ALASKA'S 

GOOD FRIDAY 

EARTHQUAKE 

MARCH 27,1964 

A Preliminary 

Geologic 

Eval uation 

GEOLOGICAL 

SURVEY 

CIRCULAR 491 

ALASKA'S GOOD FRIDAY EARTHQUAKE, MARCH 27,1964 

A Preliminary Geologic Evaluation 

By 

Arthur Grantz, George Plafker,and 

Reuben Kachadoorian 

Washington 1964 
United States Department of the Interior 

STEWART L UDALL, SECRETARY 

Geological Survey 

THOMAS B. NOLAN, DIRECTOR 

Free on application to the U.S. Geological Survey, Washington, D. C. 20242 
CONTENTS 

Introduction------------------------------------------------------------------------ 1 

Scope of present study----------------------------------------------------------- 1 

Acknowledgments--------------------------------------------------------------- 1 

The earthquake and its aftershocks, March 27-30, 1964 --------------------------------- 2 

The main shock----------------------------------------------------------------- 2 

Aftershocks and their relation to major geologic structures ------------------------- 2 

Areas of tectonic uplift and subsidence------------------------------------------------ 5 

Effects on land--------------------------------------------------------------------- 6 

Avalanches and rockslides------------------------------------------------------- 6 

Cracks, subsidence and mud spouts----------------------------------------------- 6 

Cracks and pressure ridges in lake and river ice----------------------------------- 6 

Volcanic activity---------------------------------------------------------------- 10 

VVater supplies ----------------------------------------------------------------- 10 

Damming of rivers-------------------------------------------------------------- 10 

Effects on coa~ts ------------------------------------------------------------------- 10 

Submarine landslides in fiord deltas and related large waves ------------------------ 10 

Seismic sea waves (tsunamis)---------------------------------------------------- 11 

VVaves of unknown origin in Prince VVilliarn Sound ---------------------------------- 12 

Sea life------------------------------------------------------------------------ 12 

Damage to cities, transportation routes, and industries --------------------------------- 14 

Cities ------------------------------------------------------------------------- 14 

Anchorage ----------------------------------------------------------------- 14 

Seward -------------------------------------------------------------------- 15 

VVhittier-------------------------------------------------------------------- 16 

Valdez--------------------------------------------------------------------- 16 

Horner--------------------------------------------------------------------- 24 

Transportation routes ----------------------------------------------------------- 24 

The Alaska Railroad -------------------------------------------------------- 24 

Highwayroutes------------------------------------------------------------- 25 

Oil, gas, and coal industries ----------------------------------------------------- 25 

Areas damaged bv seismic sea waves and waves of unknown origin------------------- 25 

Geologic factors influencing earthquake damage---------------------------------------- 25 

Compaction ---------------------------------------------------------------- 26 

Lurching------------------------------------------------------------------- 26 

Landslides ----------------------------------------------------------------- 26 

Damage to structures ------------------------------------------------------- 26 

Submarine landslides in fiord deltas ------------------------------------------ 34 

Land-1evelchanges --------------------------------------------------------- 34 References---------------------------------------------------~--------------------- 34 
6qo 

6oo 

50 0 

b 

0 

50 100 

/ 

/ 

/ 

~ 

200 MILES 

I 

' ' I 

OCEAN 

o-{>-

150° 1~6° 111-2° 

EXPLANATION 

D t 

Fault, showing direction of dip 

Dashed where inferred; D, net apparent 

downthrown s ide ; drr ow s hows dire c ti on 

of apparent horizo ntal •ove•ent; 

hac hures on downthrown side indicate 

•oveaent in Re ce nt tiae 

-----.iiXI?-- Sub!larine contours in meters 

• Volcan.oes, act ive since 1760 A. D.-

[). 

Ext i net vo I cano 

large earthquake epicenters 

• lnter.,.diate depth 

0 Sha 11 ow or unknown depth 

-9--

Depth unknown 

Approximate limit of human perceptibility 

ApproxiJnate 1 imit of cracking and forM.tion 

of pressure ri4ges in lake and river ice 

App roxiute 1 imit of significant earthquake damage 

1.38° 

Area of epicenter of the March 27 

eart hquake and its aftershocks 

~' loferred tec~nlc hinge zone 

0 

0 

0 

1311-0 0 130° 

Figure 1. Map of Alaska showing the area of the March 27 earthquake and its aftershocks to March 30, 1964; the area affected by the earthquake; 

epicenters of previous large earthquakes; major faults; volcanoes; and the Aleutian Trench. 
ALASKA'S GOOD FRIDAY EARTHQUAKE, MARCH 27,1964 

A Preliminary Geologic Evaluation 

By 

Arthur Grantz, George Plofker,ond 

Reuben Kachadoorian 

INTRODUCTION 

At 5:36 p.m. on Good Friday, March 27, 1964, a 

great earthquake with a Richter n:a_gnitude of 8.4 to 

8.6 crippled south-central Alaska.Y It released at 

least twice as much energy as the 1906 earthquake 

which wracked San Francisco, and was felt on land 

over an area of almost half a million square miles. The 

earthquake left about 114 dead or missing, and Alaska's 

Governor Egan has estimated that it will cost one-half 

and possible three-fourths of a billion dollars to 

replace the damaged or destroyed private and public 

property. Many water-front communities, wherefishing and shipping were the main industries, lost most 

of their means of livelihood. 

Had the earthquake occurred earlier, during the 

school and business day, the loss of life would have 

been much higher, and had it struck a more populous 

region, losses of both life and property would have 

been far greater. And if the seismic sea waves 

associated with the earthquake had struck the coastal 

communities of south-central Alaska at high, rather 

than at low tide, the loss of life and property would 

have been even greater than the crippling losses that 

were actually sustained. 

This earthquake serves as a reminder that catastrophic earthquakes are a recurring phenomenon in 

the circum-Pacific region and that man must construct his cities and public works in a manner that 

will minimize the damage. Basic to the design of 

earthquake-resistant structures is adequate knowledge of the subsurface conditions upon which the 

structures are built. 

