 12,363-12,374. 



 The centroid moment tensor (CMT) waveform inversion method of Dziewonski et al. (1981) is modified to analyze long period seismic waves generated by "single force" events such as the gigantic landslides associated with the 1980 eruption of Mount St. Helens. We refer to the method as centroid single force (CSF) inversion. As the result of the inversion we obtain the spatio-temporal centroid and three components of a vector we call the CSF vector, which is the seismic point source representation of a landslide and whose direction is the opposite of the direction of sliding. The scaler magnitude of the CSF vector measures the overall size of the landslide and is given by MCSF = MD, where M is the mass of the sliding object and D is the sliding distance. We apply CSF inversion to the long period surface waves generated by the 1980 Mount St. Helens event, the 1975 Kalapana earthquake, and the 1974 Mantaro landslide, using seismograms from the GDSN, IDA and HGLP networks. The CSF solution for the St. Helens event is remarkably consistent with the actual geological observations and proves the efficacy of CSF inversion. The CSF solution for the Kalapana event does not fit the overall waveforms better than the CMT solution does. However, because the CMT solution does not explain the observed Love wave radiation pattern, it may be necessary to invoke a combination of both types of mechanism for this event. Although the geometry of the CSF solution (the direction of the force) for the Mantaro event is consistent with the actual landslide, MCSF is about 5 times smaller than that expected from the mass and travel distance of the landslide estimated by geological observations. This discrepancy may suggest either the relatively aseismic nature of this landslide or that the total volume of the slide was overestimated. By analogy to single station CMT inversion, single station CSF inversion also appears to be stable and useful



Kazi, W., Scherbaum, F., and Wyss, M., 1987, Synthesization of strong motion records from the November 16, 1983 Kaoiki earthquake, Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 68, no. 16, p. 361. [AGU spring meeting, Baltimore, MD, May 18-21, 1987, Program and abstracts] 



 This study is an attempt to synthesize the strong motion records from the November 16, 1983 Kaoiki Earthquake in Hawaii (Ms =6.6). Available data are twelve three component accelerograms with good azimuthal coverage and radial distances of 15 to 80 km.

 A visual identification of individual pulses in the transverse components of different stations suggested at least four groups of arrivals that could be due to distinct sources. The HYPO-71 earthquake location program was used to locate the sources of these pulses in relative time and space. The expected S-pulse of the main event was located within 0.4 km of the epicentre and 0.7 km of the hypocentre of the HVO Bulletin location of the main event. All the other events were distributed within 2 km aerial distance of the main event and ranged in depths from 16 km to 5 km, well within the aftershock zone. When the expected P-arrival times for these events were checked on the corresponding vertical components, distinct arrivals of energy could be observed in 3 out of 5 cases.

 A preliminary set of synthetic seismograms, using normal mode technique, were produced by using these sources. They appeared to conform well in overall shape and duration to the original data.

 A polarization analysis and particle motion study is underway to identify the individual pulses more distinctly. Spectral analysis and auto-correlation will be used to compare shape, form and duration of the pulses at different stations from the same event. The ultimate goal is to reproduce the rupture history of the earthquake in detail and perhaps, to refine the velocity structure.



Kazi, W., and Scherbaum, F., 1988, Complex faulting mechanism derived from strong motion seismograms of the Kaoiki earthquake [abs.]: Eos, Transactions, American Geophysical Union, v. 69, no. 18, p. 567. [AGU Front Range meeting, Golden, CO, Feb. 11-12, 1988, Program and abstracts] 



 The area between the Kilauea and Mauna Loa volcanoes on the island of Hawaii is undergoing compression which results in near-vertical right- lateral strike-slip faulting alonq NE-SW criented planes. However, the horizontal contact plane between the newer volcanic crust and the underlying older oceanic crust forms a plane of weakness at about 10 km. depth, along which the whole SE flank of Hawaii may slide to the south during major earthquakes.

 The November 16, 1983 Kaoiki Earthquake with Ms 6.6 offers an opportunity to study this complicated crustal zone. Polarization and waveform analysis have revealed multiple sources observable on the horizontal transverse components of the 3-component accelerograms recorded by twelve stations. Three individual sources were located in a zone of about 1.5 km. radius near the centre of the aftershock area which had a radius of about 10 km.. The mainshock hypocentre is within 2 km. of these sources which are separated in time by 1.4 and 3.2 sec. respectively. Predicted P-arrival times for each event were checked on the vertical component and provided further evidence for multiple sources. Joint hypocentre locations will be computed to improve location accuracy. Although the P-wave first motions yield a focal mechanism as described above, many aftershocks were thrusts on the near horizontal layer of weakness (Endo, 1985). Thus it is suspected that the latter mode of rupture may also have contributed to the energy release in the 1983 mainshock. In order to test this hypothesis polarization vector properties will be studied to obtain details of source geometry of individual events of the main rupture.



Kelley, E.G., 1841, Remarks on the island of Owyhee or Hawaii: American Journal of Science, 1st ser., v. 40, p. 117-122. 



 A description of Kilauea caldera on May 8, 1838, as seen by Captains Chase and Parker of the whaling ships Charles Carroll and Ocean. They counted 26 small cones and 6 active lava lakes on the caldera floor. The frontispiece to this volume of the American Journal of Science is a view of the caldera, from sketches by Parker and Chase. No black ledge is shown, nor mentioned in the description. Kelley describes an earthquake in 1823 that threw "an entire mountain, which attained an elevation of six hundred feet . . . into the sea. . . ." [There is no hint in subsequent literature to indicate what this might have been.] The author describes a recent lava flow between Hilo and Kilauea summit from which Mauna Loa and Mauna Kea were visible on one side and the ocean on the other. [This is the same fresh flow described by Lord Byron's party in 1825. See annotation for Anonymous, 1847a.]



Kelling, A., 1994, Accounts of the great Kau earthquake of April 1868 in Hawaiian-language newspapers: Honolulu, University of Hawaii Joint Institute for Marine and Atmospheric Research, Hawaiian Tsunami History Project, 17 p. [English translations by Anthony Kelling with the help of Emily Hawkins, Assistant Professor of Hawaiian, University of Hawaii] 



 Preface

 Collected here are English translations of accounts of the great Kau earthquake of April 1868 and of other 1868 geophysical events that were published originally in Hawaiian-language newspapers. The accounts were copied from microfilms of the newspapers at Hamilton Library, University of Hawaii, by Anthony Kelling, a student of Hawaiian at the University, and the translations were prepared by Kelling with advice from Emily Hawkins, Assistant Professor of Hawaiian. The copying and translation of the accounts constitute a part of the work of the Hawaiian Tsunami History project, a project of the Joint Institute for Marine and Atmospheric Research of the University Hawaii that is supported in part by grant BCS 9208173 from the National Science Foundation.

 The April 1868 Kau earthquake was the largest in Hawaiian history; and the tsunami accompanying it was the largest generated locally. The earthquake and its accompaniments have been the subject of a large number of investigations, but the investigators have hitherto had access to only English-language accounts of the phenomena. For this reason, and because several investigators are engaged in restudy of the earthquake, the entire Hawaiian language accounts of the earthquake were translated in this study, rather than just the parts of the accounts relating to the tsunami.

 In their present form the translations are essentially literal and properly regarded as drafts. However, even in their present form, they indicate the general content of the original Hawaiian-language descriptions of the effects of the earthquakes and other geophysical phenomena. For this reason, and because I cannot at present afford to spend either my own time or that of the translator and his advisor necessary to convert them to more idiomatic English, it seems appropriate to distribute copies in this form to those with active interests in the events.

 If the translations are to be quoted, they should be edited, and in some particulars the meaning of the original Hawaiian should be rechecked. Persons interested in rechecking may obtain, from the Hawaiian Tsunami History Project, copies of the xerographic copies made from the newspaper microfilms.--Doak C. Cox, Project Manager



Kellogg, J.N., and Chadwick, W., 1987, Neotectonic study of the Hilina fault system, Kilauea, Hawaii [abs.]: Geological Society of America Abstracts with Programs, v. 19, no. 6, p. 394. [Geological Society of America, Cordilleran Section, 83rd annual meeting, Hilo, HI, May 20-22, 1987] 



 On November 29, 1975, the largest earthquake in over a century (magnitude 7.2) struck Kalapana, Hawaii. The earthquake was accompanied by a tsunami, a volcanic eruption, and vertical displacement on the Hilina fault system. The earthquake and the tsunami it generated caused property damage estimated at $4.1 million and resulted in two deaths. Similar large historic earthquakes in 1823 and 1868 suggest a recurrence interval of 50 to 100 years. Repeated displacement along the Hilina fault system has produced pali (cliffs) 25 km long and up to 500 m high.

 In 1984, we made 68 measurements of displacement along the Poliokeawe and Holei branches of the Hilina fault system. The Hilina pali are draped with historic and prehistoric lava flows. Nine of the prehistoric flows have reliable radiometric or paleomagnetic age determinations ranging up to 1500 years B.P. Often, therefore, a maximum age can be deduced for fault displacements within flows. We measured up to 2.6 m of displacement along a single ground break associated with the 1975 earthquake. The most recent displacement occurred in two distinct directions: to the southeast and to the south-southwest.

 Large landslide scarps parallel to the rift zones have also been identified on the east and west flanks of Mauna Loa. Giant submarine landslide masses have been identified adjacent to the Koolau range, the northeast flank of Molokai, and on the submarine slope south of Kilauea.



Kinoshita, W.T., 1965, May 1963 seismic episode on the Koae fault zone, Hawaii [abs.], in, Investigations of Hawaiian volcanoes, 1963, 3rd general meeting, Hakone, Japan, Oct. 26-28, 1963, Abstracts of papers: [s.l.], Japan-United States Cooperative Science Programme, p. 9. [Participating organizations: University of Tokyo Earthquake Research Institute and U.S. Geological Survey, Hawaiian Volcano Observatory] 



 An episode of frequent earthquakes in a background of continuous harmonic tremor began at 21h 50m on May 9, 1963. This episode lasted about four days and included several earthquakes that were felt in the Kilauea summit area. Although 3000 to 4000 earthquakes were recorded on the Hawaiian Volcano Observatory network, less than 30 were of magnitude 2.0 or larger and only one was larger than 3.0. The appearance of harmonic tremor on the Kilauea summit network suggested that lava was moving at a shallow depth beneath the summit region.

 An average epicenter for the 30 earthquakes is located in an area about 2 kilometers west of Puu Koae on Kilauea's southwest flank. Fresh cracks up to 2 feet in width were found in the region in a zone several miles long. A comparison of arrival times at 3 of the seismographs of the Kilauea summit network suggest a westerly drift of the average epicenter during the first 10 hours of this seismic episode.

 About 1/2 of all the earthquakes recorded during the 4 day period occurred in the first 15 hours.

 This seismic episode was accompanied by a summit deflation shown by the Kilauea summit tilt network. Two of the tilt stations that are near to and on opposite sides of the Koae fault system suggested a large inflation for the zone between them. All of the fresh cracks in this zone appear to result from tensional stresses. The combination of earthquake activity, harmonic tremor, a zone of fresh surface cracking, deflation at the summit, and inflation in the vicinity of the Koae fault system is believed cased by the underground movement of lava from the summit reservoir into the vicinity of the Koae fault system.



Kinoshita, W.T., 1967, May 1963 earthquakes and deformation in the Koae fault zone, Kilauea Volcano, Hawaii: U.S. Geological Survey Professional Paper 575-C, p. C173-C176. 



 An episode of frequent earthquakes with a background of continuous harmonic tremor began at 21h50m on May 9, 1963. During the 4 days of this episode 3,000-4,000 earthquakes were recorded on the U.S. Geological Survey Hawaiian Volcano Obseratory seismic network. The earthquakes occurred in the western half of the Koae fault system and were accompanied by abundant ground cracking. Tilt measurements on Kilauea volcano made after the episode showed that the summit had deflated.



Klein, F.W., 1981, A linear gradient crustal model for south Hawaii: Bulletin of the Seismological Society of America, v. 71, no. 5, p. 1503-1510. 



 A new crustal model with linear velocity gradients within layers does as good a job of locating earthquakes on south Hawaii as any model yet published. Incorporating linear gradients means the model can be simpler and free of artificial velocity discontinuities. Using travel-time residuals from local earthquakes and consistency of focal mechanism solutions as tests, it is seen that a low-velocity zone at the base of the crust is not required.



Klein, F.W., Koyanagi, R.Y., Nakata, J.S., and Tanigawa, W.R., 1987, The seismicity of Kilauea's magma system, in Decker, R.W., Wright, T.L., and Stauffer, P.H., ed(s)., Volcanism in Hawaii, 2 v.: U.S. Geological Survey Professional Paper 1350, v. 2, chap. 43, p. 1019-1185. 



 Earthquake-hypocenter data collected by the Hawaiian Volcano Observatory during 1960-83 provide a wealth of information on the active processes of Kilauea's magma system. The magma conduits produce volcanic earthquakes that occur in episodic swarms often accompanied by tilt changes or eruptions. Tectonic earthquakes in Kilauea's flanks and some parts of the upper mantle occur more continually and are punctuated with mainshock-aftershock sequences. Volcanic earthquakes also have smaller magnitudes, a greater proportion of small events, and frequent association with tremor. Three-dimensional earthquake patterns and separation of volcanic and tectonic seismicity can be visualized in a series of hypocenter depth slices and cross sections. Earthquakes reveal a magma system consisting of a vertical conduit from Kilauea caldera to about 60 km depth, two shallow rift zones radial to the caldera, and a shallow magma reservoir joining these three conduits.

 The shallow magma reservoir is an aseismic zone beneath the south edge of Kilauea caldera. The reservoir is surrounded on two sides by intensely active rift conduits centered near 3 km depth, above by a seismically active cap in the caldera mostly between 1 and 2 km depth, and below by the vertical magma conduit having earthquakes as shallow as 7 km. The deformation centers are mostly between 2 and 4 km depth, near the top of the aseismic zone that is between 3 and 7 km depth. Inflation of the reservoir produces earthquakes above and in the adjacent rift conduits by extension in the summit region and slow magma intrusion into the rifts.

 The vertical magma conduit, as defined by earthquakes, consists of two parts: a narrow and nearly vertical pipe between 7 and 20 km depth mostly having swarms of volcanic earthquakes, and a zone that widens into a diffuse and south-dipping region between 20 and 60 km depth. Earthquakes in the deeper conduit are larger in magnitude and more continuous in time, as if tectonic in origin. Earthquakes below 40 km depth merge with the Hawaiian hot spot below Kilauea, Loihi and Mauna Loa Volcanoes. Kilauea's deep earthquakes also join a band of seismicity along the island's south coast, which is probably caused by shear stress applied from Kilauea's mobile south flank and by the growing and asymmetrical weight of the Kilauea shield. The number of earthquakes in the vertical conduit dropped dramatically at the time of the M = 7.2 Kalapana earthquake in 1975. This decrease indicates that conduit earthquakes are partly driven by regional stresses derived from the seaward push of the south flank.

 The vertical distribution of conduit earthquakes shows pronounced gaps near depths of 5, 13 and 20 km. The first gap results from the magma reservoir between 3 and 7 km depth and the 13-km-depth gap is probably bounded by the Moho and the pre-volcanic oceanic sediments. The depth of 20 km is also a gap for earthquakes in the surrounding lithosphere, marks the change from volcanic-style earthquakes above to tectonic below, and is probably the zone of the neutral stress axis in the lithosphere bending under the island's weight. The vertical magma conduit thus is similar to a passive, weak zone in the lithosphere that triggers earthquakes mainly driven by regional stresses.

 Kilauea's rift zones produce shallow swarms of varied intensity and complexity arising from periods of summit inflation, slow intrusions, and rapid intrusions that may also result in eruptions. Slow intrusions may feed the rifts adjacent to the caldera during inflation, send slow pulses of magma (and hence earthquakes) down the rifts, or be aseismic except at the terminus of the intrusion where magma collects. Much of this paper documents earthquakes from swarms during 1962-84. To examine the dynamics of intrusion and dike formation computer plots for each swarm are designed to show the position, depth, size and shape of the seismic zone, deflation and seismicity with time, and migration of earthquakes along the rift or vertically.

 Rapid intrusions generally begin with earthquakes in a small volume near the main rift conduits at 3 km depth and may spread along the rift and upward. Migration and growth speeds are about 0.1 to 6 km/h. An intrusion often loses upward speed as it approaches the surface, or downrift speed as it nears its terminus. Earthquakes occur at and behind the front of the dike as the conduit widens and the walls compress. Barriers within the rifts, where the conduit is pinched shut or stress is concentrated, often generate clusters of earthquakes and act as places where intrusions start and stop. The most prominent barriers are adjacent to the summit magma reservoir and in the east rift zone below Pauahi Crater and Mauna Ulu, but many are present along both rifts. The Pauahi-Mauna Ulu barrier is important because many intrusions start there and move uprift and downrift, and it also marks a bend in the rift, where it intersects the Koae fault zone. A possible small magma reservoir below Pauahi Crater is recognized by the absence of earthquakes- this reservoir is dammed uprift of the Pauahi-Mauna Ulu barrier.

 The most common earthquake migration direction at Kilauea is downrift and is presumably driven by gravity and a pressure gradient along the magma conduit. Upward earthquake migration is visible in many intrusions and reflects ascending magma presumably driven by buoyancy forces. The east rift zone between Kilauea caldera and Mauna Ulu is an anomalous zone of earthquake migration; uprift, downrift and bilateral migration of earthquakes are equally likely. This zone is also unusual in its high degree of activity, its northwest trend oblique to the regional stress, its shallowness of earthquakes, its ability to feed two intrusions simultaneously, and its short 2- to 3-hour interval from the beginning of an intense earthquake swarm to the start of an eruption. The upper east rift zone thus seems to be a multi-tiered and complex honeycomb of conduits. The various directions of earthquake migration in this area may result from a complex pattern of stresses and pressure gradients, or from an uprift-traveling pressure pulse within magma flowing downrift. The latter may have caused the reflection of a downrift earthquake migration off a rift barrier back uprift, as observed in many intrusions.

 Intrusions occur in larger cycles that alternate between rifts. Intrusions are often grouped in pairs or triplicates within a few weeks of each other--they may retrace the same path or occur adjacent to their predecessors. In addition, four complete cycles of east-rift-zone to southwest-rift-zone shifts, each lasting 3-4 years, occurred during 1968-83. A basic cycle consists of several east-rift-zone intrusions (beginning near Mauna Ulu), a period of inflationary swarms at the summit, a major intrusion usually in the southwest rift, and about one year of no new intrusions before beginning the cycle again. This cycle may be an oscillatory tectonic process involving the south flank. A series of intrusions in one rift apparently helps trigger other intrusions and also compresses the adjacent flank. This compression inhibits additional intrusions and hinges open the other rift until a switch occurs. The Kalapana earthquake in 1975 may have disrupted the basic pattern set by the first two cycles: periods of inflationary swarms did not occur in 1977 and 1980-81, no southwest-rift intrusions occurred in 197778, and the switch from the southwest rift zone to the east rift zone in 1982-83 occurred without a pause.



 TABLE OF CONTENTS



INTRODUCTION 1020

 THE SUMMIT MAGMA RESERVOIR

 INFERRING MAGMA FROM EARTHQUAKES

 ACKNOWLEDGMENTS

EARTHQUAKE DATA GATHERED AT THE HAWAIIAN VOLCANO OBSERVATORY 1023

A THREE-DIMENSIONAL OVERVIEW OF KILAUEA SEISMICITY 1024

 THE SHALLOW CRUST BETWEEN 0 AND 5 KILOMETERS DEPTH

 TECTONIC EARTHQUAKES BETWEEN 5 AND 14 KILOMETERS DEPTH

 THE MAGMA CONDUIT BETWEEN 5 AND 20 KILOMETERS DEPTH

 THE MAGMA CONDUIT BETWEEN 20 AND 40 KILOMETERS DEPTH

 THE MAGMA CONDUIT AND HOT SPOT BELOW 40 KILOMETERS DEPTH

 THE MECHANISM OF DEEP EARTHQUAKES

 EARTHQUAKES AT 20-60 KILOMETERS DEPTH DURING 1960-69

 THE B-VALUES OF SHALLOW EARTHQUAKES

GENERALIZED HISTORY OF KILAUEA EARTHQUAKES 1035

 SHALLOW VOLCANIC EARTHQUAKES

 KILAUEA'S MAGMA CONDUIT BELOW 5 KILOMETERS DEPTH

 TECTONIC EARTHQUAKES ON KILAUEA'S SOUTH FLANK

 TECTONIC EARTHQUAKES IN THE KAOIKI SEISMIC ZONE

SEISMICITY NEAR KILAUEA'S SHALLOW MAGMA RESERVOIR AND RIFT ZONES 1041

 THE SUMMIT MAGMA RESERVOIR

 THE SUMMIT SECTION OF THE EAST RIFT ZONE

 EARTHQUAKE HYPOCENTERS IN THE SOUTHWEST RIFT AND CENTRAL EAST RIFT ZONES

 THE KOAE FAULT ZONE

KILAUEA'S VERTICAL MAGMA CONDUIT AND THE PATTERN OF DEEP EARTHQUAKES 1049

THE HISTORY OF KILAUEA'S SHALLOW EARTHQUAKE SWARMS, 1963-83 1055

 INTRUSIONS AND ERUPTIONS OF 1963

 THE ERUPTIONS AND INTRUSION OF 1965 AND 1967

 THE EAST RIFT ERUPTIONS OF 1968 TO MARCH 1969

 THE MAY 1969 MAUNA ULU ERUPTION AND INTRUSIONS THROUGH NOVEMBER 1969

 INFLATION-RELATED SWARMS AND INTRUSIONS, DECEMBER 1969 TO DECEMBER 1970

 INFLATIONARY SWARMS AND ERUPTIONS, JUNE 1971 THROUGH JUNE 1972

 THE MAY AND JUNE 1973 INTRUSIONS OF THE KOAE FAULT ZONE

 ERUPTIONS AND INTRUSIONS, NOVEMBER 1973 THROUGH SEPTEMBER 1974

 THE DECEMBER 1974 SOUTHWEST RIFT ZONE ERUPTION

 1976-77 EAST RIFT ZONE INTRUSIONS AND ERUPTION

 EAST RIFT INTRUSIONS AND ERUPTION, NOVEMBER 1978 TO NOVEMBER 1979

 EAST RIFT ZONE INTRUSIONS OF MARCH 1980

 CYCLIC EAST RIFT ZONE INTRUSIONS OF MAY-AUGUST 1980

 EAST RIFT ZONE INTRUSIONS OF JULY-NOVEMBER 1980

 SOUTHWEST RIFT ZONE INTRUSIONS AND CALDERA ERUPTION OF JANUARY-AUGUST 1981

 THE SOUTHWEST RIFT ZONE INTRUSIONS AND CALDERA ERUPTIONS OF MARCH-JUNE 1982

 CALDERA AND EAST RIFT ERUPTIONS OF SEPTEMBER 1982 THROUGH JANUARY 1983

DISCUSSION OF RIFT ZONE INTRUSIONS

 INFLATIONARY SWARMS AND SLOW INTRUSIONS

 SEQUENCE OF EVENTS WITHIN A RAPID INTRUSION

 THE GEOMETRY AND DYNAMICS OF INTRUSIVE SWARMS

 THE MECHANICS OF EARTHQUAKE MIGRATION

 BEHAVIOR OF THE EAST RIFT ZONE FROM THE CALDERA TO MAUNA ULU

 UPPER EARTHQUAKE MIGRATION

 THE STARTING POINT OF INTRUSIONS

 UPWARD MIGRATION OF EARTHQUAKES

 SEQUENTIAL RELATIONS BETWEEN INTRUSIONS ALONG THE RIFT ZONES

REFERENCES



Klein, F.W., and Okubo, P., 1993, Hazards from earthquakes, submarine landslides and expected levels of peak ground acceleration on Kilauea and Mauna Loa Volcanoes, Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 74, no. 43, p. 634-635. [AGU fall meeting, San Francisco, CA, Dec. 6-10, 1993, Program and abstracts] 



 The south side of the island of Hawaii experienced major earthquakes on April 2, 1868 (M-7.9) and November 29, 1975 (M=7.2). Historic earthquakes (since 1823) and the best Hawaiian Volcano Observatory catalog (since 1970) define linear frequency-magnitude distributions that imply recurrence intervals of M>7 events of 33-105 years. This is comparable with the 107 year interval between the two major events. Traditional paleoseismology is impractical in Hawaii because the large decollement events may not rupture the surface and because lava flows frequently cover any surface faulting. Frequency-magnitude distributions define the activity levels of 19 different earthquake source zones for ground motion estimations. The available measurements of peak acceleration (33 from 7 moderate earthquakes) are insufficient to define a new attenuation curve. They do indicate that one of the higher-valued published curves should be used, however. Amplification of sites on volcanic ash are about 2.4 times those of hard lava sites. We used the SeisriskIII computer program to calculate a map of expected peak accelerations in a 50 year exposure time with a 90% probability of not being exceeded. Kilauea's mobile south flank can expect peak accelerations of 1.0-1.1 g and the Kaoiki seismic zone should expect 0.9 g, allowing for variations in attenuation. Large flank earthquakes pose more of a shaking hazard than upper mantle earthquakes or shallow earthquakes caused by magmatic processed in calderas or rifts. Catastrophic submarine landslides also follow a linear frequency-magnitude distribution where magnitude is calculated from estimated subsidence energy. Magnitude 8 landslides appear to be 2 or 3 orders of magnitude less frequent than magnitude 8 earthquakes. Great flank earthquakes may often trigger a small submarine landslide, but they do not frequently produce a great submarine landslide.



Kolotyrkina, I.Y., Midson, B.P., and Malahoff, A., 1996, Hydrothermal iron and manganese relationships at Loihi [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F397-398. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 Dissolved Fe (DFe) and Mn (DMn), and total dissolvable Fe (TDFe) and Mn (TDMn) were measured in samples ranging from near the summit of Loihi to 5 km distance. Two distinct types of altered waters were observed. a shallow plume (1140m-1180m) and deeper water (1220m-1250m) filling the pit craters. The shallow plume had DFe and TDFe of 5 and 20 micromolar, and DMn and TDMn of 0.5 and 0.6 micromolar. The relationship between Fe and Mn in this plume was similar to previously measured anomalies from Loihi. The bottom-seeking pit waters were characterized by 7.0 deg C water with a salinity of 34.88 psu and had maximum DFe and DMn of 125 and 30 micromolar. A distinction also exists between bottom waters collected from the East Pit and the former site of Pele's Vents (PV), Pele's Pit. Extremely turbid water was collected from Pele's Pit, with a 9X enrichment of TDFe to DFe showing substantial Fe adsorption onto particles. The enrichment of TDMn to DMn in Pele's Pit was 2X. The East Pit had only a 1.1X enrichment of TDFe to DFe, very little Fe adsorption. Another contrast was that Pele's Pit water had the typical Loihi ratio of TDFe to TDMn 40:1, while the East Pit showed the lowest TDFe to TDMn ratio ever measured, 3:1.

 The shallow plume is the result of diffuse venting from the former location of the PV hydrothermal mound. The deeper, pit crater waters are either interstitial waters squeezed out by the summit collapse or result from the addition of a new heat source. The variability between Pele's Pit and the East Pit is caused by the resuspension of bacterial mats and Fe-rich smectite associated with the former Pele's Vents. Reducing conditions in the East Pit prevent ferrous Fe from oxidizing and adsorbing onto particles. The result is higher DFe in the East Pit, but lower TDFe than in Pele's Pit.



Kong, L.S.L., and Okubo, P.G., 1994, Seismicity at Loihi Seamount, Hawaii [abs.]: Seismological Research Letters, v. 65, no. 1, p. 55. [Seismological Society of America, 89th annual meeting, Pasadena, CA, Apr. 5-7, 1994 (Abstracts)] 



 A steady increase in seismic activity beneath Loihi Seamount has been observed by the USGS/Hawaiian Volcano Observatory (HVO) seismic network since 1971. The majority of the Loihi seismicity is registered by HVO as earthquake swarms. The 3-km high, 3 km long seamount, located about 35 km south of Hawaii, is the site of high-temperature hydrothermal vents, and represents the youngest expression of the Hawaiian hot spot. Data recorded by the HVO permanent network show that earthquake swarms, lasting less than a week, have been occurring there nearly annually since 1984. Prior to this, seismic activity was confined to two extended swarms in 1971-72 and 1975. The 1971-72 activity occurred steadily over 12 months, and the 1975 activity was recorded over a 3-month period. The 1984-93 seismicity encompasses a 40-km wide swath about the summit and rift zone, with the swarms locating in distinct elongate clusters along the N25W-trending rift zone. The earthquakes are concentrated between 8 and 1 8-km depth (average 14 km), with some events located as deep as 50 km. Earthquake magnitudes range up to 4.2, averaging 2.6. The events may be indicative of the movement of magma within the volcanic edifice, or manifestations of tectonic readjustments or landslide-type processes occurring beneath the steep slope of the seamount. The December 19-20, 1991, swarm consisted of nearly 100 events over a 2-hour period located beneath the summit, rift zone axes, and western flanks of Loihi. Independently-collected data [Malahoff, 1993] show a 40 cm change in summit elevation from December 19-23, 1991, suggesting that the earthquakes may have been associated with magmatic rift zone intrusion.



Kovach, R.L., and Hill, D.P., 1987, The 1975 Kalapana earthquake revisited [abs.], in Decker, R.W., Halbig, J.B., Hazlett, R.W., Okamura, R., and Wright, T.L., ed(s)., Hawaii Symposium on How Volcanoes Work, Hilo, HI, January 19-25, 1987, Abstract volume: Honolulu, University of Hawaii, Hawaii Institute of Geophysics, p. 46. 



 The Kalapana earthquake of November 29, 1975, was the strongest earthquake on Hawaii since at least 1868. We have re-analyzed much of the near and far field seismological data with the objective of better constraining the source mechanism. Teleseismic data only constrain one, almost vertical, nodal plane striking N 58E. Local network data and far-field surface wave data are integrated with the teleseismic data to examine the uncertainty of determining the dip angle and direction of faulting, i.e. normal or reverse.



Koyanagi, R.Y., 1964, Hawaiian seismic events during 1962: U.S. Geological Survey Professional Paper 475-D, p. D112-D117. 



 Six hundred ninety two earthquakes of magnitude 2.0 and greater were recorded in the Hawaiian Islands region during 1962. Most of these quakes were of magnitude less than 3 1/2, and only one was of magnitude greater than 6. The Kaoiki fault, the east rift of Kilauea, the Kalapana Trail region, and Kilauea caldera at 30 km depth were areas of concentrated earthquake activity.



Koyanagi, R.Y., Okamura, A.T., Kinoshita, W.T., Moore, J.G., and Powers, H.A., 1964, Hawaiian Volcano Observatory summary 31--July, August, and September 1963: U.S. Geological Survey Administrative Report, 40 p. 



 A summary of the volcanic conditions, seismicity, and tilt during the quarter.

 [U.S.-Japan cooperative study of Kilauea volcano, by J.G. Moore occupies p. 1]



Koyanagi, R.Y., Okamura, A.T., Krivoy, H.L., and Yamamoto, A., 1964, Hawaiian Volcano Observatory summary 29--January, February, and March 1963: U.S. Geological Survey Administrative Report, 36 p. 



 A summary of the volcanic conditions, seismicity, and tilt during the quarter.



Koyanagi, R.Y., 1965, The Kaoiki earthquake of June 27, 1962, and general descriptions of recent Hawaiian seismic activity [abs.], in, Investigations of Hawaiian volcanoes, 1963, 3rd general meeting, Hakone, Japan, Oct. 26-28, l963, Abstracts of papers: [s.l.], Japan-United States Cooperative Science Programme, p. 4. [Participating organizations: University of Tokyo Earthquake Research Institute and U.S. Geological Survey, Hawaiian Volcano Observatory] 



 Hawaiian seismic activity in 1962, 1963, and 1964 was characterized by frequent, small swarms of earthquakes and/or harmonic tremor, which on at least 3 occasions were accompanied by lava outbreaks (eruptions). In general, these swarms lasted from a few hours to as much as several weeks and consisted of low-magnitude earthquakes.

 During the last 3 years, about 114,000 earthquakes were recorded at the Hawaiian Volcano Observatory. Epicenter determinations were attempted for about 1,994 earthquake magnitude 2 or greater. Of these 840 occurred during 1962, 673 occurred during 1963, 481 occurred during 1964. The determinations showed that about 68% of the earthquakes occurred under the active volcanoes Mauna Loa and Kilauea. These earthquakes were relatively shallow, with hypocenters less than 5 kilometers to as much as 60 kilometers deep.

 Many of these earthquakes occurred in high concentrations in active structural region around Kilauea Volcano. The Kilauea caldera region, the Kilauea east rift zone, the Kaoiki fault system, and adjacent Kilauea southwest rift zone were areas marked by frequent earth quake occurrences. In these areas, earthquakes numbered several per day during periods, of relative quiescence, to hundreds per day during times of intense activity.

 The Kaoiki fault system was marked by intense earthquake activity during 1962 and 1963, and to a lesser extent in 1964. The 1962 episode was the first Kaoiki series of earthquakes involving considerable energy release to be recorded on the Hawaiian Volcano Observatory high-gain, short-period network of seismometers, which was installed in 1956. The dense network of seismometers near and around the epicentral zone permitted an excellent opportunity for instrumental analysis of aftershock activity, and the beginning of a systematic study of seismic events in the region.

 The 1962 Kaoiki episode consisted of an earthquake of magnitude 6.1 on June 27 with several thousand smaller earthquakes in the weeks which followed. The main shock was felt most strongly on Hawaii and consecutively weaker on Maui and Oahu. Maui and Oahu islands were located roughly 173 kilometers and 350 kilometers away from the epicenter, respectively. Only minor damage to property was reported from areas near the epicenter on Hawaii island.

 A study of the 1962 episode shows many interesting features in common with tectonic earthquakes. Among these are: (1) A time-frequency plot of aftershocks shows a roughly hyperbolic decay; the initial hours having several earthquakes per minute, and about 60 hours later having less than 10 earthquakes per hour. (2) A magnitude-frequency plot of aftershocks shows a pattern that seems to be consistent with world-wide earthquake distributions.

 Historic accounts of large, damaging earthquakes for the Hawaiian island region are few. Two past events were considerably larger in magnitude than the 1962 Kaoiki earthquake and resulted in greater damage in terms of human lives and property. These events were the Kau earthquake of April 2, 1868 with an intensity of 10 on the Rossi-Forel scale, and the Kona earthquake of August 21, 1951 with a magnitude of 6.75-7.0 on the Richter scale



Koyanagi, R.Y., Krivoy, H.L., and Okamura, A.T., 1966, The 1962 Kaoiki, Hawaii, earthquake and its aftershocks: Bulletin of the Seismological Society of America, v. 56, no. 6, p. 1317-1335. 



 At 18:27:14.3 on June 27, 1962 an earthquake of moderate intensity occurred near the Kaoiki fault system between the volcanoes Kilauea and Mauna Loa on the Island of Hawaii. It was felt strongly on Hawaii, where it caused minor property damage, and was perceptible as far as Oahu to the north-west.

 Intense aftershock activity continued for several weeks; 1540 aftershocks were recorded during the initial 60 hours. A hyperbolic decay in the number of aftershocks with increasing time was evident. The epicentral zone covered about 150 square km and focal depths ranged from 3 to 12 km.



Koyanagi, R.Y., 1968, Hawaiian seismic events during 1965: U.S. Geological Survey Professional Paper 600-B, p. B95-B98. 



 During 1965, 565 earthquakes having magnitudes of 2.0 to 4.6, were located in the Hawaiian Islands. There are exclusive of some 300 associated with the December 24-25 eruption of Kilauea Volcano. In all, nearly 30,000 earthquakes were recorded during 1965. The active volcanoes Mauna Loa and Kilauea on the island of Hawaii were zones of highest seismic concentration. In addition to 69 shocks reported as felt by local residents during 1965, many more were felt during the December swarm but were not properly documented.



Koyanagi, R.Y., Swanson, D.A., and Endo, E.T., 1972, Distribution of earthquakes related to mobility of the south flank of Kilauea Volcano, Hawaii: U.S. Geological Survey Professional Paper 800-D, p. D98-D97. 



 Many earthquakes at Kilauea are related to magmatic (extrusive or intrusive) events within the caldera or along the rift zones. During the early stage of a rift event, earthquakes are often concentrated near the site of extrusion or intrusion. During and after the later stage of the event, earthquakes spread southeastward across the south flank away from the site of initial seismicity. The seismic data are consistent with geodetic measurements and suggest that the south flank of Kilauea is mobile and that the north flank is relatively stable.



Koyanagi, R.Y., Unger, J.D., and Endo, E.T., 1973, Seismic evidence for magma intrusion in the eastern Koae fault system, Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 54, no. 11, p. 1216. [AGU fall meeting, San Francisco, CA, Dec. 10-13, 1973, Program and abstracts] 



 On May 5, 1973, a swarm of earthquakes occurred on the southeast flank of Kilauea near Mauna Ulu, the sight of an ongoing eruption. Part of the swarm was accompanied by low volume fissure eruptions from 4 vent areas on Kilauea's Upper East Rift Zone; the eruption lasted about 7 hours. The most intense part of the swarm began about 3 hours before the eruption broke out and lasted about 20 hours total. During this interval nearly 2000 earthquakes were recorded; the largest one was about 3.6 in magnitude. The epicenters of the swarm moved to the location of the final phase of the eruption about 5-6 hours before lava actually reached the surface there. The epicenters of the quakes in the swarm continued to migrate westwards in discrete episodes, a total of about 7 km from where they were first located. These data along with precisely measured horizontal and vertical ground displacements suggest that the seismic swarm was caused by an episode of magma intrusion as dikes that migrated westward into the Koae Fault System, a region of tension cracks and normal faults. This is consistent with an earlier proposed idea that the Koae grows as a tear-away zone in response to repeated dike intrusion, and is the first well documented case of migration of Koae seismicity and faulting away from a center of eruption and ground cracking.



Koyanagi, R.Y., Unger, J.D., Endo, E.T., and Okamura, A.T., 1974, Shallow earthquakes associated with inflation eposides at the summit of Kilauea Volcano, Hawaii, in Gonzales-Ferran, O., ed(s)., Symposium on Andean and Antarctic Volcanology Problems, Santiago, Chile, Sept. 9-14, 1974, Proceedings: International Association of Volcanology and Chemistry of the Earth's Interior, Special Series, p. 621-631. 



 The locations and temporal distribution of earthquakes at Kilauea Volcano between May 1 and an eruption on August 14, 1971, provide insight into the complex of dikes and magma conduits under the summit area. These and other recent seismic data interpreted in light of detailed deformation studies and electromagnetic surveys appear to outline a region of magma storage approximately 3 to 6 km beneath the summit and two zones of shallow intrusions south and southeast of the summit caldera. Earthquakes at depths from 7 to 12 km outline a conduit for magma to move from depth to the shallow reservoir.



Koyanagi, R.Y., Okamura, A.T., and Stevenson, P., 1977?, Hawaiian Volcano Observatory summary 70--April, May, and June 1973 (Chronological summary by R.I. Tilling): U.S. Geological Survey Administrative Report, 61 p. 



 A summary of the volcanic conditions, seismicity, and tilt during the quarter.



Koyanagi, R.Y., Meagher, K., Klein, F., and Okamura, A.T., 1978, Hawaiian Volcano Observatory summary 75--January-December 1975 (Chronological summary by D.W. Peterson): U.S. Geological Survey Administrative Report, 117 p. 



 A summary of the volcanic conditions, seismicity, and tilt during the year.



Koyanagi, R.Y., Klein, F.W., and Nakata, J.S., 1979, Seismicity of Hawaii, 1960-77 [abs.], in Decker, R.W., Drake, C., Eaton, G., and Helsley, C., ed(s)., Hawaii Symposium on Intraplate Volcanism and Submarine Volcanism, Hilo, HI, July 16-22, 1979, Abstract volume: Hawaii National Park, HI, U.S. Geological Survey, Hawaiian Volcano Observatory, p. 168. 



 During the past 18 years, about 45,600 earthquakes recorded by seismographs operated by the Hawaiian Volcano Observatory were processed for hypocenter and magnitude determination. Of these, nearly 3,370 events were of magnitude 3.0 to 7.2; magnitude 3.0 is generally the threshold of felt earthquakes in Hawaii. The largest earthquakes recorded were: (1) the M = 6.1 Kaoiki earthquake of June 27, 1962 (2) the M = 6.2 Honomu earthquake of April 26, 1973; and (3) the M = 7.2 Kalapana earthquake of November 29, 1975. The observation that earthquake epicenters are most highly concentrated in southeastern Hawaii and encompass the active volcanoes Kilauea and Mauna Loa supports the concept that earthquakes in Hawaii are the byproducts of volcanism. Consequently, residents of southeastern Hawaii have learned to accept felt earthquakes as common occurrences and often associate them with volcanic activity.

 Expansion of the seismic network of the Hawaiian Volcano Observatory and instrumental improvements that have led to higher quality earthquake data have been gradual. Mechanical seismographs introduced in 1912 were replaced by more sensitive electromagnetic instruments by about 1955. Eventually, crystal chronometers replaced older, standard pendulum clocks, and the cable telemetry network initiated in the summit area of Kilauea was expanded to include more distant stations by radio telemetry. In 1967, our standard drum recorders were supplemented with a 20-channel (18 stations) Develocorder. Currently, two Develocorders that accommodate 36 stations are being operated continuously. For higher resolution and detailed examination of selected events, a l-inch magnetic tape recorder is in continuous operation, recording seismic traces from the entire island-wide network of 40 telemetered stations. For versatility in data processing, a minicomputer was installed and put into operation in November 1978.



Koyanagi, R.Y., Nakata, J.S., and Tanigawa, W.R., 1981, Seismicity of the lower east rift zone of Kilauea Volcano, Hawaii 1960-1980: U.S. Geological Survey Open-File Report 81-984, 15 p. 



 1. Introduction

In mid-February 1970, seismometer PAX at Kaniahiku Village in the lower east rift of Kilauea (fig. 1) detected an increasing number of microearthquakes. To confirm and define the source area of the activity, we installed an additional station at Puu Honuaula (PHO) and operated a portable seismograph at various localities nearby. Signature characteristics and the relative number of small events recorded from the various stations indicated a concentration of activity near the 1955 eruptive vents between Puu Honuaula and Puulena. Epicenter determinations made from P-arrival times picked on the temporary and permanent stations of the HVO net indicated an epicentral area that extended south to Pohoiki and southwest to Kaimu at depths of mostly less than 10 km, although some of the scatter of hypocenters may be due to errors in locating earthquakes near the edge of the seismic net. The frequency of microearthquakes detected in February and March fluctuated from about 20 per day to about a thousand per day with peak activity on February 21 and March 2. During two months of activity, nearly 6,600 events of -1.0 to 3.9 magnitude (M) were detected. Nearby residents felt many of the apparently shallow earthquakes of M>1.5.

 Such swarms of microearthquakes have occurred intermittently and, in general, more after eruptions in the eastern and central parts of the east rift in 1960 and 1961. Since the east rift eruption in 1961, lower east rift activity became less frequent and microearthquake swarms did not correlate with specific volcanic events, although those in the upper east rift zone typically continued to do so. Nevertheless, there is repeated documentation showing evidence that the seismic activity at Kilauea is due to changes in stress conditions ultimately caused by volcanism. This report is intended to summarize seismic and other geophysical studies of the lower east rift zone near the exploratory geothermal well HGP-A, and to describe the pattern of seismicity there primarily from instrumental data collected over the past two decades.



Koyanagi, R.Y., 1982, Kilauea Volcano, in Annual report of the world volcanic eruptions in 1980: Bulletin of Volcanic Eruptions, no. 20, Dec., p. 80-81. 



 There was no significant volcanic eruption observed in Hawaii during 1980, but five subsurface magmatic events were instrumentally detected and monitored at Kilauea. Earthquake swarms, volcanic tremor, and rapid deflation of the summit area that characterized the events indicated these to be shallow emplacement of magma from the summit to the upper east rift zone of Kilauea. Gas emissions of CO2 and SO2, and electromagnetic anomalies were detected over the inferred zone of intrusion for some of the events. The following tabulation summarizes approximately the instrumental measures of the five inferred intrusions during 1980:

 

Date	 Location	 Earthquakes	 Magma Volume Gases Electro-Magnetic

	 	 n (M>0.1) n(felt)	max mag	 depth (km)

Mar. 2	 Hiiaka	 1500	 6	 3.3	 <4	 0.6 X 106m3 	 no 	 no

Mar.10-12	 Mauna Ulu	 3000	 20	 4.2	 <5	 5.3 X 106m3	 yes	 no

Aug.27-28	 Puhimau	 2500	 12	 3.9	 <4	 2.3 X 106m3	 yes	 yes

Oct.22	 Mauna Ulu	 2000	 10	 2.4	 <4	 0.6 X 106m3	 yes	 yes

Nov. 2	 Kokoolau	 1500	 15	 3.5	 <5	 2.0 X 106m3	 no	 no



Koyanagi, R.Y., Endo, E.T., Tanigawa, W.R., Nakata, J.S., Tomori, A.H., and Tamura, P.N., 1984, Kaoiki, Hawaii earthquake of November 16, 1983: a preliminary compilation of seismographic data at the Hawaiian Volcano Observatory: U.S. Geological Survey Open-File Report 84-798, 35 p. 



 Introduction

Kaoiki earthquake of November 16, 1983

Aftershocks

Historic earthquakes in the Kaoiki region

Precursors

First motion data

Comparison of large earthquakes in Hawaii

Appendix: Procedure for preliminary determination of earthquake coda decay rate

Acknowledgement

References



Koyanagi, R., Decker, R., and Neal, C., 1986, Kilauea, in Annual report of the world volcanic eruptions in 1983: Bulletin of Volcanic Eruptions, no. 23, Mar., p. 42-44. [Also published in Bulletin of Volcanology, v. 48 supp., no. 23, p. 42-44] 



 [An account of volcanic activity at Kilauea during the year.]



Koyanagi, R.Y., 1987, Hawaii earthquakes, 1983, in Stover, C.W., ed(s)., United States earthquakes: U.S. Geological Survey Bulletin 1698, p. 132-133. 



 "A summary of the year's seismicity."



Koyanagi, R.Y., Nakata, J.S., and Tomori, A.H., 1988, Seismic activity associated with eruptions at Kilauea Volcano, Hawaii, in, Kagoshima International Conference on Volcanoes, Kagoshima, Japan, July 19-23, 1988, Proceedings: Kagoshima, Japan, Kagoshima Prefectural Government, p. 195-198. 



 The temporal and epicentral distribution of seismic events, distinguished according to depth and signal characteristics, describes the internal state of stress and readiness for eruption at Kilauea Volcano. Small and shallow earthquakes (mostly smaller than 2.0 in magnitude and less than 5 km deep) indicate accumulation of magma in the summit storage complex during the preeruption period of inflation. Overpressurization of this magma reservoir results in a swarm of shallow earthquakes that track the rapid intrusion of magma into eruptive fissures at the summit caldera or along one the rift zones, generally hours before the eruption. Ultimately, the transition in seismic signature from erratic amplitude changes during the earthquake swarm to constant amplitude dominated by locally strong harmonic tremor marks the start of eruption. Harmonic tremor recorded on stations near the eruption site accompanies the vigorous movement of magma and fountaining of lava. The consequential rapid withdrawal of magma from beneath Kilauea's summit is seismically traced on nearby seismometers by harmonic tremor that evolves into long-period earthquakes.

 The sustained east rift eruption that started in 1983 developed into a sequence of episodes of high lava output alternating with longer intervals of low lava activity that was characterized by a distinct seismic pattern. Gradual increase in the number of shallow earthquakes and inflation at the summit preceded the principal outbreaks, strong tremor at the eruptive vent coincided with times of high lava fountaining, weak tremor and long-period events responded to the rapid deflation at the summit, variations in low-amplitude tremor monitored the decrease in lava movement between eruptive episodes, and microshocks recorded explosive degassing at the vent and thermal compensations on the newly formed lava flows during post eruption periods. Increase of deep tremor during the prolonged eruption inferred renewed production and more rapid ascent of magma from the mantle.

 The tectonic adjustments to internal growth of the volcano through rift intrusion are outlined by intermediate-depth flank earthquakes. These events vary widely in magnitude, time, and space, reflecting the long-term stresses introduced by intrusions into the rift zone.



Koyanagi, R.Y., Tanigawa, W.R., and Nakata, J.S., 1988, Seismicity associated with the eruption, in Wolfe, E.W., ed(s)., The Puu Oo eruption of Kilauea Volcano, Hawaii: Episodes 1 through 20, January 3, 1983, through June 8, 1984: U.S. Geological Survey Professional Paper 1463, chap. 7, p. 183-235; 5 pls. (folded maps, scale 1:50,000) in pocket. 



 Outline

Abstract	 183

 Downrift migration of the shallow earthquake swarms that occurred episodically for many months before the east-rift eruption of January 1983 reflected the process of magma movement from the summit to the east-rift storage complex as a preliminary stage to the eruption. Migration of earthquakes at a rate of 0.6 to 0.7 km/h during the final intrusion before the eruption provided a seismic measure for the rate of downrift propagation of magmatic pressure. The spatial distribution of summit, rift-zone, and south-flank earthquakes delineated the magma transport system. This progression of earthquakes in time, as well as the distribution of earthquakes in space, supports and quantifies earlier concepts of (1) the pattern of magma movement and (2) the structure of the magma transport system that feeds eruptions at Kilauea. Initially, magma rising from the mantle builds pressure in a small storage complex within a few kilometers beneath the summit. Dictated by the strength of the retaining caprock and by stress conditions in the east rift zone, the overload of fluid pressure beneath the summit may be tapped along the reservoir and its vertical conduit within a 10-km-deep structural feature, and directed laterally beneath the east rift in a conduit complex no more than a few kilometers wide. Magma transferred in this rift conduit, in turn, rises nearly vertically through a relatively confined system of fissures to feed the eruptive vents. After the preeruption intrusion or dike emplacement and the early stages of eruption, earthquakes dissipate, and tremor becomes localized. Magma movement is aseismic along certain parts of the vertical conduit beneath the summit storage system and, eventually, along an extensive length of the lateral transport system linking the summit and the middle-east-rift eruption zone. This decrease and localization of the seismicity, reflecting the increasing efficiency of the magma movement, becomes increasingly apparent during later eruptive episodes. The prolonged eruption is characterized by episodic transfer of magma batches from the summit to the east rift, presumably controlled by fluctuations of pressure above and below critical levels in the expanded summit-rift system.

 Continuation of the episodic eruption is indicated by the persistence of tremor localized near the eruptive vents. The tremor signal is intense during active lava output and decreases to a low level during repose times, when amplitudes vary mainly according to minor movement of lava and degassing activity from within the vent. The amplitude of harmonic tremor provides a measure of the vigor of the eruption and the rate of magma movement. Attenuation of tremor as a function of distance identifies the eruptive vent in the east rift as the principal source of radiation, and the summit as a secondary source. The east-rift source of tremor is many times more energetic than the summit source at the height of eruptive episodes. The amplitude of east-rift tremor during vigorous eruption is also influenced by noise generated from high fountaining.

 Introduction	 183

Limitations of the data	 185

Seismic network and data processing	 186

Data, 1982-84	 189

 Location and migration pattern of earthquakes	 189

 Depth and magnitude of earthquakes	 191

 Rate and frequency of earthquakes	 193

 Strong tremor in the east rift zone during eruptive

 episodes	 197

 Seismic events in the east rift zone between episodes	 215

 Seismic events at the summit	 215

Chronology of events, 1978-83	 218

Summary and discussion	 220

References cited	 234



Koyanagi, R.Y., Bryan, C.J., Johnson, C.E., Nakata, J.S., and Tanigawa, W.R., 1989, Preliminary evaluation of the 6.1-magnitude Hawaii earthquake of June 25, 1989 and aftershocks [abs.]: Eos, Transactions, American Geophysical Union supp., v. 70, no. 43, p. 1409. [AGU fall meeting, San Francisco, CA, Dec. 4-8, 1989, Program and abstracts] 



 A strong earthquake struck the southeast coast of the island of Hawaii on June 25, 1989. The instrumental seismic data at the Hawaiian Volcano Observatory indicated an origin time of 17:27:04 (H.S.T.), at epicentral coordinates of 19.36 N latitude and 155.08 W longitude, depth of 9 km, and preliminary magnitude of 6.1. First motions suggest that the initial rupture from the mainshock was a seaward movement of the south flank of Kilauea Volcano along a subhorizontal plane near the bottom of the volcanic pile that overlies the pre-volcanic oceanic floor; the sense of the motion is comparable to a stronger 7.2-magnitude earthquake that struck the same region about on November 29, 1975. The mainshock was reportedly felt on the islands of Hawaii, Maui, and Oahu. Except for a temporary decrease in volcanic tremor, the earthquake did not significantly affect the continuity of the long-lived east-rift eruption of Kilauea.

 Damage to structures was reported from the Puna area, with at least five homes essentially destroyed in Royal Gardens, Kalapana, and Kaimu. Ground cracks occurred in Kalapana, and rockfalls were reported in Puna and the Hamakua Coast. Other structural damage to residential property reported in the County of Hawaii included ten houses with major damage and one hundred houses with minor damage. Many of the houses suffered cracked walls, ceilings, and concrete pads, and slight shifting. A small local tsunami was generated with maximum peak-to-trough height of 57 cm at Honuapo, 21 cm at Kapoho, and 14 cm at Hilo. No damage was reported from the minor wave action. The total damage was estimated at one million dollars.

 Preliminary assessment of a partial list of aftershocks during the first two weeks of activity indicates two principal concentrations of hypocenters along Kilauea's south flank, mainly eastward from the mainshock. One trend, nearly 45 km in extent, parallels the east rift zone. Another concentration extends normal to the east rift and forms a SE elongation about 15 km long extending from near Kalapana, passing through the area of localized ground cracking, to about 8 km offshore. Focal depths indicate rupture from near surface to slightly more than 10 km.

 The mainshock region is where most of the strong south flank earthquakes of M>5.5 commonly occur, and generate aftershock activity which migrates to the west and to the east. Such significant earthquakes with instrumental data have occurred in this area in March 1954, November 1975, and September 1979. The zone trending oblique to the trend of the east rift zone for part of the aftershock sequence suggests a tear-away zone that accommodates incremental seaward displacement of the south flank.



Koyanagi, R., and Nakata, J., 1989, Loihi seamount, in Annual report of the world volcanic eruptions in 1986: Bulletin of Volcanology, v. 51 supp., no. 26, p. 87. 



 Loihi Seamount was not in eruption during 1986. A short but notable swarm of earthquakes on September 20 highlighted the year's activity.

 Regional seismicity of Hawaii consisted of several thousands of earthquakes of magnitude 1.5 to 5.0 in 1986. Most of the earthquakes were located at 5 to 10 km beneath the south flank of Kilauea and southeast flank of Mauna Loa. These earthquakes were generally dispersed throughout the year and were attributed to strain-release induced tectonically by the gradual accumulation of stresses along the flanks of the active volcanoes, in contrast to swarms of shallower earthquakes that occur in eruptive zones immediately before eruptions. See also descriptions for Mauna Loa and Kilauea. (Communication from: R. Koyanagi and J. Nakata, Hawaii Volcano Observatory, U.S. Geol. Survey, Hawaii National Park, Hawaii 96718, U.S.A.).



Koyanagi, R.Y., and Nakata, J.S., 1990, Seismicity related to eruption at Kilauea Volcano, Hawaii, 1983-1989 [abs.]: Eos, Transactions, American Geophysical Union, v. 71, no. 28, p. 955. [Western Pacific Geophysics Meeting, Kanazawa, Japan, Aug. 21-25, 1990, Program and abstracts] 



 Earthquakes and volcanic tremor relate to the evolving pattern the Kilauea flank eruption that started in 1983. Swarms of small (M<3) and shallow (<5 km) earthquakes initially outlined the region of summit inflation and downrift intrusion, allowing a forecast of the eruption in the east rift zone. Long-period earthquakes and tremor have dominated both summit and east rift zone seismicity during the succeeding years of persistent eruption. The background of shallow tremor in the rift zone indicates the continuously active state of the eruptive vents. The episodic changes in tremor amplitude and number of earthquakes are correlated with the temporal pattern of lava movement and degassing at the eruptive vents, and also reflect changes in the delicate pressure balance maintained in the internal magma transport system. The increased rate of long-period earthquakes and tremor, distributed in clusters from a few kilometers beneath the summit of the volcano down to mantle depths of nearly sixty kilometers, trace the magma supply to the eruption. Shallow seismicity below the summit, related to inflation and deflation is correlated with changes in ground-tilt. Erratic, short-period signals and tremor were also detected from submarine activity at a seismometer located near where tube-fed lava from the eruptive vent has been overflowing into the sea.

 A high rate of strain-release within the south flank of the volcano has been maintained during the years of eruption. South flank earthquakes are located adjacent to the active part of the east-rift zone through which magma continues to be supplied to the eruption from the summit region. Earthquakes in this region are attributed to the tectonic response to lateral stresses caused by magma intrusion in the east rift zone which force the unstable south flank of the volcano seaward. These earthquakes have magnitudes ranging from less than 2 to greater than 7. The largest event in recent time (November 1975, M=7.2) caused widespread damage, generated a tsunami, and profoundly affected the eruptive pattern of the volcano.



Krivoy, H.L., 1964, Direction of first motion of four earthquakes from a single focus, in Okamura, A.T., Yamamoto, A., and Kojima, G., ed(s)., Hawaii Volcano Obsevatory summary 27: seismic and tilt data, July-September 1962: U.S. Geological Survey Administrative Report, p. 1-3. 



 "First-motlons plotted on the statlon location map do not fall into the quadrant pattern typical of strike-sllp faults; the region of compresslon can be separated from that of rarefaction by a single line through the epicenter with an azimuth between about N 35W and N 80 W. The uncertainty could be materially reduced by additional stations at such sites as Puu Waawaa, Makaopuhi or Kalapana. Apparently the fault movement was predominantly dip-slip in all four quakes, the southwest side being downthrown during the first three and upthrown during the fourth.

 Because of its small size, this group of four similar quakes has proven convenient as an illustration of the needs and possibilities in analysis of first-motion data provided by the Volcano Observatory seismic net. In 6 years of modern recording we have observed about six distinctive earthquake families. Some of these appear to be endemic and are still being recorded; others, once prolific, seem now to have ceased. Some of these families consist of swarms of thousands of quakes; some come by the hundreds. We hope to be able to review and to analyze each such group in an effort to learn more about the dynamics of Hawaiian volcanism."



Lander, J.F., and Cloud, W.K., 1964, Hawaiian Islands, in United States earthquakes, 1962: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, p. 49-52. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Leeds, D.J., ed., 1976, The island of Hawaii earthquake on November 29, 1975: Earthquake Engineering Research Institute Newsletter, v. 10, no. 1B, 59 p. 



 "In the early morning hours of November 29, 1975 a series of strongly felt earthquakes occurred beneath the island of Hawaii (population 64,000), largest of the Hawaiian Islands Initial analysis and interpretation of both local seismograph and teleseismic data (WO J. Person, National Earthquake Information Service, oral commun., 12/17/75) indicate that two large earthquakes, a magnitude 5.7 event at 0335 local time (lat 19 21.15'N long 155 03.53'W) and a magnitude 7.2 event at 0447 local time (lat 19 20.06'N, long 155 01.45'W), occurred 5 km beneath the sparsely populated southeastern coastline approximately 45 km south of Hilo."



Li, Y., and Thurber, C.H., 1988, The 1983 Kaoiki, Hawaii, earthquake sequence and the tectonics of the Kaoiki fault zone [abs.]: Eos, Transactions, American Geophysical Union, v. 69, no. 44, p. 1320. [AGU fall meeting, San Francisco, CA, Dec. 6-11, 1988, Program and abstracts] 



 The 1983 Kaoiki earthquake sequence occurred in a seismically active zone between the volcanoes Mauna Loa and Kilauea. Although both the local and teleseismic focal mechanisms for the 1983 Kaoiki main shock (Ms = 6.7) are predominantly vertical strike-slip, there is a wide variety of evidence indicating significant slip also took place on a subhorizontal fault segment. This evidence includes: I) a majority of the Kaoiki aftershocks have low-angle fault planes and seem to delineate the sub-horizontal fault surface; 2) the aftershock activity surrounds two aseismic zones near the main shock hypocenter, one near-vertical and one subhorizontal; 3) published moment tensor solutions for the main shock have a significant component of dip-slip. We will present the detailed evidence from the aftershocks along with a preliminary teleseismic body-wave analysis of the main shock.

 Endo [1985] has suggested that the southeast flank of Mauna Loa is seawardly mobile over a detachment surface at the weak sediment layer along the volcanic pile-ocean crust interface. This is similar to the situation generally hypothesized for the south flank of Kilauea, site of the 1975 Kalapana earthquake (Ms = 7.2). Further, Wyss [1988] has proposed that the great Kau earthquake of 1868 took place on the detachment beneath Mauna Loa's southeast flank. We will describe a proposed PASSCAL experiment designed to investigate the existence and properties of the presumed sediment layer beneath the Kaoiki fault zone and determine the spatial relationship between it and the seismic activity. The experiment combines analyses of reflected waves from local earthquakes and shots with converted waves from teleseismic events in order to produce a clear picture of the structure at the interface between the volcanic pile of Mauna Loa and the underlying ocean crust. We will then be able to determine whether the low-angle-faulting earthquakes are occurring at that interface.



Li, Y., and Thurber, C.H., 1988, Source properties of two microearthquakes at Kilauea Volcano, Hawaii: Bulletin of the Seismological Society of America, v. 78, no. 3, p. 1123-1132. 



 The source-time functions of two microearthquakes with magnitudes 2.1 and 2.3 at Kilauea Volcano, Hawaii, are determined by using the deconvolution technique. P-wave seismograms of a smaller event with magnitude 1.6 in a nearby location are treated as empirical Green's functions and deconvolved from the waveforms of the larger earthquakes by spectral division. From the time domain analysis of the source-time functions, some of the source properties, such as the complexity and directivity, and some of the source parameters, such as pulse width, rise time, and source dimension, are determined. With a good azimuthal distribution of stations, the direction and magnitude of rupture velocity are estimated for one of the events. The rupture direction is about N85W and rupture velocity is 0.75 Vs, assuming Vp = 1.73 Vs. The result for direction agrees with one of the nodal planes of the focal mechanism. Our results indicate that there exist obvious variations in rupture durations for nearby small events with similar seismic moments, suggesting significant differences in the static stress drops. The stress drops of two events (1.5 and 16.5 bar) estimated from the rise times differ by an order of magnitude, implying heterogeneity of the stress distribution over this small area.



Liang, B., and Wyss, M., 1991, Estimates of orientations of stress and strain tensors based on fault-plane solutions in the epicentral area of the great Hawaiian earthquake of 1868: Bulletin of the Seismological Society of America, v. 81, no. 6, p. 2320-2334. 



 The 95 best-quality fault-plane solutions for earthquakes in a 30 by 10 km area near the epicenter of the 1868 Hawaiian earthquake (M about 7.9) were used for estimating the orientation of the stress and strain tensors. Most of the earthquakes had magnitudes of ML = 3 5  0.6 with nine events in the range 4.2  ML,  5.5. Although this area, Hilea, is capable of great earthquakes, it seldom produces events in the range 5.5  ML  6.5. We found that the directions of the slip and the principal strains are much more uniform in Hilea than in the neighboring regions of Kaoiki and south Kona, not varying more than 15. The directions of the stress tensor are poorly constrained because of the uniformity of fault-plane solutions. Therefore one cannot be certain that the stress tensor is uniform in this area, but we assume that it is, because the strain and slip directions are. The stress and strain tensor directions differ significantly from those in the Kaoiki and south Kona areas. The slip directions as well as the plane defined by e1 and e3 are oriented approximately perpendicular to the upper part of Mauna Loa's southwest rift, suggesting that magma intrusions there (at a distance of 20 km) probably provide the stress for the seismic activity in the Hilea area.

 We propose that a tectonic boundary exists near latitude 19 19' separating the Kaoiki and Hilea areas. The stress and strain tensor orientations are significantly different north and south of this boundary, and virtually no strike-slip earthquakes occur in the Hilea area, whereas they are the majority of solutions in the Kaoiki area.

 The fault-plane solutions in Hilea have a near-horizontal and a near-vertical nodal plane. In other areas of Hawaii, the evidence suggests that the near-horizontal plane is a zone of weakness provided by buried oceanic sediment, which allows slip of the upper crust away from the volcanic centers toward the coasts. Here, however, the stress inversion does not lead to a clear choice of preferred fault plane. Thus, it may be that both nodal planes do act as fault planes in this area and that the rupture process in large earthquakes of the 1868 type may be complex involving decollement, steeply dipping normal faulting, and even strike-slip faulting.



Lipman, P.W., Okamura, R.T., and Yamashita, K.M., 1978, Changed deformation mode of Kilauea Volcano since the 1975 M=7.2 earthquake [abs.]: Geological Society of America Abstracts with Programs, v. 10, no. 3, p. 113. [Geological Society of America, Cordilleran Section, 74th annual meeting, Tempe, AZ, Mar. 29-31, 1978] 



 Since the 1975 M=7.2 earthquake on the south flank of Kilauea, deformation patterns on the volcano have changed notably. Previously, rates of horizontal and vertical deformation at the summit were very high (several mm/day) in the 20th century, mainly reflecting inflation-deflation cycles related to eruptive activity as magma accumulated in or was withdrawn from a 2-3 km deep magma reservoir centered near the summit. The 1975 earthquake, on the seaward flank of Kilauea, involved major slumping of the entire south flank--a deformation pattern that geologic features suggest has occurred periodically in the past. Maximum vertical and horizontal changes (3.5 and 7-9 m, respectively) occurred along the coast, but the entire volcano underwent major changes. Since the earthquake, deformation patterns have been complex. The volcano has been unable to maintain sustained inflation cycles similar to those of the recent past, and the dominant deformation pattern has continued to be sizable southward displacement of the flank, presumably continued adjustment to effects of the 1975 earthquake. In September 1977, Kilauea erupted along its middle east rift zone after the longest period of inactivity in 10 years. No summit inflation preceded this eruption, which nevertheless may indicate the beginning of stabilization and return of the volcano to a more typical deformation pattern.



Lipman, P.W., Lockwood, J.P., Okamura, R.T., Swanson, D.A., and Yamashita, K.M., 1981, Ground deformation associated with the M=7.2 Kalapana earthquake of November 29, 1975, at Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 62, no. 45, p. 1071. [AGU fall meeting, San Francisco, CA, Dec. 7-11, 1981, Program and abstracts] 



 The magnitude 7.2 earthquake of November 29, 1975, the largest in Hawaii since 1868, was associated with large scale deformation of the entire south flank of Kilauea volcano. Surface breakage occurred along a 25 km-long sector of the Hilina fault system, with vertical displacements of as much as 1.5 m along individual faults. Reoccupation of the extensive horizontal and vertical geodetic networks on Kilauea revealed that the entire volcanic edifice and adjacent lower slopes of Mauna Loa were displaced downward and seaward. Maximum horizontal and vertical displacements, about 3 and 3.5 m respectively, occurred along the coastline south of Kilauea's summit area, about 30 km southwest of the earthquake epicenter. Surface displacements associated with the 1975 earthquake strongly support a gravitational slump interpretation, both for the deformation associated with this earthquake and also for the long-term tectonic evolution of Kilauea's south flank. Analysis of the tsunami generated during the 1975 earthquake indicates that a large part of the submarine south flank of Kilauea was uplifted, probably representing deformation at the toe of the slump terrain complementary to the subsidence on land. Focal mechanism determinations by others for the earthquake and aftershocks indicate seaward displacements along gently dipping fault planes at depths of 6-1O km, near the base of the volcanic edifice where it is inferred to rest on old sea floor. The basic cause of slumping was accumulation of contractional strain along the upper part of the south flank, as a result of magma intrusion as dikes along Kilauea's rift zones. In addition, inflation of Mauna Loa volcano may have contributed to destabilizing Kilauea and triggering the earthquake.



Lipman, P.W., Lockwood, J.P., Okamura, R.T., Swanson, D.A., and Yamashita, K.M., 1985, Ground deformation associated with the 1975 magnitude-7.2 earthquake and resulting changes in activity of Kilauea Volcano, Hawaii: U.S. Geological Survey Professional Paper 1276, 45 p. 



 CONTENTS

Abstract 	1

Introduction 	1

Acknowledgments 	3

Relations between structural features and eruptive activity 	3

The 1975 earthquake 	4

Ground breakage	4

 Faulting in the Hilina system 	4

 Landslides and ground cracks 	6

Vertical displacements	7

 Coastal measurements 	8

 Precise leveling 	8 

Horizontal displacements 	16

Summit deformation 1974-77 	27

Discussion	34

 Scale of movements 	34

 Gravitational slump hypothesis 	34

 Relation between the earthquake and surface deformation	35

 Effect on summit magma system	41

 Implications for the future	41

References cited	44



A magnitude-7.2 earthquake on November 29, 1975, the largest in Hawaii in over a century, was associated with large-scale deformation of the entire south flank of Kilauea Volcano. Surface ground breakage occurred along a 25-km-long sector of the Hilina fault system, with vertical displacements of as much as 1.5 m along individual preexisting fault scarps. Reoccupation of extensive horizontal and vertical geodetic networks on Kilauea demonstrated that the entire volcanic edifice and adjacent lower slopes of Mauna Loa were displaced downward and seaward. Maximum horizontal and vertical displacements, about 8 and 3.5 m respectively, occurred along the coastline south of Kilauea's summit area, about 30 km southwest of the earthquake hypocenter.