For some time, the U. S. Geological Survey has 

been studying foundation conditions in urban areas. 

Reports prepared under this program provide information directly related to the problem of designing 

and locating large structures in seismic areas. A 

Geological Survey report several years ago by Miller 

and Dobrovolny (1959, p. 103-107) containedawarning 

of the possibility of earthquake-triggered landslides 

in Anchorage and vicinity. And indeed on March 27 

such slides produced most of the damage. 

}j All dates and times given are Alaska Standard 

Time, rather than Greenwich Mean Time which is used 

in the seismological literature. 

1 

SCOPE OF PRESENT STUDY 

The present report is based on a reconnaissance 

of the earthquake-damaged area made between March 

29 and April 9, primarily to obtain firsthand information upon which to plan emergency studies that might 

aid in reconstruction of the earthquake-damaged areas. 

The emergency studies are already underway. Two 

Survey geologists are now studying the slides in 

Anchorage that occurred during the March 27 earthquake in order to determine the mechanism of failure 

which produced them and to assess the danger of 

future movements that might occur on these landslides 

and other areas susceptible to landsliding. Two geologists are working with The Alaska Railroad to suggest 

ways of repairing the major damage to the lines 

serving the ports of Whittier and S e war d. Most of 

this damage was caused by ground movement produced 

by the earthquake. Two other geologists are now 

studying the ports of Valdez and Seward. These towns 

are faced with serious problems at their waterfronts, 

and geologic study is required to resolve them. 

In addition to these emergency studies, more detailed follow-up investigations of the geologic aspects 

of the earthquake and the damage it caused are planned. 

As these studies are completed, more detailed reports 

on the geologic implications and effects of the March 

27 earthquake will be prepared and the tentative conclusions of the present study will be elaborated upon 

and perhaps revised in many particulars. 

ACKNOWLEDGMENTS 

Most of the logistic support for this investigation 

was provided by the United States Army, Alaska 

(USARAL)-and this under the difficult conditions which 

existed in south-central Alaska immediately after the 

March 27 earthquake. We wish particularly to thank 

Col. M. L. Fallwell, Lt. Col. H. E. Nolde, and their 

staffs, and the officers and men of the U. S. Army 

Headquarters Aviation Battalion at Fort Richardson 

for their efficient and enthusiastic support of our field 

work. Our special thanks are also due to those many 

Alaskans, both private citizens and public officials, 

who related their experiences, provided data, and 

facilitated our work in many other ways. Many members of the U. S. Geological Survey contributed field 
and office support without which the timely presentation of this preliminary evaluation would have been 

impossible. 

THE EARTHQUAKE AND ITS AFTERSHOCKS, 

MARCH 27-30, 1964 

THE MAIN SHOCK 

The epicenter of the March 27 earthquake was at 

lat 61.05° N. and long 147.50° W. (figs. 1 and 2), near 

the east shore of Unakwik Inlet in northern Prince 

William Sound.Y This is a region of high rugged 

topography with many glaciers, and it is sparsely 

settled. The nearest sizeable communities are the 

small cities of Valdez and Cordova, 40 and 70 miles 

to the east and southeast, and Anchorage, a city of 

about 50,000 people SO miles to the west. The focus, 

or actual point of origin of the earthquake, has been 

estimated to be about 20 kilometers (about 127.2 miles) 

below the surface. The shallow depth of the earthquake 

contributed to the large amount of damage it produced. 

The magnitude, or relative energy, released by the 

March 27 earthquake, estimated from seismograms at 

four United States stations, ranged from about 8.4 to 

8.6 and possibly 8-3/4 on the revised Richter 

magnitude scale. It was thus greater than that of the 

1906 San Francisco earthquake (8.3) and equaled or 

exceeded that of the largest individual shock of the 

1960 Chilean earthquake (8.4). The March 27 earthquake produced significant damage to structures and 

property over a land area of about 50,000 square 

miles, and ice was cracked or buckled on some lakes 

and rivers within an area of about 100,000 square 

miles (fig. 1). The quake was perceptible to people 

in at least half of Alaska, and the area of perceptibility, if ocean areas could be included, would exceed 

a million square miles. (The limit of perceptibility 

on figure 1 is shown conservatively; the earthquake 

may have been felt beyond this area under conditions 

which are particularly favorable for observing small 

tremors). 

The main quake was reported to have lasted about 

17.2 to 4 minutes in the region that suffered significant 

damage, suggesting that it occurred along a break or 

fault of considerable length. Some observers reported 

an initial short, sharp shake, followed by a strong 

rolling motion. Observers in the Anchorage area 

generally reported a north-south or northwest-southeast direction of motion or shaking, but elsewhere too 

few reports were obtained to permit generalizations. 

Independent data on the direction of ground waves 

were recorded in the pressure ridges and marginal 

zones of broken ice which formed along the shorelines 

of some lakes in the area with cracked ice outlined in 

figure 1. These features are discussed more fully in 

'],_/These epicentral and other seismological data 

concerning the March 27 earthquake and its principal 

aftershocks given here and below are in part from an 

unpublished preliminary U. S. Coast and Geodetic Survey data release, and in part from an April 17, 1964 

report by the U. S. Department of Commerce, Coast 

and Geodetic Survey, entitled, Preliminary reportPrince William Sound, Alaskan earthquake, MarchApril, 1964. 

2 

another part of this report. The largest pressure 

ridges and widest zones of crushed ice seemed to form 

along shores that are roughly normal to the reported 

direction of ground motion, at least in the Anchorage 

and Knik Arm areas and the Kenai Lowland, although 

the orientation of these pressure ridges varies widely. 

Low-altitude areal photographs of frozen lakes taken 

shortly after large earthquakes could provide clues to 

the local direction of earthquake induced ground motion. 

AFTERSHOCKS AND THEIR RELATION TO 

MAJOR GEOLOGIC STRUCTURES 

The epicenters of the 52 principal aftershocks 

before 6:53 (AST) a.m. March 30 are shown on 

figure 2 and the largest was 6. 7 in magnitude. Eleven 

were of magnitudes greater than 6; 10 of them 

occurred within 24 hours after the initial shock. The 

aftershocks to March 30 occurred in an area from 

about 15 miles north of Valdez to about 30 miles 

s::>uth of the Trinity Islands off southern Kodiak 

Island. All were northwest of the axis of the Aleutian 

Trench, and almost all lie southeast of the axis of the 

Kenai-Chugach Mountains and the mountains of Kodiak 

Island (fig. 2 ). Only one aftershock occurred northeast 

of the main shock; the epicenters are most heavily 

clustered on the northeast and the southwest ends of 

the aftershock area, and are relatively sparse in the 

central part. 

The aftershocks range in depth from less than 20 

km to about 60 km (U.S. Coast & Geodetic Survey data, 

see footnote 2, and C. F. Richter, oral communication 

April 17, 1964). The Coast and Geodetic Survey's 

report also states (p. 32) ... "There is some indication 

of a slight increase in depth of focus" of the aftershocks "towards land" that is, toward the northwest. 

The epicenters of March 27 to 30 lie within a welldefined belt of shallow and intermediate-depth earthquakes which follows the Aleutian Arc from Kamchatka 

to south-central Alaska, where the arc enters the 

North American continent (see Gutenberg and Richter, 

1954). Most of the earthquakes recorded in Alaska lie 

within this belt. A characteristic of this earthquake 

belt, and of others associated with island arcs throughout the world, is that they lie on the concave, generally 

continent a 1 side of the associated deep oceanic 

trenches. Also, the focal depth of the earthquakes 

increases from the oceanic trench toward the adjacent 

continent. This distribution of earthquakes in the 

Aleutian Arc and Trench is believed by many geologists and geophysicists to indicate that the earthquakes originate in a fault or perhaps a zone of 

movement which extends with a moderate northward 

dip from the Aleutian Trench northward beneath the 

Aleutian Arc. The March 27 earthquake and its aftershocks to March 30 conform to this typical distribution, and it is tentatively inferred that these earthquakes originated along the postulated northwestdipping fault or zone of movement associated with 

the Aleutian Arc and Trench. Although the epicenters 

of the main shock and some of the aftershocks are on 

the mainland, they are no farther inland than the 

northernmost volcanoes of the Aleutian Arc (fig. 1), 

and it is noteworthy that the major tectonic trends of 
+ 

+ 

Midd l eton l slandt? 

s 

G u F 0 F 

F c E 0 c N 

56' 

50 50 100 MILES 

CHIRIKOF ISLAND 

EXPLANATION · 

' Epicenter of the March -27th, J961J, earthquake 

and inferred tectonic hinge zone 

• 2 Epicenter of aftershocks as of March 30, 19611-

Nwnbers refer to table 

• location of many sma II rock s 1 ides 

or indi v idual large rock slides 

.. ETil2D 0 Intense Moderate Slight 

Damage to transportation rout'e 

Position of the ts.c.G. vessel Sedge 

\ 

at time of aftershock 37 

' -· I 

·----r--.y I 

~....., 

\ '" 

<>'' 

Alaskan Standud Time 

March 27 

I. 5:36 .1 ~ PM M<lg. 8 .• 28. 5:07.3 

2. 8: 08 . 8 29. 5:38.6 

3 . 8: 32 ~ 7 30. 6!12.3 

.. ~;q.o 31. 7!21 .I 

5. 9: 10.4 Mag. 6. 2 32. 7!37 . 8 

6. 9!30.5 33. a : oq .? 

7. 10!33. 8 Mag. 6.5 3 •. a: sa.4 

8. 10!3 9. 7 35 . 9:52.8 

9. 11:01 .0 Mag. 6 .2 36. 11!16 .0 

10. II :52.9 Mag. 6. 2 Ma r ch 29 

March 28 37 . 12:08 .1 AM 

II. 12:35.3 AM 38. ,·2!49.7 

12. 12:35.7 Mag. 6.3 39. t:I44.J 

13. 12!33.0 .a. 2:33.2 

"· I :08.5 .Mag. 6.2 "· 6:09 . 3 

15. 2:03.3 .2. 6!41.0 

16. 2:20 .8 Mag. 6 .5 .3. 6:53.5 

17. 3:01.3 ... 6:45.6 

18. 3!27 .7 .5. 1!.: 18. I PM Mag. 

19. 4:1l6.3 .6. 9:09.6 

20 • • 4!ll-7 .7 Mag. 6 .3 March 30 

21. 4!tt9.3 Mag. 6.5 .7. I !48.7 AM 

22. 6!1411-.6 •a. 2:05.7 

23 . I 0~29.1 Mag. 6 . 6 ... 3:03.6 

2 •. I: ll6.3 PM 50. 3:32 .3 

25 . 3:09 . 6 51. 5!07.8 

26. 3:29 . 6 52. 6!09 . 5 

27. 3!4-8.3 53. 6!53.2 

Magnitudes by Pasadena 

Figure 2. Map showing epicenter, aftershocks, inferred tectonic hinge zone, areas of significant rock slides, and damage to transportation routes. 

6 .7 
+ 

60 ° + 

58" + 

50 

-' 148° \ 144 ° T 

,.. -s+ -'"' ...... 

<}> .... 

~ + "114 

G U L F 0 F 

0 C E A N 

100 MILES 

142 ° 

I 

I 

+ __, 

I kGfLL 

14THs 

I , ·---.r--y 

EXPlANATION 

,~· Inferred tectoni c hinge zone 

EZJ ApproxiWiate area in which land level has dr opped 

ApproxiN.te area in 

~ which land level has r isen 

Mo data on real land level 

(5 ) -¢-' (6.5 "-7 .5") 

Location of tide ;auge showing record ed 

amount of and dIrection of 1 and I eve I change 

•. - () ' ) • +(6' ) 

location of station showing estimated 

uount and direc tion of I and 1 eve I change 

X 

Station reporting no apparent 

land level change 

Figure 3. Map showing land-level changes along coast of s outh-central Alaska. 
southern Alaska bend sharply southwest in the region 

between the northernmost aftershocks and the northernmost volcanoes. 