 Large ratios of horizontal to vertical displacements, associated with the 1975 earthquake, strongly support a gravitational slump interpretation, both for the deformation associated with this earthquake and also for the long-term tectonic evolution of the south flank of Kilauea. In addition to the major displacements along the Hilina system of normal faults, more inland ground deformation appears to reflect secondary adjustments to displacements along the Hilina system and to changes in the Kilauea summit area and along the rift zones related to movement of magma. Analysis of the tsunami associated with the 1975 earthquake indicates that a large part of the submarine south flank of Kilauea was uplifted by deformation at the toe of the slump terrain complementary to the subsidence on land. Focal-mechanism determinations for the earthquake and aftershocks indicate seaward displacements along gently dipping fault planes at depths of 6-10 km, near the base of the volcanic edifice where it is inferred to rest on old sea floor. Aftershocks were concentrated largely along the upper part of the south flank of Kilauea, between the rift zones and the Hilina fault system, indicating that faults of the Hilina system mark a major structural boundary on Kilauea, rather than just constituting surficial slump features.

 These relations favor an interpretation of the 1975 earthquake as due primarily to gravitational slumping along faults of the Hilina system that penetrate most of the thickness of the south flank of Kilauea Volcano and that flatten at depths of 6-8 km to accommodate seaward displacements. The basic cause of slumping was accumulation of contractional strain throughout the 20th century along the upper part of the south flank, as a result of intrusion of magma as dikes along Kilauea's rift zones. In addition, inflation of Mauna Loa Volcano to the north, culminating in its July 1975 summit eruption, may have contributed to destabilizing Kilauea and triggering the earthquake.

 Since the 1975 earthquake, deformation patterns on Kilauea Volcano have changed notably. Previously, rates of horizontal and vertical deformation at the summit were very high (several mm/day) in the 20th century, mainly reflecting inflation-deflation cycles related to eruptive activity as magma accumulated in or was withdrawn from a 2-3 km deep magma reservoir centered near the summit. Since the earthquake, deformation patterns have been complex. The volcano has failed to maintain sustained inflation cycles similar to those of the recent past, and the dominant deformation pattern has been seaward displacement of the south flank, presumably reflecting ongoing adjustments to effects of the 1975 earthquake. In September 1977, Kilauea erupted along its middle east rift zone after the longest period of inactivity in 10 years. No summit inflation preceded this eruption, which, nevertheless, may indicate the beginning of stabilization and return of the volcano to a more typical deformation pattern.



Lipman, P.W., Lockwood, J.P., Okamura, R.T., Swanson, D.A., and Yamashita, K.M., 1985, Ground deformation associated with the M=7.2 earthquake at Kilauea Volcano in 1975 [abs.]: Eos, Transactions, American Geophysical Union, v. 66, no. 46, p. 851. [AGU fall meeting, San Francisco, CA, Dec. 8-13, 1985, Program and abstracts] 



 The magnitude-7.2 earthquake of 11/29/75, the largest in Hawaii since 1868, was associated with large-scale deformation of the entire south flank of Kilauea. Surface breakage occurred along a 25-km sector of the Hilina fault system, with vertical displacements of as much as 1.5 m on single faults. Reoccupation of extensive horizontal and vertical geodetic networks on Kilauea demonstrated that the entire volcanic edifice and adjacent lower slopes on Mauna Loa were displaced downward and seaward. Maximum horizontal and vertical displacements, about 8 and 3.5 m respectively, occurred along the coastline south of Kilauea's summit, about 30 km SW of the earthquake hypocenter. Surface displacements associated with the 1975 quake strongly support a gravitational slump interpretation, both for deformation associated with this earthquake and also for the long-term tectonic evolution of Kilauea's south flank. Analysis of the tsunami associated with the 1975 earthquake indicates that a large part of the submarine south flank of Kilauea was uplifted by deformation at the toe of the slump terrain, complementary to the subsidence on land. Focal-mechanism determinations by others for the earthquake and aftershocks indicate seaward displacements along gently-dipping fault planes at depths of 6-10 km, near the base of the volcanic edifice where it is inferred to rest on old sea floor. The basic cause of the slumping was accumulation of contractional strain along the upper south flank, as a result of magma intrusion as dikes along Kilauea's rift zones. Inflation of Mauna Loa Volcano may also have contributed to destabilizing Kilauea and triggering the earthquake.



Lisowski, M., Owen, S., and Segall, P., 1996, The Kilauea Volcano, Hawaii, continuous GPS network: recent results [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F808. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 A seven-station network of continuously recording GPS receivers has been installed by Stanford University and the Hawaiian Volcano Observatory to monitor movements of the summit and south flank; of Kilauea Volcano. The first two stations were operational in July 1995, two more were added in July 1996, another in August 1996, and the last two in October 1996. Six of these stations are solar powered and controlled with radio telemetry. Episodic deformation is apparent in the displacements of stations located on the summit and on the upper south flank (10 km distant). From July, 1995, to August, 1996, steady contraction across the summit associated with the ongoing eruption from the Pu'u 'O'o vent is interrupted by several episodes of extension around the time of eruption pauses. The most significant event during this period was the February 1, 1996, eruptive surge from the Pu'u 'O'o vent. This event began with a swarm of shallow summit earthquakes and four hours of rapid summit inflation. What appeared to be an imminent summit eruption became a sudden increase in the eruptive volume at Pu'u 'O'o. The summit rapidly deflated during the surge, nearly returning to its pre-event level, and then slowly inflated (extending 2 cm) during the following ten-day-long eruption pause. This extension equaled the contraction accumulated in the previous 6 months. A slower extensional event began about a month before the five-day-long May 29, 1996, eruption pause and ended with the pause. This event coincided with the start of an increased rate of south-southeastward displacement at both GPS stations. Deformation associated with these events would be difficult to resolve without the dense temporal sampling provided by the continuous GPS network. The improved spatial resolution provided by the five new GPS stations installed in the summer of 1996 will help us understand how events at Kilauea's summit affect south flank displacements.



Lockwood, J.P., Dvorak, J.J., English, T.T., Koyanagi, R.Y., Okamura, A.T., Summers, M.L., and Tanigawa, W.R., 1987, Mauna Loa 1974-1984: a decade of intrusive and extrusive activity, in Decker, R.W., Wright, T.L., and Stauffer, P.H., ed(s)., Volcanism in Hawaii, 2 v.: U.S. Geological Survey Professional Paper 1350, v. 1, chap. 19, p. 537-570. 



 The 1975 and 1984 eruptions of Mauna Loa Volcano were both related to a decade-long period of seismic and geodetic unrest (inflation) that was first detected in April 1974. The 1975 eruption, the first of Mauna Loa in 25 years, began just before midnight on July 5, but lasted less than 19 hours. Eruptive vents were confined to the summit region and produced about 30 million cubic meters of uniform tholeiite, which covered nearly 14 square kilometers of the summit area and north flank. Intense seismic activity continued in a localized area along the middle northeast rift zone (NERZ) for a week following the eruption and was accompanied by extensions across the rift, which suggested the intrusion of magma into this area. This led to a forecast of renewed activity on the NERZ sometime before the summer of 1978. The forecast timing proved erroneous, but the scenario was correct as to the place and character of the subsequent eruption.

 The Mauna Loa summit inflated rapidly during the first two years after the 1975 eruption, but at lesser rates after 1977. Modeling of geodetic data showed that this inflation was caused by magma accumulation in a shallow storage reservoir beneath the southern edge of the summit caldera. Seismic activity was steady, although rates of intermediate-depth earthquakes began to increase in 1980, as did rates of summit deformation, resulting in a renewed forecast (1983) for an eruption of Mauna Loa within the next two years.

 The 1984 summit-flank eruption began at 0125 H.s.t., March 25 (during a fortnightly earth tidal minimum). Eruptive fissures, which initially opened in the southwest corner of Mokuaweoweo, quickly propagated down the upper southwest rift and northeast rift zones, but eruptive activity was soon limited to the NERZ. A dike propagated down the NERZ at an average rate of 1.2 km/h during the day and was marked at the surface by discontinuous echelon eruptive fissures and earth cracks. The lowest eruptive vents were 15 km from the edge of Mokuaweoweo, between 2,770 and 2,930 m elevation; activity was restricted to these vents for the last three weeks of the eruption. Eruptive temperatures throughout this period remained constant at about 1,140 C. Lava production began to diminish by early April, and lava steadily became more viscous, blocking supply channels at higher and higher elevations. When the eruption ended on April 15, approximately 220 million cubic meters of uniform tholeiite had been erupted, covering about 48 square kilometers of the Mauna Loa surface. Aa lava flowed as far as 27 km from eruptive vents to the 900-m elevation, to within 6 km of the nearest buildings in the city of Hilo.

 Repeated geodetic and gravity measurements made throughout the eruption documented a substantial deflation of the Mauna Loa summit. The maximum measured subsidence. in the southern part of the summit, was 630 mm, and typical trilateration survey lines across Mokuaweoweo contracted an average of 300 mm, after initial dike-related extensions of about 600 mm. The summit area of Mauna Loa began to re-inflate immediately after the 1984 eruption, indicating the recharge processes for the volcano's next eruption have already begun.



Logan, D., 1886, A trip to the volcano: Daily Bulletin (Honolulu), 04/08, p. 1, 3. 



 Logan gives a detailed account of a trip from Honolulu to Kilauea via Kailua and Punaluu, just after the collapse of March 1886. He quotes J.H. Maby's account in the Volcano House Register (Maby, 1886; Bevens, 1988) of the earthquake swarm and collapse of March 6-10, 1886. No earthquakes were reported at Keauhou and only two at Kapapala. [This suggests that the lava from Halemaumau might have drained into the east rift zone.] He gives an excellent description of the appearance of the caldera floor following the collapse.



Loomis, H.G., 1979, On defining the source of the 1975 tsunami in Hawaii, in, Symposium on Long Waves in the Ocean, Ottawa, June 6-8, 1978, [Proceedings]: Ottawa, Ontario, National Research Council, Manuscript Report Series No. 53, p. 94-99. [Sponsored by Marine Environmental Data Service, Ocean and Aquatic Sciences, Department of Fisheries and the Environment, Marine Sciences and Information Directorate] 



 Introduction

 The tsunami of November 29, 1975, in Hawaii was generated by an earthquake of magnitude 7.2. The fault ran along the southeastern shoreline of the Island of Hawaii and coincident with the earthquake was considerable subsidence (up to 3 m) of the shoreline. The waves generated by the earthquake were about 6 m high along 100 km of coastline with an occasional high water mark reaching as high as 15 m. This earthquake and tsunami were similar to a previous event at the same location on April 2, 1968 (Wood 1914). The earlier tsunami was perhaps twice as large as the recent one.

 I made a very careful survey of wave heights along the coastline of Hawaii as did a group from the Volcano Observatory of the USGS (Loomis 1976; Tilling et al. 1976) so that we have a good quantitative and qualitative description of this tsunami. A project was proposed and supported by the Nuclear Regulatory Commission to see if a numerical simulation of the tsunami could be constructed to approximate the measured event. To do this, we put together a time-stepping, finite-element scheme with a grid system encompassing the Island of Hawaii. At this point, we needed a good description of the source of the tsunami, which is the subject of this paper, namely, the use of seismic information in determining a tsunami source region."



Lum, W., Nielsen, N., Koyanagi, R., and Chiu, A., 1984, A survey of damage: Kaoiki earthquake, November 16, 1983: [s.l.], Earthquake Engineering Research Institute (EERI), 15 p.; figs., 9 p. [unpag.]. 



 Contents

Introduction 1

Damage to structures 1

Damage to lifelines 3

 Electrical power system 4

 Water supply system 4

 Communication systems 6

Transportation systems 7

Technical questions 8

Seismicity 9

 Seismicity related to active volcanism in Hawaii 9

 Strong motion data 11

Lessons learned from quake 12

Appendix:

 Fig. 1: Island of Hawaii

 Fig. 2: Preliminary isoseismal map

 Fig. 3: Intensity versus magnitude and epicentral distance, western United States in comparison with Kaoiki, Hawaii M 6.6 quake

 Fig. 4: Earthquake locations in four depth categories in the region beneath Kilauea and Mauna Loa Volcanoes for January 1983

 Fig. 5: Location of the 6.6 magnitude Kaoiki earthquake and aftershocks during the initial 10 hours of activity

 Fig. 6: Typical damage within 12 kilometers of epicenter

 Fig. 7: Typical damage to residential structures within 12 kilometers of epicenter

 Fig. 8: Typical damage near tail end of lava flow 50 kilometers from epicenter

 Fig. 9: Typical undamaged structures in the areas where most damage occurred



Introduction

 An earthquake, magnitude 6.6 on the Richter scale, occurred on November 16, 1983, 6:13 a.m., on the island of Hawaii about 50 kilometers (30 miles) southwest of the town of Hilo with a depth of about 12 kilometers. Figure 1 shows the location of the epicenter of the quake.



Lydecker, R.C., 1903, Meteorological report for the month of July: Pacific Commercial Advertiser, 08/17, p. 2. 



 Kohala reports earthquake at 1 p.m. on July 1; Pepeekeo, long earthquake shock July 2 at 12:30 p.m.



Lydecker, R.C., 1903, Meteorological summary for month of August: Pacific Commercial Advertiser, 09/15, p. 5. 



 Earthquakes reported: Naalehu, 1st at 11:50 a.m., 4th at 9:45 p.m., 21st at 4:15 a.m.; Hilo, 1st, 11:40 a.m. and 4th, 9:55 p.m., the latter preceded by a rumbling; Pepeekeo, 1st, 11:50 a.m.; Kohala, 17th, 1 a.m.



Lydecker, R.C., 1903, Meteorological summary for September, 1903: Pacific Commercial Advertiser, 10/14, p. 5. [Repeated in Hawaiian Gazette of Oct. 16, 1903] 



 Hilo reports earthquake on the 1st at 7:16 p.m.



Lydecker, R.C., 1903, Meteorological summary for September, 1903: Hawaiian Gazette, 10/16, p. 6. [Repeated from Pacific Commercial Advertiser of Oct. 14, 1903] 



 Hilo reports earthquake on the 1st at 7:16 p.m.



Lydecker, R.C., 1903, Meteorological summary for October, 1903: Pacific Commercial Advertiser, 11/16, p. 7. 



 A brief summary of the beginning of the eruption in Mokuaweoweo. Captain Coath of the British ship Ormsary reports having experienced a remarkable disturbance of the sea, lasting from the afternoon of Oct. 5 to the morning of Oct. 6, currents and high cross seas in every direction, the vessel making no headway, Mauna Loa bearing ESE about 80 miles. On the afternoon of the 6th the activity of the volcano was noted from the ship. There are no reports of earthquakes previous to the outbreak which occurred without warning, and it is an interesting question as to whether this disturbed condition of the sea was the result of a cause or effect of volcanic activity.

Reports from other stations: Hilo, earthquake, 6:05 a.m. on October 2; Naalehu, medium earthquake on October 7 at 2:45 p.m.; eruption of Mauna Loa first observed about 2 p.m. on October 6.



Lydecker, R.C., 1904, Meteorological summary for December, 1903: Pacific Commercial Advertiser, 01/16, p. 6. [!get first name of Lydecker] 



 Hilo, slight earthquake on the 8th at 7:15 a.m.



Lydecker, R.C., 1904, Meteorological summary for month of Jan., 1904: Pacific Commercial Advertiser, 02/17, p. 5. 



 A slight earthquake was felt in Hilo at 9:40 p.m. on Jan. 23, 1904; also felt in Waimea and Kohala (9:43 p.m.); felt as heavy in Pepeekeo (9:38 p.m.)



Lydecker, R.C., 1904, Meteorological summary for month of Jan., 1904: Hawaiian Gazette, 02/19, p. 6. 



 Reported from other stations: Hilo, . . . slight earthquake 23rd at 9:38 p.m. Pepeekeo, heavy earthquake 23rd at 9:38 p.m. . . . Kohala, earth quake 23rd at 9:43 p.m. . . . Waimea, earthquake 23rd . . .



Lydecker, R.C., 1904, Meteorological record for month of February: Pacific Commercial Advertiser, 03/17, p. 5. 



 A heavy earthquake was felt in Hilo at 1:33 p.m. on Feb. 14, 1904; an earthquake was felt in Pepeekeo at 1:05 a.m. on Feb. 19, 1904.



Lydecker, R.C., 1904, The storm reports were not exaggerated; Oahu suffered the most from the recent heavy rains--report of Meteorologist Lydecker: Hawaiian Gazette, 03/18, p. 7. [The earthquake on June 4 is also cited in the Pacific Commercial Advertiser of June 5 and 13 and the Hilo Tribune of June 10; the earthquake on June 28 is also cited in the Hilo Tribune of July 1] 



 Reported from other stations: . . .

Hilo, Hawaii--Earthquakes 14th at 1:33 p.m. (heavy) and 18th at 10:25 a.m.



Lydecker, R.C., 1904, Meteorological record for month of March: Pacific Commercial Advertiser, 04/13, p. 6. 



 Kohala, earthquake 29th at 11:45 a.m. and 30th at 12:15 p.m.; Waimea, earthquake 29th



Lydecker, R.C., 1904, Weather report for the month of April: Pacific Commercial Advertiser, 05/16, p. 6. [The earthquake of April 4th as felt in Honolulu also cited in the Pacific Commercial Advertiser of April 4, 6 and 11, 1904] 



 Honolulu: slight earthquake, 4th at 7:39 a.m.; also reported from Hawaii and Maui.

Reported from other stations: Kohala, Hawaii, earthquake at 7:40 a.m., 4th. Hilo, earthquake 7:35 a.m., 4th and 10:55 p.m., 30th. Pepeekeo, earthquake, 4th at 7:35 a.m. and heavy shock at 10:15 p.m., 29th.



Lydecker, R.C., 1904, Meteorological summary for month of June: Pacific Commercial Advertiser, 07/14, p. 5. [Repeated in Hawaiian Gazette of Jul. 15, 1904; The earthquake on June 4 is also cited in the Pacific Commercial Advertiser of June 5 and 13 and the Hilo Tribune of June 10; the earthquake on June 28 is also cited in the Hilo Tribune of July 1] 



 Honolulu--Heavy earthquake shock at 12:27:05 p.m. on June 4, lasting 23 seconds. This shock was felt generally throughout the group being heaviest on Maui.

Notes from other stations: Pepeekeo, in addition to earthquake noted above, slight shock on June 28.



Lydecker, R.C., 1904, Meteorological summary for month of June: Hawaiian Gazette, 07/15, p. 6. [Repeated from Pacific commercial Advertiser of Jul. 14, 1904; The earthquake on June 4 is also cited in the Pacific Commercial Advertiser of June 5 and 13 and the Hilo Tribune of June 10; the earthquake on June 28 is also cited in the Hilo Tribune of July 1] 



 Honolulu--Heavy earthquake shock at 12:27:05 p.m. on June 4, lasting 23 seconds. This shock was felt generally throughout the group being heaviest on Maui.

Notes from other stations: Pepeekeo, in addition to earthquake noted above, slight shock on June 28.



Lydecker, R.C., 1904, Meteorological summary for month of July, 1904: Pacific Commercial Advertiser, 08/13, p. 5. [The earthquake of July 17 is also cited in the Pacific Commercial Advertiser of July 20 and 21, the Hawaii Herald of July 21 and the Hilo Tribune of July 22.] 



 Honolulu--slight earthquake on July 23

Pepeekeo reports hard earthquake shock at 1:55 p.m. on July 17.

Hilo; heavy earthquake on July 17 [no time]



Lydecker, R.C., 1904, Meteorological summary for month of August, 1904: Pacific Commercial Advertiser, 09/15, p. 6. 



 Kohala Mission--earthquake at 7:10 a.m. on August 22.



Lyman, F.S., 1868, Earthquakes and eruptions as observed at Kau, Hawaii: Hawaiian Mission Children's Society Library, Handwritten narrative, 7 p. [Included, in part, in Pacific Commercial Advertiser, Apr. 18, 1868; Pacific Commercial Advertiser Extra, Apr. 15, 1868, p. 3; excerpted in American Journal of Science, 2nd. ser., v. 46, p. 109-112, and in Wood, H.O., 1914b, p. 174-175] 



 An account of the catastrophic earthquakes, the lava flow of Mauna Loa, and the mudflow at Wood Valley, in March and April 1868. This paper repeats some material in Lyman (1868b), and gives additional times of earthquake activity. Eruption at Mauna Loa summit began at 6:00 a.m. on March 27, and was over by 8:00 p.m. Fuming, but no glow, was seen advancing down the southwest rift zone until the 29th. Lyman describes the continuous shaking from Tuesday, March 31, culminating in the great earthquake on April 2. He describes the mudflow as going 3 mi in 3 min. He describes the tsunami: " . . . at Punaluu a long black point of lava slowly pushed out to sea and soon disappeared." Earthquakes continued, and eruption was reported on April 7.



Lyman, F.S., 1868, The eruption on Hawaii: Maile Quarterly, v. 3, Apr., p. 43-46. 



 An account of the earthquakes and mudflow of April 2, 1868, at Wood Valley. Lyman gives the following chronology:

 	March 27		Summit eruption of Mauna Loa with flow to the southeast

	March 28-30		Earthquake swarm, diminishing on March 31-April 1

	April 2, 4:00 p.m.	Large earthquake

	April 7		Eruption on lower southwest rift of Mauna Loa

Lyman quotes a letter speaking of the sea being red, and outside of Punaluu a long, black point of lava slowly pushed out to sea. [Flow into the sea was unconfirmed but led to confusion on maps long after 1868, which showed 1868 lava reaching the ocean. Lyman also thought initially that the mudflow triggered by the earthquake was molten lava. See annotation to Coan {1880} for a later comment on these observations.]

 

Lyman, F.S., 1868, [On the earthquake and eruption of 1868]: Honolulu, Hawaiian Mission Children's Society Library, Unpublished letter to "Cousin Jos[i]e", 7 p. 



 A vivid account of the events of 1868.



Lyman, E.B., 1890, Trip to Mauna Loa, August 1890: Hawaii National Park, HI, Hawaii Volcanoes National Park Library, Unpublished manuscript, 4 p. 



 Lyman describes a trip into Mokuaweoweo in August 1890. It was not in eruption. The caldera wall below Pendulum Peak had settled in 1888, and the floor had subsided away from a black ledge of pahoehoe, formed either in 1887 or before; no changes had occurred since 1888. He quotes his guide regarding an earthquake swarm on August 6-7 that did damage in Puna and Hilo. 

 . . . reaching Kau we heard that a dozen earthquakes had been felt, two of them quite severe. In Puna and in Hilo stone walls and many things in the houses were thrown down; at the volcano only three were felt and several of the cones around Halemaumau tumbled in, Strange to say we did not feel any of them [camped at Mauna Loa's summit]. All of these earthquakes occurred Wednesday night when we were on the summit. . . .



Lyman, R.A., 1902, Tidal wave at Puna: Pacific Commercial Advertiser, 09/08, p. 1. 



 Puna coast on the Island of Hawaii was swept by a five-foot tidal wave on Tuesday afternoon, Sept. 2. Such a tidal wave, had it entered Honolulu harbor, would have flooded the Esplanade and traveled up Fort street as far as the mauka end of the Custom House. At Waikiki it would have overflowed the beach and the premises directly fronting on same.

 Curtis Lyons, government meteorologist reports that tidal movements in Honolulu harbor have been more pronounced during the past week He then quotes a letter received from Rufus Lyman:

 Hilo, Hawaii, Sept. 5, 1902

 Dear Sir: My son Henry returned to Puna from the volcano yesterday afternoon and telephoned last evening, that he learns there was a tidal wave on Tuesday afternoon, September 2, about 2 p.m., and it was felt all along the coast from the east point to Kahaualea in Puna.

 At Kula it came into the lagoon, and washed the canoes around that were up on the shore where they are kept, and would have broken them if the natives had not gone after them.

 It rose about five feet above high water mark, and kept washing in for about two hours. They say it reached farther up on the land than it ever has before.

 The wave came into the Kapoho lagoon, and went about a foot over a wall that I am having built around the pond.

 At Kalapana it is reported that it washed away part of the wall of the school yard, and of a native yard, and damaged the canoes on the shore, and for two hours Representative Haaheo was in fear that it would wash the sand hills away from in front of his house, and carry his house off. At Hilo we had very high surf on the reef and along Papaikou coast all day Tuesday, but I have not heard of any tidal wave in Hilo. I write in haste, and you can give the newspapers any information that you think best.

 Yours truly

 Rufus A. Lyman



Lyman, F.S., 1912, The great earthquake of 1868, in Sarah Joiner Lyman of Hawaii: her own story: Hilo, T.H., Frederick Lyman and Son, appen. C, [unpag.]. [Reprinted 1970 by Lyman House Memorial Museum, Hilo. Pages 181-187 cover the material abstracted] 



 A dramatic account of the 1868 earthquakes, landslide, tsunami, and Mauna Loa eruption. [The material is repeated from Lyman {1868a, b}, omitting mention of lava going into the sea at Punaluu.]



Lyons, C.J., 1900, Meteorological data for month of June, in Meteorological record for month of June: Pacific Commercial Advertiser, 07/19, p. 7. 



 Earthquake reported from Pepeekeo, 7th.



Lyons, C.J., 1900, October a wet month, in Meteorological record for month of October: Pacific Commercial Advertiser, 11/16, p. 12. 



 [subheads: Beat all known records for moisture; Hail, flood, earthquake; Islands rainfall has been unprecedented as the figures show]

Earthquakes noted: Hilo, 10th, 11 p.m.; Hilo and Pepeekeo, 12th, 3:45 a.m.



Lyons, C.J., 1901, Nuuanu was very moist, in Meteorological record for month of December: Pacific Commercial Advertiser, 01/17, p. 12. 



 [subheads: Nine inches of rain in the reservoir; The total for December; Interesting weather report for last month made by Professor Lyons]

 There was a slight earthquake at Waimea, Hawaii, on the 5th.



Lyons, C.J., 1901, Weather notes, in Meteorological record for month of January: Pacific Commercial Advertiser, 02/15, p. 14. 



 [subheads: Complete report for the last month; Records unusual island rainfall; General all over the islands and of great value to plantation owners]

Slight earthquake on Jan. 16; 1:45 a.m., felt at Honolulu, Hilo and Waimea, and on Jan. 24 at 3 p.m., [felt] at Waimea and Hilo.



Lyons, C.J., 1901, Meteorology for March, in Meteorological record for month of March: Pacific Commercial Advertiser, 04/16, p. 8. 



 Earthquake at Hilo, 21st, 7:15 a.m.



Lyons, C.J., 1901, Meteorological summary for month of November, in Meteorological record for month of November: Pacific Commercial Advertiser, 12/17, p. 9. 



 Earthquake at Hilo, 15th at 10 p.m. also a light one on the 21st.



Lyons, C.J., 1902, Meteorological record for month of February, in Meteorological record for month of February: Pacific Commercial Advertiser, 03/18, p. 9. 



 Earthquakes on Hawaiian Islands--9th, 6:25 p.m.; 20th, 5:30 a.m., at Waimea, Kohala and Hilo.



Lyons, C.J., 1902, Meteorological summary for the month of March, in Meteorological record for month of March: Pacific Commercial Advertiser, 04/15, p. 12. 



 An earthquake was reported at Hilo March 30, 10:09 p.m.



Lyons, C.J., 1902, Meteorological summary for the month of April, in Meteorological record for month of April: Pacific Commercial Advertiser, 05/16, p. 12. 



 Earthquake on Hawaii on the 7th, 10:30 p.m., also noticed at Honolulu.



Lyons, C.J., 1902, Meteorological summary for month of June, 1902, in Meteorological record for month of June: Pacific Commercial Advertiser, 07/15, p. 12. 



 Earthquakes: Hamakua on the 3rd at 10 p.m.; Hilo on the 13th at 6:20 a.m. and on the 14th at 3 a.m.; Hamakua and Waimea on the 16th at 4:25 p.m.; Kau has not reported.



Lyons, C.J., 1902, Meteorological summary for the month of July, in Meteorological record for month of July: Pacific Commercial Advertiser, 08/15, p. 12. 



 Earthquake, Pepeekeo, Hilo, reports 15th, 12:45 p.m.



Lyons, C.J., 1902, Meteorological record for month of August, in Meteorological record for month of August: Pacific Commercial Advertiser, 09/16, p. 9, 12. 



 Earthquakes reported, Pepeekeo, Hilo, 8th--2:15 p.m.; Hilo, 15--2:26 p.m.; Hilo, 25th; Papaaloa, 26th, 7 p.m., 27th, 3 a.m. Lake of molten lava 400 feet in diameter appeared in the bottom of Halemaumau pit in Kilauea crater on the evening of the 25th, said to be 800 or more feet below general floor of crater, but rising.



Lyons, C.J., 1902, Meteorological summary for month of September, in Meteorological record for month of September: Pacific Commercial Advertiser, 10/15, p. 12. 



 Earthquakes reported, Pepeekeo, 24th, 9:30 p.m., and Hilo, 28th, 6:13 a.m., smart shock, "severest in six years"; Kealakekua 19th, 5:30 p.m.; Waimea 26th evening, 27th evening and the earthquake of the morning of the 28th. During the first half of the month the lava disappeared from the pit in Kilauea, on the 16th active again and rising, light visible at 30 miles distance. The "glows" brighter than in August.



Lyons, C.J., 1902, Kinds of weather during October, in Meteorological record for month of October: Pacific Commercial Advertiser, 11/17, p. 4. 



 Slight but decided earthquake felt at Honolulu, 4:31 a.m., 16th; same reported from Kohala, Waimea (2 shocks), and Hilo (Pepeekeo). On the 20th, Kohala, 5:30 a.m., 26th, Waimea, 3:05 and 11:05 p.m.



Lyons, C.J., 1902, Meteorological summary for month of November, in Meteorological record for month of November: Pacific Commercial Advertiser, 12/15, p. 12. 



 Earthquake, Kohala, 9th, 11 a.m. and 10th [19th?], 10 p.m., "hard." Hilo, 11th, 6:45 p.m. Kilauea active on the 10th, lava rising 100 feet in the pit of the lake. In the course of ten days action subsided.



Lyons, C.J., 1903, Meteorological summary for month of January: Pacific Commercial Advertiser, 02/17, p. 6. 



 Earthquake noted at Hilo, Waimea and Kohala on the 3d between 7:20 and 7:25 a.m.



Lyons, C.J., 1903, Meteorological summary for month of February: Pacific Commercial Advertiser, 03/18, p. 5. 



 Earthquakes, Hilo, 9th, 11:23 a.m., and 21st; Waimea, 10 p.m. on the 4th; Kohala, 4th, 12:20 a.m.



Lyons, C.J., 1903, Meteorological summary for month of March 1903: Hawaiian Gazette, 04/17, p. 8. 



 " . . . earthquakes, Hilo, 13th, 6 p.m.; 23rd, 11:25 p.m.; Waimea, 13th, 6:15 p.m.; Kohala, 15th, 6:15 a.m. . . ."



Lyons, C.J., 1903, Meteorological summary for month of March: Pacific Commercial Advertiser, 04/17, p. 5. 



 Earthquakes, Hilo, 13th, 6 p.m.; 23rd, 11:25 p.m.; Waimea, 13th, 6:15 p.m.; Kohala, 15th, 6:15 a.m.



Lyons, C.J., 1903, Meteorological summary for month of April 1903: Pacific Commercial Advertiser, 05/16, p. 6. 



 Slight earthquake at Hilo, 2 a.m., 19th.



Lyons, C.J., 1903, Meteorological summary for month of June, 1903: Pacific Commercial Advertiser, 07/15, p. 6. [Repeated in Hawaiian Gazette of July 17] 



 Naalehu reports light earthquake on June 9th at 7:20 p.m.



Lyons, C.J., 1903, Meteorological summary for month of June, 1903: Hawaiian Gazette, 07/17, p. 7. [Repeated from Pacific Commercial Advertiser of July 16] 



 " Naalehu reports light earthquake on the 9th, at 7:30 p.m."



Maby, J.H., 1886, [on the Kilauea collapse of March, 1886]: Hawaii National Park, Unpublished record, 03/07-10, [unpaginated]. [Originally published in the Volcano House Register (Bevens, 1988); reprinted in Logan, 1886] 



 March 7th, 1886--From June 20th, 1885, up to December 15th, both the old and new lakes were very active in the way of boiling and surging away from one side to the other. And in December, about the 15th-20th, the new commenced to build itself a wall which carried the surface of the lake up to 100 or 150 feet higher, by the first of March, 1886, than the surface had formerly been.

 On the evening of the 6th of March at 7 p.m., both the old lake, Halemaumau, and the new lake were quite full of boiling and surging lava, and very brilliant as seen from the verandah of the House, and continued to remain so up to 9:30 p.m. At which time there commenced a series of earthquakes, 43 in number and lasting until 7:30 a.m. After the third or fourth shake, in looking out upon the crater, there was nothing to be seen of the new lake and only a slight reflection from the old lake. At the hour of between 2 and 3 a.m., of the 7th all fire and lights in the crater had disappeared . . . .

 At 8 a.m. on the 7th . . . it was discovered that all the bluffs surrounding Halemaumau . . . had disappeared by falling down in the lake, along with the path that was formerly used to go over from the new lake to the old, and the whole, together with the new lake, forming a deep chasm, making it look like one large lake instead of two.

 During the night, while the shaking was going on, the ground was rent apart in several places. One large crack opened up on the road to Kilauea-Iki, and two on the road to Keauhou, about one mile and a half from the Volcano House.

 Entries for March 8 and 9 confirm the absence of fire and remark that the ground or lava still seems to be sinking.

 March 10-- . . . During the shaking here there was nothing felt at Keauhou and only two shakes felt at Kapapala Ranch.

 There has only been one slight shock of earthquake since the first night. He [Maby] believes the shocks to have been produced by the falling in of the vast bodies of rock forming the walls of the different craters proper.



Macdonald, G.A., and Wentworth, C.K., 1951, The Kona earthquake of August 21, 1951: The Volcano Letter, no. 513, p. 1-4. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 An earthquake of intensity VII struck the area between Kealakekua and Hookena on August 21, 1951, the strongest earthquake to hit the Island of Hawaii since 1868. The earthquake was followed by 1000 aftershocks ranging to intensity IV. The epicenter was offshore, close to Kealakekua Bay. The authors describe damage through photographs and histograms, and present a preliminary isoseismal map. Epicenters of both mainshock and aftershocks are associated with the Kealakekua fault. The authors speculate that the earthquake may have been an adjustment to magmatic pressure applied during the 1950 eruption of Mauna Loa.



Macdonald, G.A., 1951, The Kilauea earthquake of April 22, 1951, and its aftershocks: The Volcano Letter, no. 512, p. 1-3. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 This earthquake was the strongest felt on the southern half of the island of Hawaii since 1929, possibly since 1908. the authors describe road-cracking, rock slides in Halemaumau, and damage to buildings. The broad area over which the earthquake was felt, combined with dismantling of seismographs at Kilauea's summit by vertical forces, suggest an origin deep beneath the southern part of Kilauea caldera. Aftershocks were widespread, located on the Kaoiki fault zone, north and east of Kilauea summit, and on the Hilina fault system. [Epicenters are not well located at this time. Modern classification of Kilauea earthquakes suggests that this is a deep (30+ km) caldera event, possibly precursory to return of activity to Kilauea in 1952.]



Macdonald, G.A., and Wentworth, C.K., 1952, The Kona earthquake of August 21, 1951, and its aftershocks: Pacific Science, v. 6, p. 269-287. 



 The authors give an account of a large earthquake on the Kealakekua fault zone and illustrate with photos the damage that took place. The magnitude was estimated at 6.7-7 from California station records; maximum intensity was VII on the modified Mercalli scale. The epicenter was about 6 km offshore, and a small local tsunami was generated, measuring 1 m of withdrawal and subsequent rise.



Macdonald, G.A., 1952, The south Hawaii earthquakes of March and April, 1952: The Volcano Letter, no. 515, p. 1-5. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 Macdonald describes an earthquake swarm from March 15 to the end of April, 1952. The swarm was preceded by two larger earthquakes on March 13 and 14, felt generally over the south part of the Island of Hawaii. Epicenters occupied a linear belt 6-10 mi offshore, parallel to the Hilina fault system, appearing to migrate back and forth along that line. A plot of hourly seismicity at the Whitney vault from March 16-21 shows cycles of gradually rising seismicity, culminating in a larger earthquake, after which the seismicity drops. Seismicity peaked on March 21, diminishing thereafter.

 Macdonald offers two explanations for the earthquake swarm: (1) the swarm is associated with eruption at a submarine volcano defined by a closed contour just north of the line of epicenters. [Ironically, this contour was later shown to be a large block on a landslide. Loihi seamount, not discovered at this time, lies south of the line of earthquakes near its western extremity.]; (2) the swarm is associated with movement on a Kilauea south flank fault system similar to the Hilina fault system on land. Macdonald favors the latter, as the HVO seismographs showed no harmonic tremor accompanying the swarm.

 Macdonald compares the 1952 earthquake swarm with that of 1868, noting that precautionary measures were taken (e.g., closing a coastal school; warning residents of the possibility of a large tsunami) consistent with the possibility of a repeat of the 1868 sequence.



Macdonald, G.A., 1953, All quiet, but Isle shaken by Pele's restless sleep: Hilo Tribune-Herald, 02/08, p. 1. 



 . . . 

Several earthquakes were felt in Kona during the month. Most of them originated locally, on the Kealakekua fault or at sources between Kona and the summit of Mauna Loa.

 A small earthquake felt at Naalehu and Kapapala at 9:08 a.m. January 9 originated beneath the southeastern slope of Mauna Loa about 8 miles northwest of Kapapala, and another, at 9:10 p.m. the same day had its epicenter about 1.5 miles closer to the summit of the mountain. The latter quake was felt quite strongly all over the southern part of the island, and less strongly at least as far north as Kukuihaele.

 At 2:04 a.m. January 15, a strong earthquake originated beneath the southeastern slope Mauna Loa near the Kapapala headquarters. Objects were upset and knocked from shelves as far away as Hilo. Residents of the southern part of the island of Hawaii were generally awakened, and the quake was felt as far away as Oahu. In its epicentral area the intensity of the quake is estimated to have been about 5 on the modified Mercalli scale.

 . . .



Macdonald, G.A., and Eaton, J.P., 1954, The eruption of Kilauea Volcano in May, 1954: The Volcano Letter, no. 524, p. 1-9. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 The authors give a detailed narrative of this short eruption that began on May 31 and ended on June 3. The eruption was preceded by a swarm of small earthquakes beginning on the evening of May 30, culminating in two felt earthquakes 20 minutes before lava appeared in Halemaumau crater. They plot seismic strain release for 1953 and the first half of 1954. The eruption was not specifically forecast although Kilauea was recognized as "ready" to erupt, as there was no reduction in volcanic pressure following the 1952 eruption (i.e., no deflationary tilt). [In hindsight, it appears that increases in rate of strain release following felt earthquakes on October 25, 1953 and April 11, 1954 provided a longer term anticipation of eruption.] The article includes a map showing location of vents and the extent of lava coverage. Vents were located both within Halemaumau and on the Kilauea caldera floor, the latter line oriented ENE, pointing toward Kilauea Iki. [It is interesting that subsequent petrologic study showed that the chemistry of the 1954 eruption was identical to one of the early-erupted components of the later 1959 eruption in Kilauea Iki.] 

The authors discuss the nature of earthquakes preceding the eruption and harmonic tremor accompanying the eruption. Recording of strong harmonic tremor coincident with appearance of lava at ethe surface strengthens the long-held belief that tremor is generated by movement of magma toward the site of eruption. A partially successful attempt to measure radioactivity in the fume cloud showed no readings above background.

 The authors close by discussing the 1877 eruption, the only previous eruption known to have vents on the Kilauea caldera floor. They briefly review the history of overflows from Halemaumau in the 19th and early 20th century, including discussion of the history of "Little Beggar" spatter cone, formed in 1884. They remark that the 1952 and 1954 eruptions resemble Mauna Loa activity more than they do the eruptions of Kilauea in the preceding century. They hypothesize that the continuously open lava lake of the 19th century may have been an unusual period in the long-term history of the volcano.



Macdonald, G.A., and Wentworth, C.K., 1954, Hawaiian volcanoes during 1951: U.S. Geological Survey Bulletin 996-D, p. 141-216. 



 This is the third in a series of USGS bulletins covering the work of the Hawaiian Volcano Observatory and the activity of Hawaiian volcanoes during the year. Others are 1948-49 (Finch and Macdonald, 1951), 1950 (Finch and Macdonald, 1953), 1952 (Macdonald, 1955d), 1953 (Macdonald and Eaton, 1955), 1954 (Macdonald and Eaton, 1957), and 1955 (Macdonald and Eaton, 1964). Each bulletin describes the physical plant of the Hawaiian Volcano Observatory and summarizes eruptive activity, seismicity, ground deformation, crack measurements, fumarole temperatures, rainfall, and special studies conducted during the year.

Abstract 141

 The year 1951 produced no eruptive activity of the Hawaiian volcanoes, but much subsurface volcanic uneasiness was manifested in tilting of the ground surface and abundant earthquakes. Records of the earthquakes, of magnetic changes, of changes in the width of cracks, and of tilting of the ground surface, all reveal some of the changes that took place.

 In December 1950, rapid south-southwestward tilting of the ground at the northeastern rim of Kilauea caldera indicated a sinking of the top of Kilauea volcano, in response to a decrease of pressure beneath. Throughout the first quarter of 1951 Kilauea was quiet, but in April there began a period of marked uneasiness. This was evidenced by a strong earthquake originating on the east rift zone on April 22, followed by 108 aftershocks, and on April 24 by the beginning of rapid northward tilting at the northeastern rim of the caldera, apparently accompanying an increase of volcanic pressure at depth The increase of pressure beneath Kilauea continued until early August.

 On August 21 the uneasiness was abruptly transferred to Mauna Loa. The earthquake at 00h57m on August 21, in Kona, on the western slope of Mauna Loa, was the most severe of any on the island of Hawaii since 1868. In its epicentral area, in the vicinity of Napoopoo and Captain Cook in central Kona, it had an intensity of 7 on the modified Mercalli scale. The earthquake was felt generally and strongly over the island of Hawaii, and weakly by many people in Honolulu, 200 miles away. The Kona seismograph was severely damaged by the first shock, and was only restored to operation 2 days later. The seismographs at the western rim of Kilauea caldera, and on the southeastern slope of Mauna Loa, at an altitude of 6,700 feet, were dismantled by the first waves and provided no useful records of the main earthquake. The seismograph at the northeastern rim of Kilauea caldera recorded the preliminary waves of the quake, but was dismantled by the first surface waves. All the instruments were restored to operation as soon as possible after the main quake, and recorded more than 1,000 aftershocks through the next few weeks.

 Damage to structures and roads in the Kona district was severe and extensive. Several churches and houses and about 150 water tanks were demolished. Many houses suffered lesser damage. In every cemetery for a distance of 25 miles there was some derangement of headstones, and in those cemeteries near the epicenter damage was severe. Many stone walls were thrown down.

 A study of the instrumental records and the distribution of damage indicate that the epicenter of the earthquake was probably on the Kealakekua fault, beneath the ocean, about 4 miles west of Napoopoo, The submarine origin of the quake is confirmed by the generation of a small tsunami.

 During September a group of earthquakes originated on the Kaoiki fault zone, between Mauna Loa and Kilauea. In October earthquakes originated beneath the summit area of Mauna Loa and along both rift zones, as well as on the Kaoiki fault, and on the Kealakekua fault in Kona. On November 8 a strong quake originated on the southwest rift of Mauna Loa near Kahuku Ranch headquarters, and throughout November earthquakes came from scattered sources in Mauna Loa and Kilauea. The uneasiness of both volcanoes continued into early December, but the year closed with relative quiet prevailing.

 In view of subsequent developments, there is little doubt that the general uneasiness throughout most of the year resulted from an increase of volcanic pressure beneath both volcanoes, which led eventually to the eruption of Kilauea on June 27, 1952.

Introduction 142

Acknowledgments 143

Seismographs and tiltmeters 143

Records and investigations 146

 Earthquakes 146

 Tilting of the ground 158

 The tilt record shows the December 1950 collapse and the beginning of significant inflation in April 1951, premonitory to the eruption of Kilauea in June 1952. [Not mentioned in the text, but inferred from the tilt record, is a smaller, apparently aseismic, collapse of Kilauea in March 1951, similar to the December 1950 event.] 

 Crack measurements 161

 Geomagnetic observations 163

 Geomagnetic observaton was initiated in order to detect decrease in ground magnetization related to rise of magma beneath Kilauea summit. [Measurements were made through 1954, but the variability of the data prevented their intended use as a forecasting tool.] 

 Temperature measurements 170

 Rainfall records 171

Volcanic conditions during 1951 172

Special investigations 180

 Pneumatolytic deposits 180

 The authors also describe the results of an investigation of pneumatolytic deposits, identifying thenardite (sodium sulfate) and opal.

 The Kilauea earthquake of April 22, 1951, and its aftershocks 181

 The Kona earthquake of August 21, 1951, and its aftershocks 185

 Narrative of the earthquake 186

 Instrumental data 188

 The major earthquake 188

 The aftershocks 189

 Effects of the earthquake 191

 Topographic and geologic setting 191

 Rock slides 192

 Tsunami 194

 Damage to buildings 195

 Damage to water tanks 198

 Damage to stone walls 202

 Damage to roads 203

 Damage in cemeteries 204

 Rotation of columns 207

 Location of the epicenter 209

 Intensity of the earthquake 210

 Conclusion 212

Literature cited 213

Index 215



Macdonald, G.A., 1955, Hawaiian volcanoes during 1952: U.S. Geological Survey Bulletin 1021-B, p. 15-107. [includes plates] 



 This is the fourth in a series of USGS bulletins covering the work of the Hawaiian Volcano Observatory and the activity of Hawaiian volcanoes during the year. Others are 1948-49 (Finch and Macdonald, 1951), 1950 (Finch and Macdonald, 1953), 1951 (Macdonald and Wentworth, 1954), 1953 (Macdonald and Eaton, 1955), 1954 (Macdonald and Eaton, 1957), and 1955 (Macdonald and Eaton, 1964). Each bulletin describes the physical plant of the Hawaiian Volcano Observatory and summarizes eruptive activity, seismicity, ground deformation, crack measurements, fumarole temperatures, rainfall, and special studies conducted during the year.

Abstract 15

 The year 1952 opened with the Hawaiian volcanoes quiet. Mauna Loa had last erupted in June 1950, for 3 weeks, and Kilauea had not erupted for nearly 18 years.

During March and April a swarm of more than 4,000 earthquakes originated beneath the ocean a few miles south of the island of Hawaii. Their epicenters were distributed along a line nearly parallel to the southern shore of the island 10 to 15 miles offshore. The line crosses a broad domical structure that probably is a shield volcano built against the flank of the Kilauea shield. No evidences of submarine volcanic eruption accompanied the earthquakes.

 Early in April a series of earthquakes commenced at foci along the east rift zone and beneath the caldera region of Kilauea volcano. These were accompanied by northward tilting of the ground at the northeast edge of the caldera, indicating swelling of the volcanic structure resulting from an increase of volcanic pressure beneath Kilauea. The volcano continued uneasy throughout May and June, although there was no recognized progression of earthquake hypocenters from depth toward the surface.

Kilauea volcano erupted on the night of June 27, 1952. At about 23h40m a fissure opened in a northeast-southwest direction across the floor of Halemaumau. For the next few hours a continuous line of fountains, 2,600 feet long, played along the fissure. Most of the fountains were 50 to 150 feet high, but at the southwest end of the fissure a fountain more than 800 feet high overtopped the rim of the crater at the beginning of the eruption.

 Gradually the big southwest fountain subsided and activity became restricted to a smaller part of the fissure. By 04h on June 28 only the northeastern quarter of the fissure was active, but at about 04h30m fountains reappeared along the southwestern part of the fissure. By that time the old floor of Halemaumau was submerged beneath a pool of liquid lava 50 feet deep. Long waves, resembling ocean ground swell, rolled across the surface of the pool from the fountains to the walls of the crater. A dark crust covered the lava pool but was broken by a network of cracks that revealed the bright golden glow of the hot liquid beneath.

 The northeastern fountains continued active until July 5, building 50-foot spatter cones that were later obliterated, partly by collapse and partly by burial under new lava. The fountain at the southwest edge of the crater resumed activity on the morning of June 28 and continued for several days. During that period it alternated in activity with a sinkhole, at the same location, which received a stream of lava from the central fountains. The southwestern fountain reached a second climax on July 3 and 4, when some bursts attained a height of 600 feet.

 A chain of about 20 small fountains extended across the southwestern part of the crater floor during the first 2 weeks of the eruption. About July 11 the active length of this fissure became restricted to 400 feet, and 2 principal fountains began building a large cinder-and-spatter cone. Rivers of lava pouring out through gaps in the cone wall fed a lake of liquid lava around the cone. On August 5 this lake had an area of 34 acres.

 By late August, overflow from the central cone had largely ceased. Two active vents were building small spatter cones in the crater of the larger cone. Between the conelets was a small lava lake that had an average diameter of about 100 feet. These conditions persisted essentially unchanged throughout the eruption. Flows appeared from time to time on the floor of Halemaumau crater outside the cone. Several of these issued at the foot of the crater wall, where the lava probably was squeezed up along the line of break between the old crater wall and the mass of new lava.

 The eruption came to an end on November 10. The average depth of the new lava fill was 310 feet, and the volume of new lava was 64,000,000 cubic yards. The depth of the crater had decreased from about 770 feet, before the eruption, to 460 feet. The rise of the crater floor was caused partly by overflow of new lava, and partly by bodily elevation as new lava was squeezed into the still-mobile lower part of the new fill.

Introduction 16

Acknowledgment 16

Seismographs and tiltmeters 17

Earthquakes 20

 Description of individual earthquakes 23

 The tsunami of November 4 33

 The south Hawaii earthquakes of March and April 36

 The earthquake swarm off the south coast was possibly associated with the undersea Loihi volcano, identified by Macdonald as a shield volcano lying on the flanks of Kilauea. [Ironically, Macdonald was referring to a closed contour, defined by bathymetric surveys, that lies on a submarine landslide. Loihi Seamount, discovered later, lies to the south of the line of earthquakes.] He states that there is no evidence of actual eruption associated with the earthquake swarm and considers it more likely that the earthquakes are associated with undersea equivalents of the Hilina fault system on land. He also states that displacement on Hilina faults raises the island relative to its submerged flank. [This statement is misleading. Although the south flank rises prior to a major earthquake, the movement of the south flank associated with the earthquake is absolutely down on the ocean side, consistent with normal faulting.]

Tilting of ground 44

Crack measurements 47

Geomagnetic observations 49

Temperature measurements 50

Rainfall records 61

Volcanic conditions during 1962 51

The eruption of Kilauea 68

 Brief history of activity in Kilauea caldera 53

 Macdonald gives a brief chronology of eruptive activity of Kilauea summit from 1823 to 1924, using lava volumes from Finch (1940), and infers that the activity of Kilauea had decreased since the early 19th century. In 1952 Kilauea extruded 0.05 km3 of lava. If this is averaged over the 18 yrs of repose preceding the eruption, the rate is 0.003 km3/yr, compared with 0.005 km3/yr estimated for the late 19th and early 20th century. He concludes that continuous lava lake activity does not necessarily correlate with high magma supply rates and that the average supply rate has remained constant since 1891. [Macdonald's analysis does not take into account the inflation during the repose period or the possibility of intrusion during collapse. The 1952 eruption rate, averaged over the 5 months of eruption, is 0.12 km3/yr, comparable both to current estimates of supply rate (about 0.1 km3/yr) and to that inferred by Macdonald for the earliest years of the 19th century {1823-40; .07 km3/yr}.] 

 Narrative of the eruption 53

 The 1952 eruption was confined to Halemaumau Crater, which it filled to a depth of 91.4 m with a total volume of 45 mcm.

 Opening phase of the eruption, June 27-28 56

 The phase of the large lava lake, June 27-July 6 58

 Cone-building phase, July 5-August 9 67

 Declining phase, August 9-November 10 71

 Composition of the lava 79

 Included is one chemical analysis of lava erupted on June 27 [erroneously labeled June 22].

 Volume of the lava 81

 Rate of extrusion of lava 83

 Temperature of the erupting lava, 85

 Temperatures were measured as high as 1,155C. [Maximum temperatures are within 25C of the true temperature estimated from chemistry of the glass.]

 Viscosity of the lava 90

 Viscosity was estimated at 19,000-34,000 poises. [Viscosities are undoubtedly too high, compared with later experimental work.] 

 The lava fountains 91

 The lava lake 92

 The fume cloud 97

 Earthquakes preceding and accompanying the eruption 100

 Volcanic tremor 101

Literature cited 104

Index 107



Macdonald, G.A., and Eaton, J.P., 1955, The 1955 eruption of Kilauea Volcano: The Volcano Letter, no. 529-530, p. 1-10. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 "The 1955 eruption, on the east rift zone of Kilauea volcano in the eastern part of the Puna District, was unique in several respects and unusual in others. It was the first flank eruption of Kilauea since 1923, and the first eruption in eastern Puna since 1840. In some respects it had the aspects of three separate eruptions each accompanied by its premonitory earthquakes. It was unusual in that the opening of the eruptive fissures in part progressed up slope, toward the central vent of the volcano, and also in the irregular manner in which activity shifted from one vent area to another. For the first time in Hawaii, and probably anywhere else, scientists were able to observe and photograph at close range the entire sequence of the development of volcanic vents, from the first opening of the fissure in the ground through the appearance of lava, the formation of cones and flows, and the cessation of activity. Also for the first time in Hawaii, we observed the formation of a pit crater. Unusually good opportunities were presented to observe active flow fronts at close range and study the mechanics of their movement; and to obtain temperature measurements both on flow fronts and in the lava fountains.

 The 1955 eruption was the first to occur in any populous area in American territory. For the first time it was necessary to evacuate fairly large numbers of people with their movable belongings, because of volcanic danger. The staff of the Hawaiian Volcano Observatory worked in close cooperation with the Civil Defense Agency, the Police and Fire departments, the National Guard, the American Red Cross, and the Department of Public Instruction, in handling the disaster. In this connection, the responsibility of the Observatory staff was principally for prediction of the location of new points of outbreak and of the course of the flows. All orders of evacuation were issued by the Disaster Council of the County of Hawaii, with advice from the Observatory staff; and evacuation was on a purely voluntary basis. The eruption also saw the first modern attempts in Hawaii to construct barriers to deflect lava flows from certain areas. The barriers will be discussed in the detailed report on the eruption. The experience obtained with problems of human safety is of great value to all of us, particularly in view of the possibility of the development of even more serious situations in future Hawaiian eruptions.

 Space here does not permit a full account of the eruption. The following pages contain only a brief summary of events. A detailed report will be published later as a bulletin of the United States Geological Survey." [See Macdonald and Eaton, 1964].



Macdonald, G.A., and Eaton, J.P., 1957, Hawaiian volcanoes during 1954: U.S. Geological Survey Bulletin 1061-B, p. 17-72; pl. 1 in pocket. 



 This is the sixth in a series of USGS bulletins covering the work of the Hawaiian Volcano Observatory and the activity of Hawaiian volcanoes during the year. Others are 1948-49 (Finch and Macdonald, 1951), 1950 (Finch and Macdonald, 1953), 1951 (Macdonald and Wentworth, 1954), 1952 (Macdonald, 1955d), 1953 (Macdonald and Eaton, 1955), and 1955 (Macdonald and Eaton, 1964). Each bulletin describes the physical plant of the Hawaiian Volcano Observatory and summarizes eruptive activity, seismicity, ground deformation, crack measurements, fumarole temperatures, rainfall, and special studies conducted during the year.

 Abstract 17

 Through the early months of 1954 Kilauea volcano was uneasy. Many small earthquakes came from sources beneath the caldera and along the adjacent part of the east rift zone. On March 30 two strong earthquakes originated in eastern Puna, between Pahoa and Kalapana, probably on the system of normal faults a few miles south of the cast rift zone of Kilauea, at 1921' N., 155 W. They were followed by numerous aftershocks during the next few weeks. From the first of April, when the Pahoa seismograph was installed, throughout the rest of the year, frequent small earthquakes from the east rift zone south and southeast of Pahoa were recorded. Tilting of the ground surface at the rim of Kilauea caldera indicated a gradual tumescence of the volcano, presumably caused by an increase of magmatic pressure beneath the caldera area. At 4h30m on May 31 an eruption began in Halemaumau crater, and less than an hour later activity spread to the adjacent floor of the caldera. During the first few hours of the eruption 15 million cubic yards of new lava poured into Halemaumau from fountains on the floor of the crater and from a spectacular cascade on the wall. At the same time a rapid flow of pahoehoe covered 139 acres of the caldera floor northeast of Halemaumau. By 7h30m activity had decreased greatly, and during the late morning the pool of new lava in Halemaumau began to shrink, partly because of cooling and loss of gas, but partly also because of drainage back into the feeding conduits. Eruptive activity northeast of Halemaumau ended on the afternoon of May 31, but weak activity in Halemaumau itself continued until June 3. The eruption caused no apparent reduction in magmatic pressure beneath Kilaeuea volcano, and throughout the rest of the year the pressure slowly continued to increase. Seismic activity in the caldera area and along the east rift zone also continued, and at the end of the year Kilauea was markedly uneasy. Mauna Loa remained quiet throughout the year. The seismometric program of the Hawaiian Volcano Observatory was increased by the addition of three new stations. Tilt, temperature, and magnetic measurements continued as during previous years.

Introduction 17

Acknowledgments 18

Seismographs and tiltmeters 18

 Macdonald describes the device used to put time signals directly on a seismogram and includes a graph of strain release for 1953-54. [The means to simultaneously timing all stations was a major advance in the capability to accurately locate earthquakes; the timing principle described is still used today on the paper records. The increased attention to detailed seismic analysis reflects the addition of seismologist Jerry Eaton to the staff. This marked the beginning of a great advance in HVO's monitoring program, which led to a new and more quantitative understanding of how Kilauea works.]

Records and investigations 25

 Earthquake statistics 25

 There was no immediate increase in seismicity prior to eruption but the overall level of seismicity remained high during the rest of the year, including episodes of deep caldera earthquakes and spasmodic tremor, and increased seismicity on the lower east rift near the site of the approaching 1955 eruption. A forecast of increased likelihood of eruption was made in early 1955.

 Strain-release index 32

 Tilting of the ground 34

 Tilt records are tabulated and plotted over several years; the plots show little deflection of normal tilt by the summit eruption. The tilt record from the end of the 1952 eruption is interpreted as part of a gradual tumescence leading to the 1955 rift eruption (Macdonald and Eaton, 1964).

 Crack measurements 38

 Geomagnetic measurements 40

 Temperature measurements 40

 Rainfall records 41

History of volcanic conditions and earthquakes 42

Pneumatolytic deposition and alteration on the floor of Kilauea caldera 49

 Macdonald discusses prehistoric alteration on the floor of Kilauea caldera, correlating the altered areas with the buried margins of central basins active in the 19th century, plotting them on a map to show the comparison. The 1954 eruption occurred on a fissure system trending toward Kilauea Iki, probably the trace of the northeast rift zone coming into the caldera. He hypothesizes that the 1832 and 1868 eruptions were associated with the same fissure trace. [The chemistry of the 1954 eruption was identical to part of the 1959 eruption in Kilauea Iki, supporting Macdonald's contention.] 

The east Puna earthquakes of March 30, 1954 52

The 1954 eruption of Kilauea volcano 55

 Kilauea erupted at its summit May 31-June 3; eruption was both inside and outside of Halemaumau, an unusual circumstance which Macdonald interprets in terms of the history of activity in the 19th century.

 Narrative of the eruption 56

 The lava 62

 The paper includes a table of major oxides and trace elements in the 1954 lava. 

 Radioactivity 64

 Earthquakes associated with the eruption 65

 Conclusion 66

Publications of the Hawaiian Volcano Observatory 69

 Volcano Letter 69

 Contributions 69

Literature cited 69

Index 71



Macdonald, G.A., 1959, The activity of Hawaiian volcanoes during the years 1951-1956: Bulletin Volcanologique, ser. 2, v. 22, p. 3-70; pls., 20 p. 



 "During the decade 1940-1950 Hawaiian volcanic activity was restricted wholly to Mauna Loa. Early in the present decade, however, activity shifted to Kilauea, leaving Mauna Loa quiescent. Eruptions in Kilauea caldera in 1952 and 1954 were followed in 1955 by a flank eruption 32 kilometers east of the caldera. Thus the pattern at Kilauea during the first five years of the decade resembled the succession of summit eruption followed by flank eruption commonly observed on Mauna Loa.

 The return of activity to Kilauea did not bring a resumption of the quasi-permanent lava lake activity long considered characteristic of that volcano. Through the first century during which the volcano was known to Europeans (1823-1924) an active lava lake was present in the caldera a large proportion of the time. However, the lake disappeared during the collapse and accompanying steam explosions in 1924, and has been reestablished only for brief intervals during more recent eruptions. Not only has the continuous lava lake activity not reappeared, but the eruptions of recent years have been characterized by much larger primary lava fountains than those of the earlier typical Kilauean activity. No doubt the two differences are closely related. The continuous lava lake during the years previous to 1924 indicated a magma-filled conduit open to the surface, within which the accumulation of any large head of gas was impossible, and which consequently could not give rise to such large gas-rich fountains as have characterized the eruptions of Mauna Loa and the recent eruptions of Kilauea.

 There appear to be no good grounds for assuming that the type of activity that characterized Kilauea during its first century of observation has been characteristic of the entire history of the volcano. On the contrary, the geologic structure of the volcano suggests that its activity has more generally resembled that of Mauna Loa, with frequent flank eruptions interspersed with short periods of summit activity. Thus the change in character of activity since 1924 may be a return to normal in the long-term history of the volcano."



Macdonald, G.A., and Eaton, J.P., 1964, Hawaiian volcanoes during 1955: U.S. Geological Survey Bulletin 1171, p. 1-170; pls. 1-5 in pocket. 



 This is the seventh and last in a series of USGS bulletins covering the work of the Hawaiian Volcano Observatory and the activity of Hawaiian volcanoes during the year. Others are 1948-49 (Finch and Macdonald, 1951), 1950 (Finch and Macdonald, 1953), 1951 (Macdonald and Wentworth, 1954), 1952 (Macdonald, 1955d), 1953 (Macdonald and Eaton, 1955), and 1954 (Macdonald and Eaton, 1957). Each bulletin describes the physical plant of the Hawaiian Volcano Observatory and summarizes eruptive activity, seismicity, ground deformation, crack measurements, fumarole temperatures, rainfall, and special studies conducted during the year.

Abstract 1

 The year opened with Hawaiian volcanoes quiescent and Mauna Loa remained so throughout 1955. The outstanding volcanic event of the year was the eruption of Kilauea volcano, on its east rift zone in the eastern part of the Puna District. The last lava activity on the east rift zone had been in the vicinity of Makaopuhi crater, in 1923. Not since 1840 had there been activity in eastern Puna. In 1924, however, a very large number of earthquakes along the east rift zone accompanied the draining of lava from Halemaumau crater in the caldera and the formation of fault scarps and grabens in eastern Puna. The eastern outbreaks in 1955 closely followed the lines of fissuring and faulting in 1924.

 The eruption began on the morning of February 28, near Puu Honuaula, 24.5 miles east-northeast of Kilauea caldera. It was preceded for several months by earthquakes, which gradually increased in number to several hundred a day just before the outbreak. Lava activity at the initial vents continued for only 28 hours and on March 1 was replaced by mild phreatic explosions and clouds of steam.

 On March 2 a new series of earthquakes accompanied the formation of fault scarps and opening of fissures 2 miles farther northeast, and at 14h15m lava broke out on these fissures. Through the next 2 days the eruptive fissures gradually extended another 2 miles northeastward, to the outskirts of Kapoho village. Lava fountains at the main vents reached a height of at least 800 feet, and flows from them covered approximately 1,100 acres. Activity in that area stopped on March 6.

 On March 6 a new series of earthquakes commenced, originating in the area 2 to 12 miles southwest of the initial outbreak, and a new outbreak in that area was predicted. On March 12 lava broke out in that region, and between then and March 27 a series of new vents developed along the rift zone for 4 miles to the southwest. Three lava flows from these vents entered the ocean.

 Activity ceased on April 7 but resumed weakly on April 24 and gradually increased until a strong resurgence occurred on May 16. New flows covered much of the area covered by the heads of earlier flows and some new area, destroying one village. The eruption ended abruptly on May 26.

 The volume of erupted material was approximately 141,000,000 cubic yards. The flows covered an area of about 3,900 acres, of which 1,100 acres was under cultivation. Approximately 6.3 miles of public road and many miles of cane-field road were buried, and 21 houses were destroyed. There were no human casualties.

 The erupted lavas were basalt, becoming slightly more mafic as the eruption progressed. The temperature of lava as it was erupted was approximately 1,100C.

The eruption was preceded by swelling of the rift zone, producing a rise of the ground surface of about 1 foot. The several outbreaks of lava were accompanied by sinking o grabens along the crest of the rift zone. The sinking commonly exceeded 1 foot and locally exceeded 5 feet. Stretching of the surface across the ares of eruption resulted in the shifting of know points as much as 5 feet in a direction normal to the rift zone.

 A gradual tumescence of the volcano commenced in January 1953 and continued until the 1955 outbreak, with virtually no interruption by the brief eruption in the caldera in 1954. During the 1955 eruption there was a sinking of as much as 1.4 feet in the caldera region. The calculated volume of sinking in the summit region of the volcano had the same order of magnitude as the volume of lava extruded in east Puna. The lava was not, however, simply drained from under the caldera, because the composition of the erupted lavas was appreciably different from that of the lava erupted in the caldera in 1964.

 The eruption was accompanied by two distinct series of earthquakes. The first originated on the east rift zone in and near the eruption area and appears to have been closely related to the actual splitting open of the fissures that led the lava to the surface. The second series originated in and around the caldera, at the summit of the mountain, in response to the subsidence of the summit region that accompanied the eruption farther east. Both series were characterized.by very numerous small quakes punctuated at intervals by quakes of moderate size. Between February 23 and March 26 about 7,000 earthquakes originated on the east rift zone in the eruption area. Between March 6 and April 16 about 11,000 earthquakes originated in the caldera region. The quakes originating in the caldera area were on the average a little smaller than those coming from the east rift zone.

 Harmonic tremor of two distinct origins was recorded during the eruption Tremor with a period of 0.8 to 1.0 second was generated in the eruption area during the time lava was being extruded. From March 7 to 19 tremor with a period of 0.3 to 0.5 second appears to have originated at a depth of several kilometers in the vicinity of the caldera. During the first days of this short-period tremor no lava was erupted.

 On August 20 a disturbance was reported in the ocean about 60 miles east of Necker Island. This may have been a submarine eruption.

Introduction 2

Acknowledgments 4

The eruption in east Puna 6

 Structural and historic setting 6

 Summary of the 1955 eruption 8

 Narrative of the eruption 15

 Events preceding the eruption 15

 First phaseFebruary 28 to March 1 16

 Second phaseMarch 2 to 6 20

 Third phaseMarch 5 to April 7 28

 Quiet periodApril 8 to 23 60

 Final phaseApril 24 to May 26 61

 Events following the eruption 79

 The cones 81

 The flows 82

 Volume and rate of extrusion of the lava 83

 Composition of the lavas 85

 Sublimates 92

 Temperature of the lava 92

 Viscosity of the lavas 96

 Formation of the pit crater 98

 Ground movements accompanying the eruption 101

 Movements in east Puna 101

 Sinking in the Kilauea summit region 108

 Leveling at Kilauea caldera 111

 Earthquakes preceding and accompanying the eruption 113

 Chronological summary 113

 Earthquakes of the Kilauea summit series 118

 Earthquakes of the east rift zone series 120

 Harmonic tremor 125

 Treatment of earthquake data 127

 Mechanism of the eruption 130

 Losses caused by the eruption 132

 The authors describe losses caused by eruption and describe barriers erected in an attempt to save homes. [The barriers, although initially effective, all failed with renewed activity.] 

 Reoccupation of the area by organisms 132

 The authors discuss the rapidity with which the lava was revegetated; lichens, mosses, and ferns came in within 4 months of the end of the activity.

 Earthquake travel times and crustal structure in Hawaii l33

 The authors tabulate earthquake travel times and present a crustal structure model to be adapted for Hawaii.

 Hawaiian Volcano Observatory Summary for 1955 140

 Seismographs and tiltmeters 140

 Earthquake statistics 143

 Local earthquakes 143

 Distant earthquakes 148

 Tilting of the ground 151

 Crack measurements 151

 Temperature measurements at Kilauea caldera 154

 Chemical analyses of Mauna Loa lavas 154

 The authors give additional chemical analyses of Mauna Loa lavas (1949, Ninole Hills, prehistoric lava of different ages) and cite two charcoal dates for prehistoric lava in Puna [See below.]. The oldest Kau basalt (post-Pahala ash) has a radiocarbon date of 2000+/-250 yrs.

 Rainfall records 156

 Ages of some prehistoric lavas 156

 Volcanic conditions and earthquakes 157

 Possible volcanic eruption near Necker Island 163

Publications of the Hawaiian Volcano Observatory 164

 Volcano Letter 165

 Contributions 165

Literature cited 165

Index 169



[This is an important reference, as the 1955 eruption was the first rift eruption to occur after installation of a broader network of tilt and seismic stations. The paper is the first to discuss quantitatively the relationships among seismicity, ground tilting, and eruption.]



Macdonald, G.A., 1973, The natural environment: geology, in Armstrong, R.W., ed(s)., Atlas of Hawaii: Honolulu, University Press of Hawaii, p. 32-38. [Includes sections on volcanism, earthquakes and tsunamis] 



 The Hawaiian Islands are almost wholly volcanic. Sedimentary rocks form only a narrow fringe around the edges. The vast majority of the volcanic rocks are lava flows, formed by outpouring of liquid magma. Only a few percent are pyroclastic rocks, formed of fragments thrown out by volcanic explosions.

 The volcanoes were built along a line, probably a series of cracks, extending in a northwest-southeast direction across the ocean floor. Starting at the northwest end, at Kure Island, about 25 million years ago, the centers of eruption gradually shifted, until today only the volcanoes at the southeastern end of the chain are still active. The shifting of the eruptive centers may have resulted from a slow northwestward movement of the earth's upper layer across a point of magma generation in the region beneath, at or near the present island of Hawaii.

 The general history of formation of the islands is illustrated by the accompanying figure. Quiet eruptions of very fluid lava on the sea floor gradually built up a broad turtle-backed mountain called a shield volcano. As the mountaintop neared the surface, some steam explosions occurred, but as it built above sea level quiet eruptions resumed. Eventually, toward the end of growth of the shield, the top of the volcano sank in to form a big crater called a caldera. Continued eruptions gradually filled the caldera .

 Then, late in the volcano's history, the frequency of eruption decreased, the composition of the magma changed, and its gas content increased. The lavas became more viscous, the flows were shorter and thicker, and more-explosive eruptions formed larger amounts of pyroclastic rocks. A steep-sided, bumpy cap was built on top of the shield.

 As the late-stage eruptions gradually died out, erosion was able to take ever greater bites out of the volcanic mountain. Waves cut high sea cliffs, and streams cut deep valleys, gradually transforming the rounded shield volcano into a jagged range of mountains, such as the Koolau Range on Oahu. The gravel, sand, and clay formed by weathering and erosion were washed down, some into the neighboring ocean, but some deposited on the floors of the valleys and in shallow water around the edge of the island. At the same time colonial corals and algae started to build fringing reefs around the island.

 Meanwhile sea level repeatedly rose and fell, at least in part because of changes in the volume of ice on the continents during the glacial period. Glaciation also affected Hawaii more directly, a series of small glaciers occupying the summit of Mauna Kea. At times sea level was as much as 300 feet lower, and at others up to 250 feet higher, than now. During a stand 25 feet above present level, a broad coral reef was built along the south side of Oahu, forming the present Honolulu and Ewa plains. During later lower sea levels, streams cut valleys into the reef, and as sea level rose again the mouths of the valleys were flooded to form Pearl Harbor.

 Finally, after a long period of quiet, volcanic activity resumed, sending lava flows down the valleys and building cones such as Diamond Head and Tantalus. On Haleakala eruptions partly refilled a great cavity carved by streams into the heart of the volcano and formed the present floor of Haleakala Crater.



Volcanism



The main shield-building stage of Hawaiian volcanoes is characterized by gentle eruptions of very fluid lava containing little gas. At the vents fountains of liquid lava may reach heights of more than 1,500 feet, but there is little true explosion, and pyroclastic materials amount to less than one percent. Most of the magma forms thin lava flows that spread freely, often to distances of several miles.

 The lava flows are of two types. Pahoehoe has a smooth surface that is often wrinkled by dragging of the still-plastic crust by movement of liquid lava beneath it. The flow quickly crusts over, and as it gradually freezes inward from the edges the moving liquid portion becomes narrower until only a stream a few yards across continues to flow through a sort of pipe with solidified walls. At the end of the eruption, part or all of the liquid may drain away, leaving a lava tube. Most lava tubes are only 1 to 3 feet across, but a few are as much as 50 feet.

 As pahoehoe advances downhill, it commonly changes to aa, which has a rough surface of jagged fragments of clinker. Some flows start as aa. Usually aa flows are fed by open rivers, and at the end of the eruption the liquid in the river may drain away leaving a trench-like channel several feet deep and a few feet to 50 feet wide. Aa flows usually have layers of clinker at both top and bottom, and a center of massive lava. Both pahoehoe and aa contain many small holes (vesicles) formed by gas bubbles in the liquid lava.

 Hawaiian lava flows are more voluminous than those of most other parts of the world. Areas and volumes of flows formed during a few recent eruptions are as follows:

 

DATE	 VOLCANO	 AREA OF FLOWS	 VOLUME OF FLOWS

				 (square miles)	 (cubic yards)

1790	Haleakala		 2.2		 35,000,000

1801	Hualalai		 17.7		 410,000,000

1840	Kilauea		 6.6		 281,000,000

1859	Mauna Loa	 32.7		 600,000,000

1942	Mauna Loa	 10.6		 100,000,000

1950	Mauna Loa	 35.0		 600,000,000

1955	Kilauea		 6.1		 120,000,000

1960	Kilauea		 4.1		 155,000,000



 The lava of 1859 flowed more than 35 miles from its vent on Mauna Loa into the sea. Speeds of advance of lava flows may be greater than 5 miles an hour, but are usually between 10 and 1,000 feet an hour.

 During historic times Mauna Loa has been active 6.2 percent of the time, erupting, on an average, once every 3.7 years, and has poured out more than 0.7 cubic mile of lava. Kilauea has been active 62 percent of the time, but most of the activity was confined to the inner crater, Halemaumau. Eruptions outside the caldera have occurred, on the average, once every 7.2 years, and have poured out about 0.2 cubic mile of lava. During most of the time from 1823 to 1924, a lake of molten lava existed in Halemaumau. In 1924 a splitting open of the mountain allowed the lava lake to drain away and water from the surrounding rocks to enter the hot lava conduits below the surface, resulting in one of the rare explosive eruptions of the volcano as the water was rapidly transformed into steam. Rock fragments weighing as much as 14 tons were thrown over a large part of the caldera floor.

 The late-stage eruptions of Hawaiian volcanoes are more explosive than those of the shield-building stage, because the magma is more viscous and contains more gas. Instead of the small mounds and cones of spatter built around the vents in the earlier stage, late stage eruptions build cinder cones, some of which are several hundred feet high and as much as a mile across. Most of the flows are of aa type, and are shorter and thicker than those of the earlier stage.

 Where the rising magma encounters water the generation of steam brings about explosions which tear the liquid lava into tiny bits and throw them into the air, where they solidify to fragments mostly of sand size, known as ash. Most of the ash piles up around the vent to form a cone, and becomes cemented together to form the solid rock called tuff. This may happen during any stage, but it was particularly common during the post-erosional eruptions on Oahu. Punchbowl, Diamond Head, Koko Crater, Koko Head, Hanauma Bay and Ulupau Head are tuff cones. Others are Kilauea Cone on Kauai, Lehua Island near Niihau, Molokini Island near Maui, and Kapoho Cone on Hawaii



EARTHQUAKES AND TSUNAMIS



Volcanic eruptions on the island of Hawaii commonly are preceded and accompanied by thousands of earthquakes, but only a few of them are strong enough to be felt, and still fewer do any damage. The quakes result from shifting of segments of the volcano as the mountain swells before eruptions, due to inflation of shallow magma reservoir beneath, or shrinks during the eruption as magma is drained away. In terms of origin, they are volcanic earthquakes.

 	Tectonic activity, in the sense of crustal deformation such as that which causes most earthquakes in continental regions, is nearly absent in Hawaii. The entire Hawaiian region is tilting around a fulcrum approximately at the island of Oahu; Kauai is going up, and Hawaii Island going down at a rate of about one foot per century. The islands are partly surrounded by a trench that appears to be the result of sinking of the adjacent ocean floor, probably at least in part because of the load of the volcanoes resting on it. Minor basins have been formed by sagging of some caldera floors over shallow magma chambers, and some faults pass into monoclines, but no other folding is present.

 Major earthquakes, here as elsewhere, are the result of faulting. Some of the faults are on, and probably genetically associated with, the volcanoes. Others are on the ocean floor near the islands. Since 1925, 10 earthquakes with magnitude greater than 5.3 have occurred in the Hawaiian region. Of these, six originated on Hawaii Island and four on faults on the ocean floor. In 1951, a magnitude 6.8 earthquake originated on the Kealakekua fault, just off the Kona Coast of Hawaii. The Maui earthquake of 1938 (magnitude 6.75) had its epicenter about 25 miles north of Pauwela Point on the north shore of Maui, probably on one of the strands of the Molokai fracture zone, a great system of sea-floor faults that trends nearly westward from Baja California to Hawaii.

 The greatest Hawaiian earthquake of historic time occurred in April 1868. It was accompanied, and probably was caused, by movements on faults both on and offshore near the south end of the island of Hawaii. The road near Waiohinu was broken and offset about 12 feet by one of the faults. It is reported that every European-style building in the Kau district was destroyed. The magnitude of the quake was probably around 8.0. In Wood Valley the shaking set off a great mud flow which buried about 500 animals and a village with 31 persons.

 The offshore fault movements during the 1868 earthquake cause a huge water wave - a tsunami - which is reported to have come in over the tops of the coconut trees on the south shore of Hawaii. However, most tsunamis that affect the Hawaiian Islands come from sources in the zone of mountain building that borders the Pacific Ocean. Since 1820, eight tsunamis have caused moderate to severe damage on Hawaiian shores, but only the one of 1868 was of local origin. Five came from South America, one from Kamchatka, and one from the Aleutian Islands. Six others, including one of local origin, did a little damage. The Aleutian tsunami of 1946 drove water to heights as great as 55 feet above sea level at some places in Hawaii. At Hilo, where the water reached 32 feet above sea level, 83 lives were lost. The Chilean tsunami of 1960 created a bore in Hilo Bay which struck shore with a speed of 40 miles an hour, drove water to heights as great as 35 feet, and killed 61 persons.



Malahoff, A., Okubo, P., and Uyemura-Reyes, J.-C., 1994, Geodynamic monitoring of the Loihi submarine volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 75, no. 44, p. 165. [AGU fall meeting, San Francisco, CA, Dec. 5-9, 1994, Program and abstracts] 



 Loihi is the latest manifestation of the Hawaii mid-plate hot spot volcanism and probably marks the site of the next Hawaiian Island to arise. It offers an ideal submarine site for the geodynamic monitoring of a submarine volcano as it grows into an island. An ocean bottom recording geophysical observatory, together with precision ocean bottom recording pressure gauges, has been deployed by submersible on the summit of Loihi submarine volcano over the past three years. The instrument arrays were located at a water depth of 980 meters on the summit at a distance of 34 km south of the Island of Hawaii. In the 1991-92 deployment, the tidal- and wave-corrected pressure data showed a pressure increase that we interpret as a 35 cm deflation of the volcano. The event occurred between December 19 and December 21 of 1991 after a long steady-state period preceding the deflation. Upon commencement of the deflation event, the number of earthquakes beneath the summit increased dramatically from one per hour to over 90 per hour, two hours into the deflation event. Ten hours after commencement of the deflation event, earthquakes actively decreased to five per hour. Deflation ceased after 53 hours. No further earthquake episodes or inflation or deflation events were evident in the data for the next 22 months. Deflation of the volcano summit was followed by eight months of temperature instability in the Pele's Vents hydrothermal field. We suggest that the deflation event is due to magma withdrawal from the magma chamber located beneath the summit and probable volcanic eruptions along the south rift zone.



Malahoff, A., Smith, J.R., and Duennebier, F.K., 1996, Changes in the geology and hydrothermal venting of Loihi [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F397. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 Following the earthquake swarm of July 17 to August 18, 1996, major changes in the geological setting of Loihi submarine volcano took place. Prior to the seismic event, the geology and structure of the summit of Loihi was represented by a platform-like area 8,100 meters long and 5,400 meters wide enclosed by the 1,200-meter depth contour. The summit was characterized by the presence of two prominent pit craters and eastern and western crater located at water depths of 1,100 and 1,370 meters, respectively. A hydrothermally active volcanic cone, named Pele's Vents, was located at a depth of 960 at the southern edge of the summit. The floor of the summit of Loihi was largely covered by prismatic talus, with interstitial hydrothermal clays. Pillow and tube lavas with volcanic cones 5 to 50 meters high were exposed along the axes of the southern and northern rift zones. The inner margin of the summit displayed fissures and normal faults with the downthrown component towards the center of the summit. The pre-earthquake structural data suggest a pre-caldera structural stage for Loihi. Maximum sustained hydrothermal activity observed on Loihi over the past 10 years existed at Pele's Vents with other sporadic venting occurring along the summit platform and along the south rift. Following the earthquake swarm, the hydrothermally saturated Pele's Vent cone gave way and slid into the inner pit crater. Subsequently, the observed above-bottom hydrothermal plume source deepened from 960 to 1,160 meters, possibly emanating from the same intrusive heat source as Pele's Vents. The observed inward collapse of the summit structures and subsequent opening of fissures gave rise to diffuse venting from the newly formed caldera-like depression with the bottom-hugging hydrothermal pool located at depth between 1,250 and 1,220 meters at the sites of the pit craters. Multibeam bathymetric resurveys of the summit show little change along the northern rift, destruction by mass wasting of the Pele's Vent cones and other cones along the southern rift zone, widening and coalescing of the summit pit craters, and deepening of the summit crater floor to 1,350, probably marking the next stage of caldera development on the summit of Loihi.



Malahoff, A., and Smith, J.R., Jr., 1997, Tectonics of the summit collapse, Loihi submarine volcano [abs.]: Geological Society of America Abstracts with Programs, v. 29, no. 5, p. 27. [Geological Society of America, 93rd Annual Cordilleran Section meeting, Kailua-Kona, HI, May 21-23, 1997] 



 During the period of 16 July to 10 August 1996, an unprecedented number of earthquakes were recorded under the summit of Loihi submarine volcano. Earthquakes of up to magnitude 4.5, numbering up to 140 per day were observed at the Hawai'i Volcano Observatory during this period. This marked the most intensive period of earthquake activity ever observed under Loihi. In order to determine the effect of this intense seismic activity on the structure, geology and submarine hydrothermal activity, deep submergence expeditions were organized involving the deep submergence support ship of the University of Hawaii's RJV Ka'imikai-o-Kanaloa and the submersible Pisces V. The first expedition was carried out in August 1996 and the follow up expedition took place in September 1996. Visual observations of the summit terrain of Loihi after the earthquake showed a fractured, faulted terrain covered by talus with the downthrown component of the normal faults located towards the center of the summit. The shipboard survey, which included the remapping of the Loihi edifice using a multibeam SeaBeamTM acoustic mapping system, showed a drastically changed terrain at the southern edge of the summit. A large pit crater 1,000 meters wide and 300 meters deep had formed at the site of a now-collapsed 300 meter high volcanic cone with a former summit depth of 960 meters and a former site of the Pele's Vents. The summit surface has been extensively fractured and is now covered almost entirely by talus. The formation of the new pit crater exposed a 300 meter vertical section of the dike system that formerly supplied the heat for Pele's Vents. The dike system was observed to be hydrothermally altered and there is sufficient heat remaining to generate a new vigorous vent system at the base, at a water depth of 1,300 meters and at the rim of the crater at a depth of 1,000 meters. This seismic event marked a significant volcano-tectonic episode on Loihi, marking a summit collapse stage before further growth by summit volcanism takes place. The fate of the probable withdrawn magma that gave rise to the collapse is not known as there were no obvious bathymetric changes observed on the active south rift zone.



Malahoff, A., 1997, Growth and destruction episodes in the geological history of Loihi [abs.], in, Big Island Science Conference, 14th, Hilo, HI, Apr. 17-19, 1999, Proceedings: Hilo, HI, University of Hawaii at Hilo, v. 14, [p. 37]. [Sponsored by Sigma XI, UH Hilo Chapter and University of Hawaii at Hilo] 



 Before August 1996, bathymetric surveys and resurveys for the past 40 years showed no significant change in the configuration of Loihi submarine volcano. With the advanced shipboard high-resolution multibeam mapping techniques of the past 15 years, it became possible to map details of the surficial geology of Loihi. These new maps showed the presence of pit craters on the summit and ridges and valleys on the slopes. The earthquake history of Loihi has been well documented by the U.S. Geological Survey's Hawaiian Volcano Observatory network. The earthquake data shows periods of intense activity under Loihi at irregular intervals.

 During December 1991, a three-day period of intense earthquake activity coincided with a 40-centimeter deflation of the summit as recorded by an underwater robotic observatory emplaced on the summit. The most intense period of earthquake activity ever recorded beneath Loihi then took place between July 16 and August 10, 1996, with up to 140 earthquakes per day and magnitudes of up to 4.5. Visual observations of the Loihi summit using the submersible Pisces V after the earthquakes showed a fractured, faulted terrain covered by talus with the downthrown component of the normal faults located towards the center of the summit and the complete disappearance of a 300-meter high summit cone replaced by a 300-meter deep, 1,000-meter-wide pit crater. The shipboard survey, which included the remapping of the Loihi edifice using a multibeam SeaBeam acoustic mapping system aboard the submersible mothership, RJV Ka'imikai-o-Kanaloa, showed in detail, the drastically changed terrain at the southern edge of the summit. A pit crater had formed at the site of a now-collapsed hydrothermally active volcanic cone with a former summit depth of 960 meters. The summit surface has been extensively fractured and is now covered almost entirely by talus. The formation of the new pit crater exposed a 300-meter vertical section of the dike system that formerly supplied the heat for Pele's (hydrothermal) Vents that existed previously on the site. The pit crater resulted from a collapse of about 150 x 106 cubic meters, or about 380 x 106 tons of rock into the volcano. The dike system was observed to be hydrothermally altered and there is sufficient heat remaining to generate a new vigorous vent system at the base at a water depth of 1,300 meters and at the rim of the crater at a depth of 1,000 meters. This event allowed the observation of the formational mechanism of a volcanic pit crater and marked a significant volcano-tectonic episode on Loihi, namely, a summit collapse stage before further growth by summit volcanism takes place. The collapse was probably generated by magma withdrawal into the hot spot magmatic plumbing. The fate of the withdrawn magma that gave rise to the collapse is not known. There are no bathymetric changes observed in the SeaBeam data along the active south rift zone of Loihi.



Maley, R.P., 1973, An earthquake in Hawaii: Earthquake Information Bulletin, v. 5, no. 4, p. 11-14. 



 "Earthquakes are not strangers to the residents of the "Big Island" of Hawaii, but the strength of the tremor that shook the island on April 26, 1973, was not only surprising but frightening. Although the island experiences about four felt earthquakes a month, this was only the eight time in the last 44 years that Hilo has experienced the damaging effects of strong earthquake shaking. Earth scientists have assigned the highest earthquake risk rating to the entire island."



Maley, R.P., 1978, Comments on ''The island of Hawaii earthquakes of November 29, 1975; strong-motion data and damage reconnaissance report'' by Christopher Rojahn and B. J. Morrill: Bulletin of the Seismological Society of America, v. 68, no. 2, p. 527-529. 



 "The report by Rojahn and Morrill presents an excellent documentation of the 1975 Hawaiian earthquakes, particularly the strong-motion acceleration records that were obtained at three ground stations located on the island of Hawaii. Although a complete analysis of the records is not yet available, a visual examination reveals what appear to be some unusual characteristics compared to the "California type" strong-motion recordings. For instance, there is an obvious absence of shorter period waves on the record from Punaluu except for some high-frequency pulses that appear at the end of the earthquake. The reason for the lack of shorter period waves during the main body of the earthquake is unknown at this time. On the other hand, the postearthquake high-frequency phenomena is believed to have been caused by the tsunami that battered down the station door and washed over the instrument.

 Following recovery of the Punaluu accelerogram, there was some discussion between members of the Seismic Engineering Branch and the Hawaii Volcano Observatory (both of the U.S. Geological Survey) concerning the possible estimation of tsunami arrival time by using the strong-motion record. Initially this appeared to be a valid concept, although without real time on the accelerogram one cannot determine whether the instrument was triggered by early P waves or for that matter by P waves at all. An initial examination of the record indicated the tsunami had arrived at the accelerograph station 84 sec after instrumental triggering. If in fact the instrument was triggered by the P wave, then the impression conveyed by the Rojahn and Morrill report is that the tsunami arrival time could be approximated from the strong-motion record. On a closer and more recent inspection of the record, it is apparent the instrument automatically stopped at the end of the earthquake when ground accelerations did not exceed 0.01 g (at sec 84), and was retriggered at some later time when the tsunami struck the instrument house (Figure 1)."



Maley, R.P., 1984, Strong-motion from the November 16, 1983, Hawaiian earthquake [abs.]: Earthquake Notes, v. 55, p. 27. [Seismological Society of America annual meeting, Anchorage, AK, May 30-June 1, 1984 (Abstracts)] 



 The magnitude 6.3 (MB) earthquake of November 16, 1983, located on the eastern flank of Mauna Loa, triggered 15 strong-motion accelerographs operated by the U.S. Geological Survey on the Island of Hawaii. Each recording station was equipped with a single three-channel film recorder installed at the lowest level of a pre-existing structure, typically a smaller garage-type building. The records from this earthquake provide the most complete set of data and show the largest ground accelerations recorded during any Hawaiian shock and include peak amplitudes greater than one-half g at the three nearest stations located 18 to 30 km from the epicenter.

 Strong-motion accelerograms from Hawaii typically show unique site-dependent signatures and this earthquake was no exception. Most of the accelerograms resemble California-type recordings, but three sites exhibit strongly sinusoidal characteristics: frequencies of 7 to 10 Hz at Waimea and Honokaa in the north and about 3 Hz at one Hilo location. In contrast, the recording at Wahaula on the southeast coast is dominated by unusually long (0.6 to 1 Hz) horizontal waves throughout the earthquake.



Maley, R.P., 1986, Strong-motion results from the November 16 Hawaii earthquake: U.S. Geological Survey Circular 971, p. 13. 



 On November 16, 1983 (1613 G.m.t.), a strong earthquake shook the Island of Hawaii. The magnitude (Mg) 6.4 event was located at lat 19.430 N., long 155.454 W.; the hypocenter was located beneath the east flank of Mauna Loa at a depth of about 12 km. A total of 15 strong-motion instruments operated by the USGS on the island (fig. 13) were triggered by this earthquake; epicentral distances for these 15 stations ranged from 18 to 98 km. Each Hawaii accelerograph station is equipped with a single, three-channel film recorder, typically installed at the ground level of a fire station, school, or maintenance type of structure. The accelerograms from this event, which provide the most complete set of Hawaii strong-motion data, also contain the largest ground accelerations recorded during any Hawaii earthquake; the data include peak amplitudes greater than 0.50 g at the three nearest stations located 18 to 30 km from the epicenter.

 Strong-motion records from Hawaii typically show characteristic, site-dependent signatures, and this data set is no exception. Most of the records resemble California-type accelerograms, but three sites exhibit strongly sinusoidal characteristics (fig. 14): frequencies of 7 to 10 Hz at Waimea and Honokaa to the north and of about 3 Hz at the Hilo Fish and Wildlife station. In contrast, the record from Wahaula on the southeast coast is dominated by unusually long (0.6-1 Hz) horizontal waves throughout most of the S-wave motion.



Martin, J.H.S., 1887, [On the Mauna Loa eruption and earthquakes of 1887]: Hawaiian Gazette, 02/01, p. 1. [Letter no. 03] 



 Subheads over letters from correspondents, signed and unsigned:

Mauna Loa!; Hawaii's great volcano; twenty miles of liquid fire in motion!; Madam Pele on the rampage!; continuous earthquake shocks!; description of the flow!; notes and incidents



An account of the early stages of the eruption of 1887. The eruption first broke out on January 16 near Pohaku o Hanalei. From that time earthquakes were felt in the Kau district, and continued as often as 150 or 200 shocks per day. It was reported at Kahuku by Mr. Jones, that 379 shocks were felt up to 10 o'clock Tuesday night [Jan 18]. About 7:00 p.m., January 18, the lava broke out at Keau Hill, on the Kahuku lands, and one stream reached the sea at Hopeloa on January 20. This paper is preceded by G. Jones (1887b), followed by C.N. Spencer (1887), and refers to an earlier report (Paris, 1887).



Martin, M.G., ed(s)., 1979, The Lymans of Hilo (Revised ed.): Hilo, HI, Lyman House Memorial Museum, Part 1, 224 p. [Originally published in two parts. Part one was published in 1970; Part two, edited by Nettie Hammond Lyman, Kathryn Lyman Bond and Ethel M. Damon, was published in 1932. They are revised and combined in this 1979 edition.] 



 Selections from the letters and journals of Sarah Joiner Lyman. Reference to earthquakes and eruptions are as follows:

p. 55-56 [entry for Aug. 6, 1833] ". . . The crater [of Kilauea] is about 7 miles in circumference at the top. It has sunk several hundred feet from the surface of the ground in the vicinity and is in the form of a basin, smaller at the bottom than the top. the sides are lined with rocks and large sulphur banks. The bottom is covered with black lava. about 18 months ago there was an eruption [on Byron's ledge] which filled the basin 1/3 full with solid lava. Since then it has again sunk, leaving a black ledge several rods in width the whole circuit of the crater, so that people can descend and go around it on this ledge with comparatively little danger. At the bottom there are two lakes, one mile apart, perhaps, in action, and this evening the fires were exceedingly brilliant. There appeared to be a current as in the ocean; the boiling lava flowed from one side to the other, the waves sometimes dashing to a great height. Other small fires were visible where only smoke was seen in the daytime. There are large crevices in the ground in every direction from the volcano from whence issue smoke. the heat from them is sufficient to boil water or cook food. About 1/4 mile from the edge of the crater is a large sulphur bank from which smoke was seen rising. . . .

p. 58 "October 3, 1833. . . . Last night two shocks of earthquake were felt at this station [Hilo], one was quite heavy."

p. 64 "February 19, 1834. Whilst at the dinner table tonight, we experienced a severe shock of earthquake. the first intimation we had of it, we heard a rustling among the thatch which was instantly followed by a heavy shaking, which lasted some seconds and abated seemingly to gather more strength for a more powerful shaking. Everything seemed to be in commotion around us, and our little cottage shook so terribly that I, fearful it would be down on our heads, sprang from my chair and ran out of doors and husband followed. I looked instantly toward the houses of Mr. Dibble and Goodrich to see if they were standing, for it appeared to me that they could not stand the shock. Things standing on the bureau were upset but nothing was precipitated to the ground. The walls of Mr. Dibble's house were somewhat injured. Mr. Goodrich's sustained no injury though it is a two story building with a cellar under the whole of it. All the cream was thrown out of the pans of milk standing in their cellar. The undulations were from north to south and lasted some seconds and were rather gentle at first. I could compare the shaking of our house to nothing but the shaking of an elephant in attempting to remove a man from his back. . . ."

p. 71 "August 16, 1834. Received letters from Waimea which say that on the 3rd of August two or three hours before light (the same time a shock was felt here) they had a heavier earthquake than they ever before felt . . . a heavier one in the evening, making eight in one day. Only one shock was felt in Kailua. The natives say that in the days of Kamehameha, 80 shocks were felt in one day, some of them so hard as to throw down houses. this was soon followed by an eruption of the volcano which destroyed some lives and did much damage. . . .

p. 75 "February 21, 1835. There was a sudden rise in the sea last night. We know [not] how to account for it unless it was occasioned by some volcanic action. the water was forced back in the small streams to do some damage to the fish ponds situated some rods from the sea shore."

p. 103 "December 14, 1838. Since the 5th. of Nov. the earthquakes have been quite frequent. On the 12th inst. we felt a severe shock, one that terrified even the natives. It came on gradually, continued for several seconds, and went off with a violent shaking. I found some difficulty in keeping my balance when running out of the house."

p. 108 "April 5, 1841. About 1 p.m. there was a smart shock of earthquake. I was sitting in my room alone when I felt the premonitory shock. I arose and stepped to the verandah where the children were playing when there was such a violent shaking as to arrest them in their play and excite their fears. . . ."

p. 108-109 "April 20, 1841 "On the night of the 8th inst. we experienced a severe shock of earthquake and so much was I affected by it, I could not record it for several days and have not been able till last evening to write anyone about it. It was a memorable night. We felt the shock not far from 12. It was more severe than any former one. we arose and looked about the house and saw its effects on the plastering, milk etc. and retired. About 1 a.m. there was a jar and we sprang up expecting a heavy shock to follow but were disappointed, but our feelings had become too much excited to allow of our sleeping, we therefore dressed and sat up the remainder of the night, and never shall I forget how intensely I watched for the morning. At two there was another jar. I then raised the curtain of the children's bed and also of the crib, placing the latter near the door and kept myself in a situation to flee. . . Our plastering and chimney are cracked and some stone walls thrown down. It has been remarked by the natives that it was the most severe shock they ever felt. . . .

p. 109 "May 25, 1841." A description of a tsunami, beginning at 5:30 p.m. as water receded several rods below low water mark in Hilo Bay, returned 6 or 7 times to 12 to 15 feet above high water mark, continuing until dark at lower wave heights. The water flowed so gently that no injury was done to the houses entered.

p. 131-132 "March 2, 1852. Letter to son Frederick, Punahou School, Honolulu." Brief mention of the 1852 eruption of Mauna Loa. Pele's hair and cinders fell in Hilo. The longest strand of hair measured twenty inches. 

p. 136 "August 11, 1855. A new volcano in Mauna Loa. [1855 eruption]

p. 136 "August 14, 1855." and p. 137 "August 15 and 17, September 15, October 15 , November 1 and 25, 1855 and February 1856. Brief accounts of the lava from Mauna Loa's northeast rift zone approaching Hilo. The last entry describes lava flowing over a 30-foot-high precipice into a basin of water [Wailuku River?].

p. 150-151 "June 19, 1868. Letter to Mrs. Lorenzo Lyons, Waimea, Hawaii. . . . No one knows as I do, how much our house was damaged by that fearful quaking of April 2nd. Every room, cupboard and closet, where there was any plastering, has under gone repairs. Two rooms have been cleared of the plastering, ceiled, cloth'd and papered. The doors planed off, latches and bolts moved in order to shut them. We have pasted and puttied to close up seams which were opened in the corners and casing and when that would not do, strips of board have been called into requisition.

 . . . .

". . . as those who have not had any experience don't know what an earthquake [italics hers] is, so they cannot have any conception of the work it has made for us . . . . I have come to the conclusion that ceiled are the [italics hers] for earthquake countries, so I shall rejoice to see the last of our plastering."

p. 151 "July 24, 1868. Letter to Mrs. Lorenzo Lyons, Waimea, Hawaii

 I must begin to tell you that we were waked and driven from our beds last night by a fearful shaking, so we robed ourselves and lay on the outside of the bed the rest of the night. We have had several shakes during the week and three of them no mean ones either."

p. 151-152 "August 15, 1868. Letter to Mrs. Lorenzo Lyons, Waimea, Hawaii."

 An account of another tsunami, beginning soon after midnight the previous Thursday night, consisting of 12 larger waves with a rise not much above high water mark, quieting down after daylight. The waves carried away one bridge and damaged fish dams. The waves were not noted in Puna or at Laupahoehoe. The article closes:

" . . . There is seldom a night we do not feel earthquakes. There was one Sat. night, at twenty minutes to two, that waked us out of a sound sleep."

p. 165-168 A letter dated May 4, 1880 recounts the appearance of fire at the summit of Mauna Loa on May 1. Letters dated July 26, Aug. 3 and Aug. 4, 1881 mention the flow coming toward Hilo, and a letter dated August 16, 1881 announces the end of the eruption. A letter dated January 4, 1882 remarks that the flow came within half a mile of us.



Mattox, S.R., and Babb, J.L., 1993, Fundamentals of seismology: demonstrations and activities for inservice training of K-12 teachers in an area of high seismic risk [abs.]: Geological Society of America Abstracts with Programs, v. 25, no. 6, p. A-218. [Geological Society of America, annual meeting, Boston, MA, Oct. 25-28, 1993] 



 To prepare local teachers and students for the destructive earthquakes that occur on the island of Hawaii, we have designed, in cooperation with Hawaii Volcanoes National Park, an intensive lesson (4 hrs) on earthquake origin, distribution, and safety. The lesson, which consists of a series of demonstrations and activities that incorporates objectives from the state's curriculum guide, is conducted on the rim of Kilauea caldera in an area extensively damaged by the M=7.1 1975 and M=6.6 1983 earthquakes. Topics include strength of materials, elastic rebound, seismic waves, seismometers and seismograms, intensity and magnitude, earthquakes in Hawaii, isoseismal maps, and earthquake safety.

 Strength of materials is demonstrated using people, wood, and rock. Elastic rebound is demonstrated by applying stress to wood until it fails. Using a sledge hammer, students send energy waves to a portable seismograph. Their seismograms vary with source distance and energy input and are compared to common earthquake patterns recorded at the U.S. Geological Survey's Hawaiian Volcano Observatory. Seismograms from Hawaii's 1974 and 1983 earthquakes are used to determine Richter magnitude. Historical accounts of specific earthquakes are discussed and placed on a Mercalli scale. Students construct an isoseismal map for the I=XII 1868 earthquake and use simple equations to relate area of felt intensity to magnitude. Location of earthquakes in Hawaii are shown on maps and cross-sections. Causes of specific earthquakes, magma movement, gravitational sliding, or lithospheric flexure, are described. The lesson concludes with a discussion of earethquake safety. 

 This lesson is applicable to other areas of high seismic risk with a few modifications to account for local geology.



McClelland, L., Simkin, T., Summers, M., Nielsen, E., and Stein, T.C., ed(s)., 1989, Global volcanism 1975-1985; the first decade of reports from the Smithsonian Institution's Scientific Event Alert Network (SEAN): Englewood Cliffs, NJ, Prentice Hall, Inc., 657 p. [In Volcanology collection] 



 A compendium of Reports of volcanic activity around the world during the years 1975-1984. A sections on the Central Pacific Ocean covers volcanic activity at Loihi (p. 405), Kilauea (p. 405-454), and Mauna Loa (p. 454-460).



McFarland, W.N., 1929, Earthquakes, in Results of observations made at the Coast and Geodetic Survey magnetic observatory near Honolulu, Hawaii, 1923 and 1924: Washington, DC, Department of Commerce and Labor, Coast and Geodetic Survey, Serial No. 452, p. 99-104. [See abstract for Hazard, 1924. This series of reports ends with June 1924. Subsequent data are in quarterly seismological reports (Neumann, 1926-1931)] 



 A register of the earthquakes recorded at the Honolulu Magnetic Observatory



McLaughlin, E.A., Lilley, M.D., and Rust, T., 1996, Microbial hydrogen oxidation on the Loihi event plumes: microbial rapid response? [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F398. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 As hydrogen is a byproduct of high temperature rock/water reactions, it would be expected that fluids altered during an eruptive or intrusive event will contain dissolved concentrations well above background. We have observed evidence for this at 9N on the EPR where a significant spike (up to 30 mM H2) in endmember concentrations was present after the 1991 eruption. Elevated concentrations of bacteria have also been observed to correspond with seafloor eruptive events leading to the conclusion that a microbial bloom may occur within the resulting plumes (Holden pers. comm.). However, no activity measurements have been reported for these plumes. Given the facultative and ubiquitous nature of hydrogen oxidizers, it seems likely that the initial microbial bloom may consist mostly of hydrogen utilizing organisms. Hydrogen oxidation rates were measure during the August 1996 Loihi response cruise. Hydrothermal plumes were identified by positive temperature anomalies and were sampled with a CTD/rosette package. Oxidation experiments were run on both near-source and downstream plumes. The determined oxidation rates are significantly higher in both types of plume samples than in background seawater which indicates the presence of organisms actively oxidizing hydrogen. These rates will be compared to oxidation experiments run during the October cruise to the Loihi site so that temporal changes in the utilization and importance of hydrogen can be determined.



McNutt, S.R., Ida, Y., Chouet, B.A., Okubo, P., Oikawa, J., and Saccorotti, G., 1997, Kilauea Volcano provides hot seismic data for joint Japanese-U.S. experiment: Eos, Transactions, American Geophysical Union, v. 78, no. 10, p. 105-111. [Authors comprise the Japan-U.S. WorkingGroupon VolcanoSeismology] 



 A team of 25 researchers from the United States, Japan, and Italy joined the staff of the Hawaiian Volcano Observatory (HVO) from January 8 through February 9, 1996, to make the most detailed seismic recordings on Kilauea Volcano ever. One-hundred-sixteen portable seismographs were installed in and near Kilauea Crater in Hawaii Volcanoes National Park as a joint Japanese-U.S. research project to record volcanic earthquakes and tremor. The importance of these events has long been recognized, but their origin remains poorly understood due to inadequate network coverage and limitations of the analog instrumentation used in the past.

 On February 1, a swarm of over 500 earthquakes was recorded by the dense network, providing the best recording of an intrusive earthquake swarm at Kilauea. The data collected offer an unprecedented opportunity to understand earthquakes associated with magma transport.



McNutt, S.R., Benoit, J., Christensen, D., Estes, S., Tytgat, G., Stihler, S., Weimer, S., Jolly, A., Robinson, M., Hansen, R., Lindquist, K., Garces, M., Lahr, J., Hammond, R., Power, J., and Paskievitch, J., 1997, Broadband seismology at the Alaska Volcano Observatory, 1993-1997 [abs.]: Eos, Transactions, American Geophysical Union supp., v. 78, no. 46, p. 429. [AGU fall meeting, San Francisco, CA, Dec. 8-12, 1997, Program and abstracts] 



 AVO scientists have installed broadband seismometers at five volcanoes during 1993-1997 to increase bandwidth and dynamic range. Single stations were deployed at three volcanoes for reconnaissance studies; 3 stations were used to augment a 10-station network; and 1 station was deployed for a short-term topical study. One instrument (CRB) was deployed at Mt. Spurr, Alaska, 5 km from the Crater Peak vent, from July 1993-August 1995, beginning only 3 months after Spurr's last eruption. 12-bit digital data were telemetered to Fairbanks. Numerous earthquakes and glacial events were observed, but no true long-period (T>>1 sec) volcanic events were noted. This instrument was moved to Augustine volcano, Alaska, in October 1995 and will remain as a permanent station (AUB) 1 km from the active vent. 12-bit data are telemetered to Fairbanks and recorded in both continuous and event-triggered modes. Numerous earthquakes have been recorded during this background time at Augustine, but no long-period events have been detected. A second instrument was installed at Akutan volcano, Alaska, following a strong earthquake swarmm there in March 1996. This instrument (AKT) is 13 km from the vent, but only 5 km from the swarm locus. Data were telemetered in analog form from March 1996 until May 1997, and as 12-bit digital data thereafter. Many swarm earthquakes were recorded, but again no long-period events were observed. Three instruments were deployed to augment a network of 10 digitally telemetered broadband stations around the summit of Kilauea caldera, Hawaii. True long-period events (T>10 sec) occurred during the February 1, 1996 earthquake swarm and during a similar swarm in January-February 1997 (B. Chouet, pers. comm.). These events were clear on filtered seismograms but were quite small. In contrast, strong tremor and events known locally as whooshes and chugs were recorded 2.3 km from the vent during 2 weeks at Arenal volcano, Costa Rica, in April 1994. The tremor consisted of as many as 7 integer harmonics with frequencies >1.5 Hz. However, the only significant energy recorded below 0.7 Hz was due to microseisms, even though the volcano was erupting at the time. Our experience to date suggests that broadband signals are rare and small when they occur, and their value in monitoring or forecasting eruptions has yet to be optimized. However, in Alaska we are well posed to catch a long-period precursory sequence to a large explosive eruption, should one occur. Furthermore, many Alaskan volcanoes have high noise levels, so the high dynamic range of the broadband instruments is always helpful. Finally, digital receiving telemetry equipment is being installed in Anchorage, which will permit eventual upgrading of stations on Cook Inlet volcanoes, and recent analog station installations in remote areas have also been designed to permit eventual upgrading with broadband seismometers.



McSwanson, J.B.c., 1922, New lava flow is from Kilauea: Honolulu Advertiser, 05/30, p. 1. 



 "Prof. T.A. Jaggar, volcanologist at Kilauea volcano, after investigating the new lava outbreak, says it is a flow which has broken through a rift caused by an earthquake preceding the eruption on Sunday night [May 28]."

 The remainder of the article describes Jaggar's surprise at the location of the outbreak, as he was looking to the Kau side, and his opinion that if the eruption continues it could run to the sea in the Kalapana direction.



Midson, B.P., and Sansone, F.J., 1996, Loihi hydrothermal plume dynamics [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F397. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 A series of tow-yo and vertical hydrocasts were performed in response to the seismic crisis of 17 July to 12 August 1996. Eight lowerings included a background cast, 30 km E of Loihi, 3 tow-yos, 2 casts into pit craters and two casts W of the summit. A maximum temperature anomaly of 0.5 deg C was detected at 1160 m near the former location of Pele's Vents (PV). This plume was identified with temperature anomalies as far as 5 km W of Loihi. The two legs of the N-S tow-yo show the plume to be loosely constrained around the summit area. The E-W tow-yo did not further constrain the source region for this plume, but did confirm the presence of a predominantly W-SW current, since no anomaly was found E of Loihi and a temperature signal was seen 5 km W of the summit. The waters filling the Pit craters were the warmest measured from the surface. Both Pele's Pit, formerly PV, and the East Pit were filled with 7.0 deg C water with a salinity of 34.88 psu below 1220 m. The gradients in temperature, salinity and oxygen were extremely sharp, changing to the maximum anomaly in less than 15 m, then remaining nearly constant to the bottom of the cast. Light transmission, however, continued to decrease linearly from 91% just above the pit water to 10% near the bottom of the cast.

 At least one hydrocast showed an inverted relationship between T and S in the two types of altered water. Above The East Pit, the shallow plume had a maximum T anomaly of +0.2 deg C with an associated negative S anomaly of-0.04 psu. The pit water had a T anomaly of +3.5 deg C but an associated positive S anomaly of +0.35 psu. Density profiles, as calculated from conductivity and temperature, show the water filling the pit craters to be less dense than overlying water. This is unlikely, given the steepness of the physical gradients; we assume the actual density is greater than the overlying water, and the apparent density inversion is due to the heavy particulate load.



Monsarrat, J., 1907, Earthquakes continue at Monsarrat's ranch: Pacific Commercial Advertiser, 01/19, p. 1. 



 An earthquake swarm was continuous from midnight, January 10, to midnight, January 12, less frequent thereafter, but still continuing as of January 14. Monsarrat observes that the earthquakes of January 12-13 "were entirely different from anything I have ever experienced, in my residence of 23 years in this district, having a peculiar rotary motion, and of long duration, some lasting from two to three minutes, though not heavy."



Moore, J.G., and Koyanagi, R.Y., 1969, The October 1963 eruption of Kilauea Volcano, Hawaii: U.S. Geological Survey Professional Paper 614-C, p. C1-C13. 



 The eruption of October 5-6, 1963, occurred along an 8-mile section of the central part of the east rift zone of Kilauea Volcano. About 9 million cubic yards of lava was erupted from more than 30 fissures which show a slight right-offset en echelon pattern; the new lava covered an area of 1.3 square miles.

 A few hours before the actual outbreak, the summit of Kilauea began to subside, and strong harmonic tremor and earthquakes commenced at both the summit and the site of the later activity near Napau Crater. These phenomena were apparently caused by subsurface flow of magma from the summit reservoir through the rift zone conduits to the eruptive vents 8 miles distant.

 The lava of the eruption is a tholeiitic basalt with an average of 5.6 percent olivine. In general, lavas that erupted toward the eastern end of the eruptive zone are richer in olivine. These lavas, like others that erupted in historic times on the rift zone, show a slight differentiation when compared with lavas that erupted from the summit. The differentiation, apparently caused by cooling and crystallization within the rift zone, can be measured by the ratio (CaO/FeO+0.9 Fe2O3), which is greater than 1 for summit lavas and which decreases systematically for lavas that erupted progressively eastward along the rift zone.



Munson, C.G., Thurber, C.H., and D'Silva, A., 1994, A peak-ground-acceleration predictive equation for Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 75, no. 44, p. 448. [AGU fall meeting, San Francisco, CA, Dec. 5-9, 1994, Program and abstracts] 



 We derive a peak-ground-acceleration (PGA) predictive equation for the island of Hawaii using the Joyner and Boore [1988 and 1993] two-step linear regression method. Our data set consists of 55 horizontal PGA values from 11 events ranging in moment magnitude, Mw, from 4.9 to 7.1 including the 1975 Mw = 7.1 Kalapana event, the 1983 Mw = 6.7 Kaoiki event, and the 1989 Mw = 6.1 South Flank event. At present, we have developed an attenuation curve using 35 observations from the 7 largest events. Following Joyner and Boore [1981], we restrict our data set to events whose hypocenters are shallower than 20 km and to events recorded by more than one station. Station distances vary from 0 to 96 km. Moment magnitudes and additional earthquake source parameters are determined by a theoretical fit to the observed Fourier spectra using the method of Anderson and Humphrey [1991]. The standard deviation for our preliminary Hawaii attenuation curve (sy = .280) is comparable to that of Joyner and Boore [1981] (sy = .260) and Boore et al. [1993] (sy = .205) for North America. Klein [1994] modifies the Boore et al. [1993] attenuation curve to approximately fit the Hawaii PGA data by shifting the curve upwards by a factor of 1.2. The difference between our attenuation curve and the attenuation curve of Klein [1994] is most pronounced in the 10-to-30 km range where the Klein [1994] curve begins to fall off more rapidly. Future efforts will include a diagonal weighting matrix in the second stage of regression as suggested by Joyner and Boore [1993 and 1994].

 Quaternary ash sites on the Hamakua coast display amplifications for horizontal PGA as high as 4.8 relative to lava sites, resulting in a significant site term in the regression equation. Shear-wave velocities for these ash sites, obtained from shallow refraction profiles, are less than 100 m/s. The maximum ash site acceleration amplification for 2% critical damping is approximately 40% greater than that for lava for periods between 0.2 and 0.4 s. Ash/lava spectral ratios for Hilo accelerograph sites vary from 3 to 8 between 1 and 15 Hz.



Munson, C.G., Thurber, C.H., Li, Y., and Okubo, P.G., 1995, Crustal shear wave anisotropy in southern Hawaii: spatial and temporal analysis: Journal of Geophysical Research, v. 100, no. B10, p. 20,367-20,377. 



 Split shear wave arrivals are analyzed in seismograms from local earthquakes in southern Hawaii recorded at five temporary arrays and one permanent network station. We identify split shear wave arrivals by their orthogonally polarized pulses, linear particle motions, and similar waveforms and estimate the delay time for the slow shear wave arrival (S2) using a waveform cross-correlation method. Consistent leading shear wave polarizations were measured at the majority of our stations. Comparison of observed and predicted shear wave polarizations confirms that the former are due to anisotropy rather than earthquake source mechanism. Agreement between fast shear wave (S1) polarizations and independently estimated directions of the maximum horizontal compressive stress (sH) for the Ainapo and Punaluu Gulch arrays leads us to conclude that the predominant source of the observed anisotropy for these two areas is stress-aligned cracks consistent with the extensive dilatancy anisotropy (EDA) hypothesis. Two distinct S1 polarization directions were observed over distances less than 1 km for the Bird Park and South Flank arrays. S1 polarizations parallel to the NE striking Kaoiki Pali fault system for the Bird Park array combined with a nonhorizontal maximum principal stress (s1) for the South Flank region suggest stress-induced cracks aligned by nearby faulting as a source for the observed anisotropy. Large station-to-station variations in S1 polarization and the relationship between delay time and event depth for arrays in the Kaoiki and South Flank regions provide evidence for anisotropy that is predominantly shallow rather than pervasive. Average delay times for the five arrays vary from about 100 to 230 ms, with standard deviations of the order of 30 ms. Estimated anisotropic velocity variations and crack densities exceeding 10% indicate that the upper crust of southern Hawaii is highly fractured. A search for possible temporal changes in delay time associated with the 1983 Kaoiki main shock (ML = 6.6), at a station near the epicenter, finds no evidence for change.



Munson, C.G., and Thurber, C.H., 1997, Analysis of the attenuation of strong ground motion on the island of Hawaii: Bulletin of the Seismological Society of America, v. 87, no. 4, p. 945-960. 



 We develop a horizontal peak ground acceleration (PGA) predictive equation for the island of Hawaii by applying the Joyner and Boore (1993, 1994 two-stage regression method to a data set that consists of 51 PGA from 22 events. Magnitudes vary from 4.0 to 7.2, and event depths vary from 4 to 14 km. The resulting equation is

log10PGA = 0.518 + 0.387 (M-6) - log10r0.00256r + 0.335S



where PGA is measured in units of g, M is magnitude, r = (d2 + 11.292)1/2, and S is 0 for lava sites and 1 at ash sites. The distance parameter d is the closest distance from the recording site to the surface projection of the fault rupture area and varies from 0 to 88 km for the Hawaii PGA data set. We find that the attenuation of high-frequency strong ground motion is significantly greater than a previous relationship used for the island of Hawaii. The ash site coefficient S, which represents accelerometer sites with shear-wave velocities that vary from 60 to 200 m/sec, is generally larger than the soil site coefficients in other attenuation relationships.



Murphy, L.M., 1950, Hawaiian Islands, in United States earthquakes, 1947: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 730, p. 29. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Murphy, L.M., and Ulrich, F.P., 1951, Hawaiian Islands, in United States earthquakes, 1948: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 746, p. 27. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Murphy, L.M., and Ulrich, F.P., 1951, Hawaiian Islands, in United States earthquakes, 1949: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 748, p. 29-30. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Murphy, L.M., and Ulrich, F.P., 1952, Hawaiian Islands, in United States earthquakes, 1950: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 755, p. 18. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Murphy, L.M., and Cloud, W.K., 1953, Hawaiian Islands, in United States earthquakes, 1951: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 762, p. 18-20. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Murphy, L.M., and Cloud, W.K., 1954, Hawaiian Islands, in United States earthquakes, 1952: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 773, p. 48-49. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Murphy, L.M., and Cloud, W.K., 1955, Hawaiian Islands, in United States earthquakes, 1953: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 785, p. 27-29. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Murphy, L.M., and Cloud, W.K., 1956, Hawaiian Islands, in United States earthquakes, 1954: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 793, p. 55-56. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Murphy, L.M., and Cloud, W.K., 1957, Hawaiian Islands, in United States earthquakes, 1955: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, p. 36-38. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Naeim, F., and Anderson, J.C., 1996, Design classification of horizontal and vertical earthquake ground motion (1933-1994): Los Angeles, CA, John A. Martin & Associates, Inc., JAMA Report No. 7738.68-96, Aug., 427 p. [A report to the U.S. Geological Survey, USGS Award No. 1434-95-G-2596; a continuation of the research initiated by the 1993 FEMA/EERI Professional Feollowship Award] 



 One of the most difficult questions that the designer of earthquake resistant structures must address is the determination of the critical earthquake. This is the earthquake ground motion which will drive the structure being designed to its critical response. This study seeks to provide processed data which will help the design engineer address this problem by identification of the severity and damage potential of earthquake ground motions which are part of a large database containing 1470 horizontal and 527 vertical components.

 This report contains the results of the continuation of a research initiated in 1993 as a part of FEMA/EERI NEHRP Professional Fellowship awarded to the first author. It represents the following significant enhancements to the initial work:

 1) inclusion of more than 520 records obtained from the 1994 Northridge, California earthquake

 2) comprehensive time and frequency domain classification of vertical components of earthquake ground motion spanning the time period of 1933 to 1994

 3) revision of all previous statistical and interdependence evaluations to reflect the new data contained in our analysis

 Parameters used to classify the severity of the earthquake records are divided into two classes; one in which the parameters are obtained directly from the recorded data and the other in which the parameters are obtained by passing the recorded data through a single degree of freedom oscillator and obtaining a response or energy spectrum. The former group includes ground motion parameters such as peak acceleration, peak velocity, peak displacement, peak incremental velocity, peak incremental displacement and bracketed duration. The latter group includes elastic response spectra, effective peak acceleration, effective peak velocity, inelastic response spectra, elastic input energy spectra and hysteretic energy spectra. Statistical procedures are used to investigate correlations between the different parameters.

 Results are presented in tables in which the significant records from the database are sorted in terms of the various response parameters. Spectral data is sorted in terms of the mean value of the response parameter in bracketed bands of the fundamental period. Plots of constant strength inelastic response spectra, constant ductility inelastic response spectra, elastic and inelastic input energy spectra and hysteretic energy spectra for 141 of the more significant horizontal components are included in the report. Also included is elastic response spectra for 83 of the more significant vertical components where the response spectra for the corresponding horizontal components are superimposed for comparative purposes. [Hawaiian earthquakes covered are those of November 29, 1975, beneath Kilauea's south flank, and November 16, 1983, beneath the Kaoiki fault zone.]



Nakamura, K., 1975, Volcano structure and possible mechanical correlation between volcanic eruptions and earthquakes: Bulletin of the Volcanological Society of Japan, ser. 2, v. 20, special no., Dec., p. 229-240. 



 Volcanoes are generally classified into monogenetic and polygenetic types. Monogenetic volcanoes erupt only once to form smaller volcanoes, such as maars, pyroclastic cones and lava domes. Polygenetic volcanoes erupt repeatedly from the same general vents (summit or main crater) for up to 105 years to form larger volcanoes such as strato-volcanoes (composite volcanoes of Macdonald, 1972) and shield volcanoes of Hawaiian type. Monogenetic volcanoes tend to occur in clusters as flank and post-caldera cones. Some of the clusters are however, independent of polygenetic volcanoes and appear to be equivalent to them.

 The essential part of the conduit of a monogenetic volcano is inferred to be a simple dike, intruded into a newly formed crack, whereas a long endured pipe-shaped conduit may exist under a polygenetic volcano. The common occurrence of xenoliths in the eruptive products of monogenetic volcanoes may be related to this difference. Various lines of evidence, indicating the existence, depth, shape, volume and internal structure, of magma reservoirs are tabulated. A shallow magma reservoir appears to exist beneath polygenetic volcanoes with one to one correspondence, which is not the case for monogenetic volcanoes. Most flank volcanoes are monogenetic, thus indicating dikes within the polygenetic volcanic edifice. Dike formation is understood as a magma version of hydraulic fracturing. For the dike to intrude and propagate, would require either the increase of differential stress due to a decrease of minimum compression or increase of pore pressure over the sum of the minimum compression and the tensile strength of the rocks.

 Earthquakes are understood as the generation of elastic waves associated with an acute release of tectonic stress due to faulting. Accumulation of tectonic stress and strain prior to earthquakes is, then, a necessary part of earthquake phenomena in a broad sense, as well as their release after the event.

 Based on the above-stated understanding, possible mechanical correlations between volcanic eruptions and earthquake occurrences have been studied. Contractional strain around the magma reservoir can cause the squeezing up of magma within an open conduit causing a summit eruption on the one hand, and dike formation resulting in a flank eruption through the increase of pore pressure, on the other. Second boiling triggered by both the magmatic pressure decrease caused by dilatational strain and the dynamic excitation due to seismic waves might have the same effect as contraction. Decrease of minimum compression causing the increase of differential stress leading to dike formation will also contribute to the likelihood of flank eruptions.

 Both volcanic eruptions and earthquake occurrences can precede each other depending on geographical location in terms of faulting-related stress-strain changes which are calculated by the fault model of earthquakes.

 Actual possible examples of volcanic eruptions and earthquakes which are allegedly mechanically related are given. In order to demonstrate which mechanism is responsible for the correlation of the two phenomena, continuous strain measurement on and around volcanoes is necessary together with the observation of changes in the level of magma in crater bottoms.



Nakamura, K., 1982, Why do rift zones develop better in Hawaiian volcanoes--a possible role of thick oceanic sediments [abs.], in Schmincke, H.-U., Baker, P.E., and Forjaz, V.H., ed(s)., Activity of ocean volcanoes, International Symposium on the Activity of Oceanic Volcanoes, Ponta Delgada, Proceedings: Ponta Delgada, Azores, Universidade dos Azores, Serie Ciencias da Naturezam, no. 3, p. 59-73. 



 Rift zones are One of the characteristic features of Hawaiian volcanoes. They are long narrow zones of flank fissure eruptions but are distinct from ordinary flank eruption sites on polygenetic volcanoes in that eruptions, and therefore dike intrusions, occur repeatedly at the same general place for a long time and thus cause a considerable distance of horizontal spreading. This spreading should somehow be accommodated and the direction of the minimum compressive stress should remain the same after accommodation in order for a new dike to intrude in the same orientation.

 The Krafla spreading events in Iceland between North American and European plates revealed that the process of the lithospheric spreading is similar to that observed for Hawaiian volcanic activities, including rift zone eruptions. Accreting plate boundaries may be understood as consisting o chain o linear rift zones and their source polygenetic centers where the magma supplied from the asthenosphere is temporarily stored.

 Horizontal spreading caused by repeated dike intrusions has been accommodated in the case of the accreting plate boundaries by the lateral separation of lithosphere over asthenosphere. In the case of Hawaii sliding o the volcanic edifice over deep sea sediments may be the analogous mechanism such as appears to have occurred during the 1975 Kalapana earthquake which was anticipated by SWANSON et al. (1976) as one of the repeated events as the east rift zone has continuously dilated. Lack of rift zones in otherwise similar Galapagos shields which sit over the young ocean floor with higher relief is consistent with this view.



Nakata, J.S., Tomori, A.H., Koyanagi, R.Y., and Tanigawa, W.R., 1984, Hawaiian Volcano Observatory summary 83: seismic data, January-December 1983 (Chronological summary by R.W. Decker): U.S. Geological Survey Administrative Report, 86 p. 



 A summary of the volcanic conditions and seismicity during the year.



Nakata, J., Tanigawa, W., and Dvorak, J.J., 1990, Comparison of earthquake activity along the west flank of Mauna Loa Volcano and the south flank of Kilauea Volcano [abs.]: Eos, Transactions, American Geophysical Union, v. 71, no. 43, p. 1561. [AGU fall meeting, San Francisco, CA, Dec. 3-7, 1990, Program and abstracts] 



 The west flank of Mauna Loa and the south flank of Kilauea are tectonically similar: each is bounded on one side by a well-developed and active rift zone and is unsupported on the opposing seaward side. Both flanks have arcuate, normal faults--the Kealakekua fault on Mauna Loa and the Hilina Pali fault on Kilauea-that formed during sudden seaward movement of the flank. The occurrence of earthquakes along either flank is caused by the release of compressive strain accumulated along the flank by repeated injection and eruption of magma along the adjacent portions of the rift zones.

 During the last 40 years, three damaging earthquakes, all believed to be greater than magnitude 6.0, occurred along the west flank of Mauna Loa. The earthquake of 29 May 1950 occurred three days before the beginning of a major eruption of Mauna Loa. The second earthquake, the largest of the three, occurred on 21 August 1951 and generated a meter-high tsunami, but did not result in a permanent change in position of the coastline. The Pasadena seismological laboratory assigned a magnitude 6.75 to this earthquake. The third earthquake occurred on 23 May 1952 and was assigned a magnitude 6.0 by Pasadena. Only one earthquake larger than magnitude 5.0 has occurred since 1952: a magnitude 5.1 event on 23 Dec 1972, which originated at a depth of 15 km. Also during the past 40 years, ten earthquakes greater than magnitude 5.0 and four earthquakes greater than magnitude 6.0 have occurred along the south flank of Kilauea; the largest earthquake during this period was a magnitude 7.2 event on 29 Nov 1975.

 Since 1962, when major additions were made to the seismic network, about 30 earthquakes greater than magnitude 2.0 have been located each year along the west flank of Mauna Loa. This rate is about a factor of 50 less than the annual rate of earthquakes greater than magnitude 2.0 along the south flank of Kilauea. The difference in rate and in the occurrence of magnitude 5.0 or greater earthquakes is due to the more recent formation of eruptive fissures along the rift zones of Kilauea: during the past 100 years, several dozen rift intrusions and eruptions have occurred at Kilauea, but only five eruptions, most recently in 1950, have occurred along the southwest rift zone of Mauna Loa, which lies adjacent to the unsupported portion of the west flank of Mauna Loa.

 A significant increase in earthquake activity along the west flank of Mauna Loa might follow, and may immediately precede, the next eruption along the southwest rift zone of this volcano, as occurs along the south flank of Kilauea after eruptions along the east rift zone. During the months to years after the eruption, the likelihood greatly increases for the occurrence of an earthquake greater than magnitude 5.0 along the west flank of Mauna Loa.



Neumann, F., 1926, Seismological report: July, August, September, 1925: Washington DC, Department of Commerce, U.S. Coast and Geodetic Survey, Serial no. 328, p. 20-24, 42-43. 



 A quarterly summary of earthquake records. Table I contains non-instrumental reports of earthquakes felt around the globe; Table II contains instrumental readings from seismometers maintained at magnetic observatories in North America, including the Milne-Shaw instrument at the Honolulu Magnetic Observatory in Ewa Beach, Oahu; Table III provides a summary of earthquakes recorded in the United States, the regions under its jurisdiction (including Hawaii), and adjacent regions.



Neumann, F., 1927, Seismological report: October, November, December, 1925 and supplement for 1924: Washington DC, Department of Commerce, U.S. Coast and Geodetic Survey, Serial no. 388, p. 9, 33-38, 56-57, 97-103. [Covers July 1-December 31, 1924 in addition to the fourth quarter of 1925] 



 A quarterly summary of earthquake records. Table I contains non-instrumental reports of earthquakes felt around the globe; Table II contains instrumental readings from seismometers maintained at magnetic observatories in North America, including the Milne-Shaw instrument at the Honolulu Magnetic Observatory in Ewa Beach, Oahu; Table III provides a summary of earthquakes recorded in the United States, the regions under its jurisdiction (including Hawaii), and adjacent regions.



Neumann, F., and Service, J.H., 1927, Seismological report: January, February, March, 1926: Washington DC, Department of Commerce, U.S. Coast and Geodetic Survey, Serial no. 395, p. 5-8, 27-31, 45-47. 



 A quarterly summary of earthquake records. Table I contains non-instrumental reports of earthquakes felt around the globe; Table II contains instrumental readings from seismometers maintained at magnetic observatories in North America, including the Milne-Shaw instrument at the Honolulu Magnetic Observatory in Ewa Beach, Oahu; Table III provides a summary of earthquakes recorded in the United States, the regions under its jurisdiction (including Hawaii), and adjacent regions.



Neumann, F., 1928, Seismological report: April, May, June, 1926: Washington DC, Department of Commerce, U.S. Coast and Geodetic Survey, Serial no. 406, p. 5-6, 9-11, 31-39, 53, 55-56. 



 A quarterly summary of earthquake records. Table I contains non-instrumental reports of earthquakes felt around the globe; Table II contains instrumental readings from seismometers maintained at magnetic observatories in North America, including the Milne-Shaw instrument at the Honolulu Magnetic Observatory in Ewa Beach, Oahu; Table III provides a summary of earthquakes recorded in the United States, the regions under its jurisdiction (including Hawaii), and adjacent regions.



Neumann, F., 1929, Seismological report: January, February, March, 1927: Washington DC, Department of Commerce, U.S. Coast and Geodetic Survey, Serial no. 463, p. 8, 13, 34-37, 75. 



 A quarterly summary of earthquake records. Table I contains non-instrumental reports of earthquakes felt around the globe; Table II contains instrumental readings from seismometers maintained at magnetic observatories in North America, including the Milne-Shaw instrument at the Honolulu Magnetic Observatory in Ewa Beach, Oahu; Table III provides a summary of earthquakes recorded in the United States, the regions under its jurisdiction (including Hawaii), and adjacent regions.



Neumann, F., 1930, Seismological report: April, May, June, 1927: Washington DC, Department of Commerce, U.S. Coast and Geodetic Survey, Serial no. 468, p. 6, 26-29, 40, 42-43. 



 A quarterly summary of earthquake records. Table I contains non-instrumental reports of earthquakes felt around the globe; Table II contains instrumental readings from seismometers maintained at magnetic observatories in North America, including the Milne-Shaw instrument at the Honolulu Magnetic Observatory in Ewa Beach, Oahu; Table III provides a summary of earthquakes recorded in the United States, the regions under its jurisdiction (including Hawaii), and adjacent regions.



Neumann, F., 1930, Seismological report: July, August, September, 1927: Washington DC, Department of Commerce, U.S. Coast and Geodetic Survey, Serial no. 495, p. 5-7, 12, 31-38, 53-56. 



 A quarterly summary of earthquake records. Table I contains non-instrumental reports of earthquakes felt around the globe; Table II contains instrumental readings from seismometers maintained at magnetic observatories in North America, including the Milne-Shaw instrument at the Honolulu Magnetic Observatory in Ewa Beach, Oahu; Table III provides a summary of earthquakes recorded in the United States, the regions under its jurisdiction (including Hawaii), and adjacent regions.



Neumann, F., 1932, Hawaiian Islands, in United States earthquakes, 1931: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 553, p. 22. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Neumann, F., and Bodle, R.R., 1932, Hawaiian Islands, in United States earthquakes, 1930: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 539, p. 15. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Neumann, F., 1934, Hawaiian Islands, in United States earthquakes, 1932: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 563, p. 18. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Neumann, F., 1935, Hawaiian Islands, in United States earthquakes, 1933: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial no. 579, p. 22. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Neumann, F., 1936, Hawaiian Islands, in United States earthquakes, 1934: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 593, p. 40. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Neumann, F., 1937, Hawaiian Islands, in United States earthquakes, 1935: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 600, p. 39. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Neumann, F., 1938, Hawaiian Islands, in United States earthquakes, 1936: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 610, p. 24. [Compiled as United States earthquakes, 1936-1940, and reissued by the National Earthquake Information Center, 1969] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Neumann, F., 1940, Hawaiian Islands, in United States earthquakes, 1938: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 629, p. 28-30. [Compiled as United States earthquakes, 1936-1940, and reissued by the National Earthquake Information Center, 1969] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Neumann, F., 1941, Hawaiian Islands, in United States earthquakes, 1939: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 637, p. 29. [Compiled as United States earthquakes, 1936-1940, and reissued by the National Earthquake Information Center, 1969] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Neumann, F., 1942, Hawaiian Islands, in United States earthquakes, 1940: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 647, p. 32-33. [Compiled as United States earthquakes, 1936-1940, and reissued by the National Earthquake Information Center, 1969] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Neumann, F., 1943, Hawaiian Islands, in United States earthquakes, 1941: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, Serial No. 655, p. 21-22. [Compiled as United States earthquakes, 1941-1945, and reissued by the National Earthquake Information Center, 1969] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Nielsen, N.N., Furumoto, A.S., Lum, W., and Morrill, B.J., 1977, The Honomu, Hawaii, earthquake; report of inspection: Washington, DC, National Academy of Sciences, 79 p. [Submitted to the Committee on Natural Disasters, Commission on Sociotechnical Systems, National Research Council] 



 The island of Hawaii is the most seismically active of the Hawaiian Islands. Since 1929 twelve earthquakes of magnitude 6 or larger have been recorded. There are two volcanoes on the island that are still active. However, for larger earthquakes there seems to be no connection with volcanic activity. At the time of the earthquake the Kilauea volcano was in active eruption, but the epicenter was far removed from the volcano. The earthquake occurred on a known fracture zone; the depth of focus was approximately 41 km; Hawaiian earthquakes usually occur at much shallower depths. The magnitude of the earthquake was 6.2. The epicenter was located at Honomu, which is 10 km north of Hilo and about 2 km inland.

 About 2 months before the earthquake occurred two strong-motion accelerographs and four seismoscopes were installed in the islands. One of the strong motion accelerographs was installed at Kilauea on the island of Hawaii; its distance from the epicenter was 50 km. Another accelerograph was installed in Honolulu, about 300 km from the epicenter. Both instruments were triggered by the earthquake and the first strong-motion accelerograms were obtained in Hawaii. The maximum acceleration at Kilauea was 0.17 g and strong ground motion lasted about 7 seconds. The Honolulu record showed a maximum acceleration of 0.03 g. Three days after the earthquake additional instrumentation was flown in from Las Vegas to permit monitoring of aftershocks. The aftershock monitors recorded approximately 10 shocks of magnitudes between 2 and 3.