In contrast to the uniform and characteristic distribution of the epicenters with respect to the Aleutian 

Arc and Trench, there is no uniform spatial relationship between the epicenters and known continental 

faults, including the Chugach-St. Elias-Fairweather 

fault system, the largest in coastal Alaska. The 

western part of this fault system separates moderately deformed and unmetamorphosed Tertiary sedimentary rocks along the Pacific Coast from a broad 

terrain of severely deformed and partly metamorphosed Mesozoic marine and some volcanic rocks 

which underlie Kodiak Island and the Coast Range. 

Epicenters of the aftershocks to March 30 fall on 

both sides of this fault system and the trend of the 

belt of epicenters is oblique to it. Possibly some 

movement occurred along parts of the Chugach-St. 

Elias-Fairweather fault system during the March 27 

earthquake, but the main earthquake and its aftershocks are probably unrelated to this fault system. 

A brief aerial reconnaissance for a surface rupture 

was made in a broad northeast-trending tectonic 

hinge zone in the area that contained the epicenter of 

the main shock and numerous rockfalls and avalanches. 

This zone lies between the area to the southeast 

which was tectonically uplifted and the area to the 

northwest which was tectonically depressed (fig. 3) 

and is parallel to the trend of the epicentral region, 

the Aleutian Arc and other major geologic structures 

in this part of Alaska, and numerous faults, topographic 

features, and some geologic contacts in Prince William 

Sound (Condon and Cass, 1958). 

Despite these general similarities in trend, the 

zone between areas of tectonic uplift and subsidence 

apparently does not follow a major fault boundary 

between rock sequences of widely differing character 

as does the Chugach-St. Elias-Fairweather fault 

system. In the absence of such a major tectonic 

boundary the surface expression of the faulting which 

is inferred to have produced the very shallow March 

27 earthquake could be either a zone of slight tilting 

or flexure between the areas of positive and negative 

tectonic movement, or a surface rupture or fault. No 

surface rupture or fault line related to the March 27 

earthquake was found, but a surface break could easily 

have been overlooked, especially as new snow had 

fallen before we reached this area. It is hoped that 

detailed geologic studies will soon determine whether 

or not the March 27 earthquake produced fault displacement at the surface. 

AREAS OF TECTONIC UPLIFT AND 

SUBSIDENCE 

Tectonic uplift and subsidence accompanying the 

March 27 earthquake have affected an area of at least 

34,000 square miles in south-central Alaska (fig. 3). 

East of the tectonic hinge-zone, coastal land levels 

are up as much as 7.5 feet; to the west of this zone, 

the land level has subsided as much as 5.4 feet. 

Vertical land movements have been measured only 

in the coastal areas where sea level furnishes a 

5 

reference datum; the inland limits of the movements 

cannot be determined without precis e leveling. 

Amounts of vertical movement shown in figure 3 are 

mainly preliminary estimates obtained from staff 

tide gauges, tide changes estimated by people familiar 

with the areas, and observations made by the writers. 

Records from only five stations (shown by a distinctive 

symbol on fig. 3) were available from U. S. Coast 

and Geodetic Survey tide gauges. Work currently 

underway by the U. S. Coast and Geodetic Survey to 

install additional tide gauges andre-level existing ones 

should provide accurate data on the absolute amount 

and direction of land movement relative to sea level. 

Wherever possible, the effects of local ground compaction and differential settling of tide gauges were 

taken into account in evaluating results of tidal reference stations located on surficial unconsolidated 

deposits. 

The major area of subsidence which is shown on 

figure 3 is a zone trending from northeast to southwest that covers 22,000 square miles, and includes 

most of the Kenai Peninsula and at least the northern 

two-thirds of Kodiak Island. The largest amount of 

confirmed subsidence is at Kodiak, where tide gauges 

indicate a 5.4 foot drop. Data on land levels in southern 

Kodiak Island, the Trinity Islands, and Chirikoflsland 

are sparse, but there is some indication that the 

subsidence diminishes toward the southwest. The 

amount of subsidence on the Kenai Peninsula decreases 

westward and is imperceptible at Kenai and Ninilchik. 

There is no reported change in land level on the west 

side of Cook Inlet. 

The major area of uplift covers at least 12,000 

square miles and includes the islands and mainland 

of Prince William Sound from a line between Chenega 

and Valdez Arm eastward at least as far as the Bering 

Glacier and a large segment of the Continental Shelf 

southward to Middleton Island. Uplifts of 6.5 to 7.5 

feet are recorded on the tide gauges at Cordova, and 

unconfirmed estimates of land uplift in Prince William 

Sound are as much as 10 feet. Extensive coastal tracts 

of mud flats, beaches, and reefs throughout the area 

are now exposed that formerly were seen only at 

lowest minus tides (fig. 4A). Yakataga, the closest 

station east of Bering Glacier, reports no change of 

land level so that the eastern boundary of the uplifted 

area probably lies in the uninhabited coastal stretch 

between Bering Glacier and Yakataga. 

Possible anomalous areas in the regional pattern 

are Valdez and Yakutat, where subsidences of 2 feet 

and 3 feet, respectively, are reported. However, both 

of these places are situated on deep alluvial fills in 

which compaction, or settlement of tide reference 

markers, can be expected. Additional supporting data 

are needed before these changes in level can be 

confidently attributed to tectonic subsidence. 

Data on land-level changes between the regionally 

uplifted and downdropped areas are sparse, and it is 

not possible to determine whether the two major areas 

are bounded sharply by one or more fault breaks or 

whether they represent warped crustal segments with 

a broad zone of flexure between them. The apparent 

absence of surface breakage within the zone, and a 

single report of no apparent land-level change at Perry 
Island within this zone, lends some support to the 

latter possibility. 