 The Wailuku River, which runs into the ocean just north of downtown Hilo, is the dividing line between the Mauna Kea and the Mauna Loa lava flows. Mauna Kea is the older volcano and Mauna Loa is younger and still active. At the last stages of volcanic activity of Mauna Kea, ash deposits from the volcano covered the northeast portion of the island north of the Wailuku River. The result is that soil conditions are quite different on the two sides of the river. North of the river the ash cover is about 20 to 30 feet thick. The ground south of the river is lava rock. It was evident from the earthquake damage that behavior of the two soils was different; damage seemed to be much heavier on the volcanic ash north of the river. Aftershock equipment was installed on both sides of the river to explore the differences in response. From the records it is very clear that the velocity response was much greater on the volcanic ash than it was on the lava rock. For most frequencies the velocity response of the volcanic ash was five to ten times as large as the response measured on the lava rock. There were no signs of liquefaction, even though the volcanic ash tends to liquefy under traffic of heavy construction equipment.



Nielsen, N.N., Furumoto, A.S., Lum, W., and Morrill, B.J., 1977, Honomu, Hawaii earthquake of April 26, 1973, in World Conference on Earthquake Engineering, 6th, New Delhi, Jan. 10-14, 1977, Proceedings: World Conference on Earthquake Engineering, 6th, Proceedings, v. 1, no. 6, p. 227-232. 



 The Richter magnitude 6.2 earthquake was deep seated (50 km). A strong motion accelerograph was located about 50 km from the epicenter, the maximum recorded acceleration was 0.17 g , the duration of the strong motion was short (7 sec). Sensitive aftershock equipment was installed on two different types of soil, hard lava rock and soft volcanic ash. The aftershock records were analyzed and response spectra were calculated. The response, for most frequencies, was considerably higher for the volcanic ash. Total amount of damage was $6,000,000. A significant portion of the damage was to roads and bridges.



Normark, W.R., Lipman, P.W., Lockwood, J.P., and Moore, J.G., 1978, Bathymetric and geologic maps of Kealakekua Bay, Hawaii: U.S. Geological Survey Miscellaneous Field Studies Map MF-986, scale 1:250,000. 



 Introduction

Marine survey methods

Submarine lithologic units

Bathymetry and geology

Acknowledgements 

References cited



"Kealakekua Bay is shaped largely by the Kealakekua fault, a major arcuate normal fault along which part of the seaward flank of Mauna Loa volcano has been downdropped (fig. 3). The on-land fault scarp has topographic relief greater than 250 m, even though it is extensively draped by prehistoric (pre-19th century) lava flows from Mauna Loa. A young lava delta from one of these flows built Cook Point (fig. 2), where Captain James Cook first landed in 1778. In 1951, a major earthquake (M = 6.1), accompanied by a local tsunami, had its epicenter on the seaward end of the fault, although there was no known surface rupture. Aftershock epicenters were distributed along the curving landward extension for a distance of about 25 km. The overall seismic-tectonic pattern demonstrates south-side-down normal faulting (Macdonald and Wentworth, 1954).

 A submarine eruption occurred offshore in the mapped area on February 24, 1877 (Anonymous, 1877) (fig. 3) This eruption reportedly occurred along a west-northwest-trending line extending out 1.7 km from Palemano Point, and no active fissure vents or lava appeared on land. The submarine activity was manifested by boiling water, a strong sulfurous odor, appearance of incandescent scoriaceous basalt blocks at the sea surface, and fish kills."



Northrop, J., 1973, T Phases from the Hawaiian earthquake of April 26, 1973 [abs.]: Eos, Transactions, American Geophysical Union, v. 54, no. 11, p. 1141-1142. [AGU fall meeting, San Francisco, CA, Dec. 10-13, 1973, Program and abstracts] 



 T phases from the magnitude 6.0 earthquake near Hilo, Hawaii on 26 April 1973 were recorded at widely spaced SOFAR depth hydrophones off the Islands of Oahu, Midway and Wake, and off the coast of California. A strong P phase was also recorded on a new digital acquisition system at the Oahu hydrophone. Numerous precursors identified as T phase radiations from several islands of the Hawaiian archipelago were recorded at the other hydrophone locations. Additional arrivals following the main T phase were recorded for 2 l/2 hours after the earthquake. Some of these have been identified as reflections from underwater topographic slopes from the Aleutian Arc seamounts, atolls in the North Pacific, the continental shelf off Mexico, and the Japanese Islands.



Northrop, J., 1974, T phases from the Hawaiian earthquake of April 26, 1973: Journal of Geophysical Research, v. 79, no. 35, p. 5478-5481. 



 The magnitude 6.2 earthquake that occurred near Hilo, Hawaii, on April 26, 1973, introduced low frequency acoustic energy (called T waves) into the deep-ocean sound (Sofar) channel. The T waves traveled over long ranges to Sofar depth hydrophones off the islands ol Oahu, Wake, and Midway. Additional low-frequency precursors reached the hydrophones by travel paths through the solid earth, and later arrivals by sound reflected from shallow (< 1000 m) seamounts. Most of the reflections were from seamounts in the Gulf of Alaska.



Ohminato, T., Chouet, B., Dawson, P., and Okubo, P., 1996, Waveform inversion of very-long-period impulsive signals associated with magmatic injection beneath Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F798. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 During the volcanic crisis of Kilauea Volcano on February 1, 1996, a 10-station broadband seismic network deployed around the summit caldera detected characteristic events associated with magma injection beneath Kilauea. These events consist of a series of pulses with widths near 20s, occurring at intervals of 2-3 min. The pulses are superimposed on rapid summit inflation and display almost identical shapes, suggesting a process involving the repeated activation of a fixed source. The particle motion of each pulse is almost linear and its major swing shows compressional motion at all stations. Analyses of semblance and particle motion are consistent with a point source located 1 km beneath the northeastern edge of the Halemaumau pit crater.

 In order to estimate the source mechanism, we apply a moment tensor inversion to the waveform data assuming a point source. Synthetic waveforms are constructed by superposing impulse responses for 6 moment tensor components and 3 single force components. The original times of individual impulses are distributed along the time axis at appropriately small equal intervals and their amplitudes are determined by least squares. In this inversion, the source time functions (STF) of the moment tensor and single force components are determined simultaneously.

 However, a singular value decomposition analysis of the normal equations shows that this approach yields poorly constrained solutions for MZZ and MIZ. To alleviate this problem, we constrain all moment tensor components to have the same time history while keeping the STF for single force components free, and solve the problem again. As an assumed STF, we use the STF of well-determined components in the initial inversion.

 The results of the inversion show that the waveform data are well explained by an inclined crack from which magma is periodically injected into a larger reservoir (possibly the East Rift). Our results also point to the existence of a single force component which can be explained as the drag force generated by the flow of viscous magma through a narrow constriction in the flow path. A significant discrepancy in the amplitudes of the calculated versus observed signals remains at a station located at the southern edge of Kilauea caldera, which is suggestive of the possible existence of a second source beneath this location.



Okamura, A.T., Koyanagi, R.Y., and Krivoy, H.L., 1963, Hawaiian Volcano Observatory summary 26--April, May, and June 1962: U.S. Geological Survey Administrative Report, 44 p. 



 A summary of the volcanic conditions, seismicity, and tilt during the quarter.

 [A report on the International Symposium on volcanology held in Tokyo, 1962, by H. A. Powers occupies p. 1-2.]



Okamura, A.T., Koyanagi, R.Y., Kinoshita, W.T., Moore, J.G., Peck, D.L., and Powers, H.A., 1964?, Hawaiian Volcano Observatory summary 32--October, November, and December 1963: U.S. Geological Survey Administrative Report, 35 p. 



 A summary of the volcanic conditions, seismicity, and tilt during the quarter.



Okubo, P., Okamura, A.T., and Miklius, A., 1991, Intrusive earthquake swarms and the continuing Kilauea eruption [abs.]: Eos, Transactions, American Geophysical Union supp., v. 72, no. 44, p. 566. [AGU fall meeting, San Francisco, CA, Dec. 9-13, 1991, Program and abstracts] 



 Since December 1990, there have been three episodes of intrusive activity, in December 1990, March 1991 and August 1991, extending between Kilauea summit and the uppermost part of the east rift zone approaching Mauna Ulu. The present east rift eruption established its second vent at Kupaianaha in 1986, and intrusive activity had not been observed beneath Kilauea since that time. Although these intrusions did not appear to have affected the on-going eruptive activity, they almost certainly signify changes in magma supply and storage beneath the volcano and its flank.

 In early 1990, the eruption was still in the once-interrupted Kupaianaha stage. In February 1990, pond activity at Kupaianaha and flow activity at lower elevations stopped for several days. Following the onset of the visually confirmed eruption pauses in February 1990, Kilauea summit deflated steadily through March and remained in a relatively constant state of deflation through August 1990. As the magma distribution beneath Kilauea summit shifted through the last quarter of 1990, the eruption pauses became less obvious and less frequent.

 The December 1990 intrusion roughly coincides with the recovery of the levels of summit inflation to pre-1990, pre-pause levels. After the December intrusive pulse, the eastern summit region apparently continued to inflate, with large numbers of shallow long-period seismicity. On March 21, the summit began to deflate rapidly and the intrusive swarm occurred on March 26. This activity was concentrated in the rift system and it may reflect a continuation of the December intrusion farther into the east rift zone. After the March intrusion, the summit deflated at a more gradual rate, eventually reaching levels comparable to 1990 levels, with eruptive activity downrift apparently unchanged. In mid-July, the deflationary trend reversed as additional material was accumulated beneath the summit. The August intrusion appears to have been confined to a short segment of the uppermost system, with seismicity occurring in a region roughly one-half the extent of that activated during the December intrusion.

 Since the stage of steady lava activity originating at Kupaianaha, the eruption has entered a second different mode. First, the intermittent "pause'' stage of much of 1990 was associated with a depleted summit reservoir, The second "intrusion" stage of course requires some replenishing of the magma supply. Although post-intrusion summit levels are comparable to 1990 levels, the eruption remains continuous without any pauses in this latest stage. This suggests that the rapid deformations associated with the intrusions might have introduced changes in the magma transport and magma storage properties along the rift system.



Okubo, P., Koyanagi, R., Heliker, C., and Nakata, J., 1992, Kilauea, in Annual report of the world volcanic eruptions in 1989: Bulletin of Volcanic Eruptions, no. 29, Mar., p. 78-80. [Also published in Bulletin of Volcanology supp., v. 54, no. 29, p. 78-80] 



 The Kilauea eruption from the Pu'u O'o and Kupaianaha vents continued through 1989 without interruption. An estimate of the total erupted volume through 1989 is 1,200 million cubic meters, covering 67 square kilometers and creating a net of 144 acres of new land. The estimated eruption rate from Kupaianaha remained at 500,000 cubic meters per day. Ten additional homes were destroyed during 1989, bringing the total number of structures destroyed by this eruption since 1983 to 77. The shield area about Kupaianaha did not changed significantly during 1989, because of the rather stable lava tube system that carried material from the vent area to lower elevations near the coast. As the tube system developed over the coastal plain, numerous new lava entries into the ocean formed as the flow front spread out.

 Eleven earthquakes of magnitudes greater than 4.0 occurred beneath Hawaii in 1989. The two largest were a magnitude 6.1 event on June 25 (HST) and a magnitude 5.1 event on December 27. Both of these events were located beneath the south flank of Kilauea Volcano at depths of about 9 km. Structural damage was sustained in the epicentral region of the June 25 event, and felt reports for this event were received from up the Hawaiian island chain as far as Oahu. Neither of these events had any obvious effects on the eruption, however. Seismic activity beneath Kilauea summit associated with magmatic processes registered at steady levels punctuated by occasional bursts in activity. The largest fluctuation in long period earthquake activity at intermediate depths beneath Kilauea summit associated with resupply of magma into the summit magma chamber occurred during the fourth quarter of 1989.



Okubo, P., and Koyanagi, R., 1993, Loihi, in Annual report of the world volcanic eruptions in 1990: Bulletin of Volcanic Eruptions, no. 30, Mar., p. 112. [Also published in Bulletin of Volcanology supp., v. 55, no. 30, p. 112] 



 A vigorous earthquake swarm occurred off the S flank of Hawaii Island on March 11-19 (Fig. M21-1). More than 300 events were registered, about 15 of M 3-4, and some of M>4 (see p. 74-76 of this bulletin). No acoustic signals (T-waves) were reported.



Okubo, P., Nakata, J., and Heliker, C., 1994, Kilauea, in Annual report of the world volcanic eruptions in 1991: Bulletin of Volcanic Eruptions, v. 56, no. 31, Mar., p. 90-92. [Also published in Bulletin of Volcanology supp., v. 56, no. 31, p. 90-92] 



 The eruption in the east rift zone of Kilauea continued through 1991. This eruption began in 1983, and 1991 may be regarded as a year of transition from one part of the flow field to another. During 1991, lava activity was concentrated toward the eastern end of the flow field, with lava erupting from the Kupaianaha vent and flowing through the tube system to the coastal regions and entry points near Kalapana. Through 1990, lava production in the coastal regions was briefly interrupted 12 times. In 1991, lava activity slowly shifted to the western side of the flow field and lava production from Kupaianaha steadily decreased through the year.

 As these changes in the eruption were taking place, 3 intrusions, in December 1990, March and August 1991, occurred and indicated at least short-lived variations in shallow magma transport into the east rift zone. The earthquake swarms accompanying the intrusion were the first to be recorded since the end of the fountaining episodes from Pu'u O'o in 1986. Each of the swarms activated a different segment of the east rift between Kilauea summit and Pu'u O'o. Magma within Kilauea was redistributed at more variable rates than those presumed during steady otherwise steady activity.

 Regional activity in Hawaii included 16 earthquakes of magnitudes 4 and greater. Of these earthquakes, two were magnitude 5 and these events were both centered off of the western coast of the island of Hawaii. Microseismicity continued to register predominantly in the Kaoiki region separating Kilauea and Mauna Loa volcanoes and beneath the summit and S flank of Kilauea volcano.



Okubo, P., Nakata, J., and Heliker, C., 1994, Loihi, in Annual report of the world volcanic eruptions in 1991: Bulletin of Volcanic Eruptions, v. 56, no. 31, Mar., p. 136. [Also published in Bulletin of Volcanology supp., v. 56, no. 31, p. 136] 



 Loihi seamount continues to display activity. A strong earthquake swarm beneath Loihi began on December 19 and continued for several days. Earthquakes as large as magnitude 4 occurred during this swarm. Compared to other earthquake swarms that have been recorded from Loihi, and to extent allowed by the geometry of the HVO recording network, it appears that activity there shifts to different parts of the seamount system. The 1991 swarm apparently activated the southern and eastern parts of Loihi.



Okubo, P., Nakata, J., Chouet, B., and Dawson, P., 1996, The February 1, 1996, Kilauea summit earthquake swarm [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F798. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 During the 14-year-long east rift zone eruption of Kilauea Volcano, there have been a number of dike intrusions between Kilauea summit and the active vents, associated with strong swarms of microearthquakes. These sequences and the continuing eruption provide the opportunity to explore possible relationships between tectonic and magmatic processes in Hawaii.

 The most recent of these earthquake swarms occurred on February 1, 1996. Shortly after 0800 h, a swarm of shallow microearthquakes began beneath the Kilauea summit caldera. The onset of the swarm was quickly followed by the onset of volcanic tremor in the summit region and summit inflation. Over the next four hours, earthquakes clustered simultaneously in the summit caldera and in the adjoining section of the upper east rift zone. An increase in micro-seismicity was recorded at 1100h. This coincided with an increase in summit tilt rate which persisted until tilt reached its maximum value, shortly after 1200 h. During the afternoon of February 1, long-period earthquakes beneath the caldera accompanied summit deflation.

 The seismicity patterns observed on February 1, 1996 resembled those of other recent earthquake swarms associated with summit and upper rift zone intrusion, in particular that of December, 1990. The earthquakes in the upper east rift zone reflect the tectonic rift-zone respose to the increase in magma flow in the rift zone. However, the 1990 swarm, as well as swarms in March and August 1991, March 1992, and February 1993, was preceded by notable seismicity to the northwest of Kilauea Caldera that was interpreted as a possible precursor to the intrusion. No such precursory seismicity preceded the 1996 intrusive swarm. A change from this pattern of precursory seismicity could be linked to adjustments in the magmatic plumbing system that might have occurred following the M5 deep earthquake of February 1, 1994.

 [Ed. note: Abstract incomplete as published. Missing lines provided by author.]



Okubo, P.G., Nakata, J.E., and Gripp, A.E., 1997, Lithospheric seismicity beneath Kilauea Volcano, Hawaii - the February 1, 1994 M5.2 earthquake [abs.]: Seismological Research Letters, v. 68, no. 2, p. 319. [Seismological Society of America, 92nd annual meeting, Honolulu, HI, Apr. 9-11, 1997 (Abstracts)] 



 On February 1, 1994, a M5.2 (coda duration) earthquake occurred at a depth of 35 km beneath the south flank of Kilauea Volcano, Hawaii. Aftershocks from this earthquake define a 15 km-long, north-south trending band of seismicity that extends from the south coast of the island of Hawaii toward Kilauea's summit. The P-wave focal mechanism of the February 1 mainshock has a nearly vertical nodal plane striking N50E and a subhorizontal auxiliary plane. The events in the sequence show focal mechanisms very consistent with that of the mainshock.

 The February 1, 1994 activity appears to be part of a family of earthquakes that persistently involves a portion of the lithosphere beneath Kilauea's south flank. At a rate of about one M4 or larger earthquake per year, these earthquakes outline a diffuse source region whose bottom deepens from 25 to 35 km, north to south, away from the caldera. They feature nearly vertical, NE-SW trending nodal planes. The distribution of the seismicity triggered by the M5.2 1994 earthquake indicates a north-south trending zone within the lithosphere where this style of faulting can occur. The location of this seismicity within the active volcano is possibly directly related to the magma conduit that connects the shallow storage and transport complex beneath Kilauea's summit to a mantle magma source. Alternatively, the degree of consistency of focal mechanisms in the background lithospheric seismicity south of Kilauea's summit, including the 1994 sequence, suggests that these earthquakes are related to regional lithospheric structures.



Okubo, P., and Nakata, J., 1998, Patterns of seismic moment release rate beneath the southeast flank of the island of Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 79, no. 17, p. S227. [AGU, MSA, GS, AAS/SPD spring meeting, Boston, MA, May 26-29, 1998, Program and abstracts] 



 We present an updated compilation of seismic moment release rates in Hawaii from 1962 to present. We focus on the southeastern flank of the island of Hawaii, which underlies Kilauea Volcano and the southeastern flank of Mauna Loa Volcano. This region has generated magnitude 6 and greater earthquakes in 1989, 1983, 1975, and 1962. In addition, the largest historic earthquake in Hawaii occurred here in 1868.

 We observe an overall decreasing rate of seismic moment release following the 1975 M7.2 Kilauea south flank earthquake. At the magnitude 3 level and above, the principal moment release occurs at intermediate depths, between 5 and 13 km, where the dominant process is seaward sliding along the decollement underlying the volcanic edifice. This is not the case beneath the summit caldera of Kilauea, where this depth range coincides with the location of the principal magma storage complex that supplies Kilauea eruptions. Moment release in the region including the 1975 aftershock zone is dominated by that sequence. Significant moment release occurred prior to the 1975 earthquake in the southwest rift zone of Kilauea and in the Kaoiki region separating Kilauea and Mauna Loa volcanoes. Moment release in the Kaoiki region is dominated by M6.2 and M6.6 earthquakes in 1962 and 1983, respectively, and seismicity in the Kaoiki region has been tied to recent Mauna Loa eruptions. Understanding the patterns of seismic moment release in the Kaoiki and other regions will require integrating observations of intrusive activity within the volcanoes into viable tectonic models.



Okubo, P., 1998, Earthquakes, in Juvik, S.P., and Juvik, J.O., ed(s)., Atlas of Hawai`i (3rd ed.): Honolulu, HI, University of Hawai`i Press, p. 69-71 (333 p.). [Chief cartographer, T.R. Paradise] 



 Earthquakes are fundamental to the processes that have built and shaped the Hawaiian Islands. Unlike many other areas where seismic activity accompanies movement along tectonic (crustal) plate boundaries, in Hawai'i most earthquakes are linked to volcanic activity. Such earthquakes can occur before and during eruptions, or when magma (molten rock) migrates underground without actually erupting on the surface. Each year thousands of earthquakes occur in Hawai'i, the vast majority of them so small they are detectable only with highly sensitive instruments. However, moderate earthquakes that can be felt occur periodically and catastrophic ones occasionally rock the Islands.

 As the map of past seismic events shows, the island of Hawai'i has experienced numerous earthquakes of magnitude 5 or greater; the first to be recorded occurred in 1823. During historical times seismic activity has been concentrated beneath the island of Hawai'i and the surrounding seafloor south of the island, in the vicinity of the "hotspot" that has fueled Hawaiian volcanoes for millions of years. In April 1868, the area's largest known earthquake struck Hawai'i Island and wrought widespread damage. It was centered in the Ka'u District, at the southeastern coast of the island. Frederick Lyman, who resided there at the time, described the disaster in his diary:

 We moved forward and backward, two or three feet each time, for several secondsit made the small children seasick . . . the stone walls were all thrown down. . . . Our house was shaken off its foundations and tilted . . . when the shake came, a storm of mud and a great bank of each twenty feet high came flying all about, mixed with rocks, logs, and ferns.

 The size of an earthquake is commonly expressed in terms of magnitude. This is an instrumental measurement based on the amplitude, or size, of recorded seismic waves, which varies according to the energy released from groundshaking and the distance at which the signal is recorded. Derived from the original Richter scale, magnitude rankings are logarithmic; that is, each whole number increase represents a tenfold jump in seismic wave amplitude, or approximately a thirtyfold gain in energy released. For example, earth movements associated with a magnitude 5 quake discharge 30 times more energy than a magnitude 4 event and roughly 900 times more energy than a magnitude 3 quake. Events of magnitude greater than 3 generally are felt by people in the region of the epicenter (the earthquake's source), and those of magnitude greater than 6 can cause widespread damage.

 Closely associated with magnitude is earthquake intensity, which is typically expressed according to the Modified Mercalli Intensity Scale (MMI). Based on reports of damage and the physical sensations of those experiencing the event, the MMI is a subjective measurement scale. It ranges from Intensity I (an event not felt, or only faintly registered by instruments) to Intensity XII (an event causing nearly total destruction). MMI ratings decrease with increasing distance away from an earthquake's source.

 As Lyman's account so vividly conveyed, groundshaking during a strong earthquake can damage or destroy buildings and other structures, as well as trigger landslides and mudslides. Such eyewitness accounts and reports of damage and casualties suggest that groundshaking reached the Intensity XII level near the source region of the 1868 event. Its magnitude has been estimated at 7.9. Seismic events also can produce ground cracks and settling, and those centered in coastal regions can create tsunamis (large ocean waves), whose impacts can be more devastating than the quake itself. The 1868 earthquake generated a tsunami whose estimated maximum height along the Ka'u coast was at least 60 feet (18 m).

 Research suggests that many of the significant earthquakes on Hawai'i Island have resulted from the seaward sliding of the south flanks of Kilauea and Mauna Loa along a nearly horizontal fault. This fault is thought to be the buried boundary between the ancient oceanic crust and the volcanic edifice, approximately 6 miles (10 km) deep. Earthquakes along this fault include the November 1975 magnitude 7.2 Kalapana earthquake, which resulted in the loss of two lives, caused considerable damage on Hawai'i Island, and generated a tsunami that inundated the Ka'u and Puna coastlines. This event was the largest earthquake in the Hawaiian Islands since 1868, and it was felt as far away as O'ahu. Slippage and seismic activity apparently increase along this fault during periods of greater volcanic activity.

 Other, less frequent major earthquakes that are not directly related to the active volcanic flanks originate at greater depths (10-35 miles {about 16-56 km}). These events signal adjustments of the lithosphere (Earth's outermost region) to the weight of the islands. The most recent damaging earthquake of this type, in 1973, registered a magnitude of 6.3 and occurred about 24 miles (39 km) beneath Honomu on Hawai'i Island.



Hawai'i Earthquakes, M6 and Greater, 1918-Present

 Origin

Year Date Time Mag Source description



1918	Nov 02	2333	 6.2	 Ka'oiki, between Mauna Loa and Kilauea

1919	Sep 14	1750	 6.1	 Ka'u District, Mauna Loa south flank

1926	Mar 19	2230	>6.0	 NW of Hawai'i Island

1927	Mar 20	0452	 6.0	 NE of Hawai'i Island

1929	Sep 25	1820	 6.1	 Hualalai

1929	Oct 5	 2122	 6.5	 Hualalai

1938	Jan 22	2203	 6.9	 N of Maui

1940	Jun 16	2357	 6.0	 N of Hawai'i Island

1941	Sep 25	0718	 6.0	 Ka'oiki

1950	May 29	1516	 6.4	 Kona

1951	Apr 22	1452	 6.3	 lithospheric 

 Aug 21	0057	 6.9	 Kona

1952	May 23	1213	 6.0	 Kona

1954	Mar 30	0841	 6.5	 Kilauea south flank

1955	Aug 14	0228	 6.0	 lithospheric

1962	Jun 27	1827	 6.1	 Ka'oiki

1973	Apr 26	1026	 6.3	 lithospheric

1975	Nov 29	0447	 7.2	 Kilauea south flank

1983	Nov 16	0613	 6.6	 Ka'oiki

1989	Jun 25	1727	 6.1	 Kilauea south flank

 

MODIFIED MERCALLI INTENSITY SCALE

I: Not felt. 

II: Felt by person at rest. 

III: Felt indoors. Hanging objects swing. 

IV: Wlndows, dishes, and doors rattle. 

V: Felt outdoors. Doors swing, close open.

VI: Felt by all. Windows and dishes broken.

VII: Difficult to stand. Weak chimneys broken.

VIII. Damage to masonry. Chimneys topple. 

IX: General panic. Masonry is destroyed. 

X: Masonry, framed structures destroyed. 

Xl: Railroad tracks bent easily. 

Xll: Damage nearly total. Objects airborne.



Owen, S., Miklius, A., Segall, P., Lisowski, M., and Sako, M., 1997, Displacements from the June 30, 1997 M5.5 Kilauea south flank earthquake and preceding decrease in slip rate [abs.]: Eos, Transactions, American Geophysical Union supp., v. 78, no. 46, p. F166. [AGU fall meeting, San Francisco, CA, Dec. 8-12, 1997, Program and abstracts] 



 On June 30, 1997, a M5.5 earthquake occurred on the south flank of Kilauea. The quake's epicenter is located near the epicenter of previous large south flank earthquakes (M7.2, 1975; M6.1, 1989). Significant surface displacements were measured using GPS at more than 10 sites, 2 of them continuous, and the maximum coseismic surface displacement was 4.8 centimeters. The displacements from the earthquake are consistent with seaward slip along the decollement.

 Prior to the M5.5 quake, a decrease in the velocity of several GPS sites was observed. These sites have been measured at least once a year since 1993. A comparison of the 1994-95 velocities with the 1995-96 velocities shows that seven stations had a statistically different velocity in the 1995-96 time period. Four sites near the 1997 epicenter decreased their seaward slip rates by at least 3 cm/yr. This decrease amounts to roughly 40 to 100% of the sites' 1994-5 velocities. In addition, the seaward velocity of two stations immediately north of the east rift zone increased by approximately 3 cm/yr. It is possible that these changes in velocity, which occurred in the same region as the 1997 M5.5 earthquake, are the result of a decrease in slip at depth on the decollement. A model allowing spatially variable slip along the fault plane has been developed, and will be used to test this hypothesis.

 Whether or not the stations that experienced a decrease in velocity were moving at similar rates in 1996-97 is complicated by the occurrence of a shallow rift intrusion on January 30, 1997. Indeed, the rift intrusion itself may have triggered the M5.5 earthquake. Stress changes caused by the rift event will be computed and compared with the models of coseismic fault slip.



Owen, S.E., Segall, P., Lisowski, M., and Miklius, A., 1998, Distribution of fault slip and rift dilation on Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 79, no. 45, p. F36. [AGU fall meeting, San Francisco, CA, Dec. 6-10, 1998, Program and abstracts] 



 Kilauea Volcano, Hawaii, has recently experienced M7.2 (1975) and M6.1 (1989) earthquakes and long-lived rift eruptions. The large earthquakes are generated by seaward displacement along a subhorizontal fault plane approximately 9 km beneath Kilauea's south flank. Since 1983, Kilauea has been erupting almost continuously from Pu'u O'o or Kupaianaha, located near each other along the East Rift Zone. Six GPS campaigns from 1990 to 1996 were combined to provide average velocities at 69 stations on Kilauea. Both the horizontal and vertical velocity components show rapid displacement rates of as much as ~8 cm/yr. Constraining the geometry of the fault and rift to be consistent with geologic, seismic and geodetic data, we invert for the distribution of slip on both the fault plane at depth and the rift zones using these average GPS velocities.

 The modeling results indicate that the highest fault slip rates occur beneath the central south flank. The model includes significant fault slip offshore and in the western south flank, both seismically inactive areas between 1990 and 1996. Fault slip rates are low near the epicenters of the most recent large earthquakes. Model rift dilation extends from the Upper East Rift Zone to Heiheiahulu, ~15 km downrift of Pu'u O'o. The rates of rift dilation are highest at the base of the rift zone and are significant at greater than 3 km depth. The rift dilation rate is greatest beneath Makaopuhi Crater, which is at the bend in the East Rift Zone. Along the East Rift Zone, the lowest rates of rift dilation occur beneath Pu'u O'o. The highest rates of rift dilation correlate with microseismicity on the adjacent regions of the south flank. Southwest Rift Zone dilation is not required to fit the data. We estimate a strike-slip component along the Upper East Rift Zone, consistent with microseismicity in the Upper East Rift Zone which have focal mechanisms indicating left-lateral faulting [Gillard et al., 1996]. The highest rates of strike-slip occur at the base of the rift zone, close to the summit. The model resolution for the fault slip, rift dilation and left-lateral slip along the Upper East Rift Zone will also be presented.



Owen, S.E., 1998, GPS measurements and kinematic models of the surface deformation on Kilauea Volcano, Hawaii: Palo Alto, CA, Stanford University, Ph.D. dissertation, 152 p. 



 Table of Contents:

Abstract iv

Acknowledgments v

Table of Contents ii

List of Tables ix

List of Illustrations x

Chapter 1: the Rapid Deformation of Kilauea Volcano: GPS Measurements between 1990 and 1996 1

Chapter 2: Distribution of Fault Slip and Rift Opening on Kilauea Volcano, Hawaii 46

Chapter 3: The January 30, 1997 Eruptive Event on Kilauea Volcano, Hawaii as Monitored by Continuous GPS 73

Chapter 4: The Continuous GPS Network on Kilauea: Deformation Measurements before and after an East Rift Zone Fissure Eruption 90

Appendix A: The June 30, 1997 M5.5 Eathquake 135

Appendix B: An Up-Close Look at the Continuous GPS Data 140



Abstract

 Kilauea Volcano, Hawaii, is both volcanically and seismically active. Kilauea has been erupting at Pu`u O`o almost continuously since 1983. The volcano's south flank has been the site of M7.2 (1975) and M6.1 (1989) earthquakes. In chapter 1, campaign GPS measurements from 1990 to 1996 are used to calculate surface displacement rates on Kilauea. The GPS data shows that the south flank of the volcano is rapidly displacing seaward at ~8 cm/yr. The elastic dislocation sources required to fit the data include deep rift opening and seaward slip along a subhorizontal fault near the base of the volcano. In chapter 2, the dislocation geometry is constrained to the best-fitting model from chapter 1 and an inversion is done for the fault slip-rate and rift opening-rate distribution. In the resulting model, the highest fault slip rates are shown to occur beneath the central south flank. The rift opening rate is greatest beneath Makaopuhi Crater. Areas of rift dilation correlate well with mocroseismicity on the adjacent regions of the south flank. Strike-slip rates are also estimated along the Upper East Rift zone, with the highest rates occurring at the base of the rift zone. Chapter 3 discusses the most recent fissure eruption in Kilauea's East Rift zone. models of the GPS data indicate that the intrusion's bottom edge extended only 2.4 km deep. Continuous GPS data revealed rift opening 8 hours prior to the eruption. In the absence of precursory summit extension, the rift intrusion was caused by deep rift dilation and slip on the south flank decollement stressing the shallow rift zone. Chapter 4 discusses the continuous GPS measurements on Kilauea that started in August 1995. The installation of the network and data analysis are described. The data set records the deformation that occurred after the January 30, 1997 fissure eruption, which shows continued rift extension for ~2 months after the eruption and increased rates of south flank displacement up until June 1998.



Paris, J.D., 1868, [On the tsunami of April 1868]: Missionary Herald, July, p. 221. 



 A very brief description of the earthquake of April 2, 1868, and the effects of the tsunami that followed.

 

Paris, J.D., 1881, [On the earthquake of September 30, 1881]: Hawaiian Gazette, 10/12, p. 3. 



 South Kona--On the morning of the 30th of September, at 5 o'clock, we had the hardest and most terrible earthquake I have experienced in forty years. The first shake came suddenly, with a quick jerking, terrific crash, as if all the foundations and everything around us was shivering to pieces. It lasted about two minutes--then a cessation of about two or three minutes, and then followed another shake, simailar to the first, but not quite equal in terrific violence. Some light tremblings were felt the same day, and three moderate shakes the next day. These light shakes continued through the third inst. Many dwellings and other buildings are fearfully shattered and cracked. The foundations wrecked, and plastering torn off. Stone houses injured most. Miles and miles, many thousand fathjoms of stone-wall fencing wrecked and prostrate--most of the cisterns in the two Konas shattered and minus water. Crockery and glass-ware and bottles, everything jumbled and thrown in with confusion.

 But the wings of love were over, and the everlasting arms about us--no lives lost, and no one injured, so far as we have heard. . . .



Paris, J.D., 1887, [On the Mauna Loa eruption of 1887]: Hawaiian Gazette, 01/25, p. 8. 



 Paris gives a brief account of the opening phase of the 1887 Mauna Loa eruption, as witnessed in Kona. A continuous series of earthquakes accompanied the first 36 hrs of eruption. Kilauea was also active.

 There have been a great many earthquakes at Hilo lately, not less than seven distinct shocks being felt there, on Monday, Jan. 17. The shock of Monday night--occurring at quarter to twelve o'clock--was particularly heavy.

Mahukona--On Sunday, January 15th [sic-16th], at two or three minutes to nine a.m. . . . a stream of fire . . . from Mokuaweoweo. It lasted until eleven o'clock. Nothing was seen on Monday night, but on Tuesday and Wednesday we saw the reflection splendidly. It was also visible last night (Thursday).

Kaawaloa, Hawaii, Jan. 19, 1887-- . . For 36 hours one continuous series of earthquakes. Tremendous jars, with pretty hard shakes interspersed, running into one another. Our house has seemed like a little cap or bubble floating on the waves, sometimes of a chopped sea. . . . While I write my table rocks so that it is with considerable difficulty that I can keep my seat and hold my pen.



Perez, O.J., 1999, Revised world seismicity catalog (1950-1997) for strong (Ms 6) shallow (h 70 km) earthquakes: Bulletin of the Seismological Society of America, v. 89, no. 2, p. 335-341. 



 Using the standard earthquake catalogs provided by the International Seismological Centre (ISQ, its predecessor the International Seismological Summary (ISS), and the National Earthquake Information Center (NEIC), I analyze the worldwide consistency of teleseismic reporting, completeness of the seismicity record, and homogeneity of magnitude determination, for strong shallow earthquakes (surfacewave magnitude, Ms  6; depth, h  70 km) for the period 1950 to 1997. Under the postulates that the rate of earthquake occurrence for the entire world is constant on a time scale of decades and that well after the installation of the World-Wide Standardized Seismograph Network in the middle 1960s the earthquake catalog for strong (Ms  6) shocks is complete, and the seismicity rates are typical of all periods in the century, we find that, due to the use of different formulations and criteria to calculate the parameter magnitude, the Ms of moderate (6  Ms  7) events during the period 1950 to 1963 was systematically overestimated by as much as 0.5 magnitude unit, relative to the Ms assigned to shocks occurring after 1963. When this correction is taken into account, the new catalog of events with Ms (corrected)  6 in the period 1950 to 1997 becomes largely homogeneous in Ms. Under the foregoing postulates, this new catalog is shown to list nearly all and only the strong shocks [Ms (corrected)  6; h  70 km] that occurred in the Earth during the period, a notable exception being the time span from 1964 to 1968. The revised catalog, including the scalar moment and moment magnitude for each event, is listed on the worldwide web page http://www.ldc.usb.ve/~ojperez/catalog.



Perret, F.A., 1911, Perret reports many earthquakes; scientist gathers much material regarding general subsidence of lake--observation station had to be secured by anchors: Hilo tribune, 08/29, p. 1. [Repeated in Jaggar, 1947?] 



 Technology Station, Halemaumau (Kilauea)

Weekly Bulletin, Aug. 21 to Aug. 27 (incl.)

 The first part of the report describes activity in Halemaumau lava lake. An earthquake swarm associated with subsidence is described as follows:

 "The average seismicity of the week was 6 (normal 5), but was registered as 8 for the 25th when a series of fairly strong local shocks was inaugurated at 6:50 a.m. by two slight shocks in quick succession. these were followed by a strong shock at 7:15 which caused a heavy landslide from the north black ledge, a moderate shock at 8:10 and slight shocks at 2:10 and 2:35 p.m. A rapid though temporary rise of the lava lake testified to the local origin of the earthquakes, the lava overflowing both islands and remaining some seven feet above its former level until 4:30 p.m. when it began to sink slowly. [The timing suggests that the quakes could be beneath the East rift zone, triggering a delayed subsidence at the summit]

 "The lowest point reached (280 feet below the station) was on August 26, and this coincided with the maximum of the downfall from the ledges. It will be difficult for anyone not present to realize the extent of the changes produced during this era of subsidence, which was begun July 21."

 The report concludes with more description of the lava lake.



Perret, F.A., 1911, Two new islands appear in Halemaumau and fire lake becomes more tranquil: Pacific Commercial Advertiser, 08/31, p. 1. [Repeated in Hawaiian Gazette, Sept. 1, 1911; Repeated in Jaggar, 1947?] 



 Weekly Bulletin

Technology Station, Halemaumau, Aug. 21 to Aug. 27 (incl.)

 The first part of the report describes activity in Halemaumau lava lake. An earthquake swarm associated with subsidence is described as follows:

 "The average seismicity of the week was 6 (normal 5), but was registered as 8 for the 25th when a series of fairly strong local shocks was inaugurated at 6:50 a.m. by two slight shocks in quick succession. these were followed by a strong shock at 7:15 which caused a heavy landslide from the north black ledge, a moderate shock at 8:10 and slight shocks at 2:10 and 2:35 p.m. A rapid though temporary rise of the lava lake testified to the local origin of the earthquakes, the lava overflowing both islands and remaining some seven feet above its former level until 4:30 p.m. when it began to sink slowly. [The timing suggests that the quakes could be beneath the East rift zone, triggering a delayed subsidence at the summit]

 "The lowest point reached (280 feet below the station) was on August 26, and this coincided with the maximum of the downfall from the ledges. It will be difficult for anyone not present to realize the extent of the changes produced during this era of subsidence, which was begun July 21."

 The report concludes with more description of the lava lake.



Perret, F.A., 1911, [Observations at Kilauea]: Pacific Commercial Advertiser, Aug. 17; Aug. 24; Aug. 31; Sept. 7; Sept. 14; Sept. 21, p. 1. [Reprinted 1911 (without illustrations) in Hawaiian Annual for 1912, p. 164-175; the description of the bubble repeated in the Hawaiian Gazette of Aug. 25, 1911, p. 3] 



 A series of six weekly newspaper articles describing the activity of Kilauea from July 2 to Sept. 17, 1911. Perret describes and illustrates the Technology Station set up on the east edge of Halemaumau. He vividly and accurately describes lava lake activity, including the blowing of a glass bubble (article of Aug. 24): " . . . it [a floating island in Halemaumau lava lake] then sank, in its place on the fire lake rising a gigantic bubble of lava-glass which stretched and bulged until it covered a section of the lake of over three thousand square feet." [This exact phenomenon has never been observed since, although there are other instances demonstrating the capacity of Kilauea lava to form thin-walled bubbles. Small, frozen bubbles of translucent brown glass were observed in 1987 on the rim of Kupaianaha lava lake but were not observed as they formed. In 1988 tubes discharging lava from the Kupaianaha eruption into the ocean were photographed. A video sequence shows glass bubbles several meters across, forming at the point where a sheltered part of the tube was exposed to the ocean at the surf line. The bubbles broke into sheets which were dispersed on land to form a new type of tephra deposit, termed "limu o Pele" by local observers for its similarity to seaweed.] Other articles describe the appearance and disappearance of islands of crust in the lava lake. The final article in the series summarizes the results of 10 weeks' observation, and illustrates the Perret seismometer and microphone used in the Technology Station. Perret predicts, using astronomical data, an eruption in 1912 on the north side of Mauna Loa, but hedges his prediction on the basis of not having instrumentation on Mauna Loa. [Mauna Loa next erupted in 1914 at its summit.]

 [This is the first continuous record of Kilauea activity kept over a considerable period by a single observer, predating the establishment of HVO and its weekly and monthly Bulletins {Bevens and others, 1988}.]



Perrey, M.A., 1854, Notes sur les tremblements de terre en 1853, avec supplements pour les annees anterieures: Memoires de l'Academie des Sciences, Arts et Belles-Lettres de Dijon, 2nd ser., v. 3, p. 1-55. [Bulletins de l'Academie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique, 1854, v. 21, pt. 1, p. 475] 



 An earthquake occurred on July 25, 1853.

 [This and the The following references are part of a series of yearly catalogs of worldwide earthquake acrivity assembled and published in Europe by M.A. Perrey. Citations are given for those issues which we were able to inspect and copy. A list of the entire series, including issues not seen by us, is available from the Bishop Museum Library. Perrey's references to Hawaiian eruptions and earthquakes were obtained from various correspondents and from articles published in the Honolulu newspapers and in the American Journal of Science. Most of the earthquake information is taken from the diary kept by the Lyman family (Wyss and others, 1992). We have annotated individual articles only where there is information not published elsewhere.]



Perrey, M.A., 1856, Notes sur les tremblements de terre en 1855, avec supplements pour les annees anterieures: Bulletins de l'Academie Royale, des Sciences, des Lettres et des Beaux-Arts de Belgique, v. 23, pt. 2, p. 29, 37, 40, 49. 



 Earthquakes occurred on April 14, 1852 and July 7, 1853.

 [This and the The following references are part of a series of yearly catalogs of worldwide earthquake acrivity assembled and published in Europe by M.A. Perrey. Citations are given for those issues which we were able to inspect and copy. A list of the entire series, including issues not seen by us, is available from the Bishop Museum Library. Perrey's references to Hawaiian eruptions and earthquakes were obtained from various correspondents and from articles published in the Honolulu newspapers and in the American Journal of Science. Most of the earthquake information is taken from the diary kept by the Lyman family (Wyss and others, 1992). We have annotated individual articles only where there is information not published elsewhere]



Perrey, M.A., 1859, Notes sur les tremblements de terre en 1856, avec supplements pour les annees anterieures: Memoires Couronnes et Autres Memoires (l'Academie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique), v. 8, p. 26, 28, 55, 56, 61. 



 Earthquakes occurred on August 8 and 18, 1855, the latter felt in Kona.

 [This and the The following references are part of a series of yearly catalogs of worldwide earthquake acrivity assembled and published in Europe by M.A. Perrey. Citations are given for those issues which we were able to inspect and copy. A list of the entire series, including issues not seen by us, is available from the Bishop Museum Library. Perrey's references to Hawaiian eruptions and earthquakes were obtained from various correspondents and from articles published in the Honolulu newspapers and in the American Journal of Science. Most of the earthquake information is taken from the diary kept by the Lyman family (Wyss and others, 1992). We have annotated individual articles only where there is information not published elsewhere]



Perrey, M.A., 1860, Notes sur les tremblements de terre en 1857, avec supplements pour les annees anterieures: Memoires Couronnes et Autres Memoires (l'Academie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique), v. 10, pt. 1, p. 6-27; pt. 3, p. 83-99. 



 Earthquakes occurred on July 9, 1847, and July 14 and August 21, 1851.

 [This and the The following references are part of a series of yearly catalogs of worldwide earthquake acrivity assembled and published in Europe by M.A. Perrey. Citations are given for those issues which we were able to inspect and copy. A list of the entire series, including issues not seen by us, is available from the Bishop Museum Library. Perrey's references to Hawaiian eruptions and earthquakes were obtained from various correspondents and from articles published in the Honolulu newspapers and in the American Journal of Science. Most of the earthquake information is taken from the diary kept by the Lyman family (Wyss and others, 1992). We have annotated individual articles only where there is information not published elsewhere]



Perrey, M.A., 1861, Note sur les tremblements de terre en 1858, avec supplements pour les annees anterieures: Memoires Couronnes et Autres Memoires (l'Academie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique), v. 12, p. 42, 47, 51, 53. 



 An earthquake felt in Honolulu occurred on July 25, 1858.

 [This and the The following references are part of a series of yearly catalogs of worldwide earthquake acrivity assembled and published in Europe by M.A. Perrey. Citations are given for those issues which we were able to inspect and copy. A list of the entire series, including issues not seen by us, is available from the Bishop Museum Library. Perrey's references to Hawaiian eruptions and earthquakes were obtained from various correspondents and from articles published in the Honolulu newspapers and in the American Journal of Science. Most of the earthquake information is taken from the diary kept by the Lyman family (Wyss and others, 1992). We have annotated individual articles only where there is information not published elsewhere]



Perrey, M.A., 1862, Note sur les tremblements de terre en 1859, avec supplements pour les annees anterieures: Memoires Couronnes et Autres Memoires (l'Academie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique), v. 13, p. 25, 37-40, 42, 72. 



 Two earthquakes occurred on December 28, 1859.

 [This and the The following references are part of a series of yearly catalogs of worldwide earthquake acrivity assembled and published in Europe by M.A. Perrey. Citations are given for those issues which we were able to inspect and copy. A list of the entire series, including issues not seen by us, is available from the Bishop Museum Library. Perrey's references to Hawaiian eruptions and earthquakes were obtained from various correspondents and from articles published in the Honolulu newspapers and in the American Journal of Science. Most of the earthquake information is taken from the diary kept by the Lyman family (Wyss and others, 1992). We have annotated individual articles only where there is information not published elsewhere]



Perrey, M.A., 1864, Note sur les tremblements de terre en 1861, avec supplements pour les annees anterieures: Memoires Couronnes et Autres Memoires (l'Academie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique), v. 16, pt. 2, p. 92, 94, 101. 



 An earthquake occurred on December 5, 1861.

 [This and the The following references are part of a series of yearly catalogs of worldwide earthquake acrivity assembled and published in Europe by M.A. Perrey. Citations are given for those issues which we were able to inspect and copy. A list of the entire series, including issues not seen by us, is available from the Bishop Museum Library. Perrey's references to Hawaiian eruptions and earthquakes were obtained from various correspondents and from articles published in the Honolulu newspapers and in the American Journal of Science. Most of the earthquake information is taken from the diary kept by the Lyman family (Wyss and others, 1992). We have annotated individual articles only where there is information not published elsewhere]



Perrey, M.A., 1864, Note sur les tremblements de terre en 1862, avec supplements pour les annees anterieures: Memoires Couronnes et Autres Memoires (l'Academie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique), v. 16, pt. 1, p. 59; pt. 2, p. 126, 128, 169-70. 



 An earthquake occurred around January 29, 1862, lasting more than 5 sec.

 [This and the The following references are part of a series of yearly catalogs of worldwide earthquake acrivity assembled and published in Europe by M.A. Perrey. Citations are given for those issues which we were able to inspect and copy. A list of the entire series, including issues not seen by us, is available from the Bishop Museum Library. Perrey's references to Hawaiian eruptions and earthquakes were obtained from various correspondents and from articles published in the Honolulu newspapers and in the American Journal of Science. Most of the earthquake information is taken from the diary kept by the Lyman family (Wyss and others, 1992). We have annotated individual articles only where there is information not published elsewhere]



Perrey, M.A., 1867, Note sur les tremblements de terre en 1865, avec supplements pour les annees anterieures, de 1843 a 1864: Memoires Couronnes et Autres Memoires (l'Academie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique), v. 19, p. 4, 15-17, 20, 24-25, 29, 50-54, 85, 96, 98, 124-125. 



 An earthquake occurred on June 1, 1860.

 [This and the The following references are part of a series of yearly catalogs of worldwide earthquake acrivity assembled and published in Europe by M.A. Perrey. Citations are given for those issues which we were able to inspect and copy. A list of the entire series, including issues not seen by us, is available from the Bishop Museum Library. Perrey's references to Hawaiian eruptions and earthquakes were obtained from various correspondents and from articles published in the Honolulu newspapers and in the American Journal of Science. Most of the earthquake information is taken from the diary kept by the Lyman family (Wyss and others, 1992). We have annotated individual articles only where there is information not published elsewhere]



Perrey, M.A., 1870, Sur les tremblements de terre et les eruptions volcaniques dans l'archipel Hawaien, en 1868: Paris, Libraire de la Societe Geologique de France, 63 p. [Reprinted from Lyons, Societe d'Agriculture, Sciences, & Co., Annal., 1869, v. 2, p. 95-157] 



 Perrey gives a complete account of the events of 1868, quoting from eyewitness reports. He gives C.G. Williamson's (1868) lists of all felt earthquakes from March 28 to April 21, with notes of a light shock on April 29 felt in Kohala, a small earthquake swarm on May 3 felt at Kapapala, and a strong quake on May 27 felt in Kona. In an appendix, he lists felt earthquakes for the remainder of 1868 (July-December) and for January 1869. He wonders when the aftershocks will cease. [This reference is the only source that summarizes the entire seismic episode, including foreshock and aftershock sequences.]



Perrey, M.A., 1873, Supplements aux notes sur les tremblements de terre, ressentis de 1843 a 1868: Memoires Couronnes et Autres Memoires (l'Academie Royale des Sciences, des Lettres et des Beaux-Arts de Belgique), v. 23, p. 5, 10, 45, 49-51, 54-55, 58-59, 61, 66-67, 69. 



 Earthquakes occurred on December 1, 1847, and January 17, 1868.

 [The following references are part of a series of yearly catalogs of worldwide earthquake acrivity assembled and published in Europe by M.A. Perrey. Citations are given for those issues which we were able to inspect and copy. A list of the entire series, including issues not seen by us, is available from the Bishop Museum Library. Perrey's references to Hawaiian eruptions and earthquakes were obtained from various correspondents and from articles published in the Honolulu newspapers and in the American Journal of Science. Most of the earthquake information is taken from the diary kept by the Lyman family (Wyss and Koyanagi, in press). We have annotated individual articles only where there is information not published elsewhere]



Peters, J.H., 1928, Preliminary earthquake report of the seismological station at Honolulu, T.H.; April-June 1928: Dept. of Commerce; U.S. Coast and Geodetic Survey. [Mimeographed records sent to subscribers as a continuation of the Seismological Report series (see Neumann, 1928-1931). Station records after 1929 are supplanted by the Hawaiian Islands section of United States Earthquakes (see Neumann, 1932 and subsequent years)] 



 Phase, time, period and trace amplitude are given for earthquakes recorded by the Milne-Shaw seismometer at the Honolulu Magnetic Observatory during the second quarter of 1928.



Peters, J.H., 1928, Preliminary earthquake report of the seismological station at Honolulu, T.H.; July-September 1928: Dept. of Commerce; U.S. Coast and Geodetic Survey. [Mimeographed records sent to subscribers as a continuation of the Seismological Report series (see Neumann, 1928-1931). Station records after 1929 are supplanted by the Hawaiian Islands section of United States Earthquakes (see Neumann, 1932 and subsequent years)] 



 Phase, time, period and trace amplitude are given for earthquakes recorded by the Milne-Shaw seismometer at the Honolulu Magnetic Observatory during the third quarter of 1928.



Peters, J.H., 1928, Preliminary earthquake report of the seismological station at Honolulu, T.H.; October-December 1928: Dept. of Commerce; U.S. Coast and Geodetic Survey. [Mimeographed records sent to subscribers as a continuation of the Seismological Report series (see Neumann, 1928-1931). Station records after 1929 are supplanted by the Hawaiian Islands section of United States Earthquakes (see Neumann, 1932 and subsequent years)] 



 Phase, time, period and trace amplitude are given for earthquakes recorded by the Milne-Shaw seismometer at the Honolulu Magnetic Observatory during the fourth quarter of 1928.



Peters, J.H., 1928, Preliminary earthquake report of the seismological station at Honolulu, T.H.; January-March 1928: Dept. of Commerce; U.S. Coast and Geodetic Survey. [Mimeographed records sent to subscribers as a continuation of the Seismological Report series (see Neumann, 1928-1931). Station records after 1929 are supplanted by the Hawaiian Islands section of United States Earthquakes (see Neumann, 1932 and subsequent years)] 



 Phase, time, period and trace amplitude are given for earthquakes recorded by the Milne-Shaw seismometer at the Honolulu Magnetic Observatory during the first quarter of 1928.



Peters, J.H., 1929, Preliminary earthquake report of the seismological station at Honolulu, T.H.; January-March 1929: Dept. of Commerce; U.S. Coast and Geodetic Survey. [Mimeographed records sent to subscribers as a continuation of the Seismological Report series (see Neumann, 1928-1931). Station records after 1929 are supplanted by the Hawaiian Islands section of United States Earthquakes (see Neumann, 1932 and subsequent years)] 



 Phase, time, period and trace amplitude are given for earthquakes recorded by the Milne-Shaw seismometer at the Honolulu Magnetic Observatory during the first quarter of 1929.



Peters, J.H., 1929, Preliminary earthquake report of the seismological station at Honolulu, T.H.; October-December 1929: Dept. of Commerce; U.S. Coast and Geodetic Survey. [Mimeographed records sent to subscribers as a continuation of the Seismological Report series (see Neumann, 1928-1931). Station records after 1929 are supplanted by the Hawaiian Islands section of United States Earthquakes (see Neumann, 1932 and subsequent years)] 



 Phase, time, period and trace amplitude are given for earthquakes recorded by the Milne-Shaw seismometer at the Honolulu Magnetic Observatory during the fourth quarter of 1929.



Peters, J.H., 1929, Preliminary earthquake report of the seismological station at Honolulu, T.H.; July-September 1929: Dept. of Commerce; U.S. Coast and Geodetic Survey. [Mimeographed records sent to subscribers as a continuation of the Seismological Report series (see Neumann, 1928-1931). Station records after 1929 are supplanted by the Hawaiian Islands section of United States Earthquakes (see Neumann, 1932 and subsequent years)] 



 Phase, time, period and trace amplitude are given for earthquakes recorded by the Milne-Shaw seismometer at the Honolulu Magnetic Observatory during the third quarter of 1929.



Peters, J.H., 1929, Preliminary earthquake report of the seismological station at Honolulu, T.H.; April-June 1929: Dept. of Commerce; U.S. Coast and Geodetic Survey. [Mimeographed records sent to subscribers as a continuation of the Seismological Report series (see Neumann, 1928-1931). Station records after 1929 are supplanted by the Hawaiian Islands section of United States Earthquakes (see Neumann, 1932 and subsequent years)] 



 Phase, time, period and trace amplitude are given for earthquakes recorded by the Milne-Shaw seismometer at the Honolulu Magnetic Observatory during the second quarter of 1929.



Peters, J.H., 1930, Instrumental reports [monthly] for 1930: Dept. of Commerce; U.S. Coast and Geodetic Survey. [Mimeographed records sent to subscribers as a continuation of the Seismological Report series (see Neumann, 1928-1931). Station records for 1930 and 1931 give event times and, rarely. amplitudes. A subset of larger events are included in the Hawaiian Islands section of United States Earthquakes (see Neumann, 1932 and subsequent years)] 



 Times are given for earthquakes recorded by the Milne-Shaw seismometer at the Honolulu Magnetic Observatory during 1930.



Peters, J.H., 1931, Instrumental reports [monthly] for 1931: Dept. of Commerce; U.S. Coast and Geodetic Survey. [Mimeographed records sent to subscribers as a continuation of the Seismological Report series (see Neumann, 1928-1931). Station records for 1930 and 1931 give event times and, rarely. amplitudes. A subset of larger events are included in the Hawaiian Islands section of United States Earthquakes (see Neumann, 1932 and subsequent years)] 



 Times are given for earthquakes recorded by the Milne-Shaw seismometer at the Honolulu Magnetic Observatory during 1931.



Peterson, D.W., Christiansen, R.L., Duffield, W.A., Holcomb, R.T., and Tilling, R.I., 1974, Recent activity of Kilauea Volcano, Hawaii, in Gonzales-Ferran, O., ed(s)., Symposium on Andean and Antarctic Volcanology Problems, Santiago, Chile, Sept. 9-14, 1974, Proceedings: International Association of Volcanology and Chemistry of the Earth's Interior, Special Series, p. 646-656. 



 Kilauea Volcano has been in eruption 90 percent of the time since May 1969, when an eruption of 2 1/2-years duration began on its east rift zone 10 km from the summit. A 78-m-high basaltic shield (Mauna Ulu) formed within a lava field of 185,000,000 m3 covering 50 km2. The Mauna Ulu eruption declined in mid-1971 while the summit reinflated, leading to a series of new lava outbreaks, and followed by complete cessation of activity at Mauna Ulu in October.

 During a one-day eruption in August 1971, 10 x 106 m3 of lava fountained from the southeastern floor and rim of Kilauea Caldera. During 5 days in September 1971, 8 x 106 m3 of lava erupted from fissures on the caldera floor and along the southwest rift zone. Summit reinflation after each eruption indicated continued filling of the summit reservoir system and led to a resumption of activity at Mauna Ulu in February 1972. Alternating intense and weak activity soon gave way to continuous activity and a stable lava lake. A secondary vent opened nearby at Alae, where fountaining and lava-lake activity built another lava shield during the next year. From February 1972 through April 1973, 125 x 106 m3 of lava erupted from the vents at Mauna Ulu and Alae.

 The stable pattern ended suddenly in May 1973, 9 days after a magnitude 6.2 earthquake centered approximately 60 km north of Kilauea. In one day the lava lake drained, leaving a 200-m-deep crater, the summit deflated, and 1 x 106 m3 of lava erupted uprift from Mauna Ulu at Pauahi Crater, Hiiaka Crater and vicinity, and along the Koae fault zone. Eruptive activity resumed at Mauna Ulu and continued sporadically for several months; it stopped abrupt]y in November as a new outbreak began at Pauahi. A few days after the activity at Pauahi ended, in December, Mauna Ulu began to erupt again and its activity has continued to the present (June 1974).

 Much of the east-rift activity since 1969 has resembled past summit eruptions more than typical Kilauean flank eruptions. Long-lived active lava lakes, constant eruptive rates, and limited shallow summit seismicity or surface



Peterson, D.W., 1976, [Kilauea Volcano eruptions, 1974], in Annual report of the world volcanic eruptions in 1974: Bulletin of Volcanic Eruptions, no. 14, Dec., p. 53-55. 



 The crater at Mauna Ulu gradually filled with lava in January. On 24 January a vigorous eruptive episode occurred, lava fountains reached 60 m in height and flows reached 2 km in length; the episode lasted about 1.5 days. During ensuing months, similar eruptive episodes occurred at irregular intervals, each lasting from 5 hours to 2 days, with flows reaching several kilometers in length and fountain reaching as much as 80 m in height. These episodes were separated by quiet periods lasting from a few days to several weeks, during which lava circulated within the vents and at times overflowed quietly. The repeated lava flows and spatter gradually increased the height of the lava shield; it grew over 30 m to reach a height of 120 m above its preeruption (1969) base. A final vigorous eruptive episode occurred from 30 May to 2 June when voluminous flows inundated the flanks of Mauna Ulu and travelled southward more than 8 km. Thereafter activity declined as lava gradually drained from the crater and disappeared from view on 22 July. No further activity occurred at Mauna Ulu in 1974.

 On 19 July, after weeks of inflation at Kilauea's summit, and after a few hours of intense seismicity and sharp deflation, lava broke out at 12:30 from several fissures within and near Keanakakoi Crater. This was soon followed by lava erupting from additional fissures on the floor of Kilauea Caldera. New lava flooded much of the southeastern sector of the caldera, the floors of Keanakakoi and Lua Manu Craters, and adjacent areas. Fountains remained strong for about 10 hours, then progressively declined until activity ended on 22 July.

 Kilauea's summit reinflated following the July eruption, leading to new eruption on 19 September. Fountains began in Halemaumau about 01:15 with heights of as much as 100m, followed by a fissure extending up the crater wall to the rim and southwestward across part of the caldera floor. New lava flooded the floor of Halemaumau and the southwestern sector of Kilauea Caldera. After fountains ended about 08:00, lava drained into the fissure on Halemaumau's floor; during the following 1.5 days, almost half the new lava in Halemaumau drained away.

 Renewed inflation of Kilauea and increasing seismicity culminated on 31 December with a new eruption. Lava fountains began at 02:55 from a fissure in the Ka'u Desert about 3 km south of Halemaumau. New fissures progressively opened, mainly toward the southwest, and by 06:30 they formed an en echelon pattern in a zone 4 km long that trended S55W. Maximum fountain height was 100 m; after about 05:30 the eruptive vigor declined, and activity ended at 08:50. New flows to the southwest and south reached 13 km in length. A very large deflation and a swarm of earthquakes, some as strong as Richter Magnitude 5, accompanied and followed the eruption.



Peterson, D.W., 1977, Kilauea, in Annual report of the world volcanic eruptions in 1975: Bulletin of Volcanic Eruptions, no. 15, p. 46-48. 



 Kilauea's last previous eruption had been 31 December 1974. Ground deformation measurements showed slow, fairly steady inflation throughout 1975 and rather average levels of seismicity, typical of periods between eruptions. On 29 November, at 03:36, a H 5.7 earthquake occurred, centered on the Hilina fault system about 39 km E of Kilauea's summit. This was followed at 04:48 by a M 7.2 earthquake (Richter), centered about 3 km S of the first. This was the largest Hawaiian earthquake in more than a century, and it caused widespread damage, land subsidence as much as 3.5 m, and it triggered both a tsunami and a volcanic eruption. The maximum tsunami wave had a height of 15 m, and it claimed 2 lives and caused extensive damage around the island.

 The eruption began at 05:32, with fountains issuing from a N85-E-trending fissure (A), 500 m long, on the floor of Kilauea caldera. Fountains had a maximum height of 50 m, by 05:50 they had diminished to 5-10 m high, and they ended at 07:00. Resulting flows covered 0.25 km2. Noisy degassing continued from the vents. At 08:30 fountains began from a vent (B) about 20 m above the base of Halemaumau's NE wall. At 09:53 fountains began from another vent (C) on Halemaumau's wall about 100 m to the south. Fountaining from both vents was only 3 to 5 m high, but occasional gas bursts threw fragments as much as 100 m high. Activity decreased and then stopped by 13:30. Fountains resumed at 20:05 from vents B and C and continued intermittently, with maximum lava bursts as high as 100 m, until the eruption stopped at 22:00. Noisy degassing continued for another 4 hours. This eruption is interpreted to have been induced by the disturbance to the volcanic plumbing system caused by the shaking of the large earthquake. (The tsunami was also a consequence of the earthquake, but the tsunami and the eruption had no direct relation).



Peterson, I., 1996, Hawaii's next island suffers setback: Science News, v. 150, no. 15, Oct. 12, p. 228. 



 The underwater volcano growing off Hawaii's south coastline collapsed partially during the summer, according to a team of oceanographers scouting the shattered peak from a deep-sea submersible. The cave-in has provided scientists with an unprecedented glimpse into the often tumultuous process that gradually builds up volcanic islands from the ocean floor.

 Called Loihi, the submerged mountain is "essentially and island in the womb," says Alexander Malahoff, and oceanographer at the University of Hawaii in Honolulu and a leader of the submersible expedition, which continues through Oct. 12. "It gives us needed access to see how the Hawaiian Islands, the Marshall Islands, Tahiti, or any of the islands in the ocean form. This is the only time we have been able to see one forming in real life."

 Situated 17 miles off the coast of the island of Hawaii, Loihi rises from a base located 18,000 feet - more than 3 miles - below sea level to a broad peak at a depth of 3,000 feet. Malahoff estimates it will take another 50,000 years of growth before the summit breaks the waves.

 Hawaiian scientists first detected signs of unusual activity at Loihi in mid-July, when a swarm of small earthquakes started to shake the offshore mountain. Over the next 3 weeks, Loihi trembled with more than 5,000 quakes, 100 of which reached magnitude 4 and one of which attained magnitude 5, says Paul Okubo, a seismologist with the U.S. Geological Survey at the Hawaiian Volcano Observatory on Hawaii.

 "This is possibly the largest quake swarm to have been recorded on the volcanoes here in Hawaii," Okubo says.

 Malahoff and his colleagues first tried to dive to Loihi in August, but they found the water too turbulent. When they returned in late September, the scientists attempted to visit Loihi's peak, a region named Pele's Vents for its superheated geysers surrounded by a rich community of microorganisms. What they found in its place was a new crater.

 "This large hole, three-quarters of a mile in diameter, didn't exist before. Instead, it had been a large hill measuring 1,000 feet high," says Malahoff.

 The submersible descended along the vertical walls of the crater, past giant obelisk-shaped rocks ready to break away from the cliff face. During one dive, the researchers had to retreat quickly to the center of the crater when they heard the rumble of tumbling rocks.

 At the bottom of the crater, they found thriving colonies of bacteria that had taken up residence in the brand-new landscape. Microbial slime in orange and red hues draped over the rock surface, while lettuce like sheets of bacteria fluttered in the currents from the hot water. 

 The scientists believe that the collapse took place when lava erupted from deep fractures near the base of Loihi in July. The release of molten rock drained magma from within the mountain, causing the peak to deflate.

 Such a giant cave-in should have triggered a large wave, or tsunami, that might have damaged coastal sites in the Hawaiian Islands. But no tsunami developed, suggesting that the collapse occurred over several days instead of instantaneously, says Malahoff.

 In the future, Hawaiians may not escape so painlessly. The seafloor around Loihi and the other Hawaiian volcanoes is littered with debris from immense prehistoric landslides, one of which produced waves more than 1,000 feet high (Sn: 4/8/95, p. 216).

 To monitor geologic unrest on Loihi, Malahoff and his colleagues plan to place seismometers and chemical sensors on a stable section of the summit and connect them to the island of Hawaii via fiber-optic cable.



Powers, S., 1917, Tectonic lines in the Hawaiian Islands: Geological Society of America Bulletin, v. 28, p. 501-514 [includes plates]. 



 Powers reviews previous ideas concerning the development of the Hawaiian Chain. He considers that Hawaiian volcanoes developed at regular intervals along two parallel major fracture systems, roughly in order from west to east. No connection exists between the lines of fracture now apparent [the rift zones and calderas of the volcanoes] and the major fracture lines. Kilauea is regarded as older than Mauna Loa, as evidenced by more cones and pit craters on the Kilauea rifts and normal faulting on Kilauea's south flank. [Today, Powers' evidence is not considered relevant to the question of age.] Puu Kapukapu is probably a small horst, and the cliff north of Kealakekua is a fault scarp. Powers accepts Mohokea caldera, and Puu Enuhe, Makanao, and other hills are regarded as horsts within it. He describes the Hilina fault system and the faults bounding Kalapana. The latter are inferred to have been active in 1868. He quotes C.H. Hitchcock on subsidence near Kapoho accompanying an earthquake in September 1908. He discusses faulting on Kohala and Haleakala and offers an hypothesis for the formation of Haleakala Crater that involves faulting, as well as erosion.

 [This is a good summary of the development of the Hawaiian Chain along a major fracture system, emphasizing that the volcanic progression has been irregular, that the order of birth does not necessarily match the order of extinction, and that faulting has been important in the history of the volcanoes.]



Reasenberg, P.A., Matthews, M.V., and Wyss, M., 1988, Re-examination of seismicity rate fluctuations before the 1983 Kaoiki, Hawaii (M 6.6) earthquake [abs.]: Seismological Research Letters, v. 59, no. 1, p. 19. 



 A seismic quiescence precursor to the 1983 (M6.6) earthquake is the Kaoiki, Hawaii, Seismic Zone (KSZ), reported by Wyss (1986), is re-examined using a longer (14-year) time base, improved statistical methods, and corrections for heterogeneous reporting is the HVO catalog. Even with these improvements, critical problems inherent is the analysis and interpretation of seismicity rate fluctuations remain. Aftershocks dominate the seismicity rate is the raw catalog. Removal of the aftershock clusters leaves artificial depressions in the apparent seismicity rate corresponding to the large clusters. The strongest rate feature, a high rate interval between 1978 and 1981, does not correspond to any known geophysical or network-related event. A period of low rate in 1976 may be due to the 1975 Kalapana earthquake's effect on the catalog. The presence of such fluctuations is apparent seismicity rate makes it difficult to know which features to dismiss and which to interpret. Hence, interpretation of the low rate period 1981-1983 as an earthquake precursor, which was very convincing in the 1986 analysis, is now uncertain.

 Despite these problems, we focus our analysis on the 1981-1983 low rate interval. The concentration of the possible seismicity deficit is this interval, to the southeast of the northeast-trending fault plane inferred for the mainshock, coincides with a subregion characterized by low coda Q, high b-value, and predominantly strike-slip earthquake mechanisms. While these observations do not constitute a precursor to the 1983 mainshock, they may define a tectonic boundary that controls the occurrence of the large earthquakes characteristic of the KSZ.