Existing land-level changes along the coast of southcentral Alaska are likely to be permanent, assuming 

that all or most accumulated s t r a in energy in the 

inferred tectonic hinge zone was released by the March 

27 earthquake. If further displacement should take 

place during the aftershock sequence, the amount of 

movement is likely to be relatively minor, and there 

is no firm basis on which to predict whether it will be 

in the same or opposite direction as the initial movement. Three weeks of accurate tidal records at 

Kodiak Naval Air Station since March 27 indicate that 

the land level at that locality is stabilized at close to 

5.4 feet lower than the pre-earthquake elevation. 

EFFECTS ON LAND 

AVALANCHES AND ROCKSLIDES 

Violent ground motion during the March 27 earthquake triggered thousands of snow avalanches and 

rockslides throughout the Kenai Mountains, the 

Chugach Mountains, and the rugged islands of Prince 

William Sound (fig. 2). One rockslide at the south tip 

of Kayak Island, approximately 135 miles southeast 

of the epicenter, killed a Coast Guardsman stationed 

at the Cape St. Elias lighthouse. Innumerable snow 

avalanches, rockslides, and landslides blocked or 

threatened transportation routes between Anchorage, 

Seward, and Whittier (fig. 2). 

Rockslides, some more than 1,000 feet high and of 

great lateral extent, are most abundant along large 

segments of the rugged embayed coastline between 

Resurrection Bay and Montague Strait. Along this 

coastline there is local preferential distribution of 

rockslides and avalanches along either northwest- or 

southeast-facing steep valley walls, but the significance of this observation is not known. 

The violence of ground movement in the area is 

particularly well illustrated near Thumb Cove in 

Resurrection Bay, where a snow cornice was fragmented and thrown from a peak in a northwest direction and deposited on the mountain slopes below. Large 

rockslides and avalanches also are numerous along 

the southeast coast of Montague Island and occur 

sporadically along the eastern shoreline of the Kenai 

Peninsula as far north as Port Wells. 

One or more huge rockslides on the peaks between 

College Fiord and Unakwik Inlet may have been the 

source of a "booming explosion" heard by the crew of 

the fishing boat ~ which was in Unakwik Inlet 

close to the epicenter at the time of the initial earthquake. A group that experienced the earthquake while 

in Port Wells, immediately west of Unakwik Inlet, 

reports that ground motion there was so violent that 

the tops of some trees were snapped off. Numerous 

fresh rockslides, snow avalanches, and broken ground 

were seen by the party during the following two days 

all along the southwest shore of Port Wells and the 

shores of Passage Canal. New snow had concealed 

most of these features when the present writers made 

a reconnaissance flight over the area a week later. 

Avalanches and rockslides were surprisingly few 

in the extremely rugged Chugach Mountains to the 

6 

northwest, north, and northeast of the epicenter. 

Scattered snow avalanches were noted as far east as 

Ragged Mountain, 150 miles from the epicentral area. 

CRACKS, SUBSIDENCE, AND MUD SPOUTS 

Numerous ground cracks, areas of subsidence, and 

mud spouts occurred throughout the zone of damage 

(figs SA,B). Cracks were reported as far away as 

Kaliakh River, near Cape Yakataga, about 190 miles 

east -southeast of the epicenter. Cracks also occurred 

in the Copper River delta area, Kodiak, Glennallen, 

Anchorage, Kenai Lowland, and in other low-lying 

areas closer to the epicenter. 

The major areas of slumping or subsidence were 

observed at Portage, Homer (fig. 6), Knik Arm, Seward, 

and Valdez. 

Spectacular mud spouts were observed at Portage, 

in the Copper River delta area, at Controller Bay, and 

near the Bering Glacier (fig. SB). Mrs. George Larson 

of Portage reported that she saw a small mud fountain 

grow into a sheet of mud about 7 5 to 100 feet high and 

about 100 feet long. She also saw geysers of water as 

much as 50 feet high coming from fractures. Mr. 

Larson saw a mud and water geyser, estimated to be 

about 100 feet high, which bubbled for some time 

after receding. 

In the Copper River delta, mud spouts occurred 

during the initial shock and during some of the aftershocks. Mud deposits were observed on fresh snow 

that fell after the initial shock of March 27. Seal hunters 

at Controller Bay, 140 miles southeast of the epicenter, 

also observed mud spouts, which they described as 

"fountains of muddy water squirting from the ground." 

The frozen surficial crusts of stabilized sand dunes 

along the Copper River and south of Bering Glacier 

were severely broken by longitudinal cracks opened 

by the ground movement. No doubt there are other 

areas in the damage zone that contain cracks, subsidence, and mud spouts but this report discusses 

only those observed by or described to, the present 

writers. 

CRACKS AND PRESSURE RIDGES IN 

LAKE AND RIVER ICE 

Among the many dramatic effects of the earthquake 

was the precipitous breakage of ice throughout much 

of south-central Alaska. The area of ice breakage 

extends from the coast between Yakutat on the east 

and King Salmon on the west to the crests of the 

Aleutian Range, Alaska Range, and Wrangell Mountains (fig 1). Lake and river ice throughout much of 

this area is cracked along the shorelines where the 

floating ice broke loose. The ice cakes acted as inverted pendulums against which the oscillating ground 

pounded repeated 1 y, thereby building up pressure 

ridges in the ice and snow along the shorelines (fig SC). 

These pressure ridges, as well as many long cracks 

across the ice, were in part oriented by shoreline configuration, especially in lakes of irregular shape;however, a large percentage of them appeared to be oriented 

by ground motion during the earthquake. Approximately east-west to northeast-southwest trends were 

particularly numerous on the Kenai Peninsula and in 
Figure 4. Photographs of some geologic effects of the earthquake. A, South coast of MIDDLETON ISLAND 

showing broad uplifted surf-cut reef at base of cliff. B, Landslide damage to The Alaska Railroad 

at POTTER. C, Avalanches across railroad and highway, TURNAGAIN ARM. D, Seismic sea wave 

at SEWARD. - -

7 
Figure 5. Photographs of fractures and mud spouts in unconsolidated deposits and fractures and pressure ridges 

in lake ice produced by the March 27 earthquake. A, In glaciofluvial deposits near SKILAK GLACIER. 

B, In tidal flat alluvium south of BERING GLACIER. _g_, On lake in northern KENAI lowland. _Q_. At 

the head of SKILAK LAKE, Kenai Peninsula. 

8 
Alluvium 

BEFORE 

Original 

ground 

level 

~68' 

. . 

.. 

AFTER 

• Hote: 

• casing is .' • 

· 2.5' 1 ower · ' • 

• due to • • 

' compaction 

·,of alluvium . . 

.. 

~63' 

. . 

• Due 'to tectonic .. 

A.lluvium 

Figure 6. Schematic diagram illustrating 4-5 foot drop of land surface on the HOMER SPIT. 
the Knik Arm area; in the Copper River delta, they 

were generally east-west. On some of the larger lakes 

the surface ice was completely shattered by the combination of ground shaking during the earthquake and 

lake water oscillation during and after the earthquake. 

Skilak Lake on the Kenai Peninsula (fig 50)- is. one . · 

example. Cracks and pressure ridges were also 

observed on river ice throughout . this same area~ 

Comparable cracked lake and river ice was described 

by Davis (1960, p. 491-494) after the April 7, 1958 

earthquake in the Koyukuk River basin of west-central 

Alaska. · 

VOLCANIC ACTIVITY 

The epicentral region of the .Ma;rch 27 earthquake 

lies about 100 miles southeast of several active 

volcanoes in the eastern part of the Aleutian volcanic 

arc. Airline pilots who regularly'. fly along or across 

the volcanic arc report that there was no change in 

volcanic activity there that could be related to the 

earthquake. · · 

WATER SUPPLIES3 

Water service in the seriously damaged communities 

ceased abruptly after the main shock because of 

disruption of water mains and distribution lines and 

cessation of electric power for pumping. Wells drilled 

for public supply--both civil and military--generally 

survived the quake without serious damage. However, 

two relatively small wells in the Turnagain area were 

put out of service by damage to the surface installations. 

The March 27 quake caused significant changes in 

water levels in several artesian wells where measurements have been made periodically for several years. 

One of these, at Campbell (3 miles south of Anchorage), 

was equipped with a recording gauge which survived 

the quake. During the quake the surface vibrations 

and changing water levels combined to produce a band 

"8-hours" wide ancl the full length (2 feet) of the chart, 

at the end of which the water level in the well was 

12 feet lower than at the beginning. In the succeeding 

12 hours the water level dropped 6 feet farther, and for 

the next 3 days the water level remained approximately 

at this level, that is, 18 feet lower than before the 

quake. · 

In several other wells in the Anchorage area, the 

water levels within 5 days after the quake were also 

significantly lower than they had been before the quake. 

The amount of this lowering ranged from 3 to 18 feet, 

and in most wells the levels subsequently rose. 

Although these changes are attributed chiefly to the 

earthquake, seasonal fluctuations and the effects of 

pumping may also have been partly responsible. ln 

Palmer, the effect of the earthquake was observed 

more clearly at three wells, where water levels on 

April 1 were respectively 23.6, 13.2, and 6.0 feet lower 

than on March 24; and where, by April.13, the levels 

had recovered to within 6.6, 2.5, and 2.0feet, respectively, of their positions before the quake. In contrast, 

.1/ This statement was contributed by Harold E. 

Thomas of the U. S. Geological Survey. 

the water level in one well in Chugiak was 2. 7 feet 

higher on March 31 than it had been on March 24, but 

by April 9 was lowered 1. 7 feet. Such behavior was 

exceptional--the general rule was a lowering of the 

water level in artesian wells after the quake, and a 

subsequent rise. . 

Measurements of streamflow suggest that streams 

traversing the Anchorage area lost substantial amounts 

of water by seepage immediately after the quake. On 

March 2, the flow of Ship Creek below the diversion 

_dam at the mountain front was 18.2 cubic feet per 

second; within 4 miles downstream it diminished by 

32 percent to 11.3 cfs. On March 31 the flow at the 

dam was 35.9 cfs, but measured only 2.0 cfs at the 

downstream station--an 86 percent loss which may 

have been caused in part by landsliding. By April 3 

the rate of loss between.the dam and downstream had 

decreased to 66 percent and by April 10 to only 15 

· percent less than at ·the dam. The flow in Chester 

Creek, which heads in the lowlands and has a course 

roughly . parallel to this portion of Ship Creek but 

south of it, was sharply reduced during the week 

immediately after the quake--from 12 cfs on March 

25 to 4 cfs on March 31 but rose to 6)2 cfs on April 3, 

and more than 13 cfs by April6. Taken alone, the loss 

of water from streams_ might be attributed to earthquake-cracking of frozen banks and thus to increasing 

opportunity for seepage. In conjunction with the observed changes of water levels in wells, these streamflow 

measurements suggest that the porosity of saturated 

materials may have been increased at least temporarily by the earthquake. 

DAMMING OF RIVERS 

The great number of landslides and rockslides 

triggered by the. March 27 earthquake could have 

created potential flood hazards and destroyed salmon 

fry by blocking the flow of rivers, Consequently, all 

reports of blocked drainage were promptly investigated by Civil Defense authorities and the intelligence 

section of the U. S~ Army Alaskan Headquarters 

(USARAL), but rio report of significant stream damming 

could be substantiated. 

EFFECTS ON COASTS 

SUBMARINE LANDSLIDES IN FIORD DELTAS 

AND RELATED LARGE WAVES 

Prince William Sound is a region of high glaciated 

mountains intricately sculptured by deep steep-sided 

fiords that make good natural harbors. At places, 

especially at their heads, glacial outwash and alluvial 

streams have built deltas or deltalike platforms into 

the deep waters of these fiords, and these deltas provide almost the only large level sites for buildings, 

docking facilities, and railroad yards. These deltas 

accumulated in deep water, and they form thick prisms 

of water-saturated, poorly consolidated sediments 

which contain much glacial silt and clay, and rest on 

sloping bedrock surfaces. The outer edges of the 

prisms extend to depths of hundreds of feet and are 

commonly very steep. In the vicinity of Whittier and 

Seward, the inclination of the upper part of the submarine slopes at the outer edge of the deltalike deposits, as scaled from U. S. Coast and Geodetic Sur10 
vey Charts, is commonly 30° to 35°, and such slopes 

are probably common in the deltalike fiord fillings 

throughout the Prince William Sound region. Such inclinations are close to the highest slope angles recorded for- detrital sediments deposited in quiet water. 