Resing, J.A., Sansone, F.J., Wen, X.Y., and Midson, B., 1996, The geochemical signature of fluids issuing from Loihi Seamount after an intense seismic event [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F398. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 During an intense period of seismic activity at Loihi Seamount from late July to early August 1996, an expedition was mounted to assess effects of this activity. The data show a very distinct hydrothermal plume extending ~3 km from the source. Hydrocast temperature anomalies of ~3 C were observed. The data show a negative 2 unit anomaly in pH with an increase in alkalinity to 3.1 meq/Kg and a total CO2 = 18 mM/kg. Enrichments in Fe, Mn, Si, and NH4 were also observed. Particle concentrations showed a maximum of 250 mg/L.

 An initial assessment of the data suggest that we have sampled several different hydrothermal fluids. The most abundant fluid appears to be the type described by Sedwick et al. (1992). The evidence for this fluid are the elevated alkalinity and the presence of smectite-rich particles. A second fluid that was observed shows elevated salinity and Fe (~100 uM), suggestive of the brine phase of a phase separated fluid. Finally we observed a thin plume with a small temperature anomaly, a decrease in salinity and elevated CO2. Additional chemical analyses are underway to better distinguish these fluids from one another.

 Our observations show an effusion of gas-, particle-, and metal-rich hydrothermal fluids, most of which appear similar in composition to that previously observed. Although, the large changes in chemical and physical tracers that we measured are far greater than those that have been previously observed at Loihi Seamount during hydrocast surveys.



Richter, D.H., and Eaton, J.P., 1960, The 1959-60 eruption of Kilauea Volcano: New Scientist, v. 7, p. 994-997. 



 This dramatic and enlightening episode, with its rapid sequence of summit eruption, flank eruption and summit collapse, provided a rear opportunity of US Geological Survey observers. Although the culmination appears to have been passed, the summit is still deflating.



Richter, D.H., Ault, W.U., Eaton, J.P., and Moore, J.G., 1964, The 1961 eruption of Kilauea Volcano, Hawaii: U.S. Geological Survey Professional Paper 474-D, p. D1-D34. 



 The 1961 eruption of Kilauea Volcano, through the period February 24 to September 25, 1961, consisted of three summit eruptive phases follows by a flank eruptive phase. Tumescence of the Kilauea summit area which began in the summer of 1960, continued virtually unchanged throughout and after the three periods of summit eruption. Rapid detumescence accompanied the flank eruption. Seismic activity during tumescence was moderate and persistent, but it gave no particular safe warning of imminent eruption. However, a swarm of relatively large earthquakes and strong harmonic tremor preceded the flank eruptive phase by about 16 hours.

 The three summit eruptive phases were confined to Halemaumau, the deep crater within Kilauea caldera. During the first summit phase, which lasted only 8 hours, on February 24, a small collapse pit on the floor of Halemaumau was filled with 320,000 cubic yards of lava. Within a few hours after fountaining ceased, most of the new lava had drained back through the eruptive vents. During the second summit phase, which lasted from March 3 to 25, the same collapse pit was refilled. The third and most voluminous of the summit phases began on July 10 when lava fountains burst from the crater floor along a zone more than 1,500 feet long. The eruption continued until July 17, forming a new lake of lava 210 feet deep and 17.3 million cubic yards in volume. Backflow after fountaining resulted in a loss of approximately 1.3 million cubic yards. The 1961 eruptive cycle ended with a flank eruption along a 14-mile segment of Kilauea's east rift zone from September 22 to 25. Thirteen small, discontinuous lava flows, whose total volume was about 1.9 million cubic yards, were produced; and a large number of new cracks emitted volcanic fume and steam. Drainback of large volumes of lava into cracks apparently occurred at all the outbreaks, and no large flows were formed.

 The total volume of new lava added to the surface by all the 1961 eruptive phases is approximately 18.2 million cubic yards. Measured rates of extrusion ranged from 660 cubic yards per hour during the second summit phase to 114,000 cubic yards per hour during the third summit phase.

 Temperatures of the erupting lava ranged from 1,085 to 1,127 C in the three summit eruptive phases.

 The lavas range from tholeiite basalt in the summit and upper rift zone areas to tholeiite olivine basalt lower on the rift zone. Variation diagrams based on eight new chemical analyses indicate that the composition of the 1961 lavas was affected by three types of differentiation: (1) removal of magnesian olivine, (2) removal of augite and minor plagioclase, and (3) addition of magnesium olivine. The first type affected the composition of both the summit and flank lavas; the second type produced the characteristic differences between the summit and flank lavas; and the third type was responsible for the range in composition of the flank lavas.

 Extensive faulting and cracking along the east rift zone preceded, accompanied, and followed the flank eruptive phase. New faults having as much as 20 feet of vertical displacement were formed, and many old faults were reactivated. The 1961 flank activity occurred along the north side of the rift zone, which is noticeably bipartite; the north side is characterized by graben-horst topography and the south side, by cinder cones.



Richter, D.H., Eaton, J.P., Murata, K.J., Ault, W.U., and Krivoy, H.L., 1970, Chronological narrative of the 1959-60 eruption of Kilauea Volcano, Hawaii: U.S. Geological Survey Professional Paper 537-E, p. E1-E73. 



 In the evening of November 14, 1959, Kilauea Volcano on the Island of Hawaii renewed activity with an eruption at its summit. This chapter is a detailed pictorial chronological narrative of that summit eruption and the interrelated flank eruption and summit collapse that followed.

 The 1959 summit eruption occurred in Kilauea Iki, a collapse crater adjacent to the main summit caldera of Kilauea. The eruption consisted of 17 separate eruptive phases, which ranged in duration from 1 week to 1 3/4 hours. At the cessation of activity on December 20, 1959, Kilauea Iki Crater held 50 million cubic yards of lava in a lake 335 feet deep.

 After the summit eruption shallow earthquakes migrated out Kilauea's east rift zone, and on January 14, 1960, a flank eruption began near the town of Kapoho. During the next 37 days of virtually uninterrupted activity, 160 million cubic yards of lava, covering about 2,500 acres, was erupted. The small villages of Kapoho and and Koae, a United States Coast Guard station, and a number of residences along the coast were destroyed.

 Almost concurrent with the beginning of the flank eruption, the summit area of Kilauea rapidly deflated as magma moved from beneath the summit out the rift zone to the flank eruption area. Culmination of the summit subsidence occurred on February 7, 1960, when the floor of Halemaumaua deep crater in Kilauea calderacollapsed because of the withdrawal of the still fluid core of the 1952 lava lake. Two smaller collapses on March 9 and March 11 in Halemaumau marked the end of the 1959-60 eruption of Kilauea.



Rojahn, C., and Morrill, B.J., 1975, The island of Hawaii earthquake of November 29, 1975: Earthquake Engineering Research Institute Newsletter, v. 10, no. 1B, 59 p. 



 Preliminary report on the earthquakes--Christopher Rojahn and B.J. Morrill 1

"In the early morning hours of November 29, 1975 a series of strongly felt earthquakes occurred beneath the island of Hawaii (population 64,000), largest of the Hawaiian Islands. Initial analysis and interpretation of both local seismograph and teleseismic data (W. J. Person, National Earthquake Information Service, oral commun., 12/17/75) indicate that two large earthquakes, a magnitude 5.7 event at 0335 local time (lat 19 21.15'N long 155 03.53'W) and a magnitude 7.2 event at 0447 local time (lat 19 20.06'N, long 155 01.45'W), occurred 5 km beneath the sparsely populated southeastern coastline approximately 45 km south of Hilo."

The preliminary report on the tsunami--Harold G. Loomis 22

Newspaper clippings 26

Earthquake history of Hawaii--Earthquake Information Bulletin 48

Seismicity of Hawaii--A.S. Furumoto 50

A study of past earthquakes--A.S. Furumoto, N.N. Nielsen, and W.R. Phillips 51

Catalog of tsunamis in the Hawaiian Islands--G. Pararas-Carayannis 54

On the earthquakes of 1868 in Hawaii--Harry O. Wood 55

Sarah Lyman's log (1868) 56

Earthquake threat--Honolulu Advertiser 57

Honomu earthquake of April 26, 1973--N. Norby Nielsen 59



Rojahn, C., and Morrill, B.J., 1976, Preliminary report on the Hawaiian earthquake of November 29, 1975, in Seismic Engineering Program Report, October-December 1975: U.S. Geological Survey Circular 717-D, 16 p. 



 In the early morning hours of November 29, 1975 a series of strongly felt earthquakes occurred beneath the island of Hawaii (population 64,000), largest of the Hawaiian Islands. Initial analysis and interpretation of both local seismograph and teleseismic data (W. J. Person, National Earthquake Information Service, oral commun., 12/17/75) indicate that two large earthquakes, a magnitude 5.7 event at 0335 local time (lat 19 21.15'N long 155 03.53'W) and a magnitude 7.2 event at 0447 local time (lat 19 20.06'N, long 155 01.45'W), occurred 5 km beneath the sparsely populated southeastern coastline approximately 45 km south of Hilo.

 Four accelerographs and four seismoscopes were located on the island at the time of the earthquakes (fig. 1). Three accelerographs located at Hilo, Punaluu, and Honokaa were triggered, whereas the fourth, located in Kailua, was not triggered although it was found to be in good operating condition. Apparently, vertical motions at Kailua were below the nominal O.Olg threshold trigger level. Copies of the accelerograph records are shown in figures 2 and 3. Maximum accelerations, .05g threshold durations (time summation of record portions in which the envelope of the acceleration trace was greater or equal to 0.05g), total record lengths, accelerograph locations, epicentral distances, and other statistics are listed in table 3. As indicated in that table, a maximum acceleration of 0.22g (N16W) was recorded at the University of Hawaii in Hilo (43 km to the north of the epicenter) during the second and larger event. A 0.05g threshold duration of 13.7 seconds was measured for the same component (total record length = 76 seconds).

 Records obtained from each of the seismoscopes located at two sites in Hilo, at the Namakani Pio Campground and at Kailua are shown in figure 4. Descriptions of the instruments and data, including relative displacement response spectrum values, Sd, are listed in table 4. As indicated in that table, the maximum relative displacement, Sd=3.4 cm, was recorded in Hilo, 43 km from the epicenter with lesser values recorded 45, 31 and 108 km from the epicenter.

 The larger event generated a tsunami that caused at least one death, injury to 28 persons, and significant structural and nonstructural damage. This event was most probably also responsible for the slight to moderate structural and nonstructural damage sustained in the epicentral area and in Hilo from strong ground shaking. Most of the several dozen structures (mostly l-story wood-frame corrugated-metal-roof dwellings) located within the sparsely populated epicentral area suffered little or no structural damage. In Hilo, the closest urban center to the epicenter (45 km to the north), damage was more prevalent, but less severe (based on comparative personal observations by one of the authors) than that sustained in the April 26, 1973 Hawaii earthquake (magnitude 6.2) whose epicenter was located approximately 16 km north of Hilo.

 Outside of the immediate epicentral area (10 to 30 km from the epicenter) the authors observed only scattered evidence of strong ground shaking. At Pahoa (pop. 1000), 20 km northeast of the MS=7.2 epicenter, and in the vicinity of Kilauea Volcano, 29 km northwest of that epicenter (both areas contain mostly wood-frame metal-roof buildings), damage was minimal, a fallen unreinforced masonry chimney at the Kilauea Military Camp Cafeteria being the most serious observed damage. Near Cape Kumukahi, 29 km northeast of the MS=7.2 epicenter, stacks of lava rocks were intact, and in Lava Tree State Park, 21 km northeast of the epicenter, lava trees were not damaged.

 Within the city of Hilo the effects of strong ground shaking included: plate glass windows broken in many of the old downtown wood-frame shops; items fell from shelves in some stores; furniture moved or overturned; a few older homes reportedly collapsed or partially collapsed (owners' reports to Civil Defense Office, unverified by authors); and several engineered structures suffered slight to moderate structural and nonstructural damage.



Preliminary damage statistics compiled by the Hilo Civil Defense Office are listed in table 5. The $4,147,973 total is current to December 18, 1975 and includes damages caused both by the tsunami and by the strong ground shaking.



Rojahn, C., and Morrill, B.J., 1977, The island of Hawaii earthquakes of November 29, 1975: strong-motion data and damage reconnaissance report: Bulletin of the Seismological Society of America, v. 67, no. 2, p. 493-515. 



 Two earthquakes occurred on the island of Hawaii on November 29, 1975, a magnitude (Ms) 5.7 event at 0335 (local time) and a magnitude (Ms) 7.2 event at 0447. During the larger event, a maximum acceleration of 0.22 g was recorded in the southern part of Hilo, 43 km north of the epicenter. A 0.05 g threshold duration of 13.7 sec was measured for the same component. Smaller amplitude accelerograph records were obtained at two other locations on the island along with four seismoscope records.

 During or subsequent to the larger event, a large sector of the southeastern coastline subsided by as much as 3.5 meters. A tsunami generated by the larger event caused at least one death (one person also missing), injury to 28 persons, and significant structural and nonstructural damage.

 Only scattered evidence of strong ground shaking was observed in the epicentral area, and most of the several dozen nearby structures sustained little or no structural damage from ground shaking. In Hilo, 45 km north of the Ms = 7.2 epicenter, structural and nonstructural damage was slight to moderate but more extensive than elsewhere on the island.



Rothwell, M., 1906, A race with a lava flow: Pacific Commercial Advertiser, 08/12, p. 7. 



 An account of the trials of Captain Brown's family during the 1868 earthquake swarm and subsequent eruption, which necessitated their moving quickly out of the path of the flow.



Rubin, A.M., and Gillard, D., 1995, What are dike-induced earthquakes? [abs.]: Eos, Transactions, American Geophysical Union supp., v. 76, no. 46, p. F349. [AGU fall meeting, San Francisco, CA, Dec. 11-15, 1995, Program and abstracts] 



 Over 400 magnitude 1 to 3 earthquakes produced by the 1983 dike intrusion in the East Rift of Kilauea were located by the HVO seismic network. The catalog locations of these events extend 15 km along strike, about 3 km vertically, and 2 km perpendicular to the rift. Nearly 200 of these earthquakes can be grouped into 15 multiplets of 5 or more events that are sufficiently similar to be relocated via waveform cross-correlation. The multiplets include both earthquakes that are produced at the leading edge of the earthquake swarm, and those that occurred well after the seismic front had passed. While each multiplet spans over 1 km in the HVO catalogue, most span less than 50 m following relocation (of the order of the accuracy of the relative relocation method). In a few cases the multiplets consist of 2 or more tight clusters, separated by a few hundred meters along trend sub-parallel to the rift. These results suggest that the true width of the seismic swarm is much less than the catalog width, and that more earthquakes large enough to trigger the network are produced by a small number of "hot spots", rather than being a general feature of the propagating dike tip.

 In addition to the 1983 intrusion events, waveforms of the 40 earthquakes that occurred in the same region from 1980 to 1982 were collected. Some of the relocated multiplets consist of both intrusion and pre-intrusion events. Comparison of the waveforms in these cases revealed no obvious differences following the P-wave arrival that could be attributed to the presence of the dike. While these examples are few, they are consistent with mechanical calculations suggesting that it is difficult for dikes to produce shear failure of previously intact rocks, and that dike-induced seismicity occurs along favorably oriented pre-existing fractures.



Rubin, K.H., and Spencer, K.J., 1996, U-series disequilibrium and Pb isotopes in rocks and seawater from Loihi seamount, Hawaii: verification and dating of suspected volcanic products of the 1996 seismic event [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F398. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 Following an intense seismic swarm on Loihi in July/August 1996, UH and other scientists conducted a rapid event response expedition to the area (Aug. 1996) using the RV Ka'imikai-o-Kanaloa and Pisces V manned submersible. Large particle, temperature and chemical anomalies were observed in the water column above Loihi. Several samples of fresh-appearing lava were also collected from debris fields ringing the pit craters of the largely tectonized summit region of the seamount. We are analyzing lava and seawater samples from this expedition for U-series and Pb isotopic composition to constrain the temporal and physical aspects of this event. Seawater with extreme particle enrichments (0.22 mg/L) contained 2.1-2.5 dpm/g 210Po in the particulate phases 1 month after collection. They also contain 13.5, 1.3 and 27.5 ppm U, Th and Pb. Pb isotopic composition of the particulates is nearly identical to that of the fresh rocks noted above (which are in the range of previously-published values for Loihi). This strongly implicates Loihi as the ultimate source of this Pb. The 234U/238U activity ratio in the particulates is 1.144, essentially that of modern seawater. If 210Po-210Pb radioactive disequilibrium exists in this material, it will be found during repeat analyses with time. Identification of excess 210Po in the water column due to degassing by erupting lavas would provide strong evidence for the occurrence of an eruptive (rather than intrusive or non-volcanic) event and would help to quantify the chemical effect of eruption-related metal degassing on near-volcano water masses (as discussed in a Rubin and Sacks, this volume). Analyses are also under way to determine the age of 2 of the freshest lavas collected using the 210Po-210Pb dating technique first applied to verify and date suspected eruptive activity at 950'N on the EPR in 1991 and 1992 (Rubin et al., Nature, v. 368, p. 841, 1994). Other U-series nuclides are being analyzed as well to constrain the temporal relationship of these rocks to the observed seismicity.



Rubin, A.M., and Gillard, D., 1997, Insight into Kilauea's east rift zone from precise earthquake relocation [abs.]: Eos, Transactions, American Geophysical Union supp., v. 78, no. 46, p. F634. [AGU fall meeting, San Francisco, CA, Dec. 8-12, 1997, Program and abstracts] 



 Kilauea's shallow rift zones are sites of abundant seismicity that occurs both in dike-related swarms and as steadier background activity. This shallow region is located above the deeper aseismic (partially molten?) portion of the rift system that deforms at rates of up to 20 cm/yr. We are using a waveform cross-correlation technique [Got et al., 1994] to obtain precise relative locations for hundred of earthquakes along a 20-km stretch of Kilauea's Upper and Middle East Rift Zones. Background seismicity from the Upper East Rift in 1991 and 1992 defines a remarkable "ribbon" at about 3 km depth that extends 2.5 km along the rift but only 100 to 200 m vertically. We have interpreted these earthquakes as occurring within the stress concentration above the deforming deep rift body [Gillard et al., 1996]. The depth is consistent with the top of the deep rift body inferred from geodetic data, and the left-lateral focal mechanisms are consistent with the seaward displacement of Kilauea's south flank. The limited vertical extent and increasing moment release rate since 1983 are in quantitative agreement with an elastic boundary-element model in which the shear stress within the shallow, brittle rift was set to zero by small intrusions in 1980 and 1982, and subsequently increased by geodetically-constrained motion across the deep rift [Delaney et al., 1993]. Relocated events from the 1983 Middle East Rift dike intrusion extend 15 km along strike but also show tight clustering at 3 to 4 km depth. Based on elastic calculations indicating that a significant ambient differential stress is required for dikes to produce detectable earthquakes, we infer that these events are also produced within the stress concentration of the underlying deep rift. There is an apparent tendency for the relocated events to deepen downrift. While systematic errors in the velocity model cannot be ruled out as the cause, this is qualitatively consistent with the idea that the depth of the top of the deep rift is determined by the balance between the downrift advection of heat (magma) from beneath Kilauea summit, and conduction of heat to the surface.



Rubin, A.M., Gillard, D., and Got, J.-L., 1998, A reinterpretation of seismicity associated with the January 1983 dike intrusion at Kilauea Volcano, Hawaii: Journal of Geophysical Reseach, v. 103, no. B5, p. 10,003-10,10,015. 



 In January 1983, a dike intrusion/fissure eruption generated a swarm of 375 magnitude 1 to 3 earthquakes along a l-km segment of Kilauea's Middle East Rift Zone. We searched the Hawaiian Volcano Observatory catalog for multiplets of similar events from this region from 1980 through 1985 and obtained precise relative locations by waveform cross correlation. Over 150 of the intrusion earthquakes could be grouped into 14 multiplets of five or more events with sufficient similarity for accurate relocation. Some multiplets were active for only a few minutes during the downrift migration phase of the seismic swarm, consistent with generation near the propagating dike tip, while others were active for several days. The two multiplets nearest the origin of the seismic swarm include events from the preceding days and months. Most multiplets span only 50 to 100 m following relocation, are located at about 3 to 4 km depth, and appear to deepen downrift. The catalog depths of those earthquakes in multiplets and those not in multiplets are similar, suggesting that most of the recorded seismicity may have come from a very limited depth interval despite the fact that the dike breached the surface. By analogy with a mechanical model used to explain a similar clustering of background seismicity in the Upper East Rift in 1991, we infer that the earthquakes are generated in regions of high stress concentration immediately above Kilauea's deforming deep rift body. This conclusion is consistent with the depth of the top of the deep rift body inferred from geodetic data and with numerical calculations suggesting that a significant ambient differential stress is required for dikes to produce earthquakes larger than magnitude 1.



Rubin, A.M., and Gillard, D., 1998, Dike-induced earthquakes: theoretical considerations: Journal of Geophysical Reseach, v. 103, no. B5, p. 10,017-10,10,030. 



 Earthquakes of magnitude 1 and greater seem to be ubiquitous features of dike propagation, but their origin is not well understood. We examine the elastic stress field surrounding propagating fluid-filled cracks, with an emphasis on assessing the ambient stress required to produce earthquakes with linear dimensions of ~100 m near dikes with linear dimensions of a few kilometers. An important feature of the solutions is the dike "tip cavity," a low-pressure region where magma cannot penetrate and where the stress field differs most from the classical near-tip stress field. Two regions are considered: near the dike tip but away from the tip cavity and near the tip cavity. The stress state most conducive to failure occurs near the tip cavity-when the cavity pressure is maintained by influx of host rock pore fluids rather than by exsolution of magmatic volatiles. Even in this case, however. shear fracture of previously intact rock seems unlikely. Thus most dike-induced seismicity with a frequency content typical of "tectonic" earthquakes should be interpreted as resulting from slip along suitably aligned existing fractures. Production of magnitude I earthquakes appears to require either large ambient differential stresses or low ambient confining pressures; in the latter case. the effective normal stress on prospective faults may be low enough for slip to be aseismic. We conclude that the distribution of (recorded) dike-induced seismicity reflects the distribution of ambient stresses that are near to failure and does not necessarily reflect the extent of the dike. This result is consistent with recent images of the seismicity associated with the 1983 dike intrusion at Kilauea.



Rydelek, P.A., Davis, P.M., and Koyanagi, R.Y., 1988, Tidal triggering of earthquake swarms at Kilauea Volcano, Hawaii: Journal of Geophysical Research, v. 93, no. B5, p. 4401-4411. 



 Between 1967 and 1983, four earthquake swarms occurred on Kilauea Volcano, Hawaii, with durations ranging from 68 to 156 hours. Plots of the number of events per hour show a remarkable modulation having diurnal and semidiurnal periodicities. We test the hypothesis that these fluctuations are tidally triggered. A correlogram showing the correlation coefficient between the swarm series and tidal strain oriented at 20 intervals and phase shifted at l-hour intervals gives the orientation and phase of the tidal strain most closely resembling the swarm plots. Maximum correlation occurs at different orientations and phases for three of the four swarms, which occur in tectonically different parts of the volcano. Two of the swarms which occur in the same region can be fit with a common tidal forcing function even though they occurred more than a year apart. The discrete Fourier transform of the swarm data shows a dominance of diurnal energy over semidiurnal energy, compared with the opposite dominance for the transform of the theoretical tidal function at the times of the swarms. We checked whether the diurnal dominance might be generated by cultural noise by raising the threshold magnitude of the earthquakes used without noticeably affecting the results. Also the phase of the correlation varies from swarm to swarm relative to local Hawaii time. Diurnal dominance remains not completely understood. but tidal influences appear to be the best explanation for the modulation of the activity. These observations limit the rate of tectonic stress change in the rift zones of Kilauea to less than the tidal stress rate.



Sansone, F.J., Duennebier, F.K., Malahoff, A., and McMurtry, G.M., 1996, The 1996 Loihi Seamount rapid response and follow-up cruises: an overview [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F397. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 An interdisciplinary team studied the immediate effects of a major underwater seismic event at Loihi Seamount 30 km SE of the island of Hawaii, during a NSF-sponsored research cruise (including two submersible dives) over August 5-10, 1996. Follow-up cruises and dives are planned for September 23 - October 11.

 Significant changes were observed in the summit geomorphology. The former pinnacle at Pele's Vents has been replaced by a pit crater ca. 260 m wide and 300 m deep. Sonobuoys released from the ship recorded a variety of high frequency crackling and grinding noises from the summit during the initial cruise; these were likely the sounds of an eruption in progress. In contrast, the southern flank of the seamount was acoustically quiet.

 In August we ran three tow-yo sections: one, 7 km long, running S to N just west of the main north-south ridge axis; a second, 5 km long, running WSW to ENE (parallel to the current) over the summit of the seamount; and a third, 1.6 km long, running SW to NW just west of the summit. In additional 5 hydrocasts were conducted: 3 casts were in pit craters at the summit, 1 was taken west of the summit, and 1 was a background cast taken 48 km ENE of the summit. Hydrothermal fluids are apparently accumulating in the bottoms of the pit craters, as evidenced by sharp vertical temperature and salinity gradients, and the high particle loading in the bottom waters. Anomalies of up to 3.5 C and 0.65 psu salinity were measured in the water column within the bottoms of the pit craters, with the largest anomaly in the new pit crater at the former site of Pele's Vents. These samples are among the most hydrothermally altered waters ever collected from above an undersea hydrothermal system.

 Temperature anomalies of 0.5 C were found in water column plumes around the summit area. Anomalies of 0.1 C were recorded during tow-yos at distances ~3 km downstream of the summit. Plumes an pit waters at different locations with positive temperature anomalies had either negative or positive salinity anomalies, suggesting that the composition of the hydrothermal fluids varies at different venting site. This suggestion of phase separation in the vent fluids will be corroborated with other chemical data being collected. The spatial distribution of the water column plumes also suggests that there was venting outside of the pit craters, most likely in the area immediately north of the East Pit. This hypothesis is supported by visual observations during the submersible dives of highly turbid water coming from this area, and the collection of glassy rock fragments (presumably from a recent eruption) on the rosette when it was inadvertently dropped on the seafloor in this area during the last tow-yo.



Sansone, F.J., Wen, X.Y., Holmes, M.E., Resing, J.A., Rust, T.M., and McLaughlin, E.A., 1996, Dissolved gases in Loihi hydrothermal plumes following the 1996 seismic event [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F398. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 Hydrothermal plume samples were collected from Loihi Seamount using tow-yos and hydrocasts during the August 1996 rapid response cruise following the major seismic event of July-August. In addition, we plan to collect additional samples during our upcoming cruise to Loihi in October, and expect to present these results as well.

 In August the most altered samples were collected from hydrocasts into pit craters at the Loihi summit, although elevated dissolved gas levels were also observed in plumes surrounding the Loihi summit. The maximum concentrations observed were greater than 17 mM TCO2, 280 nM CH4, and 20 nM H2, with the highest levels deepest in the pits. Very steep vertical gradients were observed: in East Pit the methane concentration increased from 2 nM at the rim depth (1200 m) to ~250 nM at a depth of 1230 m. A smaller maximum (ca. 5 nM) was also observed above the rim depth (1170 m), perhaps from venting in the area north of the pit.

 The carbon stable isotopic ratio of the methane in Pele's Pit was -28.8 per mil, which is considerably heavier than the -32 to -42 per mil values measured previously in Loihi plumes. Strong linear relationships were observed between methane concentrations and the corresponding temperatures and particle concentrations in Pele's Pit. Methane oxidation rate measurements are currently in progress. However, initial results indicate approximately linear changes in the carbon stable isotopic ratio of the residual methane during incubation.



Savage, M.K., and Meyer, R.P., 1983, Aftershocks of an M=4.2 earthquake on the island of Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 64, no. 45, p. 901. [AGU fall meeting, San Francisco, CA, Dec. 5-9, 1983, Program and abstracts] 



 On April 12, 1982 U.T., a magnitude 4.2 earthquake occurred on Kilauea's south flank. Durlng the following 3 hours, 23 aftershocks were recorded and subsequently located using a 20 step, monotonic velocity-depth function approximating Klein's (1981) linear gradient model. The epicenters are within a 4.2x2.25 km area. All the aftershocks were located at shallower depths than the main shock (9.5 km), but all were below 6 km depth. The focal mechanisms of the main shock and son aftershocks show low angle thrust faulting, with strike parallel to the East Rift Zone and with the upper block moving away from the island. However, many aftershocks show different focal mechanisms (e.g., strike-slip faulting, thrusting in opposite directions to the main shock). Crosson and Endo's (1982) hypothesis that Kilauea's south flank is moving away from the rest of the island on a decoupling layer of old oceanic sediments at 8-9 km depth is supported by both the location and focal mechanism of the main shock. The lack of earthquakes deeper than the main shock and the widely varying focal mechanisms of the small events suggest that the thrusting of the south flank away from the main island during the main shock disturbed the material in the upper block, causing localized changes in the stress field and some rebounding, while the material below the decoupling layer was less affected by the movement of the block above it. Continuing investigations concern the source parameters of the main shock and its aftershocks.



Savage, M.K., 1984, Aftershocks of an ML = 4.2 earthquake on the island of Hawaii: Madison, WI, University of Wisconsin, M.S. thesis, 61 p. 



 Conclusions

In this paper, we have shown: 1) The aftershock epicenters occur within a roughly elliptical zone of 6.5 square km (or 7.1 square km projected on the fault plane). The area corresponds roughly with the area calculated from spectra using Brune's (1970) model. There is a lineation perpendicular to the ERZ which is made up of roughly half the events, and which is shown in cross section to vary in depth (see Fig. 10, clump above mainshock), as if some aftershocks were occurring on a vertical plane parallel to the strike of the mainshock. This vertical plane is not a fault plane for any of the aftershocks for which fault planes were determined. Thus the clustering is interpreted as being due to higher stresses directly above the location of the mainshock, which may have had its greatest movement in a linear feature parallel to its strike.

 2) The aftershocks are all closer to the ERZ than is the mainshock, which suggests that the mainshock began at its given location and propagated islandward.

 3) The majority of the aftershocks occur above the mainshock fault plane, which occurred at the bottom of the hypothesized decoupling layer, and their focal mechanisms are varied. The fine structure of the aftershock locations seems to repeat seismicity patterns found for other, unassociated earthquakes in the same region. These facts suggest that rather than aftershocks occurring on the mainshock fault plane itself and thus defining the fault plane, the changes in stress caused by the mainshock in turn caused movements on other faults above the mainshock fault plane but still in the decoupling layer. There are no earthquakes below the mainshock fault plane, which lies at the bottom of the decoupling layer. The decoupling layer is at least 1.5 km thick, thicker than required for the decoupling layer to be simply explained by ancient sediment layers. Some mechanism must exist for thickening the layer. The mechanism may be related to the greater seismicity near the east rift zone.

 4) The mainshock and the majority of the aftershocks show fault plane solutions consistent with movement of the upper block (the block above 9 km) of the south flank/East Rift Zone of Kilauea moving away from the rest of the island, toward the sea. The orientations of the fault planes showed no consistency, in contrast to a study of larger earthquakes in the same area (Crosson and Endo, 1982), which showed mainly shallow angle thrust faults. The most consistent parameters in the fault plane solutions were the P axis azimuth (122  21 deg), slip vector azimuth (150  22 deg, perpendicular to the ERZ), and plunge (8  22 deg), and auxiliary plane azimuth and dip. (60  22 deg Az, 85  24 deg dip NNW). This is consistent with results from a 10-year study in the same area, in which the major stress field was found to be compression perpendicular to the ERZ, and movement of the south flank block above the "decoupling layer' was away from the ERZ toward the ocean (Crosson and Endo, 1982).

 5) Three anomalous events near the edge of the aftershock zone either show motion in the opposite direction from the other earthquakes or show high angle reverse faulting which has not been seen in the area before. This may be due to strains at the edge of the tear pulling back on the moved segment, i.e. a rebound mechanism. Such anomalous events have not been reported before, probably because focal mechanisms of such small events have not been determined.

 6) The results of studies of a 3-hour aftershock sequence of a relatively small event (Mag. 4.2) are very similar to results of a ten-year study of earthquakes of mag > 2.8 in the same area. This means that data from portable seismographs deployed for a short period of time and recording relatively small events may be used to draw conclusions for the tectonics of an area which are as valid as much longer term seismicity studies of larger events.



Savage, M.K., and Meyer, R.P., 1985, Aftershocks of an M = 4.2 earthquake in Hawaii and comparison with long-term studies of the same volume: Bulletin of the Seismological Society of America, v. 75, no. 3, p. 759-777. 



 Study of the aftershocks recorded in a 3-hr period after a 4.2 magnitude event on the East Rift Zone of Kilauea volcano, Hawaii, on 12 April 1982 shows that the aftershocks occurred on different planes than the main shock, probably as a result of stress redistribution; the aftershock locations are probably controlled by preexisting structures. This study also suggests that these relatively small aftershocks occurred in the same seismicity patterns as larger events recorded in the same volume over a period of 10 yr. Slips on most of the aftershocks and the main shock are in the same direction, perpendicular to the East Rift Zone, as has been found in studies of other, larger earthquakes. However, fault-plane solutions varied more, as did the tensional axes, and several of the smaller events showed movement in the opposite direction from the main shock and the rest of the aftershocks, suggesting some rebound was occurring near the edges of the aftershock zone. Because ten times as much energy was released in the aftershocks in a narrow linear region as elsewhere, and since the main shock epicenter was oceanward of all the aftershocks, we suggest that rupture began at the main shock hypocenter and propagated landward, implying an almost "one-dimensional" fault.

 For the aftershocks, the relationship between moment and magnitude was: log Mo = (1.18 + 0.17) M, + (17.3 + 0.17). Differences in amplification lead to site differences of up to 0.8 units in local magnitude and 1.5 orders of magnitude in energy release. These correlated somewhat with station time corrections in that the stations with the longest delay times also had greatest amplification.



Savage, M.K., 1987, Spectral properties of Hawaiian microearthquakes: source, site, and attenuation effects: Madison, WI, University of Wisconsin, Ph.D. dissertation, 223 p. 



 Shear-wave displacement and acceleration spectra were determined for 397 Hawaiian earthquakes located near Kilauea Caldera and on the south flank of Kilauea. The events were between moment 1017.4 and 1020.8 dyne-cm and were recorded between 29 .March and 1 May, 1982 by the University of Wisconsin's 3-component digital seismographs. .An inversion of the spectra averaged the path effects, and separated the source effects from the effects of site response relative to assumed "good" stations, forming event spectra and "station" spectra, or site corrections. Large variations were seen in station spectra, which explains the drop in acceleration spectra at high frequencies (the  max effect) that was seen at some stations in an earlier study, as well as the site effects noticed in magnitude calculations. Apparent values of moment, corner frequency, and dynamic and static stress drop were computer-determined from the event amplitude spectra, yielding an apparent increase in stress drop with moment for small events with Mo<1019. The theoretical acceleration amplitude spectra for the Brune source model, modified by an assumed spectral decay parameter that is related to near-surface attenuation, were examined; the apparent, calculated values of corner frequency and moment can be fit with stress drops that are constant within each of five regions but vary from 1 to 100 bar between regions. A residual spectral decay parameter K0=0.03-0.04, postulated to be controlled by the residual attenuation from a near-surface layer that was not accounted for by corrections for Q and for station site effect, was needed to fit the data with constant stress drops. The values of K0 yielded average near-surface Q of 15-20, if we assume that the residual attenuation took place in the upper 500 m.

 We find similar average stress drops and dependence of M0 and 0 in the two regions for which we have the best station coverage, contrary to the results of Zuniga et al. (1987). Spatial and temporal variations in stress drop were reevaluated using Zuniga et al.'s stress drop calculations and Wyss et al.'s (1981) regions. The region that Wyss et al. suggested as having precursory high stress before the 1975 Kalapana mainshock had higher stress drops by a factor of two before the mainshock (11.6 bar) than after it (5.6 bar); the region just west of Wyss et al.'s proposed asperity region had no earthquakes before the Kalapana mainshock, but had earthquakes with high average stress drops (16.7 bar) after it. The stress drops in these two regions and in the region south of the SW rift zone should be monitored, since they may be earthquake precursors for future events.

 Earthquakes with Mo > 1019.5 dyne-cm occur in a plane less than 1 km thick at 9 km depth, and smaller earthquakes occur at that depth or above it. This study, studies of aftershocks of the Kalapana earthquake, and long-term studies of the south flank show that intermediate-magnitude earthquakes with depths between 5 and 13 km are concentrated in a narrow, vertically thin, curved zone that is close to the Southwest and East Rifts. and is smaller than the area of movement determined geodetically. Fault-plane solutions from locally-recorded P-wave first motions of the Kalapana mainshock, many of its aftershocks, and other South Flank earthquakes with M > 2.8 fit a double-couple mechanism with an upper block moving horizontally away from the rest of the island. However, long-period Rayleigh and Love waves from the Kalapana mainshock suggest a single force rather than a double-couple mechanism.

 Previous investigators hypothesized that the south flank of Kilauea is moving away from the rest of the island along the old oceanic sediment layer. We suggest that this layer is divided into two or three zones: one "rupture" zone that is defined by the earthquakes at depths of 9 km, and one or two "slide" zones that allow sliding along the old sea floor but do not usually support energetic fracture. The smaller, shallower earthquakes probably result from stresses in the upper layer caused by motion of the layer away from the rest of the island along the old oceanic sediment layer.

 The new model explains the long-term earthquake distribution and geodetic observations. It explains the Kalapana mainshock as a fracture of the rupture zone, which pushed the material to the south of it forward along the slide zone. This model of the Kalapana mainshock explains the small fault area estimates from aftershocks and the large fault area estimates from geodetic measurements and tsunami height, as well as the discrepancies in radiation patterns from P-wave first motions and from long-period Raleigh and Love waves.

 We speculate that the rupture zone may be in the old sedimentary layer, which has been strengthened and made capable of violent fracture by intrusion of sills into the sediments, or by thermal or hydrothermal alteration of sediments, or both.



Savage, M.K., and Meyer, R.P., 1987, A new model for tectonics of the south flank of Kilauea Volcano, Hawaii and for the 1975 M=7.2 Kalapana earthquake: rupture and slide zones in the old oceanic sediment layer [abs.]: Eos, Transactions, American Geophysical Union, v. 68, no. 44, p. 1536. [AGU fall meeting, San Francisco, CA, Dec. 6-11, 1987, Program and abstracts] 



 273 South Flank events with moment (Mo) 1017.4 to l020.8 dyne-cm, show that earthquakes with Mo > 1019 dyne-cm occur in a plane less than 1 km thick at 9 km depth, and smaller earthquakes occur at that depth or above it.

 This study, studies of aftershocks of the Kalapana earthquake, and long-term studies of the South Flank show that are concentrated in a vertically thin, horizontally narrow, curved zone that is close to the Southwest and East Rifts, and is smaller than the area of movement determined geodetically. Fault-plane solutions from locally-recorded P-wave first motions of the Kalapana mainshock, many of its aftershocks, and other South flank earthquakes with M > 2 8, fit a double-couple mechanism with an upper block moving horizontally away from the rest of the island. However, long-period Rayleigh and Love waves from the Kalapana mainshock indicate a single force rather than a double-couple mechanism.

 We extend the previous hypothesis that the south flank of Kilauea is moving away from the rest of the island along the old oceanic sediment layer, by dividing that layer into two or three zones, one "rupture" zone that is defined by the earthquakes at depths of 9 km, and one or two "slide" zones that allow sliding along the old sea floor but do not usually support energetic fracture

The new model explains the long-term earthquake distribution and geodetic observations and explains the Kalapana mainshock as a fracture of the rupture zone, that quietly pushed the material in front of it forward along the slide zone This model of the Kalapana mainshock explains the small fault area estimates from aftershocks and the large estimates from geodetic measurements and tsunami height, as well as the discrepancies in radiation patterns from P-wave first motions and from long-period Rayleigh and Love waves.

 We speculate that the rupture zone may be in the old sedimentary layer strengthened and made capable of violent fracture by intrusion of sills into the sediments and/or by thermal or hydrothermal alteration of sediments.



Savage, M.K., and Meyer, R.P., 1989, Comment on ''Apparent stresses, stress drops, and amplitude ratios of earthquakes preceding and following the 1975 Hawaii MS = 7.2 main shock' by F.R. Zuniga, M. Wyss, and M.E. Wilson: Bulletin of the Seismological Society of America, v. 79, no. 4, p. 1300-1304. 



 "Zuniga et al. (1987) calculated spectra from about 300 hand-digitized seismograms with magnitudes between 2.8 and 3.9 that had been recorded at Hilo, Hawaii, between 1962 and 1981 to study stress drops and the ratios of amplitudes of shear and compressional waves (SV/P) preceding and following the 1975 Kalapana, Hawaii, Ms = 7.2 main shock. Earlier results from geodetic studies and preliminary spectral studies had led them to expect higher stress drops before the main shock than after it (Wyss et al., 1981; Zuniga et al., 1983). However, they found no such changes, and instead observed spatial variations in previously-described "asperity regions." In contrast, in a study of about 300 digitally-recorded microearthquakes from the same source regions between March and May 1982, we found similar moment-corner frequency dependence and similar average stress drops in the regions in which Zuniga et al. (1987) had noted differences (Savage, 1987). In this comment, we explain the cause of the discrepancy: slightly larger regions used by Zuniga et al. (1987) included an area that had no seismicity before and high stress-drop events after the Kalapana earthquake. An "asperity region" originally defined by Wyss et al. (1981) actually had higher stress drops before the Kalapana event than afterwards; however, the inclusion of the larger area increased the average post-Kalapana stress drop for the region, making it appear that the region had high stress drops at all times.



Scherbaum, F., and Wyss, M., 1987, Stress drops of microearthquakes preceding the 1983, Kaoiki (Ms = 6.6), Hawaii, earthquake [abs.], in Decker, R.W., Halbig, J.B., Hazlett, R.W., Okamura, R., and Wright, T.L., ed(s)., Hawaii Symposium on How Volcanoes Work, Hilo, HI, January 19-25, 1987, Abstract volume: Honolulu, University of Hawaii, Hawaii Institute of Geophysics, p. 227. 



 Preceding the 1983, Kaoiki (Ms = 6.6), Hawaii, earthquake, nearly 700 microearthquakes have been located in its aftershock zone by the Hawaiian seismic network. Starting in 1977 more than 1400 good quality records have been obtained by the single component stations AIN, CPK, DES, KFA, MLX, and PLA. Brune stress drops for this events have been calculated from the P-wave spectra and have been examined for the occurrence of temporal and/or spatial variations.

 The interpretation of spatial stress drop patterns is aggravated by the strong influence of superficial site conditions. The spectral parameters at certain stations seem to be controlled by frequency band limitations and filtering effects which vary strongly between the individual recording sites. The observed frequency content do not show any directional variations or dependence on hypocentral distances. Thus, the sources of the site effects seem to be concentrated in the very shallow parts of the propagation paths.

 The distribution of stress drops shows a strong depth dependence which seems to correlate with the depth distribution of microearthquakes in this region. At lower depths, only a few events with relatively small stress drops are observed. In contrast to the deeper events, this earthquakes are concentrated in the SE of the 1983 Kaoiki aftershock zone and follow the strike of the main shock (N45E). The higher stress drop events are found below depths of 6 - 7 kms, where the majority of the earthquakes are located.



Scherbaum, F., and Wyss, M., 1988, Spectral analysis of microearthquakes preceding the 1983 Kaoiki, Hawaii, earthquake [abs.]: Seismological Research Letters, v. 59, no. 1, p. 30. 



 Preceding the 1983, Kaoiki (MS = 6.6), Hawaii, earthquake, nearly 700 microearthquakes have been located in its aftershock zone by the Hawaiian seismic network. Starting in 1977 more than 1400 good quality records have been obtained by the single component stations AIN, CPK, DES, KFA, MLX, and PLA. In the first step of the analysis, Brune stress drops for these events have been calculated from the P-wave spectra using the standard two-line-fitting procedure in double logarithmic representation.

 The average stress drop shows a strong dependence which seems to correlate with the depth distribution of microearthquakes in this region. At shallow depths, only a few events with relatively small stress drops are observed. The higher stress drop events are found below depths of 6-7 km, where the majority of the earthquakes are located.

 We found a strong dependence of the observed stress drops on the individual recording sites, independent of azimuth and hypocentral distance. The sources of these effects seem to be concentrated in the very shallow portion of the propagation paths and might be due to resonances in shallow low velocity layers.

 We are currently working on the reevaluation of the observed spectra using additional single layer resonance spectra to account for these effects.



Scherbaum, F., and Wyss, M., 1990, Distribution of attenuation in the Kaoiki, Hawaii, source volume estimated by inversion of P wave spectra: Journal of Geophysical Research, v. 95, no. B8, p. 12,439-12,448. 



 A new method to simultaneously invert for Q structure and source parameters was used on a set of 635 microearthquakes (0.9 < M < 2.0) in the Kaoiki area of southern Hawaii. Approximately 2800 signals were analyzed which had been recorded by 6 short period vertical seismographs at epicentral distances of a few to 10 km. The hypocentral depths ranged from 0 to 14 km, with the bulk of the sources in the 7.5-10.5 km range. The hypothesis to be tested was that the source volume of the M = 6.6 Kaoiki mainshock of November 16, 1983, may be heterogeneous in attenuation distribution. We assumed that the observed P wave displacement spectra could be modelled by a source spectrum with an w-2 high-frequency decay, a single-layer resonance filter to account for local site resonances and whole path attenuation along the ray path. In a next step the attenuation factor Q was constrained by tomographically reconstructing the three-dimensional Q structure for the source region and using it as starting model for a nonlinear inversion of the corner frequency, the seismic moment Mo, and a new Q value. This process was iterated until the results changed less than 0.1% and were accepted as final. The average Q was approximately constant and very low (105 < Q < 115) between 0 and 7 km depth. It increased to approximately 160 between 9 and 11 km. In the depth ranges were the spatial coverage was good (3-9 km) the Q values in the NW pan of the 1983 aftershock volume were larger by approximately 10-15% compared to those in the SE pan. This 12% contrast correlates with other evidence for heterogeneity. The NW region shows high coda-Q, no surface faulting, medium seismicity rate, and medium precursory quiescence, while the SE region shows low coda-Q, pervasive faulting, high seismicity rate, strong precursory quiescence, and possibly low b values. We conclude that the Kaoiki source volume is strongly heterogeneous with the contrasting density of cracks controlling the difference in crustal parameters. The new simultaneous inversion technique is well suited to derive detailed Q structure and source parameter information from microearthquake spectra recorded at close epicentral distances.



Segall, P., and Delaney, P.T., 1988, Coseismic and postseismic horizontal deformation from the 1975 M=7.2 Kalapana earthquake [abs.]: Eos, Transactions, American Geophysical Union, v. 69, no. 44, p. 1433. [AGU fall meeting, San Francisco, CA, Dec. 6-11, 1988, Program and abstracts] 



 The largest deformation event to occur on the island of Hawaii since the installation of an extensive trilateration network in 1970 resulted from the M 7.2 Kalapana earthquake of November 29, 1975. We have computed horizontal displacements for the 1970-74 preseismic, 1974-76 coseismic, and 1976-82 postseismic epochs. Network misclosures indicate measurement errors on a typical 10 km baseline of ~ 3 cm for the preseismic period, and ~ 5 cm for co- and post-seismic periods. Some misclosure may result from rapid postseismic deformation during the 1976 survey. A minimum vector norm solution for the 1976-82 postseismic epoch, which holds the networks center of mass fixed, is shown in the Figure. Large displacement gradients at 155 and 15520', isolate Kilauea's south flank, which has moved southeastward relative to the distal parts of Kilauea's rift zones. This region corresponds to the Kalapana aftershock zone and flanks the most active part of the rift system. The south flank extended 401+/- 30 ustrain normal to the rift zones during the 1974-76 coseismic epoch. The same area contracted at a rate of 8.3  0.7 ustrain/year following the earthquake (1976-82). Horizontal and vertical displacements determined by trilateration and repeated leveling place important constraints on the mechanism of the earthquake, and associated postseismic phenomenon.



Segall, P., and Delaney, P.T., 1989, Horizontal deformation of Kilauea Volcano [abs.], in Continental Magmatism, International Association of Volcanology and Chemistry of the Earth's Interior, General Assembly, Santa Fe, NM, June 25-July 1, 1989, Abstracts: New Mexico Bureau of Mines & Mineral Resources Bulletin 131, p. 237. 



 The Hawaiian Volcano Obs. has operated an EDM network on Kilauea Volcano since 1970. We computed horizontal displacements for three epochs: 1970-4, 1974-6, and 1976-82. The 1974-6 epoch spans the M 7.2 Kalapana earthquake. We estimate measurement errors from the network misclosures. Assuming the variance is s2 = a2 + b2L2 where L is line length, we estimate a and b by maximum likliehood, extending the methods of Segall and Matthews (J.G.R., 1988). For the 1970-4 epoch a ~ 5 mm, and b ~ 1 x 10-6. The misclosures in the 1974-6 and 1976-82 data are larger, possibly due to unmodeled vertical deformation or rapid postseismic deformation during the 1976 survey. Minimum vector norm solutions, which hold the networks center of mass fixed, are shown for the three epochs below, with 95 % confidence ellipses. Notice the large displacement gradients at 155 and 15520' which bound Kilauea's south flank. The south dank has moved SE relative to the distal parts of Kilauea's rift zones during all three epochs. This region corresponds to the Kalapana aftershock zone and flanks the most active part of the rift system.



Segall, P., Owen, S., Freymueller, J., Arnadottir, T., Miklius, A., and Denlinger, R., 1993, Rapid aseismic fault slip beneath Kilauea Volcano [abs.]: Geological Society of America Abstracts with Programs, v. 25, no. 6, p. A-243. [Geological Society of America, annual meeting, Boston, MA, Oct. 25-28, 1993] 



 The south flank of Kilauea volcano, consisting of the area south of Kilauea's two rift zones, has been the locus of major seismic activity. Both the 1975 M7.2 and the 1989 M6.1 earthquakes occurred on a sub horizontal fault beneath Kilauea's south flank. These earthquakes displaced the upper block seaward, away from the rift zones. The 1975 earthquake generated a tsunami that resulted in two fatalities.

 Global Positioning System (GPS) measurements in 1990 and 1992 show that the south flank moved away from the rift zones at a rate of roughiy 10 cm/yr. The motion was largely aseismic and unaccompanied by shallow episodic intrusions in the rifts. Stations north of the rift zones were stationary with respect to sites far removed from active volcanism. The rate of displacement decreased to zero rather abruptly toward the more distal ends of the rifts. The rapidly displacing zone coincides with the portion of the south flank that has been seismically active. We are able to model the GPS data with slip on a basal fault at a depth of 9 km (consistent with the focal depths of the larger south flank earthquakes) combined with deep intrusion in the rift zones. The observed displacement rates require the basal fault to be slipping at a rate of about 25 cm/yr, making this the most rapidly slipping fault known.

 Kilauea's south flank has been identified as a potential site for massive slumping and tsunami generation. Given the geologic evidence for Hawaiian tsunamis with run up heights of 300 m, rapid asiesmic displacement of Kilauea's south flank must be viewed as a significant geologic hazard. Annual GPS surveys, of the type that have been conducted, are far too infrequent to provide a warning of south flank instability. We propose that a continuously operating GPS network on Kilauea is needed to determine temporal variations in the rate of deformation. Continuous deformation monitoring will yield important information on the kinematics of seismo-volcanic processes on Kilauea and could lead to a warning of an impending tsunamigenic event.



Severance, L., 1907, Dr. Bishop and the eruption: Hawaii Herald, 02/14, p. 1. 



 [subheads: The Reverend geologist in error; Mokuaweoweo was active; Every outbreak of lava flows of Mauna Loa has been first heralded from the great summit crater]

 "The Rev. Dr. Sereno Bishop is certainly mistaken in saying that there was no evidence of eruptive activity in Mokuaweoweo either recently or at the time of the great outbreaks of '68 and '87," said Luther Severance yesterday. "The fact is that all of Mauna Loa's eruptions, like the last, have been preceded by activity in Mokuaweoweo. I have been here for thirty-seven years and have never known an outbreak not preceded by activity in the summit crater."

 "The upper crater usually dies out, apparently, and then comes the lava flow from some lower point, as this time on the Kau and Kahuku side. Outbreaks on this side have generally been swift ones and have quickly reached the sea."

 "It is very much like what seems to have happened on Haleakala and indicates that Mauna Loa is a dying mountain. she has ceased to erupt at her summit and the lava which rises to he summit finds a break somewhere lower down. The last flows on Haleakala appear to have been very low down. Perhaps the flows from Mauna Loa will be from outlets lower and lower as she slowly dies out."

 "Dr. Bishop's theory of a new volcano in Kahuku is an interesting one and may be true. But certainly he is incorrect in thinking that Mokuaweoweo has not shown activity at the times of Mauna Loa's lava flows."

 The rest of the article repeats documentation for the pattern of summit activity preceding every flank eruption.



Sheldon, H.L., 1852, [no title]: The Polynesian, v. 8, no. 42, 02/28, p. 166. 



 A brief notice of the beginning of eruption in Mokuaweoweo on the evening of Feb. 18, 1852



Smith, J.R., Duennebier, F., and Malahoff, A., 1996, New bathymetric setting of Loihi submarine volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F397. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 The July 1996 rapid response mission to Loihi seamount included multibeam and single narrow beam surveys over the southern summit area. This is where previous hydrothermal activity has been studied and where the initial seismic events were located by HVO. Analysis of the bathymetric data show significant changes in the summit geomorphology. Former high points, such as Pele's Vents (formerly rising to 980 m), have been replaced by pit craters hundreds of meters deep, as mapped by narrow beam soundings. Pele's Pit now occupies the former vent area, with a width of 260 m and a depth of 300 m, similar in size to pit craters on the subaerial Kilauea volcano. The new pit was confirmed on the same cruise by submersible observations. A new E-W trending thumb-shaped depression, ~1 km long, 500 m wide, and 100 m deep cuts across the eastern edge of the summit at 18 55'N. This feature, evident in the multibeam data, occupies the area of the previous NE rim of East Pit and corresponds to the location of the noise source as derived from the sonobuoy data. Combined submersible dive and bathymetric surveys suggest that besides new pit craters, several of the former small and large pits (East & West Pit and the Thousand Fingers depression) may have collapsed and coalesced into a larger summit caldera or plateau which could still be forming. Portions of the West Pit rim are still intact while other parts have fallen away. Several of the existing pits appear to have deepened significantly. This process of caldera formation and enlargement is evident in subaerial Hawaiian shield volcanoes such as Kilauea.



Spencer, C.N., 1887, [On the earthquake swarm and1887 eruption of Mauna Loa]: Hawaiian Gazette, 02/01, p. 1, 8. [Letter no. 05. Excerpted in American Journal of Science, 3rd ser., v. 33, p. 310- 311] 



 Subheads over letters from correspondents, signed and unsigned:

Mauna Loa!; Hawaii's great volcano; twenty miles of liquid fire in motion!; Madam Pele on the rampage!; continuous earthquake shocks!; description of the flow!; notes and incidents



Hilea Plantation, January 23, 1887--From 2 a.m Sunday, the 16th, till 7 p.m., Tuesday, the 18th, we have had no less than 618 earthquakes. At the latter time, lava broke out on the Kahuku land, about 1 mi northeast of the crater of Halepoohaahaa and about 1 mi south of Umi's heiau. Three streams of lava crossed the government road two miles west of Mr. Jones' at daybreak on the 19th, and one of which reached the sea, not far from Puuhue, at 11:40 a.m., the same day. The distance from the crater to the sea is about 18 miles. During the first twenty-four hours the crater (a long fissure) ejected thick lava (aa) and the flow . . . . moved at the rate perhaps a mile and a half per hour; but on the 20th the lava (pahoehoe) moved at the rate twenty five miles an hour. . . . .

Monday, January 24th, 1 p.m.--The flow of lava has nearly stopped and we are having a fearful shake-up. Since 8:55 p.m. [Jan. 23], we have had a frightful series of earthquakes, and they still continue. As yet I do not know the amount of damage that the shocks have caused, but I know that stone walls have suffered severely, and a large amount of crockery has been broken. . . .



Spencer, A.E., 1987, Surviving the fury of Pele: the diary of Annie Spencer [transcribed by J.S. Rodman]: Honolulu Magazine, v. 22, Nov., p. 266-269, 308-310, 316, 318, 320. 



 Annie Spencer's diary extends from March 28 to April 7, 1868, during which over 3,000 earthquakes occurred. She describes the devastation wrought by the earthquakes and the eruption of Mauna Loa that began on March l7. She wishes for eruption to relieve the pressure that is causing the earthquakes. [This is a perceptive comment, in which she recognizes the potential connection between an eruption and an earthquake swarm.]

 

Sprenke, K.F., and Breckenridge, R.M., 1997, Seismicity in the tracks of migrating hot spots: Hawaii and Idaho [abs.]: Geological Society of America Abstracts with Programs, v. 29, no. 5, p. 67. [Geological Society of America, 93rd Annual Cordilleran Section meeting, Kailua-Kona, HI, May 21-23, 1997] 



 Although the volcanic hazards of hot spots are well-recognized, the associated earthquake hazards are less well-known. Seismicity in Idaho and Hawaii suggests that effects of hot spots are widespread both in geographical space and geologic time. Most of the seismic hazard in Idaho is attributable to the migration of the Yellowstone hot spot. Seismicity in the area continues to occur in the spreading wake of the hot spot, as attested to by recent seismic occurrences near Draney Peak on the southern limb of the wake and in the Custer Graben on the northern limb. The historical earthquake catalog and studies of Holocene faults establish the area within the seismic parabola about the eastern Snake River Plain as a valid seismic zone. Although evidence of historical seismicity of Holocene scarps are lacking, the aseismicity of the former path of the hot spot itself, the eastern Snake River Plain, is by no means established. The 1871 Lanai, Hawaii event is a reasonable analogy for the type of event that might occur on the eastern Snake River Plain. Lanai is about 250 km from the present day Hawaiian hot spot and lies directly in its path. If the Hawaiian hot spot is a valid analogy, then earthquakes as high as magnitude 7 can be reasonably expected within the eastern Snake River Plain.



StateandFederalHazardMitigationTeam, 1990, Hazard mitigation team report for the Kilauea Volcano eruption, Hawaii County, Hawaii: Hilo, HI, Hawaii County, FEMA-864-DR-HI, 16 p. 



 Table of Contents

INTRODUCTION........................................... 1	

 On May 18, 1990, the President declared Hawaii County, Hawaii a major disaster area as a result of damages from eruptions of the Kilauea Volcano (FEMA-864-DR-HI). The declaration provided disaster assistance to individuals, businesses and public agencies.

This report transmits the Hazard Mitigation Team's recommendations to the Federal Emergency Management Agency's Regional Director, the Governor's Authorized Representative, Hawaii County and interested local, State and Federal agencies.

 Purpose of the Report

 This report and recommendations will provide guidance to Federal, State and County departments and agencies to reduce future volcanic eruption damage in Hawaii County. It is based on an assessment of damage sustained during the January 1983 to present lava flows and a review of existing hazard mitigation programs, measures and procedures.

 Overview of Authority and Background

As a condition to receiving federal disaster aid, Section 409 of the Disaster Relief Act (Public Law 93-288 as amended) requires that repairs be done in accordance with applicable codes, specifications, and standards. It also requires the government recipients of this aid to evaluate the natural hazards of the area in which the aid is to be used and, if appropriate, take action to mitigate the hazards. A major product and requirement of the Section 409 process is a State/Local Hazard Mitigation Plan which describes actions that have been and will be taken to mitigate hazards.

Under Section 409, the Federal Emergency Management Agency encourages governments to develop and maintain a systematic program to identify hazards, monitor changes, and develop and implement measures for reducing hazard vulnerability. Section 409 is best viewed as a dynamic ongoing process allowing a disaster declaration to become an opportunity to review and update existing hazard mitigation programs, rather than an isolated event which results in new and independent plans and programs.

To implement Section 409, Federal, State and local Hazard Mitigation Coordinators are appointed. These hazard mitigation coordinators serve on a Hazard Mitigation Team and accomplish the following:

1. Identify areas of significant hazards,

2. Visit and evaluate the impact of the disaster,

3. Review existing land use regulations, building codes, construction standards, and existing hazard mitigation legislation or programs,

4. Review and evaluate existing warning and evacuation plans,

5. Identify and recommend measures or actions to mitigate the impact of disasters, and

6. Coordinate the necessary actions to implement proposed recommendations.

 The Hazard Mitigation Team for the Kilauea lava flow disaster, with members representing Hawaii County, State of Hawaii and Federal departments and agencies, met from August 27- 31, 1990 in Hawaii County. Appendix A is a list of Hazard Mitigation Team members. The Team prepared this report based on the information gathered during site visits, discussions and reviews of existing legislation, programs and policy. This report identifies issues that should be considered to reduce damage from future volcanic eruptions and provides guidance to prepare the State/County Hazard Mitigation Plan. The Hazard Mitigation Plan will include the following:

 1. Analysis of the natural hazards in the disaster declared area.

2. Analysis of existing State and County laws, regulations and programs that pertain to hazard mitigation.

3. Identification of the strengths and weakness in existing programs.

4. Identification of mitigation measures to reduce the impacts of future volcanic eruptions.

 The final element of the hazard mitigation process is to implement the hazard mitigation measures described in this report and in the State/County Hazard Mitigation Plan.

BACKGROUND ..................................................	3

 The Disaster

 Description of Damages

 Description of Volcano Problems in Hawaii County

EXISTING MITIGATION PROGRAMS.................................	6

 Lava Flow Hazard Zones

 State Land Use Planning

 County Land Use Planning

 State and County Disaster Planning

 Kalapana Task Force

 Department of Housing and Urban Development Volcanic Hazard Policy

SUMMARY AND RECOMMENDATIONS .................................	11

APPENDIX A -- Hazard Mitigation Team Members



Stearns, H.T., and Clark, W.O., 1930, Geology and water resources of the Kau District, Hawaii: U.S. Geological Survey Water Supply Paper 616, 194 p. [Includes Meinzer, O., 1930, Ground water in the Hawaiian Islands, p. 1-29.] 



 The authors describe, with the aid of colored geologic maps, the stratigraphy, geology, and ground-water resources of the western part of Kilauea and the southern part of Mauna Loa. They discuss the products and processes of Hawaiian volcanism, including types of lava flows, ejecta, and explosions, and describe historic eruptions and structural features of the Kau district, including faults, calderas, and pit craters. The report concludes with a description of ground water perched on ash beds and description of tunnels to recover it.

 The authors distinguish a southeast and a northeast rift zone of Kilauea. [These are considered now as parts of a single east rift zone which changes direction from southeast to northeast about 7 km from Kilauea summit.] They describe the mechanism by which amphitheater-shaped valleys on the southeastern slope of Mauna Loa are formed, including an examination of the evidence for Mohokea caldera (C.H. Hitchcock, 1906), for which they find "no valid reasons for a belief in (its) existence." They describe and illustrate a unique form of lava which they call arborescent aa, a dike that fed the 1921 flow, and a thin sill, both exposed in the walls of Halemaumau after the 1924 collapse. They hypothesize that the Uwekahuna laccolith may have a similar origin. The authors discuss faulting of different types, relating fault origin to a combination of stress induced by volcanic activity and adjustments to the accumulation of the volcanic pile, and give a history of movement on the Waiohinu, Kaoiki, and Hilina fault systems. They infer that Hilina and Kaoiki began as similar fault systems involving subsidence of the unsupported volcano flank, activity shifting from Kaoiki to Hilina as the growing Kilauea edifice strengthened the south slope of Mauna Loa. They give the geologic history of the island of Hawaii: Ninole Volcano came first, followed by Kohala; Mauna Kea rose as those two were being dissected, and Kilauea and Hualalai were born about the same time; finally, Mauna Loa grew. [The authors still accept Jaggar's inferences for the relative ages of Kilauea and Mauna Loa. Kilauea is currently far more active than Mauna Loa, and modern workers consider Kilauea to be the youngest volcano.] The authors consider the Pahala ash to have come principally from Mauna Kea and to postdate the birth of Hualalai and Kilauea.

 Stearns and Clark quote Jaggar (1920) on the origin of aa and pahoehoe, adding to Jaggar's interpretation the following: ". . . (formation of) aa is due to the destruction of an equilibrium of some essential factors that cannot be restored. Field evidence indicates that these factors are amorphous glassiness, (loss of) gas, and (loss of) heat." The authors describe volcanic products, including various kinds of tephra, lava stalactites and stalagmites, and volcanic bombs. They describe ellipsoidal lava [now called accretionary lava balls]; which forms [at least for 1823 flow] by magma clots falling repeatedly back into a vent so that they are recoated, analogous to pisolite formation in an eruption cloud. They describe different types of cones and craters. [They refer to littoral cones as tuff cones.] Kapoho cone originated as a submarine eruption which possibly built the east cape of the island. Pit craters originate by removal of a former lava lake or shallow intrusive body. They enlarge by explosion as Halemaumau did in 1924 or form by collapse over a lava tube. The authors discuss explosive eruptions and describe explosion debris around Alae Crater. [Alae is now filled with lava from Mauna Ulu.] They present a contoured map showing the thickness of the Keanakakoi ash around Kilauea summit and conclude that the caldera predated the Keanakakoi ash. They interpret Menzies' reference to ash from Kilauea in 1794 [cf. C.H. Hitchcock, 1909a] as wind-blown dust from the 1790 eruption. The paper includes tables summarizing the petrography of Kau rocks from Noble (unpub.), and analyses from Washington (1923b, c).

 [This is a fine geologic study and emphasizes the essential contribution made by careful geologic mapping to the interpretation of both the historic and prehistoric record of Hawaiian volcanic activity. The paper is a model of a complete geologic study of an area, in which accurate description is followed by careful interpretation of geologic process.]

Ground water in the Hawaiian Islands, by Oscar E. Meinzer	1

 History of the Kau invegtigation	1

 Utilization of water in the Hawaiian Islands	4

 Principles of occurrence of water in the Hawaiian Islands	5

 Controlling conditions	5

 Rainfall	5

 Geology 6

Resulting conditions	7

 Surface water	7

 Runoff

 Storage	9

 Basal ground water	10

 Areas without confining structure	10

 Areas with artesian structure	15

 Perched ground water	21

 Water perched on beds of volcanic ash	21

 Water perched on soil and alluvial deposits	22

 Water perched on intrusive rocks	23

 Water perched on other structural features	27

 Future investigations of ground water	27

Part I. Geography and geology, by Harold T. Stearns	29

 Introduction	29

 Location and area	29

 Geographic relations	29

 Historical sketch	29

 Population	30

 Industries	31

 Fauna	32

 Flora	33

 Hawaii National Park	34

 Acknowledgments	34

 Previous investigations and literature	35

 Physiography	41

 Volcanic forms of accumulation	41

 Volcanic cones	41

 Mauna Loa	41

 Kilauea

 Secondary cones	44

 Lava flows	45

 Volcanic forms of subsidence	46

 Calderas

 Mokuaweoweo	46

 Kilauea

 Pit craters	50

 Fault scarps	50

 Mauna Loa	50

 Kahuku fault scarp	50

 Waiohinu fault scarp 5 l

 Kaoiki fault scarp 5 l

 Kilauea	51

 Hilina fault scarp 51

 Kapukapu fault scarp	51

 Valleys	52

 General features	52

 Cause of amphitheater-headed valleys	54

 Explanation of the "Mohokea caldera"	56

 Plains	57

 Shore features 57

 Effects of wind work 59

 Stratigraphy 60

 General character and age of the rocks 60

 Tertiary or older lava flows	61

 Ninole basalt	61

 Unconformity	 62

 Pleistocene (?) lava flows	65

 Pahala basalt	65

 General character 65

 Ash member at top 66

 Late Pleistocene (?) and recent lava flows 69

 Kamehame basalt	69

 Character 69

 Prehistoric flows 70

 Historic flows	70

 Mauna Loa flows	71

 Kilauea flows	77

 Intrusive rocks		81

 Soils	82

 Structure	84

 Faults	84

 Cause of faulting	84

 Normal faults	85

 Reverse faults	90

 Examples of faults	90

 Makukoa faults		90

 Waiohinu fault	92

 Kahuku fault 94

 Effects of faulting 94

 Epochs of faulting	95

 Cross sections 97

 Geologic history	101

 Island of Hawaii	101

 Kau District	104

 Volcanic products	107

 Magma	107

 Lava flows		108

 Driblet or spatter 112

 Cinders	112

 Scoria and pumice	112

 Pele's hair and Pele's tears	113

 Lava stalactites and stalagmites	113

 Bombs		114

 Ellipsoidal lava	116

 Explosion blocks	117

 Lapilli		118

 Volcanic sand	118

 Volcanic ash	118

 Volcanic dust	119

 Mud flows	119

 Gases and chemical deposits	119

 Types of cones	120

 Lava cones	120

 Driblet cones	122

 Cinder cones	123

 Tuff cones	125

 Pit craters	127

 Volcanic processes	129

 Fissure eruptions 129

 General character	129

 Kilauea rifts 130

 Southwest rift	130

 Quiet eruptions of very fluid lava	130

 Quiet eruptions of viscous lava	131

 Moderately explosive eruptions	131

 Highly explosive eruptions	132

 Crater chains	133

 Southeast rift	133

 Quiet eruptions	134

 Moderately explosive eruptions	134

 Highly explosive eruptions	134

 Crater chains	135

 Mauna Loa rifts	135

 Southwest rift	135

 Quiet eruptions	135

 Moderately explosive eruptions	135

 Highly explosive eruptions	136

 Crater chains	137

 Northeast rift	137

 Conclusions regarding fissure eruptions	138

 Relation of fissure vents to ground water	140

 Volcanic explosions 141

 Types of explosions	141

 Explosions at Kilauea	143

 Phreatic explosions	143

 Prehistoric phreatic explosion	143

 Alae Crater, Puna District	143

 Historic phreatic explosions	143

 Explosions at the Great Crack in 1823	143

 Explosions at Halemaumau in 1924	145

 Magmatic explosions	146

 Prehistoric magmatic explosions	146

 Kapoho Crater, Puna District	146

 Kamakaia fissure eplosion	148

 Early explosions at Kilauea caldera	148

 Historic magmatic explosions	152

 Explosions at Kilauea in 1790	152

 Explosions on Mauna Loa	153

 Prehistoric explosions near Mokuaweoweo	153

 Prehistoric explosions at Lua Poai	154

 Magmatic explosions	155

 Cause of explosions	155

 Petrology	157

 Petrography	157

 Ninole basalt	157

 Pahala basalt	160

 Kamehame basalt	161

 Chemical analyses	163

 Magmatic differentiation	165

Part II. Water resources, by William O. Clark and Harold T. Stearns 166

 Climate	166

 Temperature	166

 Precipitation	167

 Distribution relative to slopes and altitude	167

 Areal distribution	168

 Some heavy rainfall records	172

 Distribution in time 172

 Surface water	173

 Ground water	174

 Occurrence 174

 Main water table	175

 Perched or high-level water	177

 Water-bearing formations	179

 Water in the Ninole basalt	179

 Water in the Pahala basalt	180

 Water in the Kamehame basalt	181

 Water supplies and prospects	181

 Central Kau	181

 Eastern Kau		185

 Kalae or South Point region		187

 Western Kau	188

 Quantity of ground water 189

 Thermal water	190

Summary	190

Index	193



Stearns, H.T., 1942, General geology and ground-water resources of the island of Maui, Hawaii, in Geology and ground-water resources of the island of Maui, Hawaii: Hawaii (Terr.) Division of Hydrography Bulletin 7, pt. 1, p. 1-222; 2 folded maps in pocket, scale 1:62,500) [includes plates]. 