Such thick steep-fronted submarine sedimentary 

fills are not stable under the impact of the strong 

ground motion produced by large earthquakes, and the 

March 27 earthquake caused large submarine landslides along the waterfronts at Valdez and Seward, 

at Thumb Cove in Resurrection Bay, and probably at 

Whittier (see fig. 7). Similar submarine landslides 

probably occurred at many other unrecorded localities 

in the Prince William Sound region. At Seward and 

Valdez they carried away large parts of the waterfront (see figs. 8A, and 9) including docks, warehouses, 

and part of a railroad yard, and left deep water where 

previously there were docks, buildings, and mudflats, 

At Seward, for example, water at the site of a former 

waterfront office is reported to be 30 to 60 feet deep, 

and 150 to 200 feet deep at a place where it was previously only about 30 feet. Similarly, at Valdez, water 

in the former dock area is reported to be about 110 

feet deep where formerly it was about 35 feet. 

The submarine landslides apparently moved downslope quickly en masse, and their movement forced 

sudden withdrawal of water from the areas which 

they had occupied. Immediately thereafter 1 a r g e 

"boils" of muddy debris-laden water rose above the 

surface of the fiords offshore from the areas that 

had slid. These "boils" were variously estimated 

by eyewitnesses to have formed from a few hundred 

feet to a mile offshore and were described as mounds, 

cones, or irregular masses of dirty water containing lumber, piling, oil drums, and other shore-derived 

debris (see fig. 10 and 11). Large waves which did 

much damage to Seward, Valdez, and Thumb Cove 

were generated at these "boils", and a "boil" for 

which no submarine landslide has been specifically 

identified produced a destructive wave at Whittier. 

Although these locally generated waves were destructive, their height and force were substantially less 

than the seismic sea waves which followed later at 

Seward and Valvez. 

It could not be definitely determined from eyewitness accounts whether the landslide-induced waves 

produced seiches at Seward or Valdez; possibly a 

seiche developed at Whittier, where three large waves 

reportedly inundated the waterfront within 4 minutes. 

Dr. Merritt Starr and Mr. Robert Hayes of Anchorage 

reported that a submarine landslide on the south shore 

of Thumb Cove caused an initial withdrawalofwater at 

the landslide site which returned as a large wave and 

formed a seiche that reportedly lasted for about an 

hour. A surface oscillation of the water was also reported in Unakwik Inlet by the fishing boat Quest, but 

its origin is not known. 

SEISMIC SEA WAVES (TSUNAMIS) 

The tsunami generated by the March 27 earthquake 

struck with destructive force all along the coast of 

Alaska between the southern tip of Kodiak Island and 

Cordova (fig. 7). These waves, which can travel at 

speeds in excess of 400 mph in open ocean, were recorded on tide guages as far away as Japan, Hawaii, 

and southern California. 

11 

The combination of violent earthquake shaking, and 

battering by earthquake-generated waves of one form 

or another, left south-central Alaska without a single 

operative recording tide gauge. The only good record 

of the tsunami along the Gulf of Alaska through the late 

hours of March 27 and the early hours of March 28 

was kept by personnel of the U.S. Navy Fleet Weather 

Station at Kodiak. By timing and marking the crest 

heights of successive waves and estimating the ebb 

levels and times, they were able to construct a record 

of the sequence of sea level changes (see fig. 12). The 

area affected by the tsunami generated on March 27 is 

grimly defined by the trail of death and destruction 

along the Gulf of Alaska. However, other than a Kodiak, the times and sequences of wave arrivals in 

south-central Alaska are known only from fragmentary 

accounts of eye-witnesses, most of whom were more 

concerned with saving their lives and property than 

with keeping track of the movement of the sea. 

The initial tsunami wave was first reported on Ko-

.diak Island at Cape Chiniak (20 miles southeast of 

Kodiak) approximately 30 minutes after the initial 

earthquake shock. At that time the Fleet Weather 

Station issued a tsunami warning, and evacuation of 

coastal residents in the Kodiak area and the mainland 

was begun. This prompt action greatly reduced the 

toll of lives taken by the waves. The water level in 

the Kodiak area came up like a fast-rising tide, without an initial withdrawal, and peaked 15 minutes later 

at 22 feet above mean lower low water (adjusted for 

tectonic land submergence of 5.4 feet during the earthquake). The first wave inundated low-lying portions 

of the naval base and Kodiak where the high-tide line 

after the submergence was only about 5 feet above the 

former mean lower low water. Two more waves followed the first with periods of 55 minutes. The fourth, 

and highest, wave crested at 30 feet between 11:16 p.m. 

and 11:20 p.m., almost 1!2 hours after the third wave. 

Successive waves, with irregular periods ofbetween 1 

and 1!2 hours, gradually diminished in height and the 

tsunami died out at about 3:55 a.m. It is of interest to 

note that smaller wave oscillations attributable to 

aftershocks felt at Kodiak were superimposed on the 

larger amplitude tsunami waves. The successive 

waves inundated large areas of the coastline up to 

an elevation of 26.5 feet above normal highest tide. 

(Figure 13 shows the approximate extent of the highest, 

or fourth, wave in the Kodiak area and the general 

direction of wave movement). 

At Seward, on the west side of Prince William Sound, 

the first tsunami wave arrived approximately 30 minutes after the earthquake began. The initial tsunami 

waves that reached Cordova, on the west side of the 

Sound, arrived at low tide and after the land area had 

been elevated 6.5 to 7.5 feet by tectonic uplift during 

the earthquake. Consequently, the first waves, which 

must have been close to 20 feet high, did not even 

reach to the now elevated highest high-tide level, which 

after the earthquake was 21.5 to 22.5 feet above mean 

lower low water. At approximately 8:20p.m. the U. S. 