 Abstract 7

 Maui, the second largest island in the Hawaiian group, is 48 miles long, 26 miles wide, and covers 728 square miles. The principal town is Wailuku. Sugar cane and pineapples are the principal crops. Water is used chiefly for irrigating cane. The purpose of the investigation was to study the geology and the ground-water resources of the island.

 Maui was built by two volcanoes. East Maui or Haleakala Volcano is 10,025 feet high and famous for its so-called crater, which is a section of Hawaii National Park. Evidence is given to show that it is the head of two amphitheater-headed valleys in which numerous secondary eruptions have occurred and that it is not a crater, caldera, or eroded caldera. West Maui is a deeply dissected volcano 5,788 feet high. The flat Isthmus connecting the two volcanoes was made by lavas from East Maui banking against the West Maui Mountains. Plate 1 shows the geology, wells, springs, and water-development tunnels. Plate 2 is a map and description of points of geologic interest along the main highways. Volcanic terms used in the report are briefly defined. A synopsis of the climate is included and a record of the annual rainfall at all stations is given also. Puu Kukui, on West Maui, has an average annual rainfall of 389 inches and it lies just six miles from Olowalu where only 2 inches of rain fell in 1928, the lowest ever recorded in the Hawaiian Islands. The second rainiest place in the Territory is Kuhiwa Gulch on East Maui where 523 inches fell during 1937. Rainfall averages 2,360 million gallons daily on East Maui and 580 on West Maui. Ground water at the point of use in months of low rainfall is worth about $120 per million gallons, which makes most undeveloped supplies valuable.

 The oldest rocks on East Maui are the very permeable primitive Honomanu basalts, which were extruded probably in Pliocene and early Pleistocene time from three rift zones. These rocks form a dome about 8,000 feet high and extend an unknown distance below sea level. Covering this dome are the Kula volcanics, extruded probably in early and middle Pleistocene time, and characterized by andesites, andesitic basalts, and picritic basalts. They are 2,000 feet thick on the summit, and 50 to 200 feet thick at the periphery. They contain a sufficient number of interbedded soils, thin vitric tuff beds, and lava-filled valleys in their upper part to give rise to valuable perched springs in wet areas. The Kula lavas accumulated during a waning volcanic phase which u as followed by a quiescence long enough for the erosion of deep amphitheater-headed valleys in the east or wet half of the mountain. Volcanic activity was renewed in middle (?) to late Pleistocene time and continued until Recent time, during which the Hana volcanic series was laid down. The last lava flow was erupted about 1750. The Hana lavas comprise andesitic, picritic, and olivine basalts. They veneered large areas of the east and south slopes, partly filled the deep amphitheater-headed valleys, and deeply buried the smaller valleys in the eastern half of the mountain. The Hana rocks are exceedingly permeable and much rain sinks into them.

 The oldest rocks on West Maui are the very permeable primitive Wailuku basalts, which were extruded probably in Pliocene and early Pleistocene time from two rifts and from many radial fissures. The basalts form a dome about 5,600 feet high and extend an unknown distance below sea level. Iao Valley is the eroded caldera of this dome, forming an incomplete veneer over the dome are the Honolua soda trachytes and oligoclase andesites. They were extruded in late Pliocene (?) or early Pleistocene time, chiefly from bulbous domes. The clinker beds carry some water but the rocks are generally too dense to be good aquifers. During early (?) Pleistocene the West Maui volcano was cut by deep amphitheater-headed valleys and then all of Maui was deeply submerged.

 Four scattered eruptions occurred on West Maui in middle (?) and late Pleistocene time. The cones and lavas cover only small areas and are called the Lahaina volcanic series.

The sedimentary rocks of both East and West Maui are chiefly late Quaternary and comprise fans, landslide debris, delta deposits, and valley fills, mostly of poorly permeable and poorly assorted bouldery alluvium. They are overlain on the Isthmus by extensive calcareous dunes of three ages. A mud flow more than 300 feet thick is exposed in Kaupo Valley. During the fluctuations of the ocean in the Pleistocene, the island was emerged and submerged several times. Calcareous fossiliferous marine conglomerates deposited during this period are found up to an altitude of 250 feet on West Maui.

 The Honomanu, Wailuku, and Kula lavas are the chief aquifers. They supply 28 irrigation wells which yield an average of 170 million gallons a day of basal water. These wells are mine-like shafts with infiltration tunnels and are called Maui-type wells. Well 16 yields 40,000,000 gallons daily with a 2 1/2-foot drawdown, which is the largest amount yielded by any well in the Hawaiian Islands. The largest spring (no. 26) on the island is artesian. It yields 10,400,000 gallons daily and issues from Kula lavas near Nahiku. West Maui has numerous perennial streams supplied by springs from a dike complex. Twenty-three tunnels in West Maui recover 20.5 million gallons a day of high-level water, mostly from this dike complex. East Maui has few perennial streams in proportion to its size, and they are chiefly small due to the water sheds being underlain with permeable lavas. Forty tunnels recover 6 million gallons a day of high-level water in East Maui and all from structures other than dikes.

 It is estimated that about 100 million gallons a day of basal water wastes into the sea from West Maui and about 700 million gallons a day from East Maui. A number of sites are described where wells could be sunk to recover this water. Sites are also described where tunnels could be driven to recover high-level supplies. The hydrology of East and West Maui is conspicuously different in many respects, mainly because of the difference in the stage of dissection, the extensive veneer of very permeable Hana lavas on East Maui, and the comparatively small area of the Lahaina lavas of similar age on West Maui. The only thermal water known in the Hawaiian Islands, except on the active volcano of Kilauea, is in a well in West Maui.

Introduction 9

 Location and area 9

 Historical sketch 10

 Abbreviations of company names 11

 Industries 11

 History and purpose of the investigation 14

 Base map 15

 Acknowledgments 15

 Previous investigations 16

Vocabulary of volcanic terms 18

 Composition of the volcanic rocks 18

 Shield-shaped domes 18

 Calderas and craters 19

 Secondary cones 20

 Cinder cones 20

 Spatter cones 21

 Bulbous domes 21

 Lava cones 23

 Tuff cones 23

 Breccias 23

 Explosion breccia 23

 Vent breccia 24

 Extrusive rocks 24

 Pahoehoe 24

 Aa 25

 Kipuka 25

 Crater-fills 25

 Intrusive rocks 26

 Dikes and sills 26

 Stocks bosses and plugs 26

Climate 27

 Temperature, wind, and humidity 27

 Tida waves 28

 Precipitation 28

 Disposal of rain 33

Surface wnter 43

Value and source of water supplies 49

Geomorphology of East Maui 53

 Original form 53

 Origin of Haleakala Crater 53

 Origin of the Isthmus 53

 Emerged and submerged shore lines 54

 Marine features 55

 Depth of weathering 57

 Geomorphic effects of lava flows filling large canyons 58

 Earthquake of 1938 and its geomorphic effects 59

 The authors briefly describethe effects of the 1938 earthquake, indicating that it had little effect on homes built on bedrock but caused lots of damage to homes built on surficial deposits. The earthquake triggered landslides and destabilized steeper slope so that the frequency of landslides during heavy rains was high three years after the earthquake.

 Geology of East Maui 61

 General character age and water-bearing properties of the rocks 61

 East Maui volcanic rocks and their water-bearing properties 63

 Stratigraphic section of East Maui 66

 Honomanu volcanic series 68

 Distribution 68

 Character and structure 68

 Tuff and breccia deposits 71

 Water-bearing properties 71

 Dikes 72

 Angular unconformity in the summit depression 72

 The authors describe (p. 72-73) an unconformity high on the mountain, which they interpret as an Hilina-type slump later filled in by lava. The Kula series shows lots or erosional unconformities and canyon-filling lavas, which indicate more time between eruptions.

 Kula volcanic series 74

 Distribution 74

 Character and structure 75

 Cones and tuff deposits 80

 Dikes and plugs 83

 Interstratified conglomerates 84

 Water-bearing properties 85

 Great erosional unconformity 89

 Hana volcanic series 90

 Distribution 90

 Kipahulu member of the Hana lavas 91

 Members of the Hana lavas in Keanae Valley 94

 Character and structure 96

 They describe (p. 97-99) some very fluid lavas that left thin plasters on steep valley walls.

 Cones and ash deposits 99

 Explosion deposits on the southwest rift 101

 Dikes 101

 Interstratified gravels 101

 Water-bearing properties 102

 Historic lava flow 102

 Quaternary sedimentary rocks 107

 Kaupo mud flow 107

 Calcareous marine deposits 108

 Consolidated and unconsolidated dunes 109

 Consolidated earthy deposits 110

 Unconsolidated deposits 110

 Geologic structure 111

 Geologic history 111

 All altitudes in this chapter are based on the assumption that Maui is now submerged 1,200 feet. The projection of the large canyon walls below sea level indicates that the submergence was probably not materially less than this amount. The amount may be more if the 1,800-foot submarine shelf off West Maui is a submerged shore line. It has been estimated also that 500 to 1,000 feet have been removed from the summit by stream erosion. The geologic history of Haleakala is summarized as follows:

 PROBABLY PLIOCENE AND EARLY PLEISTOCENE TIME

1. Building of a shield- or dome-shaped island of highly fluid primitive Honomanu olivine basalts about east, southwest, and north rifts with a crater at their intersection (pl. 23A).

2. Culmination of the Honomanu dome about 8,500 feet above present sea level. The flows of the East Maui volcano, banking against the older West Maui volcano and Kahoolawe, built up isthmuses, and Haleakala ceased to be a separate island. A large fault apparently existed on its south side, and possibly a caldera was formed by collapse on its summit. Plate 23C shows this stage just before the joining of the dome with West Maui and Kahoolawe.

3. Eruption of the Kula lavas and their bulky cinder cones. Volcanic activity gradually waned, allowing soils to form and streams to cut valleys. These lavas steepened the dome, added 2,000 to 3,000 feet to the summit, and deeply buried the fault cliff on the south slope. Haleakala reached a height about 12,000 feet above the shore of that time (pl. 24A).

EARLY(?) PLEISTOCENE TIME

4. Long period of erosion during which canyons more than 5,000 feet deep ate headward beyond their summit divides, and high sea cliffs were cut (pl. 24C). A few lava flows may have been erupted during this period.

5. Gradual submergence, probably of more than 1,450 feet, deeply drowning the valley mouths and separating East and West Maui again (pl. 25A). Meager evidence of a shore line at this level exists on Haleakala, but on West Maui it is the well established Olowalu shore line. The submergence may have been as much as 2,500 feet. Sedimentation occurred at the valley mouths.

MIDDLE(?) PLEISTOCENE TIME:

 6. Fairly rapid emergence of 550 feet or more with several short halts on the way and the development of a shore line about 300 feet below present sea level, correlative with the Kahipa minus 300+-foot stand of the sea. East and West Maui were again joined, and they also connected with Lanai, Kahoolawe, and Molokai to form a large island (pl. 25a). Renewed stream erosion removed most of the sediments deposited previously.

7. Kaupo mud flow moved into the sea and became consolidated and eroded (pl. 25a).

8. Resubmergence of about 400 feet and the deposition of thick conglomerates at the mouths of the large canyons and over the Isthmus. East and West Maui became separated for the second time by a narrow strip of water. Marine fossiliferous sediments were deposited on the Isthmus, and gravels in the valleys previously cut in the Kaupo mud flow. This shore line corresponds to the 100-foot Kaena stand of the sea.

LATE: PLEISTOCENE TIME

9. Re-emergence of about 160 feet, corresponding to the Waipio shore line. Formation of calcareous dunes on the Isthmus and terraces in the alluvium, especially at the mouths of Keanae and Kaupo Valleys. Valleys were cut about 60 feet below present sea level into the gravels that overlie unconformably the Kaupo mud flow. Renewed volcanism on the southwest and east rifts and the extrusion of the Hana volcanics (pl. 26A). Probably the early Kipahulu lavas were poured out in the preceding epoch and there was activity elsewhere on Haleakala, but the earliest geologically dated Hana lavas are those filling valleys of Waipio age at the mouths of Keanae and Kaupo Valleys.

l0. Resubmergence of about 85 feet forming a shore line correlative with the Waimanalo stand of the sea. The earlier formed dunes were part]y submerged and cliffed. Benches were cut into the partly weathered lavas near Maliko Gulch. Again the streams alluviated their valley mouths and Hana lavas continued to be erupted, deeply filling the great valleys eroded at the end of Kula time.

11. Re-emergence of 20 feet and a halt corresponding to the Kahipa shore line. Streams cut into the alluvium deposited in the preceding stage, leaving terraces at their mouths. The sea remained long enough to cut only a narrow bench along the lava coasts. Continued eruption of Hana lavas.

RECENT

12. Re-emergence of 5 feet and partial destruction of fringing marine bench (pl. 26a). Continued eruption of Hana lavas with a lava flow about 1750 near La Perouse Bay from the southwest rift.

Road metal 115

 Ground water in East Maui 116

 Basal water in East Maui lava rocks 116

 Definition 116

 Permeability of the lava 116

 Relation to underlying salt water 117

 Ghyben-Herzberg principle 118

 Form of the water table 118

 Fluctuations in water level 119

 Effect of draft on quality 121

 Maui-type wells 126

 Ancient Hawaiian wells 127

 Basal springs 128

 Recharge 129

 Undeveloped basal supplies 130

 Basal water in East Maui sedimentary rocks 130

 High-level ground water in East Maui- 132

 General statement 132

 Artesian water 132

 Water confined by dikes 133

 Water perched on ash beds 135

 Water perched on soil 137

 Water perched on alluvium 139

 Water perched on lava sheets 141

 Quality of perched water 141

 Tunnels 141

 Springs 141

 Undeveloped high-level supplies 143

 Inventory of ground water in East Maui 146

 Geomorphology of West Maui 147

 Valleys 147

 Dome-shaped hills 148

 Plains 148

 Eke swamp and sink holes 149

 Effects of wind work 151

 Shore features 152

 Evidence of emergence and submergence 153

 Geology of West Maui 156

 General character age and water-bearing properties of the rocks 156

 Stratigraphic section of West Maui 158

 West Maui volcanic rocks and their water-bearing properties 160

 Wailuku volcanic series 160

 Lava flows 160

 Cones and vitric tuff deposits 162

 Intrusives 163

 Caldera complex 166

 Vent breccias 167

 Explosion breccia and lithic tuff 172

 Honolua volcanic series 173

 Lava flows 173

 Cones and tuff deposits 175

 Intrusives 179

 Lahaina volcanic series 180

 Kekaa cinder cone 180

 Laina volcanics 180

 Kilea volcanics 181

 Hele cinder cone 181

 Quaternary sedimentary rocks 182

 Consolidated earthy deposits 182

 Consolidated calcareous deposits 183

 Unconsolidated deposits 184

 Geologic structure 184

 Geologic history 185

 PROBABLY LATE TERTIARY AND EARLY PLEISTOCENE(?) TIME

l. Building of a steep-sided shield- or dome-shaped island of highly fluid primitive olivine Wailuku basalts around a north rift and a south rift with a vent at their intersection (pl. 23A)

Numerous dikes radiating from the apex of the volcano indicate that fissure eruptions were not confined exclusively to these rifts.

2. Collapse stage with the formation of a caldera on the summit 3 miles across and several hundred feet deep.

3. A relatively short rest period during which a thin soil formed and differentiation took place in the magma reservoir.

4. Outpourings of the thick soda trachyte and thinner oligoclase andesite Honolua flows, chiefly from bulbous domes located along fissures. These lavas formed a veneer over part of the great Wailuku volcanic dome. Starting of streams, especially in areas not covered with the Honolua lavas (pl. 23).

EARLY(?) PLEISTOCENE TIME

5. Cessation of volcanism followed by a long epoch of weathering and erosion. Canyons as much as 4,000 feet deep were carved and high cliffs were made on shores exposed to strong wave action (pl. 24). The lava flows from East Maui joined West Maui to form a single large island.

6. Submergence of an unknown but large amount, perhaps as much as 2,500 feet, drowning the mouths of the valleys and alluviating their floors. East and West Maui again became two islands.

7. Culmination of the submergence in a short halt at about 1,200 feet above present sea level.

8. Gradual emergence of about 950 feet with a short halt at the Olowalu shore line 250 feet above present sea level (pl. 25A).

The larger streams partly filled their canyons to their heads with alluvium.

MIDDLE(?) PLEISTOCENE TIME

9. Fairly rapid emergence of 550 feet or more with several short halts and the development of the Kahipa shore line about 300 feet below present sea level. Rivers cut deeply into their alluvial fans and the sea cliffed the exposed parts of the coast. East and West Maui were again joined (pl. 25a).

10. Resubmergence of about 400 feet to the Kaena 100-foot shoreline and the deposition of thick conglomerates in the valleys, especially at their mouths. East and West Maui became separated again by the ocean flooding the Isthmus.

LATE(?) PLEISTOCENE TIME

11. Re-emergence of about 160 feet to the Waipio minus 60-foot strand with a short halt at the Laie shore line 70 feet above the present sea. East and West Maui were joined for the final time. The wind blew great quantities of sand shoreward from the emerged reef flats to form extensive calcareous dunes on the Isthmus. Valleys were cut into the alluvium laid down during the 100-foot stand of the sea. Scattered eruptions produced the short flows and cinder cones of the Lahaina volcanic series about this time (pl. 26A).

12. Resubmergence of about 85 feet and the formation of a shore line about 25 feet above present sea level, during which some of the dunes were drowned and others cliffed.

13. Re-emergence of about 20 feet with the formation of a fringing shore bench about 5 feet above the present strand.

RECENT TIME

14. Further emergence to the present strand (pl. 26C).

 Road metal 187

 Ground water in West Maui 188

 Basal water in West Maui lava rocks 188

 Occurrence and permeability of water-bearing rocks 188

 Form of the water table 189

 Fluctuations 189

 Effect of draft on quality 190

 Recharge 191

 Thermal water 192

 Wells 192

 Undeveloped basal supplies 194

 Basal water in the West Maui sedimentary rocks 194

 High-level ground water in West Maui 195

 Water confined by dikes 195

 High-level water-development tunnels 195

 High-level springs 199

 Undeveloped high-level supplies 199

 Water perched on tuff and soil beds 201

 Quality of high-level water 201

 Inventory of ground water in Maui 202

 Ground-water statistics 203

 Water supplies of towns and villages on Maui 205

 Perched springs on Maui 212

 Tunnels driven for perched ground water in Maui 213

 Test holes on Maui 215

 Records of Maui-type wells 216

 Water pumped by the Pioneer Mill Co. 1918 to 1941 218

 Salt content of water pumped by the Pioneer Mill Co. 1926 to 1940 219

 Water pumped by the Hawaiian Commercial and Sugar Co. 1899 to 1941 and average grains of salt per gallon 220

 Water pumped by the Maui Agricultural Co. 1913 to 1941 221

 Salt content of water pumped by the Maui Agricultural Co. 1929 to 1941 222



Stearns, H.T., 1983, Memoirs of a geologist: Honolulu, Hawaii Institute of Geophysics, 242 p. 



 1. BOYHOOD DAYS	1

 Boys Will Be Boys	3

 A Rockhound Is Born	12

 My First Published Writing	16

2. A COLLEGE MAN	19

 Collecting for Fun and Profit	24

 World War 1	28

3. MY FIRST JOB AFTER COLLEGE	31

 Roughing It	35

 Craters of the Moon	40

4 WITH THE USGS	43

 Assignment to Hawaii	48

 1924 Eruption of Kilauea Volcano	50

 Mapping on the Big Island	54

5. TRAVEL AROUND THE WORLD	58

 Back to Washington and a Ph.D.	64

 Damsites in California and Oregon	66

 The Snake River Plains of Idaho	71

 The Crash of 1929	74

 Pleistocene Mammals	76

6. GROUND WATER FOR THE HAWAIIAN ISLANDS	77

 Publication of Bulletin 1	80

 Island of Maui	86

 Maui-Type Wells	91

 1938 Earthquake at Sprecklesville	94

 Developing Water Resources on Oahu	97

 The Hydrography Bulletins 102

 Experiment in Resistivity	103

 New Zealand and Australia	104

 Island of Molokai	105

 The 1935 Eruption of Mauna Loa Volcano	107

 Water for the Island of Lanai	109

7. ISLANDS IN THE PACIFIC	111

 Guam	111

 Ben Silbert, South Seas Artist	114

 Lecture Tour on the Mainland	114

 Midway and Kahoolawe Islands, and Kona, Hawaii	116

 The Samoan Islands	119

8. WORLD WAR II IN THE PACIFIC	125

 Samoa, Ellice and Wallis Islands	126

 Espiritu Santo and New Caledonia	129

 Guadalcanal, Tulagi, Florida Island, Fiji, Eua	130

 Ascension Island in the Atlantic	131

 Saipan, Tinian, Guam	134

 Wartime in Hawaii	144

 The 1942 Eruption of Mauna Loa	144

 Waimanu Valley	146

 Niihau and Kauai	147

9. AFTER THE WAR, A NEW LIFE	153

 Search for a New Home	154

 A Trip to Mexico	157

 Our Search Resumes	159

 A Lighthouse in Canada	161

 Poverty PeakOur Homesite	164

 Back to Geology	174

 Poverty Peak Transformed	177

 Nature Around Us	180

 Our Lakeshore Property Condemned	182

 Business in Canada	184

10. CONSULTING IN THE PACIFIC NORTHWEST	187

 Snake River Dams	188

 Work for the Atomic Energy Commission	189

 Cabinet Gorge and Noxon Dams	190

 Work in Oregon and Washington	192

11. RETURN TO HAWAII	200

 Lanai, Oahu, and Molokai	200

 The Pali Tunnel on Oahu	203

 Work on Maui	204

 Our Own Land in Hawaii	204

 Piggery GulchKnown Later as Waipio Acres	205

 Waikakalaua Valley	208

 Waipio Acres	209

 Harold's Hole	214

 Tsunami at Haleiwa	215

 Melemanu Woodlands	216

 Headrick Litigation	218

12. RETIREMENT YEARS	220

 Trip to the Bottom of the Sea	221

 The Society Islands	224

 Work Again on Oahu and Maui	226

 Becoming a Philanthropist	227

 Peace in Our Garden	230

Epilogue	232

Publications of Harold T. Stearns	233



Stevens, J.L., and Oleson, W.B., 1894, Volcanoes and lava flows, in Picturesque Hawaii; a charming description of her unique history, strange people, exquisite climate, wondrous volcanoes, luxurious productions, beautiful cities, corrupt monarchy, recent revolution and provisional government: Philadelphia, World Bible House, p. 63-78. 



 A popular account of the Hawaiian Islands. The authors briefly describe the flows of 1855, 1859, and 1880 from Mauna Loa, quoted from other sources; a brief description of the 1868 earthquakes; a description of Kaumana Cave, a lava tube in the 1880 lava near Hilo; and photographs and an undated description of Kilauea caldera.

 

VOLCANOES AND LAVA FLOWS:

 Volcanic Origin

Fissures in Earth's Crust

Depth of Surrounding Sea

Artesian Borings 

Subsidence and Upheaval

Relative Age of Islands

World Building

Mokuaweoweo, The Terrible

Great Interior Plain

The Lava Flow of 1855

The Lava Flow of 1859

The Lava Flow of 1880

The Hilo Viaduct

The Forges of Vulcan

Kilauea

Floor of the Crater

The Lake of Fire

The Goddess Pele

At Closer Range 

Remarkable Disappearance of Fires

Sulphur Deposits

From Chaos to Paradise

Earthquakes of 1868

Legend of Halai

Heathen Oblations



Stockman, W.B., 1906, Weekly Weather Bulletin for the week ending September 29, 1906: Pacific Commercial Advertiser, 10/02, p. 6. [Repeated in Hawaiian Gazette of Oct. 2, 1906, p. 5] 



 Laupahoehoe--A slight earthquake shock was felt at 5:15 a.m. September 25.



Stockman, W.B., 1907, Weekly Weather Bulletin for the week ended January 12, 1907: Pacific Commercial Advertiser, 01/15, p. 6. 



 Slight earthquake shocks were felt at several of the stations in the northern part of Hawaii from the 8th to the 10th inclusive [no earthquakes listed in individual station reports]. [precursory seismicity to the 1907 eruption of Mauna Loa on the north side of Mauna Loa summit and southwest rift zone?]



Stockman, W.B., 1907, Weekly Weather Bulletin for the week ended January 19, 1907: Pacific Commercial Advertiser, 01/22, p. 5. [Repeated in The Hawaiian Star of Jan. 22, 1907] 



 Earthquake shocks were felt during the week at a number of stations in the western and southern portions of Hawaii. The observer at Kau (Waiohinu) reports that there were many earthquake shocks felt on the 10th and 11th, and a light one on the 16th. Also, that an eruption occurred on the south side of Mauna Loa on the 11th, and that three streams of lava, all from one source, were flowing toward the sea in south, southwest and west directions. Very little of the glow from the eruption was seen at Kealakekua (Davis), Hawaii.



Stockman, W.B., 1907, Weekly Weather Bulletin for the week ended May 18, 1907: Pacific Commercial Advertiser, 05/21, p. 6. 



 Earthquakes were reported on the morning of the 11th from the following stations on Hawaii: Kohala Mill, a double one at 8:24; Kohala Mission, 7:38; Niulii, slight, 8:00; Waimea, 7:40, and Pepeekeo, heavy, 7:30.



Stockman, W.B., 1907, Weekly Weather Bulletin for week ended June 15, 1907: Pacific Commercial Advertiser, 06/18, p. 5. 



 Earthquakes were reported as follows from the Island of Hawaii; Paauilo--11th, two shocks, 20 minutes apart, the first one occurring at 3:40 a.m.; Laupahoehoe--11th, two shocks about 4:00 a.m.; Naalehu--11th, two heavy shocks during the early a.m.; Kealakekua (Wallace)--11th, two light and one heavy shock between 4:00 a.m. and 5: 00 a.m., and Kealakekua (Davis)--11th, 1 shock at 4:10 a.m., lasting 3-4 second.



Stockman, W.B., 1907, Weekly Weather Bulletin for the week ended Jul. 13, 1907: Pacific Commercial Advertiser, 07/16, p. 6. [Not listed in Honolulu Bulletin (Hazard, 1911)] 



 A slight shock of earthquake was felt at Makawao [Maui} at 11:40 p.m. July 5th



Stockman, W.B., 1907, Weekly Weather Bulletin for week ended August 3, 1907: Pacific Commercial Advertiser, 08/06, p. 2. 



 Earthquakes occurred at Naalehu, Hawaii, about 8 a.m. on July 25, and 8:45 a.m. on July 31 at Waimea and Kealakekua (Wallace), Hawaii.



Stockman, W.B., 1907, Weekly Weather Bulletin for the week ended September 14, 1907: Pacific Commercial Advertiser, 09/18, p. 5. 



 The following stations on Hawaii report earthquakes: Kealakekua (Davis), 5th, 7:00 p.m., 1-3 second; Kealakekua (Wallace), 5th, 6:45 p.m., several seconds, not severe; Ookala, several light ones; Paauilo, 6th, a sharp rotary one, 7:10 p.m., light ones 7:25, 8:00 and 11:00 p.m., and 7th, light at 1:00 and 9:00 a.m.



Stockman, W.B., 1907, Weekly Weather Bulletin for the week ended September 21, 1907: Pacific Commercial Advertiser, 09/24, p. 6. 



 An earthquake shock was felt at 8:15 p. m. of the 16th, at Waimea, Hawaii. [same event as reported in Lyman diary (Wyss and others, 1992) at 8:45 p.m.?]



Stockman, W.B., 1907, Weekly Weather Bulletin for the week ended September 28, 1907: Pacific Commercial Advertiser, 10/01, p. 6. 



 Earthquake shocks were felt at the following stations on Hawaii: on the 20th--Puakea Ranch, evening, slight; Laupahoehoe, 8:20 p.m. [daylight time?], light, and Waimea, 7:35 p.m., stiff.



Stockman, W.B., 1907, Weekly Weather Bulletin for the week ended October 12, 1907: Pacific Commercial Advertiser, 10/15, p. 6. 



 Earthquakes were felt between 5:40 and 5:50 p.m. October 9 at Kohala mill (double), Waimea (hard) and Kealakekua (Davis and Wallace)--all on Hawaii.



Stockman, W.B., 1907, Weekly Weather Bulletin for the week ended December 21, 1907: Pacific Commercial Advertiser, 12/25, p. 9. 



 A double earthquake shock was felt at the local office of the Weather Bureau in Honolulu at 8:51 p.m. of the 19th. The first shock was light, and the second--which occurred but a few moments later--was heavier and apparently had a rotary motion. The following stations also report the occurrence at about the same time: Hawaii--Puakea ranch, very violent, and lasting several seconds, and severely shaking buildings and their contents; Kohala Mill, a succession of shocks lasting several seconds; Niulii, heavy, lasting one minute; Honokaa, lasting 10 or 15 seconds; Ookala, severe, and Laupahoehoe and Pepeekeo, heavy. Maui--Huelo, lasting about 30 seconds; Haiku, sharp; Puunene, lasting 30 seconds; Wailuku, two, with but an instant between, lasting from 8 to 10 seconds, the second the heavier, more resembling a tremor than a wave motion; Kaanapali, severe. Oahu--Waianae; Ewa, light. Molokai--Mapulehu, light direction NE; Molokai ranch, sharp.



Stockman, W.B., 1907, Weekly Weather Bulletin for the week ended December 28, 1907: Pacific Commercial Advertiser, 12/31, p. 6. 



 The occurrence of the earthquake on the evening of the 19th is reported from the following stations on Hawaii: Kaueleau, Naalehu, lasting 1/2 minute; Kealakekua (Davis), two to three seconds, and Kealakekua (Wallace), severe and long; and Kihei, Maui, lasting 20 seconds.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended January 4, 1908: Pacific Commercial Advertiser, 01/07, p. 7. 



 An earthquake occurred at Waimea, Hawaii, at 6:30 p.m. on Dec. 30, 1907.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended February 1, 1908: Pacific Commercial Advertiser, 02/04, p. 5. 



 Waimea, Hawaii, reports an earthquake at 1:45 p.m. on Jan. 25.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended Mar. 7, 1908: Pacific Commercial Advertiser, 03/10, p. 8. 



 A light earthquake shock occurred at Hakalau, Hawaii, at 8:25 p.m. on Mar. 4.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended Mar. 14, 1908: Pacific Commercial Advertiser, 03/17, p. 6. 



 An earthquake shock was felt at 11:14 a.m. on Mar. 5 at Naalehu, Hawaii.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended Mar. 28, 1908: Pacific Commercial Advertiser, 03/31, p. 8. 



 Ookala, Hawaii, reports a slight earthquake shock at 8:30 p.m. on Mar. 26.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended Jul. 11, 1908: Pacific Commercial Advertiser, 07/14, p. 5. 



 A short and rather violent earthquake shock was felt at Honokaa, Hawaii, at 9:15 a.m. on Jul. 8.



Stockman, W.B., 1908, Weekly Weather Bulletin for the week ended September 12, 1908: Pacific Commercial Advertiser, 09/15, p. 11. 



 A slight earthquake shock occurred at 6:00 p.m. of the 5th at Ookala, Hawaii.



Stockman, W.B., 1908, Weekly Weather Bulletin for the week ended September 26, 1908: Pacific Commercial Advertiser, 09/29, p. 7. 



 A severe earthquake shock was felt generally over Hawaii a few minutes after 8:00 p.m. on the 20th. In connection with the first shock a lighter one was felt at Hakalau at 8:11 p.m., and several slight ones 10-15 minutes thereafter; and at Naalehu a slight shock was felt about a half hour after the first shock. The first shock was likely most severely felt in Kona. Rev. S.H. Davis reporting it as lasting six to eight seconds and being the longest and heaviest since 1887; Mr. R. Wallace reports it as lasting 10 seconds. The earthquake was slight at Molokai Ranch, Molokai; and it was also reported to have been felt in Honolulu.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended Oct. 10, 1908: Pacific Commercial Advertiser, 10/14, p. 12. 



 Two moderate earthquake shocks were felt at Honokaa, Hawaii, 6:37 p.m. on Oct. 5.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended Oct. 17, 1908: Pacific Commercial Advertiser, 10/20, p. 12. 



 At Laupahoehoe, Hawaii, nine earthquake shocks were felt during the forenoon of Oct. 9, and two on Oct. 13. At Kealakekua (Wallace), and Kohala Mill, Hawaii, a light shock was felt at 5:00 a.m. on Oct. 9 [presumably this shock corresponds to one of the nine shocks felt at Laupahoehoe].



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended Oct. 31, 1908: Pacific Commercial Advertiser, 11/04, p. 12. 



 The following earthquake shocks were reported--all from Hawaii: 24th--Naalehu, light followed by heavier, Kealakekua (Davis) 5:45 p.m., lasting two seconds; 27th, and all about 10:00 p.m.--Kohala Mill, light, Kohala Mission; Kukuihaele, light; Kealakekua (Wallace), first, light, second heavier; Kealakekua (Davis) lasting three seconds, and Naalehu.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended Nov. 14, 1908: Pacific Commercial Advertiser, 11/17, p. 11. 



 A slight earthquake shock was felt at 3:16 p.m. on Nov. 7, at Kukuihaele, Hawaii.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended Nov. 21, 1908: Pacific Commercial Advertiser, 11/24, p. 12. 



 A slight earthquake shock was felt at Kohala Mill, Hawaii about 3:00 a.m. of the 17th.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended Nov. 28, 1908: Pacific Commercial Advertiser, 12/01, p. 12. [Not reported in Honolulu Station Bulletin (Hazard, 1911)] 



 A slight earthquake shock was felt at 5:30 a.m. on Nov. 27, at Makaweli, Kauai.



Stockman, W.B., 1908, Weekly Weather Bulletin for week ended Dec. 12, 1908: Pacific Commercial Advertiser, 12/15, p. 12. 



 A slight earthquake shock was felt at about 8:00 p.m. on Dec. 6, at quite a number of stations on Hawaii. Honokaa describes the motion as long and swaying.



Stockman, W.B., 1909, Weekly Weather Bulletin for week ended Jan. 9, 1909: Pacific Commercial Advertiser, 01/12, p. 12. 



 The following earthquake shocks were reported--all about 12:30 p.m. of the 4th: Hawaii--Kohala Mill, sharp; Kealakekua (Wallace), slight; Ookala; Kohala Mission, slight, and Kukuihaele, severe; and 6th, Kohala Mill, 3 p.m., slight.



Stockman, W.B., 1909, Weekly Weather Bulletin for the week ending Jan. 23. 1909: Pacific Commercial Advertiser, 01/26, p. 12. 



 A slight earthquake shock was felt at Kapoho, Hawaii, at 6:45 p.m. on Jan. 20.



Stockman, W.B., 1909, Weekly Weather Bulletin for week ended Apr. 17, 1909: Pacific Commercial Advertiser, 04/20, p. 10. 



 Kaueleau, Hawaii, reports a sharp earthquake shock at 5:25 p.m. of the 14th.



Stockman, W.B., 1909, Weekly Weather Bulletin for week ended Aug. 14, 1909: Pacific Commercial Advertiser, 08/17, p. 10. 



 Earthquake shocks were felt at Kohala Mission, Hawaii, at 4:30 a.m. on Aug. 12, and Kukuihaele, during the night of Aug. 11.



Stockman, W.B., 1909, Weekly Weather Bulletin for week ended Oct. 2, 1909: Pacific Commercial Advertiser, 10/05, p. 5. 



 An earthquake shock was felt at Naalehu, Hawaii, during the night of Sept. 26.



Stockman, W.B., 1909, Weekly Weather Bulletin: Pacific Commercial Advertiser, 10/20, p. 12. 



 Earthquake shocks occurred in the Kona districts of Hawaii about 8:30 p.m. of the 8th.



Stockman, W.B., 1909, Weekly Weather Bulletin for the week ended October 23, 1909: Pacific Commercial Advertiser, 10/26, p. ? 



 Earthquakes were reported by Kohala Mission--double--and Kohala Mill, Hawaii about 4:30 a.m. of the 18th



Stockman, W.B., 1909, Weekly Weather Bulletin for the week ended Dec. 4, 1909: Pacific Commercial Advertiser, 12/08, p. 12. 



 Naalehu, Hawaii--A severe thunderstorm occurred on the first, followed by an earthquake.



Stockman, W.B., 1910, Weekly Weather Bulletin for week ended Jan. 8, 1909: Pacific Commercial Advertiser, 01/11, p. 6. 



 Warshauer notes: An earthquake shock was felt at Kaueleau, Hawaii 7:00 a.m., on Jan. 3.



Stockman, W.B., 1910, Weekly Weather Bulletin for week ended Mar. 12, 1909: Pacific Commercial Advertiser, 03/15, p. 11. 



 Naalehu, Hawaii reports . . . light earthquakes on Mar. 3 and 4.



Stockman, W.B., 1910, Weekly Weather Bulletin for week ended Apr. 30, 1910: Pacific Commercial Advertiser, 05/03, p. 6. 



 An earthquake shock was felt generally over Hawaii at about 10 p.m. on Apr. 26. At Kohala mission, the shock was a double one; and at Niulii its movement was from east to west.



Stockman, W.B., 1910, Weekly Weather Bulletin for week ended Aug. 13, 1910: Pacific Commercial Advertiser, 08/16, p. 6. [Tidal effects described in the Pacific Commercial Advertiser of Aug. 15] 



 A heavy southwest swell, which is assumed to have been a tidal wave due to a submarine volcanic eruption, did considerable damage along the northwestern coasts of Maui, on the night of Aug. 8. [No local earthquakes were recorded at this time; submarine eruption local to Maui possible but unlikely].



Stockman, W.B., 1910, Weekly Weather Bulletin for week ended Oct. 1, 1910: Pacific Commercial Advertiser, 10/04, p. 2. 



 Earthquakes were reported on Sept. 24th, 5:50 p.m., from Kealakekua (Wallace), Hawaii, with a short and sharp movement. . . . Kealakekua (Davis), Hawaii, reports a quake at 5:50 p.m. on Sept. 25 [same event as above, wrong date reported?]



Stockman, W.B., 1910, Weekly Weather Bulletin for week ended Oct. 22, 1910: Pacific Commercial Advertiser, 10/25, p. 6. 



 Kukuihaele, Hawaii, reports a quick, double, slight earthquake shock at 6:33 p.m. on Oct. 16.



Stockman, W.B., 1910, Weekly Weather Bulletin for week ended Dec. 17, 1910: Pacific Commercial Advertiser, 12/20, p. 11. 



 . . . Kealakekua (Wallace), Hawaii [reports] an earthquake at 11:30 on Dec. 9.



Stockman, W.B., 1911, Weekly Weather Bulletin for week ended February 11, 1911: Pacific Commercial Advertiser, 02/14, p. 11. 



 Slight earthquake shocks occurred at Kohala Mill and Niulii, Hawaii, on Feb. 9, about 10:40 a.m., and at Naalehu, Hawaii, on Feb. 6 at 8:25 p.m.



Stockman, W.B., 1911, Weekly Weather Bulletin for week ended February 18, 1911: Pacific Commercial Advertiser, 02/23, p. 11. 



 A moderate earthquake shock was felt at Kaueleau, Hawaii, on Feb. 10.



Stockman, W.B., 1911, Weekly Weather Bulletin for week ended February 25, 1911: Pacific Commercial Advertiser, 02/28, p. 4. 



 Earthquake shocks were felt at Kohala Mission and Kohala Hill [Mill?], Hawaii, just after midnight on Feb. 21.



Stockman, W.B., 1911, Weekly Weather Bulletin for week ended Mar. 11, 1911: Pacific Commercial Advertiser, 03/14, p. 12. 



 Kaueleau, Hawaii [reports] a sharp earthquake shock at 9:30 p.m. on Mar. 8.



Stockman, W.B., 1911, Weekly Weather Bulletin for week ended May 7, 1911: Pacific Commercial Advertiser, 05/10, p. 7. 



 A short, sharp earthquake was felt in the North Kohala District of Hawaii at 4:10 a.m. on May 2.



Stockman, W.B., 1911, Weekly Weather Bulletin for week ended May 21, 1911: Pacific Commercial Advertiser, 05/23, p. 12. 



 At Kaueleau, Hawaii, there was an earthquake shock at 7:20 p.m. on May 13.



Stockman, W.B., 1911, Weekly Weather Bulletin for week ended July 15, 1911: Pacific Commercial Advertiser, 07/19, p. 7. 



 An earthquake shock was felt generally over the section about 11:30 a.m. on July 14. Kaueleau, Hawaii, reports one at 5:00 a.m. on July 8, and another at 9:30 a.m. on July 9.



Stover, C.W., and von Hake, C.A., 1981, Hawaiian Islands, in United States Earthquakes, 1979: Washington, DC, U.S. Government Printing Office, United States Environmental Data and Information Service report, p. 57-64. [Published jointly by the U.S. Department of Commerce, National Oceanic and Atmospheric Administration (NOAA) and U.S. Department of the Interior, Geological Survey (USGS). The same data were published quarterly in U.S. Geological Survey Circular 836A-D (authorship divided among Simon, R.B., Stover, C.W., Minsch, J.H., Reagor, B.G., Smith, P.K., and Person, W.J., 1980 and 1981), and by Klein, F., p. 109-114, in, Stover, C.W. and von Hake, C.A., U.S. Geological Survey Open-File Report 84-979, 1984.] 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Stover, C.W., and Coffmann, J.L., 1993, Seismicity of the United States, 1568-1989 (revised): U.S. Geological Survey Professional Paper 1527, p. 201-213. 



 A listing of origin time, hypocenter, magnitude, and intensity for earthquakes originating beneath the Hawaiian islands from 1823 to 1989. Descriptions of the larger earthquakes are abstracted from the literature.



Swanson, D.A., Duffield, W.A., and Fiske, R.S., 1976, Displacement of the south flank of Kilauea Volcano: the result of forceful intrusion of magma into the rift zones: U.S. Geological Survey Professional Paper 963, 39 p. 



 	 Page

Abstract	1

Introduction	1

Acknowledgments	2

Structural subdivisions of Kilauea	3

Earthquake distribution	7

Long-term horizontal displacements during the 20th century	8

 Existing data and their quality	8

 Results	9

 1949-70	9

 1958-70	11

 1949-58	11

 1896-(1914)-1970	12

 1896-(1914)-1958	12

 1961-70	12

 August September 1970 to October 1971	13

 Summary of long-term horizontal deformation	13

Horizontal deformation during specific intrusive or extrusive

 events	14

 February-May 1955 east rift eruption	14

 February-May 1969 east rift eruptions	15

 September 1971 eruption	15

 Specific displacement events on the south flank	15

 Strains between March 6 and August 27, 1970	16

 Linear contraction of a geodimeter line between 1965

 and 1970	16

 Summary and interpretation of horizontal deformation

 on the south flank	16

Vertical displacement of south and north flanks of Kilauea 17

 Central part of south flank	19

 Eastern part of south flank and lower east rift zone	20

 Western part of south flank and Koae fault system	21

 North flank	21

 Summary and interpretation of vertical deformation on the

 flanks	21

Relative magnitude of horizontal and vertical displacements 23

A structural model for the south and north flanks of Kilauea 24

Numerical comparison of volumes of intrusion and deformation 27

The rift zones and Koae fault system as zones of dilation	27

Relative importance of the two rift zones in governing mobility

 of the south flank	29

Southward migration of the rift zones and summit reservoir 29

 East rift zone	29

 Southwest rift zone	32

 Summit reservoir	33

The Hilina fault system	33

Application to other oceanic volcanoes	35

Supplemental information	36

 Problem of ground deformation occurring during the horizontal surveys	36

 Baseline selection	36

Procedure for treating triangulation data	37

References cited	37

Seismic evidence has long indicated that the south flank of Kilauea Volcano is mobile. Examination of triangulation, trilateration, and leveling data obtained throughout the 20th century shows that the south flank of Kilauea has been displaced upward and away from the rift zones by as much as several metres. The amount of horizontal displacement approximates the probable amount of dilation that accompanies the intrusion of magma as dikes in the rift zones and is greatest for periods of most intense intrusive activity, as evidenced by the frequency of eruptions. Displacement and seismic events on the south flank take place soon after intrusive activity, indicating that the displacement is the result of forceful intrusion in the rift zones, not the cause of relatively passive intrusion. The dikes are thought to be nearly vertical or to dip steeply southward, on the basis of both interpretation of seismic and displacement data for Kilauea itself and comparison with dikes exposed in older, eroded Hawaiian shield volcanoes.

 In contrast to the south flank, seismic and geodetic data indicate that the north flank is virtually immobile. This contrast is believed to reflect the fact that Kilauea was built on the south slope of Mauna Loa and was consequently influenced by the gravitational stress system of Mauna Loa, which favors displacement away from the volcanic edifice. The north flank of Kilauea is effectively buttressed by Mauna Loa, whereas the south flank is unbuttressed and free to move away from the edifice when prompted by forceful intrusion of magma.

 The active part of the east rift zone of Kilauea has apparently migrated several kilometres southward with time. This is shown by the location of recent vents and by the location of the axis of a positive gravity anomaly along the north edge of the active part of the rift zone. The southward migration helps explain several features of the geometry of the east rift zone, particularly its prominent bend near Kilauea Caldera. The southwest rift zone and the caldera also show some evidence of southward migration.

 The Hilina fault system is considered to be a gravity-controlled system not directly related to the rift zones. Gravitational instability resulting from uplift and seaward displacement is eventually relieved by normal faulting along the seaward part of the south flank. The Hilina faults are thought to bottom at shallow depth without intersecting magma reservoirs, except possibly along part of the lower east rift zone, where the fault system impinges upon the rift zone. Strains have been accumulating within the Hilina system throughout this century, and a high level of instability may have been reached. We anticipate a subsidence event in the not too distant future, possibly similar to the damaging events of 1823 and 1868. (While this paper was in press, such an event occurred on November 29, 1975).



Switzer, J.C., and Porcella, R.L., 1995, Catalogue of U.S. Geological Survey strong-motion records, 1993: U.S. Geological Survey Circular 1121, 10 p. 



 During the period January-December 1993, only 83 accelerograph records were recovered from permanent National Strong-Motion Program (NSMP) stations operated by the U.S. Geological Survey; this compares with an annual average of more than 300 recordings for the period 1974 through 1992. Accelerograms were recovered from NSMP instrumentation triggered by 12 California earthquakes in the magnitude 3 to 6.2 range; 4 Hawaii earthquakes, including magnitude 4.8 and 4.9 events on January 26 and June 8, respectively; magnitude 5.7 and 5.9 earthquakes in northern Oregon on March S and southern Oregon on September 21, respectively; and by a 5.2 earthquake in southern Alaska on May 18. Also included are recordings from 14 stations in the greater Anchorage region (see table 1).

 	Peak ground acceleration exceeded 0.10 g at NSMP sites only twice during 1993: 0.11 g during an unidentified southern California event near San Bernardino, and 0.28 g at Kau Hospital in Pahala, Hawaii, during the MD=4.8 earthquake on January 26.



Talandier, J., and Bouchon, M., 1979, Propagation of high frequency Pn waves at great distances in the central and South Pacific and its implications for the structure of the lower lithosphere: Journal of Geophysical Research, v. 84, no. B10, p. 5613-5619. 



 Using 17 seismic stations in French Polynesia, we study the propagation of high-frequency Pn waves in the Central and South-Central Pacific. This study is prompted by the presence of striking Pn wave phases on the seismograms of the Hawaii earthquakes recorded in the Tuamotu and Society islands (Tahiti), almost 40 away. The Pn velocity inferred from these observations (7.95  0.03 km/s) is in good agreement with the values obtained in the North Pacific by Walker (1977a, b) and shows the existence over most of the Pacific basin of a remarkably efficient Pn wave guide of relatively low velocity. Compared to Pn, Sn waves are much less efficiently transmitted. The Pn velocities measured from intraplate earthquakes in the South-Central Pacific suggest the presence of a 2-3% anisotropy in the wave guide, the direction of maximum velocity being parallel to the trend of the island chains. All these observations are interpreted as evidence of the presence of minimum velocity channels within the subcrustal lithosphere and a discussion of the models which can account for these features is presented.



Tanigawa, W.R., Nakata, J.S., and Klein, F.W., 1981, Hawaiian Volcano Observatory summary 80: seismic data, January-December 1980 (Chronological summary by R.W. Decker): U.S. Geological Survey Administrative Report, 76 p. [Part 2, designated to cover deformation studies, has not been published] 



 A summary of the volcanic conditions and seismicity during the year.



Taylor, A.P., 1924, Airplane field at Volcano now resembles battlefield in European war zone; strewn with huge boulders and pitted with "shell craters;" Pele working on amazingly regular schedule; Professor Finch highly praised: Honolulu Advertiser, 05/25, p. 3. 



 . . . .

 . . . About 8 o'clock Thursday morning [May 22] there was a shock which rocked the hotel [Volcano House].

 What struck the scientists as remarkable was the exact schedule which is maintained by Pele in eruptions and quakes. Every six hours, almost to a minute, these have been recorded. At 2 a.m. Thursday [May 22] the guests at the Volcano House were aroused by a heavy quake which shook the building.

 Most of the article describes the experiences of various observers of the 1924 Halemaumau eruption.



The1996LoihiScienceTeam, 1997, Researchers rapidly respond to submarine activity at Loihi volcano, Hawaii: Eos, Transactions, American Geophysical Union, v. 78, no. 22, p. 229, 232-233. 



 "The largest swarm of earthquakes ever observed at a Hawaiian volcano occurred at Loihi Seamount during July and early August 1996. The earthquake activity formed a large summit pit crater similar to those observed at Kilauea, and hydrothermal activity led to the formation of intense hydrothermal plumes in the ocean surrounding the summit.

 To investigate this event, the Rapid Response Cruise (RRC) was dispatched to Loihi in early August and two previously planned LONO cruises (named for a Hawaiian warrior god) sailed in September and October on the RN Kaimikai-O-Kanaloa. Calm weather and a newly refurbished ship provided excellent opportunities for documenting the volcanic, hydrothermal plume, vent, and biological activities associated with the earthquake swarm.

 The Loihi rapid response cruises and earthquake records provided a wealth of data that, for the first time, documented the submarine eruption and pit crater formation of a hotspot volcano. Researchers conducted a total of 15 PISCES V submersible dives, 41 water sampling operations, and 455 km of swath bathymetry surveys, and deployed 40 sonobuoys and one ocean bottom seismometer (OBS). Glassy rocks were recovered from a 1996 eruption."

Earthquakes and Noise

Structure

Hydrothermal Plumes

Hydrothermal Vents

Petrology

Radiochemistry

Microbiology

Macrobiology



The1996LoihiScienceTeam, 1997, Rapid response to submarine earthquake activity at Loihi seamount, in SOEST 1995 & 1996 report: Honolulu, University of Hawaii School of Ocean and Earth Science and Technology (SOEST), p. 14-18. 



 The largest swarm of earthquakes ever observed at any Hawaiian volcano occurred at Loihi seamount during July and early August, 1996. To investigate this event, a marine expedition was dispatched to Loihi in early August (Rapid Response Cruise: RRC), and two previously planned cruises sailed in September and October (LONO Cruises) on the R/V Kaimikai-o-Kanaloa. Calm weather and a newly refurbished ship combined to provide excellent conditions for documenting the volcanic, hydrothermal plume, vent, and biological activities associated with this swarm. These cruises conducted a total of 15 Pisces V submersible dives, 41 water sampling operations, and 455 km of SeaBeam surveys, and deployed 40 sonobuoys and one ocean bottom seismometer (OBS, photo at left). The most obvious result of the earthquake activity was the formation of a large summit pit crater similar to those observed at Kilauea. Greatly expanded activity was also observed resulting in the formation of intense hydrothermal plumes in the ocean surrounding the summit. Glassy rocks were recovered from possibly two 1996 eruptions.



Earthquakes and noise

 Between July 16 and August 9, 1996, more than 4000 Loihi earthquakes were detected by the seismic network of the U. S. Geological Survey's Hawaiian Volcano Observatory (HVO). The initial phase of activity, consisting of 72 located earthquakes, continued for two days. After 30 hours of quiescence, activity resumed and continued at a higher rate, averaging more than 88 located events per day for the next 10 days before slowing.

 Preliminary locations calculated using the HVO seismic network data placed the majority of events between depths of 10 and 14 km shallowing seaward. However, P-waves detected at an OBS deployed on Loihi summit during the third week of the swarm arrived about two seconds early, suggesting that the velocity model used for the island of Hawaii is inappropriate beneath Loihi and that initial locations are suspect. Using HVO's preferred model for velocity under Hawaii and lower velocities at shallow depths under Loihi, reasonable hypocentral locations are obtained between 7 to 8 km depth (Figure 1). Despite the obvious topographic modifications of the summit, few shallow earthquakes (between 0 and 5 km) were located.

 Sonobuoys dropped from the Kaimikai-o-Kanaloa to listen for earthquakes and eruption sounds detected bangs, pops, and grinding noises with frequencies from tens to several hundred Hz at three distinct locations on the NE side of the summit, moving from south to north with time. An active quake area just north of East Pit (Figure 2B) was detected during the RRC, and two areas were located during the first LONO cruise: one on the east flank at a depth of about 1600 meters and one just north of the summit. Other priorities prevented detailed surveys of these sites although turbid water was observed drifting in from these areas during submersible dives.



Structure

 SeaBeam surveys documented the bathymetric changes at Loihi summit (Figure 2A) associated with the seismic swarm. Peles Vents, at a depth of 980 m and previously the prime locus of Loihis hydrothermal activity, collapsed, forming a pit crater (Pele's Pit, Figure 2B) approximately 600 m in diameter with its bottom 30o m below the previous surface. Portions of the West Pit rim and areas to the north have faulted down several meters toward the summit center, bisecting Pisces Peak. The Sand Channel, a preexisting large fissure extending westward from the East Pit, now intercepts Peles Pit. East pit crater has shallowed by ~23 m, apparently as a result of infilling by mud. Evidence of recent fracturing, hydrothermal activity, and emplacement of black sands were noted along the upper south rift. Surveys on the northern half of Loihi revealed no obvious changes.

 The collapse that formed Pele's Pit exposed massive columnar jointed flows and hydrothermally lithified talus, which now form large spires on the near-vertical north face of Pele's Pit. Much of the southern summit appears to be newly shaker); previously light brown pillow surfaces are now littered with broken weathered pillow debris and fresh-appearing glassy rocks (Figure 3). The glassy rocks fine in size away from the edges of the craters, suggesting ejection of the rocks from the craters.



Hydrothermal plumes

 Intense hydrothermal plumes resulting from the seismic event were studied using hydrocasts (vertical water sampling at a single site) and tow-yos (sampling by an instrument package raised and lowered behind a moving ship). Temperature anomalies of 0.5C were common during the RRC in the water column around the summit at depths of 1050-1250 m, with anomalies of 0.1C at distances greater than 8 km (Figure 4). In contrast, mid-ocean ridge plumes typically have maximum anomalies of 0.02-0.1C, although event plume anomalies of up to 0.3C have been observed. One surprise was the observation of a very intense plume at 1600-1800 m depth at a "background" station 50 km NE of Loihi. A marked decrease in pH (0.2 units) and a remarkable 3He enrichment (150%) were measured, suggesting an injection of magmatic gasses to the water column during a large short-lived, but rapidly cooled, volcanic episode well below the summit of Loihi during the early stages of the seismic event.

 Sharp vertical temperature and chemical gradients measured by RRC hydrocasts showed that hydrothermal fluids were accumulating in the bottoms of the pit craters. Anomalies of up to 3.5C and 0.65 psu salinity were measured. Tracers of hydrothermal and volcanic emission in the pits were greatly enriched with respect to ambient sea water: Fe = 45,000x (45 mM), Mn = 29,000x (5.7 mM), CH4 = 560x (280 nM), H2= 100x (20 nM), and TCO2= 7x (17 mM). The pH of this water was 5.6 (as compared to the ambient value of 7.8), which was likely due. to the acidity of the injected magmatic CO2. No sulfide smell was detectable, suggesting that the vent fluids had not been in contact with the basalt at high enough temperatures or for a long enough duration for the formation of H2S.

 LONO hydrocasts showed that temperature anomalies within Pele's Pit had decreased to 0.6C after the RRC. Nevertheless, a hydrocast 1.2 km west of the summit detected numerous plumes with anomalies up to 0.10C between 1050 and 1330 m, the largest coming from the intense venting near the bottom of Pele's Pit. The hydrothermal plume was detected more than 12 km west of the summit.



Hydrothermal vents

 Vent fields with temperatures of up to 77C were discovered during the LONO cruises, one near the bottom and two on the north wall of Pele's Pit, two on the south rift, and one west of the summit (see Figure 2). Venting was generally diffuse, exiting through nontronite-coated talus, although 1-3 m wide fissures vented large volumes of water in the south rift vent area. Rocks bearing several high-temperature sulfide minerals were collected, suggesting that vent waters were hot (at least 250C) during formation of these deposits. This apparent decrease in temperature with time will be verified by temperature recorders and samplers for year-long sampling of vent fluids.

 Fluid samples were collected from seven vents. Gas content of the fluids was more than 52 mmol/kg, or 17 times the background seawater value. As noted in previous Loihi vent fluids, carbon dioxide continues to be the dominant vent fluid gas, but its ratio to dissolved silica and vent temperature (heat) has decreased dramatically during the last decade: dissolved CO2/heat ratios decreased by about 30% between 1987 and 1992. The CO2/heat ratios from the LONO cruise continued this trend, decreasing by over 90% relative to fluids collected in 1987-1992. These decreases have been ascribed to progressive degassing from a magmatic intrusion. The much lower CO2 values in the fluids collected in 1996 [~10 mmol/kg CT (total carbon), compared with ~300 mmol/kg CT in 1987 and ~200 mmol/kg CT in 1992] could reflect a continuation of this degassing trend or indicate that the magma supplying gases to the hydrothermal vents degassed substantially during the seismic event.



Petrology

 Rocks and sediment were collected using the Pisces V submersible during the RRC and LONO cruises. The RRC sampled a "young" breccia on the western rim of West Pit, yielding three of the freshest lavas collected from Loihi. The LONO cruises collected talus fragments, some with sulfides (pyrite, bornite, sphalaite) and amorphous silica coatings, in situ lavas, and sediment. The sediment consists of coarse black sand, Pele's hair, and paper-thin bubblewall fragments produced by the reaction of fluid lava with seawater, mixed with planktonic foram tests.

 The RRC lavas are low SiO2 tholeiites, typical of recent Loihi lavas. They contain 1 to 2 vol.% clinopyroxene phenocrysts (rare in Hawaiian tholeiites) and two chemically distinct populations of olivine, which are in equilibrium with the two endmember glassy rock compositions (i.e., 8.2 and 10.3 wt% MgO). The clinopyroxenes have inclusions of strongly resorbed olivine and reversely zoned rims. This reverse zoning and two olivine populations indicate magma mixing, probably just before or during eruption. The olivine inclusions in clinopyroxene apparently formed at moderate pressures (~2.8 kb) based on modeling of equilibrium crystallization of the observed rock compositions using the MELTS program. Analyses of RRC glasses yield trace element ratios (e.g., La/Yb) which continue a decreasing temporal geochemical trend for young Loihi tholeiites, supporting the hypothesis chat they were recently erupted. These results indicate that the RRC rocks are young and were stored at 8 to 9 km (compared to 2-6 km depth for the nearby Kilauea magma chamber) before being mixed with a more mafic magma, which may have triggered the eruption of these rocks.



Radiochemistry

 Preliminary 210Po-210Pb ages of two fresh-appearing RRC lavas indicate that they were almost certainly erupted sometime between early 1996 and the seismic event and probably were erupted a month or more apart. The 210Po-210Pb dating technique can provide ages of lavas erupted within the past 2.5 years. Although these ages are preliminary, one or both may pre-date the seismicity "event" at Loihi by several months. Final ages won't be available until late 1997 because three to four separate analyses of 210Po in a lavaeach several months apartare required to establish the lava's age (see page 21 for more details on this technique).

 Analyses of the abundance and isotopes of several volatile trace metals in RRC particle-enriched seawater (0.22 g/L) were conducted to detect anomalies from magmatic degassing. Particulates show large (10-33x) enrichments of the volatile elements Po, Pb, Mo, W, Sb, As, Tl, and Te relative to Loihi summit lavas, a Pb isotopic composition indistinguishable from Loihi summit lavas, and a Nd isotopic composition that represents a maximum admixture of 10% sea water Nd with Loihi compositions. Together, these data strongly implicate young Loihi rocks, along with effluent (enriched by Loihi magmatic volatiles) rather than local sea water, as the primary sources of the trace elements adhering to the particles. Shipboard 222Rn analyses during the LONO cruises revealed elevated water column Rn activities (60-75 dpm/l00L) at 1000-1300 m depth and up to 30,000 dpm/l00L in the vent fluids. This radon distribution is similar to that found in 1993, indicating that any potential eruptive pulse of Rn in August had already gone by early October.



Microbiology

 Microbial mats surrounding hydrothermal vent orifices were abundant and were observed to reform within a day following sampling. Samples of mats from different sites were brought into enrichment culture using a method designed to focus the bacteria along opposing iron-sulfur vs. oxygen gradients. These enrichments are being prepared into pure cultures for physiology studies. Additionally, microbial mat samples were collected to address questions such as community succession. The majority of the taxa observed previously in Loihi microbial mats are most closely related to mesophilic iron- and sulfur-oxidizing bacteria.

 The geomorphology and venting character of Pele's Pit has created a "themostat-like" reservoir. As the entire circumference of Pele's Pit comprises relatively steep walls rising ~200 m from the pit bottom, fluid exchange is restricted to vertical mixing, presumably influenced by hydrothermally induced buoyant updrafts and ambient cold water down drafts. These conditions may contribute to the high microbial biomass observed within the pit.



Macrobiology

 Loihi seamount hydrothermal vent systems lade the luxuriant macrobenthic communities characteristic of vents from mid-ocean ridges. The only two vent-specific macrofaunal species described from Loihi have been a bresiliid shrimp, Opaepele loihi, and a lineage of pogonophoran worm. The post-event dives, however, reported seeing no bresiliid shrimp and only one pogonophoran worm. Thus, the long term impact of the 1996 event on these species is unknown.



Conclusion

 The Loihi rapid response cruises and earthquake records have provided a wealth of data that have, for the first time, documented the submarine eruption and pit crater formation of a hot-spot volcano. While the synthesis of these data will take several years to complete, the value of quickly obtaining a diverse database is clearly demonstrated. Dives planned for the upcoming two years, and the concurrent establishment of an underwater observatory at Loihi, should more fully document these and future events at this active submarine volcano.



Thornber, C.R., Heliker, C.C., Reynolds, J.R., Kauahikaua, J., Okubo, P., Lisowski, M., Sutton, A.J., and Clague, D., 1996, The eruptive surge of February 1, 1996: a highlight of Kilauea's ongoing east rift zone eruption [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F798. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 The ongoing eruption of Kilauea is nearing the end of its 13th year. The flow field has expanded to 95 sq km and 2.2 sq km of new land have been added to the island. Since early 1992, the eruption has been fed by vents on the SW flank of the Pu'u 'O'o cone, 16 km from the summit. The current vent feeds directly into lava tubes that extend 11 km to the ocean. Since September 1995 there have been five eruptive pauses, lasting from 1 to 10 days. During periods of eruption, the level of the pond in Pu'u 'O'o stands at ~90 m below the crater rim; during pauses the pond rises as much as 30 m. There was a dramatic eruptive surge at Pu'u 'O'o on February 1. This event was followed by a 10 day pause from February 4-14. Between pauses, the lava flux ranged from 400,000 to 500,000 m3/day; it increased temporarily by an order of magnitude on February 1. Glass-thermometry results from September 1995 through January 1996 show nearly constant temperatures of 1150C (s=3) for near-vent skylight samples and 1153C (s=2) for Pu'u 'O'o pond samples. On February 1, skylight and pond temperatures roseto 1156C and 1160C, respectively, and both fell to 1153C when the eruption resumed on February 14. Lava compositions, which have varied little since January 1994, have displayed a distinct trend toward more primitive olivine-saturated compositions, beginning on February 1.

 The February 1st event began abruptly at 0809 hrs with an intense swarm of shallow (0-3 km) earthquakes and tremor beneath the summit caldera. Fifteen minutes after the onset of the swarm, the summit began to inflate rapidly, accompanied by a dramatic increase in the CO2/SO2 gas ratio. By 1210 hrs, earthquakes and tremor had subsided and the summit began to deflate. Summit tilt decreased exponentially over the next 3 days until the eruption paused. CO2/SO2 ratios at the summit also declined to near normal levels over this interval. At its maximum, the summit tiltmeter recorded 19 micoradians of inflation, equivalent to 6 cm of uplift in the center of the caldera. Meanwhile out on the rift, a surge of lava reached the eruption site at 1130 hrs. The pond in Pu'u 'O'o briefly rose to within 40 m of the rim and spattered over the SE side of the crater as dome fountains played above four upper-elevation skylights. The largest dome fountain (7.6 m high at 1400 hrs) fed a channelized flow that turned to 'a'a as it descended through forest on the steep slope of Pulama Pali. This flow stagnated at the 400 ft elevation after advancing ~7 km in less than 6 hours. The volume of lava that broke out of the upper skylights on February 1 is estimated at 3.82x106 m3.

 Integration of seismic, geodetic, gas emission and petrologic data suggest that the February 1st eruptive surge may be attributed to a sudden convective overturn of the subcaldera magma chamber, resulting in catastrophic degassing and rapid volume expansion. This pressurized, newly mixed magma came close to erupting at the summit but instead found a well-worn escape route along the dike system feeding the long-lived East Rift Zone eruption. However, an explanation involving the injection of new magma into the system has not been entirely ruled out.



Thornber, C.R., Sherrod, D., Heliker, C., Kauahikaua, J., Trusdell, F., Lisowski, M., and Okubo, P., 1997, Kilauea's ongoing eruption: Napau Crater revisited after 14 years [abs.]: Eos, Transactions, American Geophysical Union, v. 78, no. 17, p. S329. [AGU-MSA-GS spring meeting, Baltimore, MD, May 27-30, 1997, Program and abstracts] 



 The current eruption on Kilauea's east rift zone began on January 3, 1983, when fissures opened in Napau Crater, 12 km downrift from the summit. After six months, the eruption localized at a principal vent, 4.5 km east of Napau, and from 1983 to 1986 was characterized by episodic high-fountaining phases that built the 257-m-high Pu'u 'O'o cone (Episodes 1-47). In 1986, the vent migrated 4 km further downrift to the Kupaianaha vent (Episode 48), and eruptive activity was characterized by continuous low level effusion. In 1991, a short-lived fissure eruption occurred between Kupaianaha and Pu'[u] 'O'o (Episode 49). In 1992, the eruption returned to the flank of Pu'u 'O'o, and since 1993 lava has issued from a vent on the uprift side of the cone (Episodes 50-53). Episode 53 continued through January 29, 1997, with lava flowing through a 10-km-long tube system from Pu'u 'O'o to the ocean.

 Episode 54 began at ~0240 hrs on January 30, when a new eruptive fissure opened on the floor of Napau Crater. Seismic tremor near the site of this event was first detected at 1841 hrs on January 29. Eleven minutes later, low-level shallow tremor was detected at Kilauea's summit and was followed at 1930 hrs by the onset of rapid summit deflation. Summit tremor and shallow earthquake swarms intensified at 2015 hrs. During Episode 54, a total of 30 mrad of deflation were recorded by the water-tube tiltmeter at the summit and 0.1 m of summit contraction was measured with EDM and GPS. Leveling across the summit caldera shows subsidence localized within a few kilometers of Halema'uma'u pit crater. Summit tremor, subsidence, and contraction continued until the eruption stopped at 0033 hrs on January 31, after which time, summit tilt reversed with slow inflation accumulated 5 mrad of east-northeasterly tilt and 0.02 m of extension by February 10.

 The early east rift zone seismic activity (1845 to 2015 hrs on January 29) may correspond to the timing of a complete drainback of the lava pond within the Pu'u 'O'o crater, followed by collapse of the west side (summit and flank) of the Pu'u 'O'o cone. The Pu'u 'O'o crater floor, previously 60 m below the low point on the rim, dropped over 150 m, to a level ~60 m below the pre-1983 surface and the collapse of the flank generated a debris deposit extending 5 km southeast from the cone. From 0240 hrs to 0630 hrs, on January 30, Fissures A, B and C erupted along a 0.8 km long, N60E line striking from the center of Napau Crater. Fissure D erupted from 1239 to 1450 hrs, overlapping C and extending another 0.5 km northeastward. Fissure E, less than 100 m in length, opened en echelon and 150 m SE of D and was active from 1639 to 1840 hrs. Fissure F erupted from the west wall of Napau Crater from 2043 hrs until 0033 hrs on January 31.

 About 300,000 m3 of lava were erupted from six fissures in the Napau Crater area. Surface cracks indicate 1.8 m of opening of the crater floor. GPS stations located 2 km uprift of the fissures and several kilometers away from the rift zone show 0.3 m of extension across the rift during the event. Chemical analysis of Episode 54 lava samples indicate that two separate and distinct rift-stored magma bodies near Napau Crater supplied lava for the eruption. Both Episode 54 magmas are differentiated relative to the lava erupted at Pu'u 'O'o since late 1983 which has been supplied directly from the summit magma chamber.



Thrum, T.G., 1886, Kilauea; an ideal volcano trip to Kilauea during its quiescent period, March, 1886: Honolulu, Press Publishing Co., pamphlet, 16 p. [Extracted in Hawaiian Annual for 1887, p. 66-74] 



 Thrum describes the lava subsidence at Halemaumau on March 6 and 7, 1886 [see Maby, 1886], and the condition of Halemaumau on March 24 and 25. Halemaumau lava lake and the "new lake" had been unusually full, but drained on the night of March 6, accompanied by an earthquake swarm, leaving empty pits about 570 ft deep at Halemaumau and 135 ft deep at the "new lake." [The author incorrectly considers the rockfalls to have caused the earthquakes, rather than the reverse.]



Thurber, C.H., and Li, Y., 1988, Seismotectonics of the Kaoiki fault zone, Hawaii [abs.]: Seismological Research Letters, v. 59, p. 19. 



 The 1983 Kaoiki earthquake (Ms = 6.6) was the most recent of a number of significant seismic events to occur in the area between the Hawaii volcanoes Kilauea and Mauna Loa. Local and teleseismic P-wave first motions indicate almost pure strike-slip faulting for the main shock, but the centroid moment tensor solution suggests some component of low-angle thrust faulting. Our analysis of 45 days of the aftershock sequence reveals three spatially distinct zones: 1) a 15 km long, diffuse NE-SW zone containing the main shock; 2) a 10 km long NW-SE zone, divided by a gap in seismicity, trending from the NE edge of zone 1 to Kilauea's Southwest Rift Zone; 3) a 15 km long NE-SW zone offset by 5 km to the SE of the main zone which partially overlaps the 1974 Kaoiki sequence to the NE. Our results and interpretations based on the seismicity differ somewhat from those of Endo (1985). Zones 1 and 2 are interpreted as conjugate strike-slip fault zones, with some additional low-angle faulting in zone 1. Zone 3 is dominated by low-angle faulting, representing the detachment of the seaward-moving Kaoiki block. Interestingly, the 1974 M=5.5 sequence (mostly strike-slip) connects zone 3 to zone 2, filling the latter's gap in seismicity. The 1983 Kaoiki mainshock presents an interesting example of the triggering of earthquakes on two sets of conjugate faults. We will describe some techniques that may help resolve questions of fault plane and detachment surface identification.



Thurber, C.H., Li, Y., and Johnson, C., 1989, Seismotectonics of active Hawaiian volcanoes [abs.]: Eos, Transactions, American Geophysical Union supp., v. 70, no. 43, p. 1191. [AGU fall meeting, San Francisco, CA, Dec. 4-8, 1989, Program and abstracts] 



 Although the volcanic hazards of Kilauea and Mauna Loa are well known, the potential for earthquakes along the flanks of these volcanoes is of equal or greater concern. The great Kau earthquake of 1868 and the 1975 Kalapana event (M - 7.2) may be the "characteristic" earthquakes for the flanks of Mauna Loa and Kilauea, respectively. Recent moderate events between the summits of Mauna Loa and Kilauea (10/15/83, M - 6.6) and along Kilauea's lower east rift (6/25/89, M - 6.1) are good indicators of both the continuing seismic hazard and the complicated tectonics of the volcanoes.

 The Kaoiki earthquake and its aftershocks ruptured multiple fault segments spanning roughly a 2O x 25 km epicentral area. Body-wave modeling and aftershock focal mechanisms indicate the main shock initiated as a strike-slip event which triggered the main moment release on a low-angle thrust fault. Strong evidence for a low velocity layer (LVL) at the same depth as this low-angle fault has been observed via reflected arrivals in microearthquake seismograms from a station above the aftershock zone. This LVL is almost certainly the same buried marine sediment layer thought to be the locus of the 1975 Kalapana event beneath Kilauea's south flank. Wyss has proposed that the great 1868 earthquake occurred along this layer as well. We will be carrying out a field experiment in 1990 to map the LVL beneath the Kaoiki region.

 The 1989 east rift sequence ruptured along the south flank from near the 1975 Kalapana epicenter eastward. The 1989 sequence bears some similarities to the 1975 sequence, including a concentration of activity in the 7 to 9 km depth range, and a lack of seismicity offshore. All of these events will be discussed in the context of a conceptual model for the behavior of the rift zones and flanks of Kilauea and Mauna Loa.



Thurber, C.H., 1990, Microearthquake investigation of the Kaoiki fault zone, Hawaii: Reston, VA, U.S. Geological Survey, Final Technical Report (for grant no. 14-08-0001-1G1529), 10 p. 



 Objectives: The seismically active Kaoiki fault zone lies between the Hawaiian volcanoes Mauna Loa and Kilauea, and is thought to be an expression of the horizontal compressive forces induced by the growth of the two volcanoes. A detailed investigation of the 1983 Kaoiki earthquake sequence was undertaken, and the relation of this sequence to two previous earthquake sequences (1974, 1962) was examined in order to improve our understanding of the seismotectonic setting of this active fault zone. Data analyzed included patterns of event occurrence, aftershock fault plane solutions, and the main shock mechanism from local and teleseismic data For the final stage of the project, seismograms of microearthquakes in the Kaoiki seismic zone were analyzed to seek evidence for seismic phases reflected from a hypothesized low velocity layer (LVL) at the base of the volcanic pile.



Thurston, L.A., 1921, The story of a volcano: Mid-Pacific Magazine, v. 21, Jan., pls., p. 2-16; text, p. 17-32. 



 This paper is an excellent reference on the early history of the Hawaiian Volcano Observatory and its relation to the Hawaiian Volcano Research Association. Thurston discusses the purposes and work of both organizations, gives a brief history of volcanic activity, and mentions Wood's (1914b) theory for the origin of the 1868 earthquake. He outlines a project to form a seismic network of 12-20 stations run by amateurs, with data sent to HVO in order to properly locate earthquakes, and a drilling program to locate the breadth and depth of the Kilauea magma column. [The latter is practically the only one of Jaggar's original plans not realized.] This article is directly preceded by a group of 15 excellent photographs of volcanic features at Kilauea.

 

Thurston, L.A., 1924, Bringing the Kapoho earthquake situation up to date: Honolulu Advertiser, 05/04, p. 1, 6. 



 Thurston spent a week at Kapoho, returning to Hilo on Sunday April 28. At that time there had been no earthquakes since midnight April 26. Earthquakes began again at 4 a.m. on Monday April 29, continuing at intervals of 10 or 15 minutes all day and into Monday night. There were also 4 or 5 on April 30. None were reported on May 1 or 2 up to 5 p.m.

 He describes the subsidence, in excess of 8 feet, and the cracks, up to 15 feet wide and 25-30 feet deep. The area of subsidence at the ocean is described in detail and illustrated by photographs [in the original newspaper, missing from the microfilmed copy]. He mentions previous episodes of coastal subsidence in 823, reported by Ellis and 1868, noting that the area affected by the 1924 subsidence is far smaller.

 He indicates that no person was injured and building damage was minimal. There is no excess heat arising out of any of the new cracks.



Thurston, L.A., 1924, New outbreaks at volcano may be imminent: Honolulu Advertiser, 05/09, p. 1. 



 Hilo, May 8--Roy [sic] H Finch. assistant director of the volcano observatory, says that the vibration of instruments at the volcano again indicates a surging of lava in the districts of Kau and Puna. This may portend an outbreak of lava, although the result might be deep subterranean action.

 An earthquake at 5 o'clock this morning, the center of which was estimated at 20 miles from the volcano, was felt in Hilo. Instruments continue to register a slight daily subsidence of the mountain side between Kilauea and Puna.



Thurston, L.A., 1924, Frequent avalanches enlarge volcano pit; earthquakes continue; small dust eruptions rain downpour and earth tremors comprise activity; Hilea district visited by heavy ash fall: Honolulu Advertiser, 05/22, p. 1. 



 . . . .

 One severe quake--A number of earthquakes were felt at the volcano house today [May 21], one being quite severe shortly before 4 o'clock this afternoon. Almost continuous quakes have been recorded during the past two days at Hilea, which has also been visited with a very pronounced ash fall.

 . . . .



Tilling, R.I., Holcomb, R.T., Lipman, P.W., and Lockwood, J.P., 1975, Rates of structural and landforms evolution of Hawaiian volcanoes: role of short-lived and catastrophic processes, in Reports of accomplishments of planetology programs, 1975-1976: Washington, DC, National Aeronautics and Space Administration, NASA TM X-3364, p. 157-158. 



 "The development of planetary surface features has been analyzed and interpreted largely by analogy with morphologically similar features on Earth. Most geologic features of the Earth have evolved over long time spans by gradual changes at slow rates, but some features have originated from abrupt or short-duration transformations at relatively infrequent intervals. Such contrast between essentially continuous, perhaps steady-state, processes and rapid or catastrophic changes is especially important in tracing the evolution of volcanic features, whether on the Earth or on extraterrestrial bodies.

 Historic observations (ca. 1750 A.D. to present) of Kilauea and Mauna Loa, then volcanoes, indicate that major landform and structural changes do not occur gradually, but, rather, suddenly during short-lived, sporadic bursts of eruptive activity or catastrophic, seismo-volcanic events. Mapping and other geologic evidence suggest that short-duration phenomena were also important in prehistoric (pre-1750 A.D.) times: some prominent features have formed by abrupt processes at intervals too infrequent to have been observed directly."



Tilling, R.I., Koyanagi, R.Y., Lipman, P.W., and Lockwood, J.P., 1976, Earthquake, tsunami, and volcanic eruption, island of Hawaii, November 29, 1975: a preliminary report [abs.], in Big Island Science Conference, 2nd Annual, Hilo, HI, May 1976, Proceedings: Big Island Science Conference, 2nd, Proceedings, p. 11-12. 



 At 0448, November 29, 1975, the largest earthquake in 107 years (magnitude 7.2 on the Richter Scale) struck the Island of Hawaii. The south flank of Kilauea Volcano slipped downward and seaward along pre-existing and new faults. Such ground movements resulted in localized subsidence as much as 3.5 m, leaving coconut palms standing in the sea and nearly submerging a small nearshore island at Halape. Horizontal displacements of 3 m or more were measured in many places. The earthquake and associated catastrophic ground movements also triggered a brief eruption in Kilauea's summit caldera.

 The earthquake was located approximately 5 km WSW of Kalapana (19 20.1'N, 155 01.4'W) at a depth of about 5 km. For three weeks prior to November 29, 12 felt earthquakes (magnitude 4 to 5) rocked the south flank of Kilauea; the largest of these foreshocks, magnitude 5.7, occurred 72 minutes before the main shock. Aftershock seismicity was intense for the two weeks following the 7.2-magnitude event but then began to decline. At present writing (February, 1976), about 500 aftershocks per day are still being recorded, and seismic activity is not expected to return to normal until well into the summer.

 The tsunami generated by the earthquake touched all the Hawaiian islands, and the passage of the wave was detected by tide gauges at many points on the California coast, American Samoa, Alaska, and other distant locations. However, significant tsunami damage was confined entirely to parts of the Big Island, especially at Punaluu on the Ka'u coast, Hilo harbor, and sections of the Kona coast. The maximum height of the wave above normal sea level was 14.5 m near Halape, where the wave was channeled against a low fault scarp; more commonly, tsunami heights along the Puna-Ka'u coast were 10 m or less.

 The November 29, 1975, earthquake and accompanying phenomena represent the latest in a recurring pattern of behavior for Kilauea. A similar large earthquake, tsunami, subsidence, and eruption took place in 1868, and a less powerful earthquake and related processes are believed to have occurred in 1823. Geologic evidence suggests that such events have been repeated many times in Kilauea's past and will surely continue as long as Kilauea remains highly active. The 1975 events serve as an important, though tragic, reminder of the dynamic nature of the volcano and emphasizes the need for careful consideration of land use and for an improved warning system for locally generated tsunamis to minimize damage and loss of life from similar future events.



Tilling, R.I., Koyanagi, R.Y., Lipman, P.W., Lockwood, J.P., Moore, J.P., and Swanson, D.A., 1976, Earthquake and related catastropic events, island of Hawaii, November 29, 1975: a preliminary report: U.S. Geological Survey Circular 740, 33 p. 



 Page

Abstract	1

Narrative	1

The earthquake			3

 Structural damage				3

 Earthquakes probably related to main earthquake					4

The tsunami					9

 Chronology					9

 Characteristics					14

The eruption					15

Ground movements					17

 Subsidence of the south coast					17

 Faulting in the Hilina system					19

 Postearthquake adjustments					21

 Landslides and ground cracks					21

 Deformation related to magma movement					26

Cause of earthquake and ground movements					28

Comparison with 1868 events					29

Lessons for the future					30

Acknowledgments					32

Suggested reading	33

 The largest earthquake in over a centurymagnitude 7.2 on the Richter Scalestruck Hawaii the morning of November 29 1975 at 0448. It was centered about 5 km beneath the Kalapana area on the southeastern coast of the island (lat 1920.1 N. long 15501.4 W.). The earthquake was preceded by numerous foreshocks the largest of which was a 5.7-magnitude jolt at 0336 the same morning and was accompanied or closely followed by a tsunami (seismic sea wave) massive ground movements hundreds of aftershocks and a volcanic eruption.

 The tsunami reached a height of 12.2-14.6 m above sea level on the southeastern coast about 25 km west of the earthquake center elsewhere generally 8 m or less. The south flank of Kilauea Volcano which forms the southeastern part of the island was deformed by dislocations along old and new faults along a 25-km long zone. Downward and seaward fault displacements resulted in widespread subsidence locally as much as 3.5 m leaving coconut palms standing in the sea and nearly submerging a small near-shore island. A brief small-volume volcanic eruption triggered by the earthquake and associated ground movements occurred at Kilauea s summit about three-quarters of an hour later. The earthquake together with the tsunami it generated locally caused severe property damage in the southeastern part of the island; the tsunami also caused two deaths. Damage from the earthquake and related catastrophic events is estimated by the Hawaii Civil Defense Agency at about $4.1 million.

 The 1975 Kalapana earthquake and accompanying events represent the latest events in a recurring pattern of behavior for Kilauea. A large earthquake of about the same magnitude tsunami subsidence and eruption occurred at Kilauea in 1868 and a less powerful earthquake and similar related processes are believed to have occurred in 1823. Indeed the geologic evidence suggests that such events have been repeated many times in Kilauea s past and will continue. The 1975 events serve as a critical though tragic reminder of the dynamic nature of the volcano and point up the need for careful land-use planning and adequate building codes to minimize damage and loss of life from similar events in the future.

 Detailed scientific study of the cause and effects of the November 29 1975 event will take many months. This report summarizes information available in February 1976.



Tilling, R.I., 1976, The 7.2 magnitude earthquake, November 1975, island of Hawaii: Earthquake Information Bulletin, v. 8, no. 6, p. 5-13. 



 The largest earthquake in over a century struck Hawaii the morning of November 29, 1975, at 4:48 AM HST. The earthquake was of magnitude 7.2 on the Richter scale.

It was centered about 5 km beneath the Kalapana area on the southeastern coast of Hawaii, the largest island of the Hawaiian chain (fig. 1) and was preceded by numerous foreshocks. The event was accompanied, or followed shortly, by a tsunami, large-scale ground movements, hundreds of aftershocks, and an eruption in the summit caldera of Kilauea Volcano. The earthquake and the tsunami it generated produced about 4.1 million dollars in property damage, and the tsunami caused two deaths. Although we have some preliminary findings about the cause and effects of the earthquake, detailed scientific investigations will take many more months to complete.

 This article is condensed from a recent preliminary report (Tilling and others, 1976).



Tilling, R.I., 1985, Possible disruption of the magma reservoir of Mauna Loa Volcano, Hawaii, by the great 1868 earthquake: evidence from lava composition [abs.]: Eos, Transactions, American Geophysical Union, v. 66, no. 46, p. 851. [AGU Fall Meeting, San Francisco, CA, Dec. 8-13, 1985, Program and abstracts] 



 Reevaluation of available data disfavors the long-standing notion that composition of Mauna Loa lavas does not vary systematically with time. Instead, abundant recent chemical data, MgO-adjusted to eliminate olivine-control variation, define a long-term trend characterized by decreasing abundances of olivine-incompatible constituents. This progressive temporal variation is perturbed by a distinct compositional step--expressed by significantly lower MgO-adjusted mean abundances of Ti, K, Sr, Zr, and Nb--between the 1868, and older, lavas and the 1877, and younger, lavas. The step change is interpreted as an effect of the Great Earthquake of April 2, 1868 (M-7.5), the largest to strike the Island of Hawaii in historic time, which occurred during an ongoing Mauna Loa eruption and also triggered two separate eruptions at Kilauea that same day. The shift in lava chemistry also coincides with a greatly reduced average lava-production rate for Mauna Loa after 1877. Variation in lava composition since 1877 appears to demonstrate a decades-long gradual recovery process and return to the long-term compositional trend. The apparent coincidence between the sudden compositional shift, the reduction in lava-production rate, and the 1868 earthquake may be purely fortuitous. But if it is not, the 1868 earthquake may represent the first known documentable case of a catastrophic tectonic event that, in addition to wreaking tremendous surface destruction, also may have caused major disruption of a subsurface magma reservoir, as reflected in the output and composition of its erupted lavas for decades afterwards.



Tilling, R.I., 1987, Disruption of the Mauna Loa magma system by the 1868 Hawaiian earthquake: geochemical evidence: Science, v. 235, p. 196-199. 



 To test whether a catastrophic earthquake could affect an active magma system, mean abundances (adjusted for "olivine control") of titanium, potassium, phosphorus, strontium, zirconium, and niobium of historic lavas erupted from Mauna Loa Volcano, Hawaii, after 1868 were analyzed and were found to decrease sharply relative to lavas erupted before 1868. This abrupt change in lava chemistry, accompanied by a halved lava-production rate for Mauna Loa after 1877, is interpreted to reflect the disruptive effects of a magnitude 7.5 earthquake in 1868. This interpretation represents a documentable case of changes in magmatic chemical variations initiated or accelerated by a major tectonic event.



Tokuuke, J., Okubo, P., and Okamura, A., 1991, Seismicity in the eastern Kaoiki region, Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 72, no. 44, p. 335. [AGU fall meeting, San Francisco, CA, Dec. 9-13, 1991, Program and abstracts] 



 The Kaoiki region of the island of Hawaii lies between the summits of the two active, subareal volcanoes, Kilauea and Mauna Loa. Significant earthquakes have occurred in this region, the most recent being a M6.6 event in November 1983. In November 1990 an intense earthquake swarm occurred within the eastern Kaoiki region approximately 4 km west of Kilauea summit. This swarm has been followed by similar but smaller swarms in March and July of 1991.

 Prior to the 1983 earthquake, low levels of seismicity were recorded in the eastern Kaoiki, but aftershocks from the M6.6 1983 event extended through this region. In a 50 sq. km area, 5 km west of the Kilauea summit. two groups of aftershocks were located with their centers separated by about 3 km. The eastern cluster of hypocenters deepens from 0 to 5 km toward the southeast. At that point, the events begin to deepen from 5 to 8 km toward the west. Except for isolated deeper activity, the 1990 swarm was concentrated in the same region as the eastern cluster of 1983 aftershocks. Depths of the western group of aftershocks ranged between 8 and 12 km, deepening to the west. Activity of this cluster has steadily diminished since 1983.

 Focal mechanisms of 1989-1991 earthquakes at O to 4 km depth in the eastern cluster generally have steeply-dipping planes with northeastward and northwestward strikes. The northeast-striking planes possess a significant component of right-lateral slip. Others have argued the importance of right-lateral strike-slip tectonics in the Kaoiki through the study of focal mechanisms and geologic mapping. From a regional perspective, then, it would be reasonable to interpret the northeast-striking planes as the fault planes for these shallower earthquakes.

 The primary orientation of pressure and tension axes from 1989-1991 events at various depths suggest a regional south-southeast tensional stress for the eastern Kaoiki area. This stress may be related to the deflation of Kilauea's southwest rift zone suggested by tilt, leveling and EDM measurements. Mauna Loa's gradual reinflation since its last eruption in 1984 may also be producing compressional forces that complement the tensile forces.



Tokuuke, J.P., and Okubo, P., 1992, Estimating the stress tensor orientations based on fault plane solutions for the eastern Kaoiki region, Hawaii [abs.]: Eos, Transactions, American Geophysical Union supp., v. 73, no. 43, p. 342. [AGU fall meeting, San Francisco, CA, Dec. 7-11, 1992, Program and abstracts] 



 The Eastern Kaoiki Region. a 50 km2 area, is 5 km west of Kilauea Caldera on the island of Hawaii and appears to be the most seismically active section of the Kaoiki Region. In November 199O, a seismic swarm, unusual for this area, prompted a closer look at the regional seismicity. It revealed that only 4 ML  2.0 events occurred per year until aftershocks from the 1983 Kaoiki ML = 6.6 event formed two distinct clusters of events. By the beginning of 1985, the western cluster's seismicity decreased logarithmically to background levels, however, the eastern cluster's seismicity rate remained higher than normal and dramatically increased in November 1990. Consequently. a reason for the seismicity was searched for.

 Earlier studies of the Eastern Kaoiki Region suggested that Kilauea's deflation due to its continuing eruption. may have created a tensional stress in the area. Deformation data suggest that the center of deflation is just south of Kilauea Caldera which is southeast of the Eastern Kaoiki Region. Consequently. stress inversions based on the region's focal mechanisms were conducted to determine if the stress tensor orientations support this claim.

 Focal mechanisms were calculated for the ML  2.5 events that occurred after the 1983 Kaoiki event up to the end of June 1992. The first motions and arrival times were reread for the events occurring after 1985. Of the original 96, 73 focal mechanisms were of sufficient quality and used for the stress inversion. Stress inversions for each cluster suggest that an inhomogeneity exists in the region The stress tensors for the eastern cluster has a steeply plunging s1 axis oriented in an east-southeast direction and a shallow plunging s3 axis with a southeast orientation This result conforms to the hypothesis. However. the stress tensors for the western cluster are significantly different with s1 plunging steeply towards the south-southwest and s3 plunging approximately 30 to the north-northeast. At this time. it is difficult to find an explanation for this result. We are in the process of evaluating the S-wave polarization at the nearby station MLO as independent evidence for the directions of the least and greatest principal stresses.



Treadway, 1871, Earthquake: Hawaii State Archives [entry under: Malo Prison], 02/22, p. ? 



 /for effect on court house & prison see those entries/

 We had a bad scare I can assure you. An old woman who is living in the David Malo house hearing the plaster falling rushed out and roared Haul in at the top of her voice and insisted that drunken men were demolishing the old house - and it was some time before the Turnkey at the prison could make her aware of the fact of an earthquake.

 Mrs. Morse was in the old house opposite /sic/ mine She rushed out of the bed room with a child in each arm, but a lump of adobe took her on the head when she took to the bed room and went under the bed-little Jim Morse crawled under a wheelbarrow after he got out-of doors. I find that the southern end of Stone buildings have suffered much more than the north, and the east and west sides in many buildings have not been hurt. very old walls have fallen on the East and west sides. Shelves setting East and west were emptied while those North & South were hurt very little very little knocked off. the ground opened in Several places, no one knows how much, as it was dark, but the cracks remain still to be seen. I felt very weak in the knees for several hours, and a very curious sensation at the stomach ... I call the time of the shock lasting a full minute.



Udias, A., and Buforn, E., 1985, Focal mechanism and locations of earthquakes in the vicinity of the 1975 Kalapana earthquake aftershock zone 1970-1979; implications for tectonics of the south flank of Kilauea Volcano, Island of Hawaii [Crosson and Endo, 1982]; comment: Tectonics, v. 4, no. 2, p. 247-250. 



 In the discussion of the fault plane solutions presented by Crosson and Endo (1982), the use of graphically determined solutions is justified because "the available programs do poorly on data which have many inconsistencies or on data which provides little constraint" this statement is not proved. Furthermore, it is stated that "we know of no programs which provide widely accepted measures of variations, indeed the problem of adequately measuring error of solutions is not solved". Regarding both problems, we would like to point out to the algorithm and computer program developed by Brillinger et al. (1980) and further modified by Udias and Buforn (1980) and Udias et al. (1982): This program allows, not only individual fault plane solutions, but also joint solutions in which case they are statistically separated into groups of equal mechanism. This type of treatment fits very well to the problem presented in the commented article. The method consists in an iterative process of maximization of a likelihood functions, does not depend on the initial values and rapidly converges to a solution even for scarce and inconsistent data. The program gives maximum likelihood estimates of the standard deviations of the parameters that define the solutions, i.e., nodal planes or principal axes of stress. These estimates are considered a realistic measure of the error in the parameters involved in the solutions.

 The algorithm has been accepted by the subcommission on earthquake algorithms of the Commission on Practice of the IASPEI, and the computer program (FORTRAN IV) may be obtained from the authors on request. A further development of this program also exists in which the polarities of first motions of P, SV and SH waves are used (Buforn and Udias, 1984).



Unger, J.D., Koyanagi, R.Y., and Ward, P.L., 1973, An important Hawaiian earthquake [abs.]: Eos, Transactions, American Geophysical Union, v. 54, no. 11, p. 1136. [AGU fall meeting, San Francisco, CA, Dec. 10-13, 1973, Program and abstracts] 



 On April 26, 1973, a magnitude 6.2 earthquake occurred at a depth of about 45 km beneath the northeast coast of the island of Hawaii some 25 km northeast of Hilo. This event caused about $5.6 million damage on the island and is the first earthquake larger than magnitude 6 since 1962. First motions from the main shock and larger aftershocks show two well-defined nodal planes: one striking NNE and dipping steeply NW, and the other striking WNW and dipping steeply south. The admissible fault motions are right-lateral strike slip on the NNE plane and left-lateral strike slip on the WNW plane. The main shock apparently triggered seismic activity at two other regions on the island, as well as a minor eruption on Kilauea 9 days later. We located about 250 aftershocks ranging in magnitude from 2.0 to 4.8. They crudely outline a broad zone about 25 by 10 km extending northeastward perpendicular to the coast. Aftershock hypocenters determined using only P-wave arrivals are as much as 20 km deeper than hypocenters computed with both P and S-wave data. This discrepancy is probably due to the fact that the earthquakes occurred on the edge of the U.S.G.S. network, but it also may be due to lateral variations in seismic velocity structure under Hawaii. An examination of local long- and short-period seismograms failed to yield evidence of any obvious core reflection phases.



Unger, J.D., and Ward, P.L., 1974, Travel time delays and tectonic stress from a subcrustal Hawaiian earthquake [abs.]: Eos, Transactions, American Geophysical Union, v. 55, no. 12, p. 1150. [AGU fall meeting, San Francisco, CA, Dec. 12-17, 1974, Program and abstracts] 



 On 26 April 1973, a magnitude 6.2 subcrustal earthquake occurred beneath the northeast coast of the island of Hawaii. Because of the size of this event, sharp P-wave arrivals were observed at seismographs around the world. Careful analysis of the P-wave arrivals at the 30 stations on the island of Hawaii show that the earthquake occurred at 19.90N 155.13W and 46 km in depth; the origin time was 20:26"30.8 GMT. Analysis of the absolute travel times using the Herrin earth model gives uniformly slow residuals that average about 3.0 seconds; however, the Jeffreys-Bullen earth model, with average residuals of about 0.5 seconds, appears to be a better fit for this mid-ocean earthquake. Detailed comparison of the J-B residuals to the northeast of Hawaii with those to the southwest reveals evidence for a region of abnormally low P-wave velocity in the upper mantle beneath the island of Hawaii or to the southwest. Analysis of the local and teleseismic first motions from this earthquake show a maximum compression axis oriented almost horizontally at N70E and a horizontal least compression axis also about horizontal at N22W.



Unger, J.D., and Ward, P.L., 1979, A large, deep Hawaiian earthquake--the Honomu, Hawaii, event of April 26, 1973: Bulletin of the Seismological Society of America, v. 69, no. 6, p. 1771-1781. 



 The largest subcrustal earthquake ever recorded from the Hawaiian Island chain (magnitude 6.2) occurred at a depth of 48 km on April 26, 1973. The proximity of the Hawaiian Volcano Observatory's extensive seismograph network and our knowledge of the crustal and upper mantle structure beneath the island made it possible to calculate accurate hypocenters for both the main shock and 57 aftershocks. The earthquake may have triggered swarms of small, shallow earthquakes at two different locations on the island: one 25 km and the other 50 km from the epicenter of the earthquake. The polarity of the P-wave arrivals for the main shock and most of the aftershocks, as recorded by the local network and worldwide stations, define nodal planes oriented N26E dipping 77W and N70W dipping 61S. Comparison of the inferred directions of the greatest and least principal stresses derived from these data with the stress direction within the Pacific plate assumed for various hypotheses of the formation of the Hawaiian island chain show closest agreement with the concept that the orientation of the archipelago is aligned parallel to the direction of the maximum shear stress and is not perpendicular to the orientation of the least principal stress.



Unger, J.D., and Koyanagi, R.Y., 1979, Evidence of the effects of shallow magma intrusion on Kilauea Volcano [abs.], in Decker, R.W., Drake, C., Eaton, G., and Helsley, C., ed(s)., Hawaii Symposium on Intraplate Volcanism and Submarine Volcanism, Hilo, HI, July 16-22, 1979, Abstract volume: Hawaii National Park, HI, U.S. Geological Survey, Hawaiian Volcano Observatory, p. 176. 



 On May 5, 1973, an intense swarm of shallow earthquakes occurred on the upper east rift zone of Kilauea volcano. During the period of highest seismic activity, which lasted about 20 hours, nearby seismographs recorded approximately 2000 earthquakes. Low volume fissure eruptions from 4 separate vents located in the epicentral area accompanied the earthquake swarm; this eruptive activity lasted a total of about 7 hours. As the episode of earthquake and volcanic activity continued, the locations of the eruptive fissures moved progressively westwards following a similar migration of the locations of the earthquakes in the swarm. The final earthquake activity was located about 4 km beyond the westernmost eruptive fissure. Extensive monitoring of horizontal and vertical ground surface changes and ground tilt before, during, and after this episode combined with the seismic data appear to show clear evidence for shallow magma intrusion from the east rift zone into the upper section of the Koae fault zone and the propagation of the effects of this intrusion further into the Koae fault zone.



von Hake, C.A., and Cloud, W.K., 1965, Hawaiian Islands, in United States earthquakes, 1963: Washington, DC, U.S. Government Printing Office, United States Coast and Geodetic Survey report, p. 41-44. 



 [This report covers the location, time, and damage for earthquakes felt in the Hawaiian Islands during the year.]



Waesche, H.H., 1938, The Maui earthquake of January 22, 1938: The Volcano Letter, no. 457, Mar., p. 1-5, 7 (map). [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 A description of an earthquake whose hypocenter was located beneath the ocean floor northeast of the island of Maui. The earthquake caused extensive damage on Maui and was felt on all the other islands. [See also Wyss and Koyanagi, 1992.]



Walker, D.A., 1994, Tsunami facts: Honolulu, University of Hawaii School of Ocean and Earth Science and Technology, SOEST Technical Report 94-03, 93 p. 



 INTRODUCTION

From 1900 through 1965, a total of 13 significant tsunamis (i.e., those with wave heights 1 meter) produced by distant earthquakes were reported for the Hawaiian Islands (Table 1 and Figure 1). For some of these, amplitudes in excess of 10 m (or 32.8 ft) have been reported with substantial losses of life and property damage. However, from 1965 through 1993, no Pacific-wide tsunamis have struck the Hawaiian Islands. This has led to a false sense of complacency and lack of awareness that may add to the dangers associated with tsunamis, especially for the youth of Hawaii. Since 1965 the population has experienced substantial growth with much of the development in potential tsunami inundation areas. There are now more shoreline recreational areas with more people at risk in these coastal inundation zones. A majority of the people in these areas are the youth of Hawaii. With both parents working, or with single-parent families, many of these children may have no adult supervision. In the event of a destructive tsunami, lack of knowledge an unnecessary repetition of past tragedies.

 Although most of the destruction and loss of life due to tsunamis in Hawaii has been produced by distant earthquakes, 5 locally generated tsunamis with runups 1 meter have been reported from 1900 through 1993 (see Appendix I). Three were the result of earthquakes near the southeastern coast of the Island of Hawaii. One was produced by an earthquake near Hookena along the Kona Coast and another was the result of the slumping of volcanic material which had flowed into the ocean several days earlier near Milolii. Only one locally generated tsunami is reported prior to 1900. This tsunami was also produced by an earthquake near the southeastern coast. Years of occurrence and maximum reported runups in meters are: 1868, 13.7; 1908, 1.2; 1919, 4.3; 1951, 1.2; 1952, 3.0; and 1975, 14.3. The large tsunamis of 1868 and 1975 had significant runups all along the southeastern coast (in excess of 6 meters at several locations). The 1868 tsunami also had reported runups of 3.4 m for Kailua, Kona and 2.7 m for Hilo. The 1975 tsunami had values of 3.3 m for Napoopoo, 2.9 m for Keauhou Bay, 1.8 m for Kailua, Kona, and 2.6 m for Hilo. The data which follows are for the more frequent and devastating tsunamis generated by distant earthquakes.

 This report is intended as a source book for increasing awareness and knowledge of tsunamis. It is hoped that "Tsunami Facts", "What You Should Do", and the "Self-Quiz" contained in this report would be copied and distributed by educators to students in public and private schools throughout the State. We would also hope that these materials would be discussed in the classroom and possibly even be used as a learning tool. The topic of tsunamis can be incorporated into discussions of earthquakes and volcanoes, plate tectonics, sea-floor spreading, ocean waves, earth science, natural hazards (e.g., tsunamis, hurricanes, storms, or flash floods), or the Civil Defense Warning System. Island by island summaries and comparisons are presented to assist educators in personalizing the information for their school and students. This booklet is intended primarily for students at the intermediate or high school level. It may, however, be a useful source of information for teachers of other students, or for the general public. All of the tables and figures may be freely copied for classroom use or for other educational purposes.

 For interesting discussions and first person testimonies on the devastating and tragic effects of past tsunamis in Hawaii, we recommend Tsunami by Walter Dudley and Min Lee (University of Hawaii Press, 1988). This book is available at most bookstores and local libraries. Other publications which we recommend for increasing tsunami awareness are Tsunami Warning and Tsunamis in Hawaii. Tsunami Warning may be especially appealing to elementary and intermediate school children because of its "comic book" format. It is published by the International Tsunami Information Center in Honolulu. Tsunamis in Hawaii is a poster-sized, color map which shows the source locations, years of origin, maximum runups in the Hawaiian Islands, and tsunami travel times to Honolulu Harbor for many tsunamis from 1819 through 1993. Also shown are runup values throughout the Hawaiian Islands for the 1 April 1946 tsunami, and listings of "Tsunami Facts" and "What You Should Do." This map is published by the School of Ocean and Earth Science and Technology of the University of Hawaii. Tsunami Warning and Tsunamis in Hawaii may be available in most school libraries throughout the State.



Wentworth, C.K., 1951, Destruction of water tanks during the Kona earthquake of August 21, 1951: The Volcano Letter, no. 514, p. 1-3. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 About 200 water tanks were severely damaged by the earthquake. Wentworth describes the types of damage and lists ways in which damage could be prevented during future events.



Wheat, D.G., Jannasch, H.W., Sansone, F.J., and Plant, J., 1998, Changes in the chemical composition of hydrothermal effluent from Loihi Seamount resulting from the 1996 event [abs.]: Eos, Transactions, American Geophysical Union supp., v. 79, no. 17, p. S338. [AGU, MSA, GS, AAS/SPD spring meeting, Boston, MA, May 26-29, 1998, Program and abstracts] 



 In July-August 1996 a tectonic-volcanic event occurred on Loihi Seamount, a hydrothermally active, mid-plate, hot-spot volcano located about 35 km SE of the island of Hawaii. Before the event hydrothermal venting was focused at Pele's Vents. Venting at three other sites was sporadic and all of these vent sites were shallower that 1234 m. The composition of the 30C fluids from Pele's Vents was uniform for at least 9 years prior to the event. These fluids have a chlorinity of bottom seawater, an Fe/Mn of 20, and an alkalinity that is 2.5 times that of seawater. The 1996 Event altered the pattern of fluid circulation through the seamount. Two submersible operations were conducted in Oct. 1996 and Sept. 1997 to investigate the processes that define the recovery and evolution of a hydrothermal system after an event and the spatial and temporal scales over which these processes are observed. Nine vent fields have been located at depths from 1714 to 1099 m with most of the heat flux emanating from the newly formed pit at a depth of 1290 m. The composition of these hydrothermal fluids is distinct from fluids collected prior to the event. In 1996, 17 to 23C fluids from two vent sites on the South Rift had chlorinities that were less than that of seawater, implying that phase separation occurred. In addition these fluids have 4 times the alkalinity of seawater and an Fe/Mn of 60. In contrast, 200C fluids were sampled in the newly formed pit. These fluids have higher chlorinities (1.06 x) and alkalinities (2x) than seawater and an Fe/Mn of 1. Continuous water samplers, OsmoSamplers, and temperature recorders were deployed at two vent sites to record the temporal scale of chemical and thermal changes. Yearlong continuous records of temperature from these recorders show a gradual decrease throughout the year. Changes in the chemical composition also were documented; one of the samplers captured the gradual transformation from a fluid with a vapor component to one without, while the other sampler collected fluids with a cyclic chemical change that had a period of about 30 days. These temporal and spatial changes provide insights for understanding fundamental properties of the structure and fluid circulation within this hot-spot volcano.



Whitney, H.M., 1868, The eruption of 1868!; full details of the earthquakes, mud-flow, shower of ashes and lava stream, as seen by eye-witnesses: Pacific Commercial Advertiser, 05/09, p. 1, 4. 



 Whitney gives a brief chronology of Hawaiian volcanic activity preceding the 1868 earthquake swarm and eruptions. He notes that the earthquake of April 2 was felt as far away as Kauai and describes the character of the earthquake motion at different places on Hawaii and Oahu. He gives a detailed description of the mudflow in Wood Valley, noting that a stream of water was newly flowing from the scarp left by the landslide and ascribes the mudflow to subterranean interaction of lava with groundwater. He describes the tsunami and the destruction of coastal villages and gives a detailed description of the eruption on Mauna Loa's southwest rift zone. He describes ash and pumice falling on April 6, before fountaining began on the seventh. [This is a very definite statement with no obvious explanation.] The eruption began on April 7 and died quickly. On the same day, eruption broke out a farther downrift, beginning continuous flow that went to the ocean at speeds estimated at 10-25 mi/hr. The fissure was traced after the eruption was over. It was 10-20 ft wide, 3 mi long, with fume being visible for another 10 mi. He describes the fountains as emerging with a rotary motion, always toward the south [counterclockwise, as viewed from the shore]. The eruption lasted 5 days, ending on April 12. He describes a littoral cone as forming initially as an island, later being connected to the land. He notes that the amount of lava erupted at Mauna Loa rises inversely with amount of gas released, comparing 1859 (high volume, little gas) with 1868. He briefly describes the activity at Kilauea summit. Prior to April 4, there was intense activity. On the fourth, at 1:00 p.m., following a sharp earthquake, lava began to subside. A large chasm opened up on the north side of the main lake, extending past and cutting the Kau road. Between 5:00 and 6:00 p.m., lava broke out in the "old crater," and the lava level in Halemaumau had dropped 100 ft. [The "old crater" was Kilauea Iki. The name Kilauea Iki was at that time used for what we now call Keanakakoi.]



Whitney, H.M., 1868, [On the 1868 eruption of Mauna Loa]: Pacific Commercial Advertiser Extra, 04/15, p. 3. [Also published in Apr. 18 issue, p. 3. Excerpted in American Journal of Science, 2nd ser., v. 46, p. 112-115] 



 An account of the lava flow in the Kahuku area, in April 1868, reprinted from the Pacific Commercial Advertiser as part of a series of reports that includes Coan (1868a), F.S. Lyman (1868a), and Hillebrand (1868). On Tuesday, April 7, lava broke out from a crater 10 mi up the mountain and quickly died. On the same afternoon, a lower crater began erupting; the area around the vent collapsed, five acres in all being consumed. A flow from the lower vent was moving 10-25 mi/hr. Whitney vividly describes the narrow escape of residents who were nearly trapped by the flow. The eruption lasted 5 days, ending on the evening of April 11-12. He describes the effects of the April 2 earthquake on residents, cracks opening, and some closing again at a later time. He estimates the tsunami generated by the earthquake as 60 ft high, going over coconut trees and traveling 1/4 mi inland. He describes an island rising out of the sea and being connected to land by eruption going into the ocean. [This was not confirmed. See annotation to Coan, 1880.] He notes that a shower of ashes fell on Kau on the evening before the eruption began. [This is unexplained. It is possible that ash fell from the summit activity prior to rift eruption.]



Whitney, H.M., 1868, Latest from the volcano! Greatest eruption on record! One hundred lives lost! Whole villages destroyed! Several lava streams flowing: Pacific Commercial Advertiser, 04/11, p. 3. 



 Communications describing the earthquake swarm and damage done by the April 2 earthquake, landslide, and tsunami. Fatalities are estimated. Whitney describes ground cracking associated with the earthquake: "At Waiohinu . . . a crack has opened from one to seven feet, extending to the beach and mauka as far as one can see. . . . the end[s] of the road, at the chasm, are not opposite each other, one side having moved the width of the road mauka or makai." He mentions lava from Mauna Loa entering the sea near South Point.



Whitney, H.M., 1899, Lava flows stop: Pacific Commercial Advertiser, 07/29, p. 3; 08/01, p. 3. [Also published in Hawaiian Gazette, Aug. 1, p. 2] 



 Eruption ended on July 23, 1899, followed by an earthquake swarm. A nearby shock was felt in Hilo around noon on July 24.



Wieczorek, G.F., Wilson, R.C., Jibson, R.W., and Buchanan-Banks, J.M., 1981, Seismic slope instability--a consequence of sensitive volcanic ash? [abs.]: Earthquake Notes, v. 52, no. 1, p. 77. [Seismological Society of America, Eastern Section, 76th annual meeting] 



 According to eyewitness accounts, the April 2, 1868, Hawaii earthquake triggered a landslide at Wood Valley that broke loose from "the side of pali (ridge), burying in a minute thirty-one human beings, many hundred head of cattle, and entire flocks of goats, and ending four miles from its beginning in a mighty river of mud". According to descriptions, the shaking intensities of this 1868 earthquake were much higher than those of the 1975 Ms=7.1 event in the same area. Extensive landslides also occurred in other valleys during the 1868 earthquake: during the 1929 earthquake (M=6.5), large landslides occurred in Honokane Nui Valley, Hawaii; and the 1973 Honomu, Hawaii, earthquake (Ms=6.1), soil falls, soil slumps, and rock falls were common along roads north of Hilo. Thus, slope instability during earthquakes is a major hazard on the island of Hawaii.

 In most of these localities, the landslides occurred in weathered Quaternary volcanic-ash deposits. Ash deposits near Hilo were hand augered and sampled to a depth of 4.7 m. The ash has very high natural water contents, as much as 392%. A downhole vane shear device measured sensitivities (ratio of peak to remolded strength) of more than 6.9. The ash in an exposure of the Wood Valley mudflow resembles ash examined in the Hilo area.

 Because of their high sensitivity, the ash deposits in Hawaii are susceptible to seismically induced landsliding. Ash deposits with high natural water contents and high sensitivity have also been associated with flow-type landslides in the 1978 Izu-Ohshima-Kinkai earthquake (M=7.0). Studies of Hawaiian ash are being used to evaluate seismic slope stability hazard near Hilo, Hawaii.



Wilkes, C., 1845, Narrative of the U.S. Exploring Expedition during the years 1838-1842: Philadelphia, Lee and Blanchard, v. 4, 539 p. [Pages 87-231 cover the material abstracted] 



 This is the principal account of the famous U.S. Exploring Expedition's visit to the Hawaiian Islands in 1840. [Other accounts by persons accompanying Wilkes are by Brackenridge {1841}, Dana {1849b}, Eld {1841}, and Pickering {1841}. Additional information is given by Tyler {1968} and Appleman {1987}.]

Wilkes describes Kilauea caldera during December 1840 and January 1841, and the 1840 lava flow from Kilauea. He also describes Pickering's descent into Kilauea 10 days later. He describes Mokuaweoweo and South Pit [which he calls Pohakuohanalei], and an ascent of Mauna Kea by himself (chapter 6) and by Messrs. Pickering and Brackenridge. The depth of Mokuaweoweo was 784 ft on its west side and 470 ft on its east side, with no black ledge as at Kilauea. He found Mauna Kea to be 193 ft higher than Mauna Loa. He states that activity was reported in Mokuaweoweo not long after Cook's visit (1778), and 5 yrs before Wilkes' visit. [The latter reference is ambiguous as to whether 5 yrs refers to Cook's or Wilkes' visit, i.e., 1784 or 1836.] Wilkes is the first person to use the term "pit crater"; he defines it as "that description of crater of which there is no appearance whatever until one is close upon it, and which never throws out lava." He believed that pit craters were formed by collapse of lava tubes, but is unclear as to the circular symmetry of collapse. He describes Pele's hair and correctly interprets the origin of lava tubes. He states that the conduits of Kilauea and Mauna Loa are not connected and that the lava lakes within Kilauea caldera also rise and fall independently of each other.

 Wilkes describes the trip to the Kilauea caldera from Hilo. Past Olaa, they traveled on fresh lava with small scrub trees. [See the annotation to Anonymous, 1847a, for a different interpretation of the trail to Kilauea.] At Kilauea, he estimates that the black ledge was 660 ft down from the caldera rim and that the bottom of the inner crater was 384 farther down. Later in the report, he says that the total depth of the crater was 992 ft, 342 ft up to the black ledge. The black ledge was uneven, with much evidence of overflow, although there was no evidence of overflow of the caldera itself. On the caldera floor, he describes a small lake 200 ft across and 38 ft deep before overflow and a large lake 1,500x1,000 ft. He gives an account of Dr. Judd's narrow escape from the lava [cf. G.P. Judd, 1911], describes the flow into Alae Crater during the 1840 eruption, and the 1840 aa flow to the sea, using, as did others, the analogy with ice breakup in a river at the time of spring thaw. He cites native accounts regarding eight lava breakouts and 3 days of earthquakes before the eruption in Puna and the absence of earthquakes felt in Hilo. He briefly mentions Pickering's visit to the 1840 lava, remarking that earthquakes were frequent and violent at Kealakekua Bay but were not felt in Hilo. [This seems unlikely.] He describes the sand hills at Nanawale (littoral cones) but does not understand their origin. He notes Brackenridge and Drayton's further exploration of the 1840 lava pads and quotes their description of a lava pad about 2 mi down from Alae on the side of Kane Nui o Hamo. [This is a confusing description, with crater names incorrect.]

[This is a difficult report to follow. Wilkes first-hand observations seem to be accurate, in contrast to his citation of the observations of other members of the expedition, which seem confused and contradictory.]



Williamson, C.G., 1868, Earthquakes: Hawaiian Gazette, v. 4, no. 38, 10/07, p. 3. 



 Rev. C.G. Williamson, of Christ Church, South Kona, has favored us with his observations of the earthquakes that have, for the last three months, been felt on Hawaii. The shocks have been frequent, though slight, and fears of another eruption are gradually subsiding. Mr. Williamson's record of the earthquake period of last April, published in the Gazette, was a most valuable contribution to science, as we believe the following will be also:



Williamson, C.G., 1868, Earthquakes at Kona: Hawaiian Gazette, 04/15, p. 3. 



 Williamson lists foreshocks and aftershocks of the great April 2, 1868, earthquake, as felt in Kona from Wednesday, April 1, to Wednesday, April 8.



Williamson, C.G., 1868, [On the earthquake swarm and eruption of 1868]: Hawaiian Gazette, 04/29, p. 3. 



 Williamson lists the earthquakes felt in south Kona from April 1 to April 21, 1868 (republished in Brigham, 1869), and states that the Mauna Loa eruption had ended by the 17th. He describes two lava streams, pahoehoe side-by-side with aa. The flow ran into the sea and formed a small hill away from the land. [This could have been a littoral cone seen from a distance.]



Williamson, C.G., 1869, On the volcanic phenomena of Hawaii: Quarterly Journal of the Geological Society of London, v. 25, p. 432-434. 



 Williamson briefly summarizes the history of Mauna Loa and Kilauea. Volcanism on the island of Hawaii appears to have shifted gradually southward, Kohala being the oldest of the major volcanoes. He presents a table of earthquakes during 1868 and briefly describes the Wood Valley mudflow and the eruptions of 1868. The author attributes the landslide to explosion caused by contact of water with hot lava underground. He also supposes that the collapse at Kilauea summit indicated a magmatic connection with the eruption at Mauna Loa.



Wilson, M.E., and Wyss, M., 1981, Stress drops and amplitude ratios of small earthquakes preceding the 1975 Hawaii M=7.2 mainshock [abs.]: Eos, Transactions, American Geophysical Union supp., v. 62, no. 45, p. 963. [AGU fall meeting, San Francisco, CA, Dec. 7-11, 1981, Program and abstracts] 



 S wave spectra and SV to P amplitude ratios of 50 small earthquakes (3<ML<4) which occurred in Southern Hawaii between 1969 and 1977 were obtained from Wood-Anderson seismograms at Hilo, Hawaii. Epicenters of the earthquakes were located within the aftershock zone of the 1975 Hawaii earthquake (M=7.2), at distances of 40-50 km from station Hilo. Fault plane orientations were calculated from first motion data recorded by the Hawaiian Volcano Observatory seismic array. Seismic moment, corner frequency and stress drop were analyzed as a function of space and time in order to detect precursory changes related to the 1975 mainshock.

 Seismic moments ranged from 1021 to 1023 dyne-cm and did not vary significantly over space and time. Relatively low stress drops of 5-20 bars were observed for earthquakes located within a seismically quiescent region in the central part of the aftershock zone. In contrast, earthquakes in the two regions flanking the center of the aftershock zone where no quiescence was observed, had stress drops averaging 30-40 bars. Stress drops of all earthquakes appeared to decrease by an average of 20 bars sometime in late 1971 and partially returned to normal (pre-1972) values in early 1974. A modified form of a strain softening model for the preparatory process of the 1975 Hawaii earthquake proposed by Wyss et. al. (1981) is consistent with the stress drop observations of this study.



Wingate, E.G., 1931, Puna shoreline subsidence: The Volcano Letter, no. 361, p. 1-2. [In The Volcano Letter, compiled and reprinted in 1987 by Fiske, R.S., Simkin, T., and Nielsen, E.A., eds., Smithsonian Institution Press, 539 p.] 



 Wingate reviews the subsidence at Kapoho that occurred during the 1924 earthquake swarm. He conducts a house-to-house survey of local residents to confirm or deny reports of continued subsidence since 1924. He concludes that subsidence all took place in 1924 and is not continuing. [Over longer periods of time, there is confirmed coastal subsidence associated with (1) the volcanic load on the island, and (2) ongoing deformation along the axis of the east rift zone.]



Wingate, E.G., and Finch, R.H., 1942, Detailed report made on Mauna Loa eruption: Honolulu Daily Advertiser, 06/01, p. 5. 



 Wingate summarizes the 1942 eruption of Mauna Loa. The eruption was preceded by one deep earthquake followed by a shallow earthquake swarm beginning near the eruption site on the northeast rift and extending across Mokuaweoweo. The summit eruption began March 26 and was over by March 27. Earthquakes resumed on the northeast rift March 27, and the eruption broke out on March 28. Sites were selected for bombing to redirect the flow, and bombing took place on May 1. A natural diversion of lava at the vent occurred on May 4, and the eruption stopped on May 10.



Wingate, E.G., and Finch, R.H., 1943, Eruptions of Mauna Loa, April 26 to May 10, 1942: Bulletin of the Seismological Society of America, v. 33, no. 1, p. 65-67. 



 !need abstract



Wingate, E.G., and Finch, R.H., 1945, Volcanic and seismic phenomena in Hawaii during 1944: Bulletin of the Seismological Society of America, v. 35, p. 43. 



 A press release reports that, for 18 months beginning in 1943, seismographs indicated the pressure under the Kilauea-Mauna Loa system to be high. In November 1943 and August 1944, fume was liberated by Mauna Loa. A minor earthquake swarm occurred at Kilauea, beginning on November 12, 1944, with an earthquake 8 mi deep below Halemaumau. This was followed on November 15 by another 5 mi deep, and from then to November 30, by 12 more, with gradually shallower foci, the last only 1 or 2 mi deep. The earthquakes were accompanied by tumescence at Kilauea summit. On December 6 and 7, 29 earthquakes were accompanied by reversal of tilt, suggesting subsidence of the magma column. A strong earthquake centered under Mauna Loa on December 27, 1944, at 4:41 a.m., was felt as far away as Oahu. Others occurred on December 27, 30, and 31, all but the last originating 18-19 mi below the eastern edge of Mokuaweoweo. No forecast of eruption was issued.



Wolfe, E.W., Banks, N.G., Neal, C.A., Okamura, A.T., Koyanagi, R.Y., and Greenland, L.P., 1983, East-rift-zone eruption of 1983, Kilauea Volcano, Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 64, no. 45, p. 901. [AGU fall meeting, San Francisco, CA, Dec. 5-9, 1983, Program and abstracts] 



 An eruption in Kilauea's east rift zone began at 00:31 (H.S.T.) on January 3, 1983. After 24 hours of rapid subsidence at the summit of Kilauea and Intense shallow earthquake activity and accompanying harmonic tremor beneath the east rift zone, a discontinuous line of fissure vents opened progressively downrift for a distance of about 6 km from Napau Crater, where the initial outbreak occurred. This intense shallow earthquake activity continued until January 7, when the easternmost vent, approximately 7 to 8 km downrift of Napau, opened and erupted for nearly a day. Horizontal displacements greater than 2 meters occurred across the rift as the feeder dike was emplaced. Subsequent eruptive activity as well as harmonic tremor has been concentrated along the fissure system in a zone 4 to 6 km downrift of Napau. As of late August, 7 major eruptive phases have occurred (January 1-15, February 10-March 4, March 28-April 9, June 13-17, June 29-July 3, July 21-25, August 10-17). Seven lava flows have extended down the south flank of Kilauea for distances ranging from 5 to 8 km, and three of these flows have destroyed residences in a subdivision. An estimated 50 to 100x106 m3 of lava has been erupted, and the cumulative deflationary tilt measurements at Kilauea's summit indicate that a minimum volume of about 100x106 m3 of magma has drained from the summit storage reservoir. Periods of lava emission, increased harmonic tremor, and summit deflation have alternated with periods of non-eruption, summit inflation, and low but constant harmonic tremor in a cyclic pattern reminiscent of the early months of the Mauna Ulu eruption in 1969. Interphase periods are also characterized by gradual extension across the fissure system and continued emission of hot (~800C) gases that maintain local incandescence at the vents.



Wolfe, E.W., Garcia, M.O., Jackson, D.B., Koyanagi, R.Y., Neal, C.A., and Okamura, A.T., 1987, The Puu Oo eruption of Kilauea Volcano, episodes 1-20, January 3, 1983, to June 8, 1984, in Decker, R.W., Wright, T.L., and Stauffer, P.H., ed(s)., Volcanism in Hawaii, 2 v.: U.S. Geological Survey Professional Paper 1350, v. 1, chap. 17, p. 471-508. 



 The Puu Oo eruption began at Napau Crater in the east rift zone of Kilauea Volcano on January 3, 1983. After an initial series of intermittent fissure eruptions, the style changed to one of episodic central-vent eruptions. By early June 1984, 20 eruptive episodes had occurred, including the initial fissure-eruption episode, and approximately 240 x 106 m3 of new basalt covered an area of more than 30 km2. Fountains ranging up to nearly 400 m high built large cones at the central vents.

 The eruption occurred in a part of the rift zone that had a long history as a locus for intrusions. Tilt changes and flurries of shallow earthquakes recorded accumulation of magma from 1978 through 1980 and again in late 1982. We interpret geodetic and seismic evidence to indicate a shallow magma reservoir in the area before emplacement of the feeder dike in early January 1983. Lava erupted during the first several months was differentiated beyond olivine control and was apparently derived from magma that had undergone prolonged storage and crystal fractionation in the rift zone.

 The central-vent eruptive episodes, which began in February 1983 with episode 2, lasted from 9 hours to 12 days. They were characterized by high-volume discharge of lava, vigorous fountaining, rapid summit subsidence, and strong harmonic tremor in the vent area. The repose periods lasted from 8 to 65 days and were characterized by gradual reinflation of Kilauea's summit and persistence of weak harmonic tremor in the vent area. Alternating inflation and deflation in the summit and vent areas occurred sympathetically, suggesting that reservoirs in the rift zone and summit area were hydraulically linked.

 After the initial episode, lava was erupted at an average rate of 13.4X106m3/mo. Long-term tilt change in the summit region was minimal, and, following the approach of Swanson (1972), we have calculated an average magma-supply rate of approximately 10X106m3/mo after correction for 25 percent porosity. This rate is higher than some estimates for long-term supply to the volcano, but evidence from SO2-emission rates in the summit region also indicates that the Puu Oo eruption may have coincided with a period of increased magma supply.

 After Puu Oo became established as the sole vent, olivine-controlled lava was erupted. Beneath Puu Oo, a column of magma, which may have been nearly vertical and several kilometers long, underwent short-term compositional changes during repose periods that apparently reflected fractionation of olivine. This process repeatedly produced a finite volume of MgO-depleted magma, which would be exhausted whenever the volume of the next eruptive episode exceeded that of MgO-depleted melt. A long-term compositional change manifested by gradually increasing CaO and MgO may have been a consequence either of gradually decreasing contamination of fresh summit melt by differentiated magma present in the rift zone or of gradually changing composition of the melt generated in the mantle.



Wolfe, E.W., Koyanagi, R.Y., and Okamura, A.T., 1987, Pu'u 'O'o I: setting and episodes 1-3 [abs.], in Decker, R.W., Halbig, J.B., Hazlett, R.W., Okamura, R., and Wright, T.L., ed(s)., Hawaii Symposium on How Volcanoes Work, Hilo, HI, January 19-25, 1987, Abstract volume: Honolulu, University of Hawaii, Hawaii Institute of Geophysics, p. 271. 



 The Pu'u 'O'o eruption began at Napau Crater in Kilauea's east rift zone on January 3, 1983. Twenty-four hours before the first lava discharge, the beginning of dike emplacement was indicated by tilt changes in the upper east rift zone, development of weak harmonic tremor, and initiation of a shallow seismic swarm that migrated downrift at approximately 0.7 km/h from the vicinity of Makaopuhi Crater. Rapid subsidence of Kilauea s summit began an hour after initiation of the seismic swarm. During intermittent fissure eruptions through January 7, the vent system extended progressively northeastward for nearly 8 km to the vicinity of the prehistoric cone, Kalalua. Additional intermittent fissure eruptions of episode 1 continued locally on the eastern part of the vent system through mid-January. Episode-1 flows were mainly pahoehoe sheets. Following nearly a month of repose and then 15 days of low-level emission that built a small shield, central-vent eruptions occurred February 25-March 4 (episode 2) and again March 28-April 9 (episode 3). Spatter from high fountains built the 60-m-high cone, Pu'u Halalu, during episodes 2 and 3; a'a flows originating there in lava rivers advanced nearly 8 km to enter a sparsely populated subdivision on the south flank of Kilauea. Less voluminous emission also occurred during these episodes at the site where Pu'u 'O'o would eventually grow. Approximately 50x106- m3 (dense-rock equivalent) of lava was erupted during episodes 1-3, and an estimated additional 100x106m3 formed the feeder dike.

 The main eruptive vents were apparently localized over a shallow magma reservoir. Intrusions related to eruptions from 1961 through 1968 may have introduced magma to storage in the area. Several kinds of observations indicate that magma accumulation continued in a zone broadly centered on the Pu'u Kamoamoa-Kalalua area: (1) Spirit-level tilt measurements and leveling surveys in the years following the 1975 Kalapana earthquake defined this as a zone of inflation. (2) Shallow seismic swarms in the area during the same period identified repeated intrusions. (3) Early on January 2, after the advancing dike tip had passed Napau Crater, the rate of downrift migration of the initial deformation created by the dike tip accelerated, indicating that the dike tip may have impinged upon a preexisting zone of melt. In addition, the earthquake swarm recording emplacement of the feeder dike abruptly lost its distinct leading edge that morning in the same area; the swarm then degenerated to a pattern of scattered shallow earthquakes. (4) Most of the lava discharged during episodes 1-3 was differentiated beyond olivine control, implying that had undergone storage and crystal fractionation within the rift zone.



Wood, H.O., 1912, Earthquake rings a bell and starts machine to working; scierntists at Kilauea installing instruments at Observatory---records to be made of every earth quiver: Pacific Commercial Advertiser, 07/06, p. ? 



 The article descibes the installation of seismic instrumentation at HVO, including the Omori [strong-motion] seismograph.



Wood, H.O., 1914, On the earthquakes of 1868 in Hawaii: Bulletin of the Seismological Society of America, v. 4, p. 169-203. 



 Wood reviews all information pertinent to understanding the April 2, 1868, earthquake and its relation to eruptive activity and uses this information to construct approximate positions of isoseismal lines. He concludes that the 1868 earthquakes were probably tectonic in origin. [Wood defines tectonic earthquake as one that "origin (ates) upon a fracture or fault-slip, or a system of these, resulting from a culmination in the regional elastic strain in the rock crust, the grating and grinding relief of a regional shear or warp." He is correct in his assessment that the 1868 event was more than just a shallow volcanic disturbance. Current interpretation would place the hypocenter of this shock at the base of Mauna Loa, where it meets the sea floor, and have it indirectly related to volcanically-induced strain on Mauna Loa's south flank, much as more recent events have been instrumentally recorded on Kilauea's south flank. Thus, both Wood, and previous workers who described the event as a volcanic earthquake, are correct.] He also discusses the tsunami which accompanied the big earthquake of April 2.

 [This is a classic paper that presents the first detailed analysis of a seismic event not instrumentally recorded, at a time when seismic instrumentation was just being introduced to Hawaii.]



Wood, H.O., 1915, The seismic prelude to the 1914 eruption of Mauna Loa: Bulletin of the Seismological Society of America, v. 5, p. 39-51. 



 The eruption was preceded by many small local earthquakes, 72 being recorded in the 25 days preceding the outbreak on November 25. At Kapapala, 29 quakes were felt during a 2-day period about September 28, and two unfelt shocks were detected instrumentally at the Volcano Observatory on September 27. Strong northeast tilt was recorded by the seismographs preceding the eruption. Wood reviews earthquake precursors to previous Mauna Loa eruptions from 1832-1907. He finds that few eruptions were preceded by felt earthquakes but is of the opinion that seismic instrumentation would have detected precursory activity. The data for 1914 were not good enough to confidently predict an eruption.



Wood, H.O., 1916, Reconnaissance of the Kahuku flow of 1916: Weekly Bulletin of the Hawaiian Volcano Observatory, v. 4, no. 6, p. 51-57. [Compiled and reprinted in Bevens, D., Takahashi, T.J., and Wright, T.L., 1988, The early serial publications of the Hawaiian Volcano Observatory: Hawaii National Park, Hawaii Natural History Association, v. 2, p. 469-475] 



 Wood describes a visit to the 1916 Mauna Loa eruption. On his return he identifies a broad and deep fissure believed to be associated with the events of 1868.



Wood, H.O., 1917, [no title]: Pasadena, CA, H.O. Wood Archives, Unpub. earthquake catalog [Hawaii], 09/1915-06/1917, [unpag.] 228 p. 



 This catalog, obtained in January 1998, is a continuation of the catalog of earthquakes recorded at the Hawaiian Volcano Observatory during the latter part (1915-1917) of H.O. Wood's tenure as resident seismologist (1912-1917). Beginning January 1, 1915 eight months of seismicity were published by Wood as bimonthly bulletins entitled Systematic report of the Whitney Laboratory of Seismology, v. 1, nos. 1-4. The unpublished catalog directly follows the published catalog, beginning in September 1915 and extending through June 1917, a month before Wood left HVO to join the U.S. Army. The format is the same as the published issues. It appears that this was prepared for publication, but due to various circumstances, was never published.



Wood, H.O., 1917, Notes on the 1916 eruption of Mauna Loa: Journal of Geology, v. 25, p. 322-336, 467-488 [includes plates]. 



 Wood describes the eruption and lava flows of 1916. The eruption began on May 19, preceded by an earthquake felt offshore, and accompanied by a swarm of earthquakes. The initial summit eruption and earthquake swarm died, then earthquakes resumed, and the flank eruption broke out on May 21 from vents at 7,000 ft; flows went to either side of the rift, neither reaching the road. The eruption ended May 27 or 28. The earthquake swarm continued after the eruption began to wane, and new flows were cut by cracks that continued to open. He presents a series of photos showing the development of a cumulous cloud over the eruption site. Wood considers the eruption to be a consequence of a larger tectonic event rather than the earthquake swarm being a consequence of purely volcanic pressure. [Modern study, with much more precise seismic data than available to Wood, favors the volcanic origin, the earthquakes and ground cracks being a direct response to magma forcing its way into previously unopened parts of the rift zone.] He mentions the upper vents of 1916 (not visited) and estimates their map position at 11,000-12,000 ft on the southwest rift zone. He describes the advance of an aa front and discusses the formation of aa (p. 333-335). He describes the mechanism as fragmentation or granulation of lava grown too stiff for plastic flow, quoting Brigham on the analogy with development of ice floes on a freezing body of water.



Wood, H.O., 1921, The tectonic aspect of volcanic eruptions in Hawaii, in Pan-Pacific Scientific Conference, 1st, Honolulu, HI, Aug. 2-20, 1920, Proceedings: Bernice P. Bishop Museum Special Publication 7, p. 346-353. 



 Wood repeats his suggestion, with particular reference to the 1868 eruption, that many eruptions are tectonic in origin, resulting from the opening of fissures by crustal movements, rather than from gas tension or tumescence. Sudden magma subsidences at Kilauea are accompanied by swarms of earthquakes and are believed to be due to opening of fissures and subsurface intrusion. Wood recapitulates the earthquakes of 1868, 1914, and 1916 and their relation to subsequent and accompanying volcanic activity, and again formulates the hypothesis that Hawaiian volcanic activity is triggered by tectonic events rather than the reverse.



Wood, H.O., 1933, Volcanic earthquakes, in Physics of the Earth, VI. Seismology: National Research Council Bulletin, no. 90, p. 9-31. 



 Wood discusses the causes of volcanic earthquakes and describes the great Hawaiian earthquake of 1868, concluding that it was of tectonic origin. He attributes the accompanying tsunami to dropping of the ocean floor south of the island and recapitulates facts regarding the 1868, 1914, and 1916 earthquake swarms and accompanying eruptive activity. During the 1914 eruption of Mauna Loa, fuming occurred only during the first 24 hrs, but lava output continued for weeks and was much greater after the 21st day than before it. Continued eruption, long after most of the gas had been released, suggests that lava extrusion may result from tectonic pressure on the walls of the reservoir. Swarms of earthquakes accompanying lava subsidence at Halemaumau may result from tectonic opening, at depth, of fissures into which intrusion occurs. He suggests that the Hualalai earthquakes of 1929 may have been of tectonic origin. Wood discusses the distinction between tectonic and volcanic earthquakes and the application of this distinction to Hawaii. He criticizes de Montessus de Ballore (1924) for misunderstanding Wood's previous papers.

 [Our present understanding is that swarms of small earthquakes related to rift eruptions are volcanic, triggered in response to magma pressure. Large earthquakes on the south flanks of Mauna Loa and Kilauea are a direct but delayed response to accumulated strain from magma intrusion into the rift zones. A few eruption at Kilauea, for example, those following events in 1868 and, more recently, in 1975, are considered to be accidental consequences of deep fault movements opening up to an unusual degree the Kilauea edifice and its magmatic plumbing.]



Wright, T.L., and Pool, G.B., 1992, Understanding Kilauea's south flank: an historical perspective [abs.]: Eos, Transactions, American Geophysical Union supp., v. 73, no. 43, p. 505. [AGU fall meeting, San Francisco, CA, Dec. 7-11, 1992, Program and abstracts] 



 Inquiry into the nature of Kilauea's faulted south flank has been an exciting scientific journey, involving keen observation and intuition, first applied to field data, and later to instrumental observations obtained through monitoring of Kilauea Volcano in the 20th century. Observations began in the late 19th century when it was recognized that subsidence of Kilauea's south coast had occurred during the M=8 1868 earthquake and that steep pali (faults) were formed by tectonic processes. By 1947 Stearns and co-workers inferred the pali to be gravity faults related to submarine landslides, and Jaggar suggested that rift inflation "implied a seaward tilting of the fault blocks along the rift. . . ." In 1956 Macdonald expanded on the latter idea, suggesting that faults parallel to the rift, inland side upthrown, were formed by inflation of the rift. In 1964, Moore and Krivoy related the south flank to the overall structure and magmatic plumbing system of Kilauea, as modeled in 1960 by Eaton and Murata. Moore and Krivoy related earthquakes located south of the east rift zone to a seaward-dipping rift structure. South flank faults were inferred to intersect the rift zone at moderate depths. They concluded that gravity-driven seaward movement of the south flank led to formation of the rift zone.

 Expansion of geodetic monitoring in the 1970s and re-evaluation of earlier geodetic data showed that the south flank had moved upward and seaward since at least the early 20th century. Expanded seismic studies identified a separate class of south flank earthquakes extending to 10-13 km. This depth range corresponded to the base of the volcanic pile, defined in 1969 by Hill's seismic refraction study. In 1976, using the new seismic and deformation data, Swanson and co-workers reversed both Macdonald's and Moore's interpretations, postulating that intrusion of magma in a steeply dipping rift zone pushed the mobile south flank seaward. They viewed the south flank faults as shallow, gravity-driven features not connected with the rift zone. A M=7.2 earthquake in November 1975 provided important new insights into Kilauea's south flank. Focal mechanisms published by Ando and by Furumoto and Kovach in 1979 fit seaward movement on a shallow-dipping surface at 10 km depth; they explained the tsunami that accompanied the earthquake through uplift of the sea floor. These papers, some of which were greeted with skepticism at the time, overturned previously held ideas and substituted fresh ideas that framed a new understanding of the tectonic response of Kilauea's south flank to eruption and intrusion on the rift zones.

 In 1985 Lipman and coworkers summarized geodetic changes accompanying the 1975 earthquake and found them to be consistent with Swanson's and Ando's models. In 1987 Ryan formulated a 3-D model of Kilauea's plumbing system showing a wedge of magma extending to deeper parts of the east rift zone. In 1990 Dvorak, and Delaney and co-workers, suggested that rift magma storage extended to the base of the volcanic pile to account for, respectively: (I) a close relationship between intrusions on the east rift zone and subsequent south flank earthquakes, and (2) geodetic changes, independent of specific volcanic events that define long-term south flank movement. In 1988 a new interpretation of the 1975 earthquake by Eissler and Kanamori produced spirited argument in the literature on whether the earthquake impulse was single-couple (landslide) or double-couple (thrust). In 1991 Bryan's and Arnodottir and co-workers' modeling of seismic and geodetic data for the 1989 M=6.2 south flank earthquake identified shallow as well as deep slip planes and showed different focal mechanisms for main- and after-shocks. Interpretations now postulated an initial basal thrust, followed by vertical movement accompanying horizontal slip at several levels in the volcanic pile.

 We continue to expand our understanding of Kilauea's south flank. The insights resulting from a far broader array of observational data and theoretical modeling than available before, including data from newly established GPS networks, are presented in this symposium.



Wright, T.L., and Klein, F.W., 1995, Seismic moment history of Kilauea Volcano, Hawaii, 1933-1975 [abs.]: Eos, Transactions, American Geophysical Union supp., v. 76, no. 46, p. F681-682. [AGU fall meeting, San Francisco, CA, Dec. 11-15, 1995, Program and abstracts] 



 Seismic data from 1933 to 1975 form a continuous record at Kilauea. Instrumental magnitudes were first assigned in 1957; since 1960, the seismic catalog is complete for earthquakes M 2. Prior to 1957, earthquake magnitudes were given a qualitative classification based on amplitude range on a Bosch-Omori seismometer at Kilauea's summit. Using data for 1957, when earthquake sizes were reported by both methods, we have reconstructed a nomogram and equations that relate magnitude to distance and amplitude, thereby obtaining maximum and minimum magnitudes for earthquakes recorded back to 1933 when approximate earthquake locations were first published. Kilauea has been divided into 13 geologically significant regions, for which we relate the accumulation of seismic moment to times of eruption and intrusion.

 Kilauea's seismic network grew from 3-5 stations (1933 to 1953) to 12 stations in 1959. Seismic patterns prior to 1960 are resolvable and are similar to patterns after 1960 (e.g., south flank response to rift events). The summit eruption that began in June 1952 was preceded by a swarm of 170 earthquakes on the Koae fault zone (12/50), an M 6.3 earthquake 30 km beneath the summit (4/51), an intense swarm on the offshore south flank (3-5/52) with a moment equal to M 6.3, and smaller moment releases on both rift zones closer to the start of the eruption. Together, these indicate endogenous growth and dilation of the edifice; it is possible that this growth was a prerequisite for resumption of eruption after the long 1934 to 1952 repose.

 The data from 1960 to 1975 show: 1). Seismicity of the volcano's south flank persists during times of no rift activity at a background rate of 1.7-2.2x 1021 dyne-cm/yr, approaching half the rate during periods of high rift activity; 2). In two-thirds of the cases where earthquake swarms accompany eruption or intrusion on Kilauea's rift zones, flank earthquakes occur as precursors to rift activity by several hours to several days; 3). Seismic moment release associated with one-half of the events on the upper east rift zone is accompanied by moment release of lower magnitude on the southwest rift zone; 4). One-third of the shallow (0-5 km) earthquake swarms beneath the summit are followed within a day by deeper (5-20 km) earthquakes.

 All observations support the existence of a laterally and vertically extensive magma system consisting of a central magma supply channel and magma storage reservoir beneath Kilauea's summit connected to a deep magmatic system beneath the rift zones. Re-supply of magma after rift zone eruptions and intrusions and seismic response of the south flank both take place at depths of 3 to 10 km.

 Magma-supply earthquakes (20-35 km deep) with moments (x1021 dyne-cm) of 332 (4/51), 155 (8/55), 25 (8/61-8/62), and 45 (9/72-11/75) have followed large intrusions/eruptions in 12/50, 2-5/55, 1-2/60, and 5/69-7/74, suggesting coupling of deep magma supply from the Hawaiian hotspot with magma storage in the volcanic edifice.

 Prior to 1969, the seismicity of Kilauea's southwest rift zone was about one-tenth that of the east rift zone. Since 1969, earthquake swarms south of Kilauea's summit have defined a mirror image of the earthquake distribution beneath the upper east rift zone, and moment release has been nearly twice that on the east rift zone. From 1971 to 1982, the locus of volcanic activity on the near-summit southwest rift zone moved eastward to coincide with the shift in seismicity.

 Kilauea's south flank has been seismically active at least from 1936, and rates of seismic moment release have increased gradually, accelerating dramatically following the beginning of the Mauna Ulu eruption in 1969. The 11/29/75 M 7.2 earthquake is interpreted as a consequence of accelerated endogenous growth of the volcano.



Wright, T.L., and Fiske, R.S., 1996, A supply-side view of Kilauea Volcano, 1950-1975 [abs.]: Eos, Transactions, American Geophysical Union supp., v. 77, no. 46, p. F798. [AGU fall meeting, San Francisco, CA, Dec. 15-19, 1996, Program and abstracts] 



 We investigate the relationship between seismic energy release at 20-35 km depth, assumed to represent Kilauea's magma supply conduit, with that released on the east rift zone (0-10 km) and that associated with seaward movement of the south flank (0-15 km). We recognize a pattern of cause-and-effect, in which magma supply activity leads to and is the cause of subsequent rift zone and flank energy release. The lead time diminished through the study period, and was a heretofore unrecognized precursor to the 1975 M7.2 earthquake.

 Kilauea reawakened near the end of an 18-yr eruption repose when its summit began to inflate in March 1950. This was followed by large (M5-6) magma supply conduit earthquakes in December 1950 and April 1951. The east rift zone responded from February to April 1952 (M3.3-4.7 earthquakes) and the south flank responded in March 1952 with an intense offshore earthquake swarm (aggregate M6.4) lasting through the year. Kilauea erupted at its summit in June 1952.

 High seismic energy release in all three regions continued through 1955, then slowed through 1960. The last east rift zone earthquake of M>4 occurred in September 1961, after which rift seismicity declined, with few events of M>3. Earthquake swarms associated with magma supply began at the end of 1960, followed by earthquake swarms on the south flank in February 1962. The swarms represent a shift from episodic energy release to more continuous release related to both magma supply and south flank motion. Dilation of the east rift zone as a consequence of flank motion led to a series of rift eruptions without intervening summit activity between 1962 and 1966.

 From 1950 to 1967, seismic release associated with magma supply led by 12-16 months a comparable seismic release on the south flank. From 1967 through the end of the Mauna Ulu eruption in 1974, the times separating magma supply energy release and flank energy release became less obvious, apparently decreasing to 3-6 months. The rates of both magma supply and south flank energy release increased in the year preceding the 1975 M7.2 south flank earthquake. During this time three episodes of magma supply energy release preceded south flank energy release by one to four weeks. The last magma supply release occurred on November 6-7, south flank release on November 10-18, and the earthquake on November 29.

 The relationship between magma supply and south flank motion has been obscured since the 1975 earthquake, perhaps related to activation of Kilauea's deep ultramafic system. Magma supply seismicity diminished after the earthquake and continues to diminish following the onset of continuous east rift eruption in 1983. This may be a consequence of a deep magma transport system that progressively has become hotter and less brittle since Kilauea's reawakening in 1950. 

 Our study has important implications for the understanding of magma supply to Kilauea. Recent sustained eruption and intrusion rates vary within narrow limits (0.09-0.12 km3/yr) constrained by the geometry of the shallow plumbing; true estimates of magma supply must consider changes in edifice volume accompanying seaward motion of the south flank, as noted by Owen et al., 1995. We hypothesize that incrementally increasing magma supply since 1950 was a contributing cause for the 1975 earthquake. We speculate that a future increase in magma supply will not be accommodated by a sustainable increase in eruption rate, because the shallow magmatic system is operating near its maximum "carrying capacity." Instead, such an increase will likely be accommodated by accelerated south flank motion, another large flank earthquake, or by failure of the deep plumbing system precursory to voluminous eruption on the submarine east rift zone.



Wyss, M., Klein, F.W., and Johnston, A.C., 1978, Seismicity pattern precursory to the 1975 Hawaii M=7.2 earthquake [abs.]: Earthquake Notes, v. 49, no. 4, p. 61. 



 The Kalapana earthquake had a rupture length of 40 km and was located on the south flank of the active volcano Kilauea. The source mechanism was dip-slip normal faulting on a plane dipping 20 to the SE, with the greatest principal stress oriented in that direction and built up over 107 years by volcanic intrusions into Kilauea's rifts. Seven seismographs located within 5 km from the aftershock area had been in operation for 3 to 8 years before the mainshock. Eight earthquakes, with the largest registering M=5.9, occurred during 1.2 hours before the mainshock and were located within 5 km from it. In addition to this short term seismicity precursor we were able to demonstrate, at the 99% confidence level, that the following long term seismicity pattern preceded this mainshock: In the foreshock-mainshock hypocentral volume of dimensions (5 km)3 the seismicity increased slightly with time before the mainshock. Outside this nucleus the seismicity was decreased by 50% (from 72 to 34 events per year) during the 3.5 years before the main event in an area about 20 km long and 10 km wide. In the rest of the rupture area seismicity remained approximately constant during the eight years of homogeneous data studied. We conclude that this seismicity decrease was a precursor to the Kalapana earthquake because it's location was centered on the mainshock epicenter, and because it coincided in space and time with the anomalous decrease of P-wave travel times, the rotation of the stress tensor, and the anomalous stress unloading in Kilauea's south flank crust. These observations suggest that the crust acted as a stiff system in which dilatancy and precursory creep probably took place, but in which fluid migration and fluid pressure changes did not play a major role.



Wyss, M., Klein, F., Johnston, A.C., and Ihnen, S.M., 1980, A multiple asperity model for precursors based on detailed data for the M=7.2 Hawaii earthquake [abs.], in Ewing Symposium on Earthquake Precursors, New York, May 1980, [Abstracts]: Ewing Symposium on Earthquake Precursors, Abstracts, 1 p. 



 The Kalapana, Hawaii earthquake of November 1975 had a rupture length of 40 to 50 km and was located on the south flank of the active volcano Kilauea. The source mechanism was dip slip normal faulting on a plane dipping 20 degrees to the SE, with the greatest principal stress oriented in that direction and accumulated by volcanic intrusions into Kilauea's rifts. The source area of the 1975 earthquake was subject to intensive geological and geophysical research for many years before this earthquake because of its proximity to the volcano. We studied the distribution of epicenters for small earthquakes from 1962 to 1975. Seven seismographs located within 3 km of the aftershock area had been in operation for 4 to 10 years before the mainshock and geodetic triangulations and trilaterations in the source area had been carried out repeatedly since 1914. We found that precursory changes occurred throughout most of the rupture area but in two distinctly different patterns. In the larger foreshock anomalous area the seismicity rate was reduced by 50% during the 3.8 years before the mainshock; in addition, several geodetic lines indicated anomalous strain release during this time. Within two inner areas the seismicity remained high, then increased shortly before the mainshock. In one of the inner areas a P wave travel time delay of 0.2 s could be detected, which began about 3.5 years before the mainshock. Within the other inner anomalous area geodetic strain was accumulating until the first half of 1975 when 3.5x10-4 strain (35 bars), was released aseismically. By contrast, the outer anomalous volume was experiencing strain softening from 1970/1971 on. We interpret these observations as indicating that strain softening by fault creep in the outer anomalous area transferred stress into two major asperities (locked portions of the fault). A velocity decrease and foreshocks were observed in one asperity and high stress accumulation in the other, implying that dilatancy of the crust probably occurred. Our model is qualitatively supported by the independent evidence of strong motion records which show that the Kalapana earthquake was a complex multiple rupture. We conclude that the Kalapana earthquake was preceded by a preparatory process which lasted 3.8  0.3 years and which had dimensions of 45 x 10 km covering approximately the aftershock area.



Wyss, M., Johnston, A.C., and Klein, F.W., 1981, Multiple asperity model for earthquake prediction: Nature, v. 289, no. 5795, p. 231-234. 



 Large earthquakes often occur as multiple ruptures reflecting strong variations of stress level along faults. Dense instrument networks with which the volcano Kilauea is monitored provided detailed data on changes of seismic velocity, strain accumulation and earthquake occurrence rate before the 1975 Hawaii 7.2-mag earthquake. During the ~4 yr of preparation time the mainshock source volume had separated into crustal volumes of high stress levels embedded in a larger low-stress volume, showing respectively high- and low-stress precursory anomalies.



Wyss, M., Klein, F.W., and Johnston, A.C., 1981, Precursors to the Kalapana M=7.2 earthquake: Journal of Geophysical Research, v. 86, no. B5, p. 3881-3900. 



 The Kalapana, Hawaii earthquake of November 1975 had a rupture length of 40 to 50 km and was located on the south flank of the active volcano Kilauea. The source mechanism was dip slip normal faulting on a plane dipping 20 degrees to the SE, with the greatest principal stress oriented in that direction and accumulated by volcanic intrusions into Kilauea's rifts. The source area of the 1975 earthquake was subject to intensive geological and geophysical research for many years before this earthquake because of its proximity to the volcano. We studied the distribution of epicenters for small earthquakes from 1962 to 1975. Seven seismographs located within 3 km of the aftershock area had been in operation for 3 to 10 years before the mainshock, and geodetic triangulations and trilaterations in the source area had been carried out repeatedly since 1914. We found that precursory changes occurred throughout most of the rupture area but in two distinctly different patterns. In the larger outer anomalous area the seismicity rate was decreased by 50% during the 3.8 years before the mainshock; in addition, several geodetic lines indicated anomalous strain release during this time. Within two inner areas the seismicity remained high, then increased shortly before the mainshock. In one of the inner areas a P wave travel time delay of 02 s could be detected, which began about 3.5 years before the mainshock. Within the other inner anomalous area geodetic strain was accumulating until the first half of 1975 when 3.5x10-4 strain (35 bars), was released aseismically. By contrast, the outer anomalous volume was experiencing strain softening from 1970/1971 on. We interpret these observations as indicating that strain softening by fault creep in the outer anomalous area transferred stress into two major asperities (locked portions of the fault). A velocity decrease and foreshocks were observed in one asperity and high stress accumulation in the other, implying that dilatancy of the crust probably occurred. Our model is qualitatively supported by the independent evidence of strong motion records which show that the Kalapana earthquake was a complex multiple rupture. We conclude that the Kalapana earthquake was preceded by a preparatory process which lasted 3.8  0.3 years and which had dimensions of 45 x 10 km covering approximately the aftershock area.



Wyss, M., Wilson, M.E., and Zuniga, R., 1982, Stress drops of M = 3.5 earthquakes preceding and following the 1975 Hawaii mainshock [abs.]: Earthquake Notes, v. 53, no. 1, p. 51. [Seismological Society of America, Eastern Section, 77th annual meeting, Anaheim, CA, Abstracts] 



 Stress drops for about 80 events were estimated based on SH spectra of a Wood-Anderson seismograph located at 40 to 50 km epicentral distance. While all of these earthquakes were located in the source volume of the M = 7.2 mainshock, about half of them occurred during the 7 years before and the other half during the 2 years after the mainshock. The stress drops of pre- and post-mainshock events did not differ strongly. From this we conclude that stress drops are not strongly dependent on the ambient stress level. During the years before the mainshock the stress drops of those events which were located within the precursory asperities exceded by a factor of 2 stress drops of earthquakes located outside of the major asperities. This observation may suggest that the properties of the fault surface control the size of the stress drops. Foreshocks did not show larger than average stress drops. While it may be possible to delineate fault asperities it is unlikely that foreshocks can be identified by stress drop estimates.



Wyss, M., and Habermann, R.E., 1984, Precursory seismic quiescence shows similar patterns for thrust, normal and strikeslip earthquakes along plate boundaries and elsewhere [abs.]: Eos, Transactions, American Geophysical Union, v. 65, no. 45, p. 987. [AGU fall meeting, San Francisco, CA, Dec. 3-7, 1984, Program and abstracts] 



 The 1979 Coyote Lake, ML=5.9, earthquake was a near vertical strike slip rupture along the Calaveras-Hayward fault, a strand of the San Andreas plate boundary. The 1983 Kaoiki, ML =6.6, earthquake was a near vertical strike slip rupture which occurred between the volcanoes Kilauea and Mauna Loa at the center of a plate. In spite of their different tectonic settings both earthquakes were preceded by similar highly significant periods of quiescence (20% and 37% of background rate)-starting approximately 2.4 years before the respective mainshocks. Also, the 1975 Hawaii Ms=7.2 near horizontal thrust was preceded by a quiescence period of 3.8 years while the 1976 Kermadec Ms =8.0 plate boundary thrust and the 1977 Tonga, Ms =7.2, normal faults were preceded by precursory quiescence starting 5.25 and 2.1 years before the respective mainshocks. In all of these cases and several additional plate boundary thrust events the seismicity rate during the anomaly was 3515% of normal, and the change in rate was significant at the 99.9% confidence level according to the standard deviate z-test. Based on the similarities between these precursors in different tectonic settings a crude general scenario for quiescence precursors is proposed: (I) Quiescence precursors to earthquakes with M<5.5 may not be detected because the volumes and seismicity rates are too small. (2) Mainshocks with 5.8<M<7.2 are preceded by quiescence starting 2.2  l years ahead of them and the anomalous rate is typically 3515% of normal. (3) The duration of precursors preceding 7.2<Ml<8.0 events is 2 to 6 years. (4) Exceptions, false alarms (quiescence but no mainshock) and failures (no quiescence) must be expected.



Wyss, M., 1984, Asperities of the 1975 Hawaii (Ms = 7.2) earthquake: their identification by seismicity patterns and stress-drops, and their influence on precursory anomalies [abs.], in, International Association of Seismology and Physics of the Earth's Interior, Regional Assembly, Hyderabad, India, Oct. 31-Nov. 7, 1984, Abstract book: Hyderabad, India, National Geophysical Research Institute, p. 73. 



 The 1975 Hawaii rupture was approximately 40 km long, with two strong motion records (epicentral distances 45 km) showing about 6 major events (5.0<ML<6), which were separated by 5 to 10 sec, occurring over a time span of 70 sec. Approximate locations calculated for the individual events of this complex rupture are consistent with the definition of asperities based on precursory seismicity patterns. A detailed analysis of ML >2.0 earthquakes which occurred in the source volume during 14 years before the mainshock showed that the seismicity rate within asperities was constant throughout, while the rate in the rest of the volume (soft regions) decreased by 50% 4 years before the mainshock. In contrast the soft region produced more aftershocks per unit time than the asperity did. Stress drops and apparent stresses were calculated from S-wave signals for 294 earthquakes (3<ML<4) which were located within the mainshock source volume and which occurred between 1962 and 1981. The Wood-Anderson records of station Hilo located at 45 km epicentral distance were photographically enlarged and digitized by hand for analysis. The stress drops and apparent stresses in the asperity were twice as large as those in the soft region at all times. Within the foreshock volume the stress drops equaled in the average those of the asperity except for the precursor and aftershock time when they equaled those in the soft region.

 It is concluded that strong stress heterogeneities existed in the source volume of the 1975 Hawaii mainshock due to the presence of asperities. The asperities could have been identified before the mainshock based on the higher stress drops of small earthquakes within them. The presence of asperities caused complex precursor patterns: (1) Seismic quiescence was documented in the soft region but not in the asperities. (2) Crustal transit times of teleseismic P-waves decreased only in the foreshock region but not in the soft region. (3) Precursory strain release occurred earlier in the soft regions then in the asperities. (4) A precursory attenuation increase may also have existed but it is not known whether it correlated with asperities or soft regions.



Wyss, M., 1986, Seismic quiescence precursor to the 1983 Kaoiki (Ms = 6.6), Hawaii, earthquake: Bulletin of the Seismological Society of America, v. 76, no. 3, p. 785-800. 



 A remarkable seismicity rate decrease of 65 per cent occurred in most of the aftershock volume 2.4 yr before the 1983 Kaoiki Ms = 6.6 main shock. If the background seismicity rate (1978 to mid-1981) is extrapolated to the time of the main shock, more than 300 earthquakes of ML 1.8 are missing because of the quiescence. Subvolumes measuring 5.5 km on a side, and located within the aftershock zone, showed seismicity rate decreases ranging from 0 to 90 per cent. The volume of no change had dimensions of approximately 10 x 3 km. It contained the main shock hypocenter, and was located near the center of the 10 km radius aftershock area. The seismic quiescence in different subvolumes of the aftershock volume surrounding this central non-quiet zone varied somewhat in starting time, amount of rate decrease, and statistical significance. According to the standard deviate z-test, the reported rate decrease is the most pronounced example of precursory quiescence defined to date. The seismicity pattern before the 1983 Kaoiki shock conformed to the quiescence hypothesis proposed on the basis of the precursors to the 1975 Hawaii main shock: no quiescence was observed within the immediate surrounding of the hypocenter, while strong rate decreases occurred in most of the rest of the main shock source volume. It is thus hypothesized that major asperities which contain high stress levels, and from which main ruptures can emanate, may be recognizable as volumes of constant seismicity rate within surrounding volumes of quiescence, provided that decreases of seismicity rate as a function of time can be defined quantitatively.



Wyss, M., 1986, Regular intervals between Hawaiian earthquakes; implications for predicting the next event: Science, v. 234, no. 4777, p. 726-728. 



 During the years 1941 through 1983 five earthquake mainshocks of moderate magnitude occurred at regular intervals of 10.5 + 1.5 years within a 6-kilometer radius in Hawaii. It is proposed that these Kaoiki earthquakes will continue to occur at regular intervals because the strain accumulation rate and the strained volume remain constant. With appropriate instrumentation, it may be possible to refine predictions of subsequent Kaoiki earthquakes.



Wyss, M., 1987, A proposed source model for the Great Kau, Hawaii, earthquake of 1868 [abs.]: Eos, Transactions, American Geophysical Union, v. 68, no. 44, p. 1353. [AGU fall meeting, San Francisco, CA, Dec. 6-11, 1987, Program and abstracts] 



 On April 2, 1868 a destructive earthquake occurred in southern Hawaii which was felt at 600 km distance, and for which ground shaking of intensity VIII reached 200 km distance. Based on these observations and on the very strong destruction in the epicentral area it is estimated that the magnitude of this earthquake must have been at least 8. One fore- and one aftershock probably exceeded magnitude 6 5 The foreshock sequence lasted 5 days, the aftershocks lasted for years to perhaps a decade It appears that this earthquake was one of the very few largest events in historic time in the United States, excluding Alaska, but its return period is unknown.

 It is proposed that the source of this earthquake was slip of the upper crust by about 8 m towards the SE along a near horizontal plane at 92 km depth The rupture plane must have had dimensions of at least 50x80 km It is proposed that its eastern edge extended from near Mauna Loa's summit to the south along the volcano's southwest rift. In this model magma intrusions into Mauna Loa and its southwest rift provide the stresses which act perpendicular to the rift and which push the volcano's southwest flank away from the edifice of the island of Hawaii. The oceanic sediment layer upon which this edifice is deposited acts as a layer of weakness containing the fault plane This model explains the eruptive pattern of Mauna Loa and its southwest rift, as well as the growing separation between the southwest rift zones of the two volcanoes Kilauea and Mauna Loa



Wyss, M., 1987, Regular recurrence intervals between Kaoiki mainshocks (5.5 < Ms > 6.6) [abs.], in Decker, R.W., Halbig, J.B., Hazlett, R.W., Okamura, R., and Wright, T.L., ed(s)., Hawaii Symposium on How Volcanoes Work, Hilo, HI, January 19-25, 1987, Abstract volume: Honolulu, University of Hawaii, Hawaii Institute of Geophysics, p. 274. 



 During the years 1941 through 1983, five moderate magnitude mainshocks occurred at intervals of 10.51.5 years within a volume of 6 km radius in the Kaoiki fault system. It is hypothesized that this source volume produced mainshocks at approximately regular intervals in the past, and that it will rupture again in 1995.251.2 years. This extrapolation is based on the 95% confidence limit of a line fitted through 6 mainshock occurrences. Extrapolating the series of shocks back in time an event was expected to have occurred in early 19311.5 years. It is proposed that the rupture which occurred on 25 May 1930 was another Kaoiki mainshock, and it was used as the sixth event in defining the above expectation time for the next future Kaoiki earthquake.

 The regularity of the recurrence times is probably due to the facts that (a) the strain rate is approximately constant because of the constant magma supply rate in the two volcanoes Mauna Loa and Kilauea, and (b) that the volume which is strained at a high rate is constant (volumes which are not located between the two volcanoes are strained at a lower rate by a factor of two at least). Based on this simplified model one would expect approximately constant magnitudes for the Kaoiki mainshocks. However, the range 5.5Ms6.6 is considerable and requires explanation. It is proposed that the smaller events are strike-slip ruptures along a near vertical plane, while the larger ones consist of a combination of near-vertical strike-slips in the crust and thrusting along a near horizontal plane in the buried oceanic sediments at about 10 km depth. This model is supported by the fact that all aftershocks of the Ms = 5.5 (1974) rupture were near vertical strike slip ruptures, while those of the Ms = 6.6 (1983) mainshock consisted of strike-slip and horizontal thrust types (Endo, 1985).



Wyss, M., 1988, A proposed source model for the great Kau, Hawaii, earthquake of 1868: Bulletin of the Seismological Society of America, v. 78, p. 1450-1462. 



 On 2 April 1868, an earthquake occurred which destroyed all stone buildings in southern Hawaii. It was felt on Kauai Island at 600 km, and ground shaking of intensity VII was reported up to 130 km distance. Based on the magnitude versus felt-area relationship for Hawaii, it is estimated that the magnitude of the earthquake was about 8. The foreshock sequence lasted 5 days, and the aftershocks lasted for years to perhaps a decade. It appears that this earthquake was one of the very few largest events in historic time in the United States, excluding Alaska, but its return period is unknown.

 It is proposed that the source of this earthquake was slip of the upper crust towards the southeast along a near-horizontal plane at approximately 9 km depth. The rupture plane may have had dimensions of at least 50 km x 80 km. It is proposed that its eastern edge extended from near Mauna Loa's summit to the south along the volcano's southwest rift. In this model, magma intrusions into Mauna Loa and its southwest rift provide the stresses which act perpendicular to the rift and which push the volcano's southwest flank away from the edifice of the island of Hawaii. The oceanic sediment layer upon which this edifice is deposited acts as a layer of weakness containing the fault plane. This model explains the eruptive pattern of Mauna Loa and its southwest rift, as well as the growing separation between the southwest rift zones of the two volcanoes: Kilauea and Mauna Loa.

 Geodetic monitoring of southern Hawaii, particularly of the area between the two active volcano's southwest rifts, could test this hypothesis and lead to an estimate of the recurrence time.



Wyss, M., and Kovach, R.L., 1988, Comment on "A single-force model for the 1975 Kalapana, Hawaii, earthquake" by Holly K. Eissler and Hiroo Kanamori: Journal of Geophysical Research, v. 93, no. B7, p. 8078-8082. 



 "Eissler and .Kanamori [1987] propose that a single force landslide model best describes the source of the Ms=7.2 Kalapana earthquake of November 29, 1975. The chief observation on which they base their model is the Love wave radiation pattern, and as supporting evidence they cite the existence of landslides in the source area. However, there are many other facts which strongly indicate that the Kalapana earthquake was a rupture under compressive stress as envisioned in the elastic rebound model [Reid, 1911]. Below we outline some of the facts not noted by Eissler and Kanamori, and we conclude that the Kalapana earthquake was a multiple rupture on a near horizontal plane, at 8 km depth in the crust, due to the compressive stress exerted by magmatic intrusions in the volcano Kilauea and its rift zones.

 The main reasons for preferring a tectonic model are as follows: (1) All the seismological short- and long-period data, as well as geodetic and tectonic data, indicate that the fault plane had a near-horizontal orientation. This explains the two-lobed Love wave radiation pattern, and there is no need to propose the single-force model of Eissler and Kanamori [1987]. (2) The Kalapana rupture was clearly a multiple event during which the dip and slip angles varied [Harvey and Wyss, 1986]. Thus the expected Love wave radiation pattern should be a mixture of several two- and four-lobed patterns of different orientation Therefore the Love wave data are less reliable, and should receive less weight, than other data in formulating a source model for the Kalapana earthquake. (3). The elastic strain that was accumulated in the source volume over 70 years [Swanson et al., 1976] and released in the earthquake [Lipman et al., 1985] was measured geodetically and reveals the classical pattern expected by the rebound theory (4). The main shock hypocenter and the aftershocks were at 8 km depth inside the crust [Tilling et al., 1976]; hence there is no appreciable gravitational potential to move the crust in the hypocentral volume. (5) Background seismicity and aftershocks in the source volume exhibit the usual characteristics of crustal earthquakes of the double-couple type with the same source geometry as the 1975 main shock. (6) The Kalapana earthquake profoundly influenced the rate of occurrence of subcrustal earthquakes [KIein et al., 1987], an observation which suggests that a stress reduction took place in the upper mantle."



Wyss, M., 1988, Earthquake hazard in Hawaii, in SeniorAdvisorstoECEGovernmentsonScienceandTechnology, ed(s)., Seminar on the Prediction of Earthquakes, Lisbon, Portugal, Nov. 14-18, 1988, [Proceedings]: [s.l.], United Nations, Economic Commission for Europe, 17 p. 



 The southern half of the island of Hawaii is highly active seismically with several thousand earthquakes being located per year. In most of the Hawaiian crust, earthquakes are not directly associated with magmatic activity. However, the volcanoes provide the energy source for the earthquakes, apparently through forceful magma intrusions. The majority of tectonic earthquakes with known focal mechanisms can be interpreted as near horizontal thrusts with slip-directions perpendicular to the volcano's rift zones.

 Most of the seismic zone in Hawaii apparently has ruptured in major to great earthquakes during historic time, except for a segment in southwestern Hawaii which may be a seismic gap. Unless the strain is reduced by fault creep, this gap may be capable of approximately a magnitude 7 earthquake.

 The source volumes of five Hawaiian earthquakes with M  5.5 have been searched for precursory seismic quiescence (30 November 1974, M=5.5; 29 November 1975, M=7.2; 21 September 1979, M=5.5; 21 January 1982, M=5.6; 16 November 1983, M=6.6). No seismicity rate decrease could be identified for the smallest two of these. Rate decreases of 70%, 87% and 70%, respectively, were measured with high to moderate statistical confidence levels for the other three mainshocks. The quiescences were constrained mostly to the source volumes, or portions of the source volumes, and they lasted for 200, 46 and 125 weeks respectively. Thus, the precursor times may be proportional to magnitude.

 The November 1983 earthquake occurred in a crustal volume (Kaoiki) which apparently produces a mainshock in the range of 5.5 < M < 6.6 every 10.4 years  1.5 years. The earliest known earthquake of this sequence occurred on 2 November 1918. The great (M ~ 8) earthquake of 2 April 1868 may also have been part of this regular series of earthquakes. However, it ruptured a much larger area (about 80 km by 50 km) of southern Hawaii. Based on the regular return time of the Kaoiki mainshocks, the next M=6  0.5 earthquake is expected to occur in 1994/95 within a radius of about 6 km of the 1983 Kaoiki epicenter. If this shock will be preceded by seismic quiescence its prediction may be refined during the 1990s.



Wyss, M., and Fu, Z., 1988, Precursory seismic quiescence before the 1982 Hilea, Hawaii, earthquake [abs.]: Eos, Transactions, American Geophysical Union, v. 69, no. 29, p. 730. [AGU spring meeting, May 16-20, 1988, additional abstract] 



 Among the seismic quiescence precursors reported in the literature there are only 17 for which quantitative measures of the anomaly are available The amount of rate decrease ranges from 45% to 90%. For two thirds of these cases the statistical significance of the rate decrease is larger than 97%, for the others it is near 95%. These seismic quiescence anomalies have abrupt beginnings, and the rate during the anomalous period is fairly constant. The durations of the quiescence precursors range from 15 to 15 months. The larger magnitude earthquakes have somewhat longer precursor times, however the correlation between precursor time and magnitude is weak For two examples from the creeping segments precursor times are unusually long (3O months) for small mainshocks (ML~4 3/4). Observations of crustal deformations for two cases are contradictive: Strain accumulation was reversed into strain-release during at least one year before the Kalapana earthquake (1975, M, = 7.2, Hawaii). In this case the seismic quiescence could be interpreted as due to precursory slip-softening along the fault plane of the mainshock, because the decrease in seismicity rate was observed for the entire crustal volume above the near horizontal rupture surface. The Stone Canyon earthquake of 1986 (.ML = 4-7, 31 May 1986) was predicted based on precursory seismic quiescence and fault-creep retardation. This combination of observations can better be explained assuming that the fault surface was arrested leading to a reduction of creep in the vicinity and to a reduction of the seismicity rate on the fault surface. The false alarm and the failure rate of predictions based on seismic quiescences is as yet difficult to estimate because there are few precedents. Based on searches for false alarms and failures in four tectonic areas we estimate that both of these phenomena may occur at a rate approximately equal to the rate of successes.



Wyss, M., and Gillard, D., 1988, Major crustal earthquakes in Hawaii [abs.]: Eos, Transactions, American Geophysical Union, v. 69, no. 18, p. 566. [AGU Front Range Meeting, Golden, CO, Feb. 11-12, 1988, Program and abstracts] 



 Hawaii experienced at least 5 crustal earthquakes with M6.5 during historic time (1832-1987). Local mechanisms and geodetic measurements for the two most recent mainshocks (November 29, 1975, M, = 7.2; November 16, 1983, M, = 6.6) show that the strain energy is accumulated by magmatic intrusions in the active volcano Kilauea and the rift zones emanating from it. In the case of the 1975 mainshock the strain release occurred by slip on a near horizontal plane perpendicularly away from the rifts. Hypocentral depths of these earthquakes were 8 to 11 km. Based on these observations and on macroseismic data we propose that the strain energy for the largest known Hawaiian earthquake (M~ 8, April 2, 1868) was accumulated by intrusions in .Mauna Loa s rift zones and that slip occurred on a near horizontal plane at about 10 km depth east of .Mauna Loa's rift. West of Mauna Loa earthquakes in the magnitude range 6.5 M7 occurred on October 5, 1929 and August 21, 1951. We propose that the stress causing these two events was accumulated by intrusions in the rift zones of the volcanoes Mauna Loa and Hualalai, located east and north of the epicentral area respectively. In order to test this hypothesis we have examined new and previously published focal mechanisms of ML = 3.50.5 earthquakes which occurred since 1969 in the source areas of these major earthquakes. We find that in general these focal mechanisms support our hypothesis that all major crustal Hawaiian earthquakes are caused by strain accumulated in volcanic rift zones, because they show that the greatest principal stress directions and slip-vectors of small earthquakes are oriented approximately perpendicular to the rifts.



Wyss, M., 1988, Magnitudes of historic Hawaiian earthquakes estimated from macroseismic maps [abs.]: Seismological Research Letters, v. 59, p. 18. 



 Macroseismic maps were compiled for 33 Hawaiian earthquakes which occurred during the period 1868 to 1983. Their magnitudes ranged from 4.3 to 8.1, with most of them around M = 6 +0.6. The maximum intensities ranged from V to X, and some of the radii of the felt areas reached 600 km, the extent of the Hawaiian island chain. The two largest historic ruptures (M >7) occurred along the south coast of the island of Hawaii in April 1868 and November 1975, and the two next largest events (M <7) were located along its west coast (October 1929, August 1951). Major shocks also occurred off Maui (M >6.5). The Kaoiki region located between the summits of Mauna Loa and Kilauea volcanoes, products the largest number of moderate earthquakes (M >5.5).

 The gradient of the isoseismals as a function of epicentral distance is steeper than in other areas of the United States and indicates a stronger attenuation of seismic waves. The difference in isoseismal gradients between earthquakes of crustal and subcrustal depths beneath the volcanic systems of Hawaii is noticeable, and on this basis, two of the 18 earthquakes without instrumental hypocenter locations were tentatively assigned sub-crustal depths. A relationship between magnitude and felt area was derived from 9 earthquakes for which instrumental magnitudes exist, and this was used to estimate the magnitudes of 14 historic earthquakes without instrumental magnitudes.



Wyss, M., and Zhengxiang, F., 1989, Precursory seismic quiescence before the January 1982, Hilea, Hawaii, earthquakes: Bulletin of the Seismological Society of America, v. 79, p. 756-773. 



 Two earthquakes of ML= 5.4 occurred within half an hour of each other within the Hilea area of Southern Hawaii on 21 January 1982. The aftershock distribution suggests that together they ruptured an area of approximately 5-km radius, and their joint equivalent magnitude was 5.6. The first motions indicate faulting on a near horizontal plane at 10 km depth, with the crust slipping to the southeast.

 The seismicity rate in the source area was studied using the earthquake catalog of the Hawaiian Volcano Observatory. This catalog contains some reporting rate changes that affect the count of smaller earthquakes strongly, with a period of low reporting during 1974 to 1977. Although we have used 2.5 as the minimum magnitude of homogeneous reporting after 1971, some of the artificial rate changes are still present in the data. The catalog was declustered using Reasenberg's algorithm, and a magnitude correction of -0.1 was applied to the data between 1974 and 1984.

 The seismicity rate for the period of November 1971 through 1985 was examined in four adjacent regions; one of these contained the aftershocks. The aftershock volume and the 3-km annulus around it showed a period of 46 weeks of low seismicity rate immediately before January 1982, during which the rate was decreased by 87 per cent. The seismicity rate in the other three volumes was normal during this time. We conclude that this low reporting rate was not likely due to artificial changes in the catalog. The fact that the quiescence anomaly coincided in space with the 1982 aftershock volume and that its termination coincided with the 1982 main shocks suggests that the quiescence was a precursor.

 Comparing the seismicity rate within all possible 46-week windows to the background rate, we found that the precursory rate decrease was more significant than any other rate decrease in all volumes studied except artificial low rate periods. Thus this quiescence precursor could be recognized without false alarms. However, the statistical significance estimated by the z- and b-tests was low, <75 per cent and <49 per cent, respectively. More case histories are needed to determine empirically the thresholds of these tests for accepting precursory anomalies without too many false alarms.

 The M = 6.6 Kaoiki earthquake that was located about 25-km north of the 1982 source area was preceded by 125 weeks of quiescence, while the M = 7.2 Kalapana earthquake quiescence precursor lasted about 200 weeks. These observations suggest that in Hawaii quiescence precursor times may be a function of magnitude.



Wyss, M., and Gillard, D., 1992, The role of normal faulting in large earthquakes along Hawaii's south-east coast [abs.]: Eos, Transactions, American Geophysical Union supp., v. 73, no. 43, p. 506. [AGU fall meeting, San Francisco, CA, Dec. 7-11, 1992, Program and abstracts] 



 Subsidence along the south-east coast of Hawaii was observed in the large earthquakes of 1868 (M7.9) and 1975 (M7.2). In 1975 the maximum drop of 3.5m occurred near Halape. within a 15 km coastal segment that subsided more than 2m, Kapoho subsided .3m, and west of 155.25 W there was no change. In 1868 the segments that subsided more than 2 and 3m were approximately 100 and 70 km long, respectively, with the maximum values between Apua and Honuapo. Also, the entire south-east coast probably subsided, with Kapoho dropping 1.2m. Thus the amount and extent of subsidence in 1868 were 3 to 5 times larger than in 1975. Co-seismic dip-slip of 1.5m was observed on the normal fault system of Hilina in 1975. This observation, together with the discovery of enormous landslide deposits on the ocean door around the Hawaiian islands, lead to the hypothesis that these large earthquakes are landslides along normal faults which penetrate to depths of 9 km, where they join the decollement plain below the volcanic edifice. We prefer the model in which the rupture in these earthquakes occurs on the decollement plain, and normal faulting in the shallow crust, as well as landsliding, is triggered by the strong shaking. Fault plane solutions cannot be used to test these hypotheses because earthquakes are located north and east of the south dipping Hilina system only. The following facts support our model and contradict the landslide model. (1) The 1975 mainshock and 551 focal mechanisms (67%) are of the decollement type. (2) Geodetically measured deformation of the south flank conforms to the model of earthquake generation by elastic rebound: The compressive strain of 400 microstrain, which was accumulated between 1914 and 1970, was released in the 1975 earthquake. (3) The south flank crust responds to intrusions in the rift zones by earthquake sequences that have the characteristics of aftershocks decaying according to the Omori law, i.e., intrusions generate stresses. (4) The 1975 mainshock was followed by an aftershock sequence in the south flank, and by a decrease of seismicity by a factor of 4 below the Kilauea summit to depths of 60 km. Thus this event redistributed the stress in the crust and upper mantle. (5) The greatest principal stress is directed to the SE, perpendicular to the east rift zone, dipping at 45. (6) Extending the normal faults to depths below the abyssal plain does not explain the large volumes of the landslide deposits on the sea floor. (7) Triggering of slip by shaking within 50 km of mainshocks has been observed on several faults in California.



Wyss, M., and Koyanagi, R.Y., 1992, Isoseismal maps, macroseismic epicenters, and estimated magnitudes of historical earthquakes in the Hawaiian Islands: U.S. Geological Survey Bulletin 2006, 93 p; addendum, 1 p. 



 Abstract 1 

 Macroseismic data were compiled for 56 moderate to large Hawaiian earthquakes that occurred between 1823 and 1989. The magnitudes (M) of the earthquakes range from 4.7 to 7.9, but most are 60.6. The maximum intensities (I) range from V to XII, and some of the radii of the felt areas are as much as 600 km, the extent of the chain of Hawaiian islands. For 43 earthquakes macroseismic maps were drawn. The two largest earthquakes (M>7) ruptured the south coast of Hawaii in April 1868 and November 1975. The two next largest events (M7) were located along its west coast (October 1929, August 1951), and major to large shocks (M6 3/4) also occurred off the island of Maui. The Kaoiki area, between the summits of the volcanoes Mauna Loa and Kilauea, produces the most frequent major earthquakes (M5.5) at the approximate rate of one every 10 years. A catalog for Hawaiian earthquakes for which the maximum intensity probably exceeded V contains 460 events for the period 1833 through 1955. Thus, the expected frequency of events having intensities greater than or equal to V in Hawaii is approximately 3.7 per year. The conditional probability for earthquakes having ImaxVII and VIII and M6, 6.5, and 7 for the next 10 years in the Hawaiian archipelago (and southern Hawaii) is 0.67 (0.63), 0.50 (0.39), and 0.84 (0.71), 0.50 (0.39) and 0.17 (0.17), respectively.

 The fact that gradients of the isoseismals as a function of epicentral distance are steeper for earthquakes in Hawaii than for those in other areas of the United States indicates stronger attenuation of seismic waves in the crust. For earthquakes located along the southeast coast of the island of Hawaii, intensities are lower in the epicentral area than at 40 km to the north and west. This may suggest unusually strong attenuation below the southeast coast. The difference in isoseismal gradients between earthquakes of crustal depth and those deeper than about 15 km is noticeable in Hawaii. Peak accelerations for four recent earthquakes measured at 23 locations and having known intensities are greater than the values estimated using the average acceleration versus intensity relationship by a factor of four. This agrees with the observation that the relationships between magnitude and felt area derived from 15 earthquakes located on the island of Hawaii,

 M=l.0 log (A(VI))+2.9 and

 M=l.1 log (A(V))+1.6,

yield magnitudes about 0.7 units greater than the same relationships for California earthquakes. Four subcrustal earthquakes and two earthquakes located offshore from Maui do not follow this relationship. Their magnitudes are approximately 0.7 units less for the same felt areas. The magnitudes of the well-documented historical earthquakes for which instrumental magnitudes are not available were estimated using these equations. For some of the earlier events the felt reports were not sufficient to estimate epicenter or magnitude and further compilation of data is needed.

Introduction 

Data 5 

Calibration data set 15 

Magnitude scales in Hawaii 21 

Magnitude as a function of the felt area 23 

Maximum intensity versus magnitude 25 

Historic earthquakes with reports of strong shaking 27 

Gradient of isoseismals as a function of epicentral distance 35 

Magnitude estimates based on felt areas 39 

Relationship between peak acceleration and intensity 39 

Earthquakes having maximum intensity V 39 

Conditional probability for earthquakes in Hawaii 42 

Discussion and conclusions 44 

References cited 47 

Appendix IPrincipal reference locations on the Hawaiian Islands mentioned in the text 52 

Appendix 2Modified Mercalli Intensity Scale 56 

Appendix 3Macroseismic data for strong Hawaiian earthquakes 57 

Appendix 4Population distribution of the County and the State of Hawaii 91

 FIGURES

1. Map showing epicenters of earthquakes on the island of Hawaii for which isoseismal maps were compiled 15

2-17. Isoseismal maps for the earthquakes of:

 2. June 25, 1989 16

 3.	November 16, 1983	16

 4. January 21, 1982 17

 5.	September 21, 1979	17

 6.	November 29, 1975	18

 7.	November 30, 1974	18

 8.	April 26, 1973	19

 9.	January 8, 1963	 19

 10.	June 27, 1962	20

 11.	August 14, 1955	 20

 12.	March 30, 1954	 21

 13.	May 23, 1952	21

 14.	August 21, 1951	 22

 15.	April 22, 1951	22

 16. September 25, 194 1 23

 17. June 16, 1940 23 

18-20. Graphs showing:

 18. Comparison of magnitude scales for Hawaiian earthquakes 24

 19. Instrumentally determined magnitude as a function of felt area for Hawaiian earthquakes 26

 20. Instrumentally determined magnitude as a function of maximum intensity for Hawaiian earthquakes 26

 21-35. Isoseismal maps for the earthquakes of:

	21.	May 29, 1950 27

	22.	July 14, 1939 27

	23.	May 23, 1939 28

	24.	January 22, 1938 28

	25.	November 21, 1935	28

	26	June 28, 1935 29

	27.	January 2, 1935 29

	28.	May 25, 1930 29

	29.	October 5, 1929 30

	30.	September 25, 1929	30

	31.	March 20, 1927 31

	32	March 19, 1926 31

	33.	August 20, 1924 31

	34.	September 14, 1919	32

	35. November 2, 1918 32

36-41. Intensity maps for the earthquakes of:

 36. September 13, 1896 32

 37. January 23, 1887 33

 38. January 13, 1885 33

 39. September 30, 1881 34

 40.	May 31, 1877 34

 41.	December 29, 1874	34

 42.	Isoseismal map for the earthquake of February 19, 1871	34

43-45. Intensity maps for the earthquakes of:

 43. August 7, 1870 35

 44. April 30, 1868 35

 45. April 4, 1868 35

46, 47. Isoseismal maps for the earthquakes of:

 46. April 2, 1868 36

 47. March 28, 1868 36

48-51. Graphs showing:

 48. Intensity as a function of epicentral distance for Hawaiian earthquakes 37

 49. Normalized intensity as a function of distance for all earthquakes of Hawaii 38

 50. Horizontal acceleration as a function of intensity for four Hawaiian earthquakes 41

 51. Number of earthquakes as a function of time for the Hawaiian archipelago 43

52. Maps showing highest intensities from earthquakes compiled in this report 45

53. Photograph showing en echelon cracks from surface rupture of Kaoiki earth-

 quake of November 16, 1983 45

 TABLES

1. Destructive earthquakes in Hawaii County since 1868 (Imax >VIII)	2

2. Moderate to large earthquakes in Hawaii with felt reports 4

3. Radii of felt area for Hawaiian earthquakes 6

4. Earthquakes in Hawaii 1833-1955 having maximum intensity >V	7

5. Comparison of magnitude scales for Hawaiian earthquakes 25

6. Areas within intensity V and VI isoseismals of Hawaiian earthquakes for which there are instrumentally determined magnitudes 26

7. Accelerations and intensities for Hawaiian earthquakes 40

8. The Lyman scale for earthquake strength in Hawaii 42

9. Conditional probability estimates for earthquakes in the Hawaiian archipelago and in the southern parts of the island of Hawaii 44



Wyss, M., and Koyanagi, R.Y., 1992, Isoseismal maps, macroseismic epicenters, and estimated magnitudes of historical earthquakes in the Hawaiian Islands [abs.], in, Earthquake, Tsunami, and Volcano Hazards Seminar, Hilo, HI, Aug. 6, 1992, [Abstracts]: Hilo, HI, University of Hawaii at Hilo, Center for the Study of Active Volcanoes, [unpag.]. 



 Macroseismic data were compiled for 56 moderate to large Hawaiian earthquakes that occurred between 1823 and 1989. The magnitudes (M) of the earthquakes range from 4.7 to 7.9, but most are 6  0.6. The maximum intensities (I) range from V to XII, and some of the radii of the felt areas are as much as 600 km, the extent of the chain of Hawaiian islands. For 43 earthquakes, macroseismic maps were drawn. The two largest earthquakes (M > 7) ruptured the south coast of Hawaii in April 1868 and November 1975. The two next largest events (M  7) were located along its west coast (October 1929, August 1951), and major to large shocks (M  6 ) also occurred off the island of Maui. The Kaoiki area, between the summits of the volcanoes Mauna Loa and Kilauea, produces the most frequent major earthquakes (M > 5.5) at the approximate rate of one every 10 years. A catalog for Hawaiian earthquakes for which the maximum intensity probably exceeded V contains 460 events for the period 1833 through 1955. Thus, the expected frequency of events having intensities greater than or equal to V in Hawaii is approximately 3.7 per year. The conditional probability for earthquakes having Imax  VIII,  VII and M  6,  6.5 and  7 for the next 10 years in the Hawaiian archipelago (and Hawaii) is 0.50 (0.39), 0.67 (0.63), and 0.84 (0.71), 0.50 (0.39) and 0.17 (0.17), respectively.

 The steeper gradients of the isoseismals as a function of epicentral distance for earthquakes in Hawaii than for those in other areas of the United States indicate stronger attenuation of seismic waves in the crust. For earthquakes located along the southeast coast of the island of Hawaii, intensities are lower in the epicentral area than at 40 km to the north and west. This may suggest unusually strong attenuation below the southeast coast. The difference in isoseismal gradients between earthquakes of crustal depth and those deeper than about 15 km is noticeable in Hawaii. Peak accelerations for four recent earthquakes measured at 23 locations and having known intensities are greater than the values estimated using the average acceleration versus intensity relationship by a factor of four. This agrees with the observation that the relationships between magnitude and felt area derived from 15 earthquakes located on the island of Hawaii, M = 1.0 log (A(VI)) + 2.9 and M = 1.1 log (A(V)) + 1.6, yield magnitudes about 0.7 units greater than the same relationships for California earthquakes. Four subcrustal earthquakes and two earthquakes located offshore from Maui do not follow this relationship. Their magnitudes are approximately 0.7 units less for the same felt areas. The magnitudes of the well-documented historical earthquakes for which instrumental magnitudes are not available were estimated using these equations. For some of the earlier events the felt reports were not sufficient to estimate epicenter or magnitude and further compilation of data is needed.



Wyss, M., 1997, Cannot earthquakes be predicted?: comment on Geller and others, 1997: Science, v. 278, p. 487. 



 Robert J. Geller et al. are on shaky ground when they state, in the title of their Perspective (1), that earthquakes cannot be predicted. In spite of their advice, we should not stop studying the physics of preparation for catastrophic rupture, in the held, the laboratory, and theoretically; neither should we stop measuring crustal parameters that might furnish constraints for physical models; and we should continue researching statistical methods to evaluate prediction claims and to test hypotheses quantitatively.

 Some of the arguments Geller et al. put forward are incorrect. For example, the "slip on geological faults" is not always as "sudden" as they state. In 10% to 30% of large earthquakes, foreshocks occur days (2) to months (3) before the main shock. Seismologists agree that foreshocks are a symptom of some preparatory process to the main rupture. Thus, foreshocks are precursors. If that process could be detected and understood by measuring the several physical parameters of Earth's crust that probably change during it then prediction would be possible, even if foreshocks themselves can be identified with a low probability only (4).

 When Geller et al. state that "[t]here are no objective definitions of 'anomalies'" and that "statistical evidence for a correlation is lacking," they appear to be referring to specific papers that have been criticized (5). However, there are examples of clearly formulated, even tested, hypotheses. Evison and Rhoades (6) formulated a rigorous statistical test and applied it in real time to their well-defined hypothesis of precursory earthquake swarms. The algorithm M8 (7) has been tested in real time, and critically evaluated by others (8). The hypothesis of precursory quiescence also has been clearly stated (9), and specific predictions have been made to test it (10). On the basis of a mathematical model of failure of earth materials, the hypothesis of increasing moment release has been formulated (11) and tested by predictions (12).

 Geller et al. are also incorrect in stating that "no quantitative physical mechanism links the alleged precursors to earthquakes." Laboratory rock fracture experiments have shown that dilatancy occurs in rocks under high deviatoric stresses and that rock properties are drastically altered by this phenomenon (13). Dilatancy could explain many precursors, as proposed by Scholz et al. (14). An alternate mechanism to explain precursors is a reduction in ambient stress level that results from strain softening (15) during days to years before catastrophic failure in a major earthquake. This phenomenon is routinely observed in the laboratory in stiff rock presses, and it has been modeled quantitatively by modem friction laws (16), with the result that years before large subduction shocks occur, a reduction of stress is expected near the source volume (17). Thus, several types of measurements could furnish observable precursors. Finally, the pore pressure of underground fluids, which is known to play an important role in rupture initiation along many faults (18), can be altered in a number of ways, which also could lead to precursors. Some of these models are quantitative, others not yet because too few constraints exist at this time.

 Geller et al. are again incorrect when they say that "the leading seismological authorities of each era have generally concluded that earthquake prediction is not feasible." They should have added "with the current knowledge" to this sentence. I remember the frustration of Richter, when asked sensationalist questions about unfounded predictions, instead of the science of earthquakes. However, as cited by Geller et al., Richter did not advocate an opinion that earthquake prediction was inherently impossible.

 Geller et al. state that they believe that earthquakes occur at random. Randomness would require the assumptions that the tectonic stress is near failure everywhere and at all times, and that the stress drops are small, depleting the local elastic energy available for further ruptures only to an insignificant degree. But the accumulation and release of strain that has been measured leading up to and following earthquakes, respectively, suggests otherwise. For example, the M7.2, Kalapana, Hawaii, earthquake in 1975 was anticipated on the basis of the observed accumulated strain (19). Over decades, compressive strain of 4 (10-4) accumulated, and during the earthquake the same amount of strain was released (20). This conclusion was also reached by Reid et al. (21) for the 1906 San Francisco earthquake. Precise leveling along the coast of Japan (22), and geological records of recent sedimentation along beaches (23) show that strain is released in great earthquakes only after it has been accumulated over centuries.

 The figure in the Perspective by Geller et al. (p. 1617) does not support the idea that earthquakes are unpredictable. It shows, instead, that the sizes of cracks available for failure in earthquakes are fractally distributed. In volumes where no strain energy has been built up by tectonic processes, however, large earthquakes cannot occur regardless of the nature of the crack distribution. Along the plate margins, where the vast majority of all earthquakes occur, the stresses are likely to be low, and the stress release may be nearly complete (24).

 At the time of Columbus, most experts asserted that one could not reach India by sailing from Europe to the west and that funds should not be wasted on such a folly. Geller et al. make a similar mistake, but I doubt that human curiosity and ingenuity can be prevented in the long run from exploring fully the extent to which at least some earthquakes are predictable, although it is not easy. Such discoveries will be made in Japan, Europe, or China if the current lack of funding for earthquake prediction research continues in the United States.



Wyss, M., 1997, Case 23: nomination of precursory seismic quiescence as a significant precursor, in Wyss, M., and Dmowska, R., ed(s)., Earthquake prediction - state of the art: Pure and Applied Geophysics, v. 149, no. 1, p. 79-113. 



 "Documentation in Support of the Nomination Submitted by the Author



 Summary. The purpose of this document is to nominate seismic quiescence for the IASPEI List of Significant Precursors. Precursory seismic quiescence is defined as a statistically significant decrease of the background seismicity rate restricted to a mainshock volume (and possibly its vicinity), that precedes this mainshock by months to years, and that occurs in all magnitude bands (or possibly in the larger magnitude bands only). The size of the mainshock can vary from 3.5 to 9.5, depending on the tectonic environment, but it must be a major event and it is usually followed by an aftershock sequence.

 There have been at least two successful earthquake predictions based on quiescence. In three additional predictions there are questions whether the prediction may have been fulfilled by chance. In spite of these successes I do not view the method as fully matured and ready for application. Rather I see it as needing further development but matured enough to be placed on the List. More case histories, refinements of the detection method, and constraints for the physical explanation are still needed. The total number of quantitatively measured case histories of seismic quiescence that can be viewed as reliable is between 10 and 20. If false alarms are defined as instances of quiescence that are as significant or more than some precursory quiescences, then the false alarm rate may be approximately 50%. This rate of false alarms is tolerable. The rate of failures to predict is less well-known, but it may also be in the 50% range.

 The greatest source of errors that interferes with correctly identifying precursory seismic quiescence is the heterogeneous reporting in earthquake catalogs. Many reductions in reporting rate can be traced to artificial sources. Without a careful study of the reporting history of a catalog, and testing of proposed quiescences, false claims of precursors are possible.

 After careful consideration of the current state of our understanding of quiescence, I feel that several very strong case histories exist as do several weaker ones. Thus I no longer doubt that the phenomenon of precursory quiescence actually occurs, although I feel that its characteristics are poorly known at the present."



Zuniga, F.R., Wyss, M., Wilson, M., and Wahr, J., 1983, Stress drops of earthquakes in the source volume of the Kalapana earthquake and finite element modeling of the build up process [abs.]: Eos, Transactions, American Geophysical Union, v. 64, no. 45, p. 901. [AGU fall meeting, San Francisco, CA, Dec. 5-9, 1983, Program and abstracts] 



 The Kalapana earthquake of November 29, 1975 (Ms = 7.2) has provided an opportunity to study in detail the preparatory process that may build up to produce a large tectonic earthquake due to the amount and quality of data recovered by geodetic and seismic networks. Stress drops were estimated for more than 10O earthquakes (ML = 3.5 + 0.5) which occurred in the mainshock source volume between 1962 and 1980. The SH-spectra were obtained from a station located 45 km to the north of the source area. Subvolumes of the main rupture which we previously identified as asperities had stress drops which were approximately double the values found in the rest of the source volume during the pre-mainshock period. During the aftershock period this distinction no longer existed. In order to further test the hypothesis of locked portions of the fault (asperities), a numerical approximation to the build up process was carried out using finite elements and an algorithm which, includes the nonlinear characteristics of the fault zone. Thus, parameters such as position of the peak asperity strength can be matched to actual geodetic observations, and a model can be developed relating the ambient stress to the average stress-drop. The model also attempts to account for the geodetically documented precursory strain softening by varying the stress regime on the fault surface in time and space.



Zuniga, F.R., Wyss, M., and Wilson, M.E., 1987, Apparent stresses, stress drops, and amplitude ratios of earthquakes preceding and following the 1975 Hawaii Ms = 7.2 main shock: Bulletin of the Seismological Society of America, v. 77, no. 1, p. 69-96. [See later comments (Savage and Meyer, 1989; Zuniga and Wyss, 1989).] 



 S-wave spectra for approximately 300 earthquake signals (2.8  ML  3.9) were obtained from hand-digitized Wood-Anderson records from Hilo, Hawaii. All sources were located within part of the rupture volume of the 1975 Hawaii M5 = 7.2 earthquake. The epicentral distance to Hilo was about 45  3 km, the back azimuth was 180  10 (south), and the sources were located at depths of 9  1.4 km. The apparent stress and Brune stress drop, based on 3-sec windows of the S waves, were examined for possible temporal and spatial dependence. Most of the data showed a remarkable constancy of the average apparent stress and stress drop per event as a function of time. No measurable change in average signal content took place at the time of the main shock. A statistically significant difference in the average stress parameters per event was found between neighboring subvolumes (radius ~ 5 km) of the 1975 aftershock zone: a volume previously proposed as asperity based on seismicity pattern interpretation contained earthquakes with higher apparent stresses of hs = 9.0  8.8 bars compared to the neighboring volume with hs = 4.2  6.1 bars. Seventy-eight spectra obtained from a second station showed the same difference between the two volumes as that found at station Hilo, suggesting that the signal differences should be interpreted in terms of source differences. In addition, amplitude ratios of SV/P waves measured at Hilo showed that a systematic difference of 10 in fault plane orientation existed during years before the 1975 main shock. This agrees with the rotation of the fault plane during the main rupture reported elsewhere. We hypothesize that heterogeneities along the fault plane with dimensions of about 5 km cause changes in fault plane dip, differences in average stress release per earthquake, strong contrasts in seismicity patterns, and differences in aseismic strain release by fault creep. These same heterogeneities in the fault plane apparently also control the location of major earthquakes and the complexity of their ruptures.



Zuniga, F.R., 1987, A study of earthquake source parameters and stress processes: Boulder, CO, University of Colorado, Ph.D. dissertation, 178 p. 



 The frequency content of signals emanated from small earthquakes which occurred in the aftershock area of the Kalapana, Hawaii mainshock of November 1975 in the period 1962-1981 were analyzed by spectral methods. Two of the source parameters obtained, namely the stress-drop and the apparent stress, were then employed as measures of the high- to low-frequency ratio of the signals and these ratios were correlated with the location of the generating events. Events occurring in anomalous zones, previously proposed to be asperities, were shown to have higher frequency content than those in neighboring volumes.

 By analyzing events which took place before the occurrence of the mainshock and comparing them with those which took place after it we also reached the conclusion that the average stress release per event is not a measurable function of ambient stress in the volume studied.

 The partitioning of stress involved in the generation of south flank events was studied. Events occurring before the Kalapana mainshock had the same amount of partial stress drop in the average than those occurring after it. No change was detected as a function of space. Our results reflect that properties such as the strength of the rocks remain unaltered and therefore asperities remain asperities after the occurrence of a large event.

 The stress build-up that lead to the occurrence of the Kalapana mainshock was modeled using finite elements and by simulating the nonlinear behavior of the fault zone (assuming the existence of an asperity) through a varying friction law which depends on space and slip. Results indicate that an asperity such as the one proposed could be responsible for much of the observed deformation and that this type of numerical modeling can be employed in order to evaluate the possible onset of a future large event.

 The focal mechanism and depth of an earthquake occurring off the coast of Crete were determined by means of synthetic seismogram computation via the reflectivity method. Results show that the method can be successfully applied to digital teleseismic long period data. The mechanism and depth obtained provide another piece of information about the state of stress of the Hellenic arc.



Zuniga, F.R., and Wyss, M., 1989, Reply to Savage and Meyer's ''Comment on 'Apparent stresses, stress drops, and amplitude ratios of earthquakes preceding and following the 1975 Hawaii MS = 7.2 main shock''': Bulletin of the Seismological Society of America, v. 79, no. 4, p. 1305. [See Savage and Meyer, p. 1300-1304] 



 Savage and Meyer have correctly pointed out that events west of a zone previously identified as an asperity are responsible for the lack of statistically significant change reported between stress drops of events preceding and following the Kalapana, Hawaii, main shock when grouping them together with those events occurring inside the asperity as defined in previous studies (Wyss et al., 1981).

 They also mention, however, that after the Kalapana main shock no statistically different pattern of stress drops emerge between adjacent regions (labeled 4 and 5, not including the events to the west). They employ a Student's t test to measure the difference, applicable to small samples (i.e., <30), but using a standard deviate z test we find that the difference still holds at a confidence level better than 95 per cent.

 Results from small, digitally recorded events which occurred in January 1981 also show a difference in their average stress drop when comparing data from the two regions, as reported in our study. None of these events lie west of the original region 5. This observation does not agree with the results by Savage and Meyer for earthquakes which took place between March and May, 1982.

 Thus it seems that an interpretation satisfying all the observations is the following: At the time of the main shock, the high-frequency content of small events in parts of the source area decreased slightly. The contrast in high-frequency radiation between subvolumes existed in the earlier data sets but decreased after 1981 to a point where it could no longer be measured.



Zuniga, F.R., 1989, Relationship between apparent stress and Brune stress drop of small earthquake signals in Hawaii [abs.]: Seismological Research Letters, v. 60, no. 1, p. 25. [Seismological Society of America, 84th annual meeting, Victoria, British Columbia, Apr. 19-21, 1989 (Abstracts)] 



 The relationship between apparent stress (AS) and Brune stress drop (BSD) is investigated with focus on the validity of (Brune's) "partial stress-drop" vs. "friction overshoot" stress drop mechanisms. Data comes from the spectral analysis of earthquake signals in the south flank of Kilauea volcano in Hawaii between 1962 and 1981, recorded on two stations, one analog and one digital.

 Even though differences in tectonic regime were previously found through other indirect measurements such as geodetic strain and seismicity, the relation between AS and BSD for signals in different volumes inside the source volume of the Kalapana, 1975 mainshock, appears quite constant. Results indicate that, within the limitations of the corrections and assumptions involved, the majority of over 400 signals analyzed conform to the Orowan model (e.g. final stress equal to frictional stress) and that those events not fulfilling this hypothesis indicate a mechanism of partial stress-drop. There also appears to be a tendency for events which show smaller ratios of BSD over effective stress to also have small stress drop values. Our results give further support to the idea that the Savage and Wood inequality is usually violated in reality.