Coast Guard vessel Sedge ran aground in Orca Inlet 

near Cordova during a 27 -foot drawdown of sea level 

between successive waves. 

The highest wave, which reportedly reached Cordova 

some time between midnight and 1:00 a.m., rose to 

about 5 feet above the highest high-tide line, floated 
away houses and boats along the waterfront, and caused 

extensive damage to piers and docks, Ten cabins at 

Point Whitshed near Cordova were floated away "in a 

precise line like coaches of a train" and one of the 

owners, who had returned to his cabin thinking that the 

tsunami danger had ended, was lost. 

WAVES OF UNKNOWN ORIGIN IN 

PRINCE WILLIAM SOUND 

A number of highly destructive waves were experienced locally in coastal areas during and almost immediately after the March 27 earthquake. Several of 

these early waves, notably the first ones that hit Seward 

and Valdez, were definitely generated by submarine 

landslides; they are described on later pages, The 

origin of other waves that were responsible for the 

loss of at least 43 lives and extensive property damage is not certain; their general distribution and direction are shown on figure 7. Because Prince William Sound is sparsely populated, the loss in lives 

and property there from earthquake-generated waves 

is proportionally extremely high. This tragic loss 

occurred even though the earthquake and attendant 

waves came at low tide and probably after the entire 

eastern part of the Sound was tectonically elevated 

4 to 7.5 feet. 

The wave that destroyed all but the school and one 

house in the village of Chenega (locality 7 on fig. 7) 

and swept away 25 of the 76 inhabitants is described 

as a "wall of water 90 feet high." This wave, which 

struck within 3 minutes after the earthquake ended, 

was preceded by a smaller wave and a pronounced 

withdrawal of water. The actual wave was at least 

35 feet above high-tide level, and runup entered the 

school building, which stands on a knoll above the village at an elevation of 90 feet. The exceptional height 

of this wave may be attributed to "focusing" of the onrushing water by refraction around a small group of 

islands situated in the middle of Knight Island Passage 

approximately 4 miles southeast of Chenega. 

Similar, but much lower. waves were experienced 

almost simultaneously at the following places: Port 

Ashton and San Juan (loc. 6 on fig. 7), resulting in the 

loss of one life; Port Oceanic (loc. 8 on fig. 7), where 

a cannery was damaged and one boat was sunk; Point 

Nowell (loc. 9 on fig. 7) where two cabins were destroyed and the owner is missing; Perry Island (loc. 

10 on fig. 7), where the two Comstock brothers were 

roughly treated by a wave that rose to 25 feet above 

sea level and washed 4 feet over a sand bar on which 

their home is situated; and Fairmount Point (loc. 13 

on fig. 7), where a wave broke across a sand bar 15 

to 20 feet above high-tide level. 

At Port Nellie Juan, where 3 people are missing, 

dock facilities were apparently damaged by a surge 

of water that came from the south end of Cullross 

Passage immediately north of Port Nellie Juan (loc. 

11 on fig, 7). Paul Selanoff, who was in a boat near 

the north er.d of Cullross Passage at the time of the 

earthquake, witnessed an ebb-current of "water down 

through the passage like a big waterfall about 8 to 10 

feet high" for a period of about 30 minutes after the 

earthquake. Evidence of the violence of the southward 

surge of water at the north end of Cullross Passage is 

clearly visible locally along the shoreline (fig. 14A). 

12 

At an unknown time after the earthquake, a surge of 

water shot into Valdez Arm and Port Valdez (loc. 14 

on fig. 7; fig. 11 ). The wave overtopped and destroyed a 

navigation light in Valdez Passage, struck the north 

shore of Port Valdez near the Cliff mine, was reflected 

to the southeast shore, which it struck at Jackson Point, 

and dissipated toward the head of Port Valdez. The 

wave destroyed wooden buildings at the Cliff mine and 

deposited debris 170 feet above sea 1 eve 1. Run up 

reached 220 feet, as indicated by broken and freshly 

scarred shrubs. At Jackson Point the Dayville cannery 

was floated away and the wave heaped driftwood to a 

height of 17 feet above the highest tide level. 

Mr. Jackson, whowasatshelteredSawmillCoveoutside Valdez Passage (fig. 11), reports that during and 

immediately after the earthquake the sea withdrew 

briefly and then rose rapidly to about the highest tide 

level but that no large waves were observed. The villages of Tatitlek and Ellamar. on the mainland east of 

Valdez Passage, were sheltered by Bligh Island from 

destructive waves from the south. Residents there report a 15-foot withdrawal of water immediately after 

the earthquake; following withdrawal, the water level 

rose rapidly about 18 feet, approximately to the highest 

tide level despite a 4- to 6-foot tectonic uplift of the 

land during the earthquake. A generally similar sequence of events is reported by eyewitnesses residing 

on Peak Island, which is in a sheltered location behind 

the Naked Islands; by Ed Brenner, who was in Port 

Wells at the time of the earthquake; and by residents 

of Whittier. 

The destructive waves that appeared at widely separated localities in Prince William Sound within minutes after the earthquake tremors ceased must have 

been generated locally and almost simultaneously. A 

general impression gained from the scantydataavailable is that most of the wave damage was due to a 

general northward surge of water throughout the sound. 

A movement similar to that of water in a tilted pan 

could have resulted from the sudden tectonic uplift of 

the western part of Prince William Sound and the contiguous continental shelf during the earthquake. Seiche 

waves, local tsunami waves, and landslide-generated 

waves may have been superimposed on this general 

movement of water away from the tectonically elevated 

areas. Detailed studies of the complex pattern of wave 

effects in Prince William Sound are needed before a 

satisfactory reconstruction of their origin and movements can be made. 

SEA LIFE 

The March 27 earthquake resulted in mass mortality 

of certain species of deep-water marine fish and shellfish through disturbance of their normal ecological 

environments. 

The most sudden and dramatic effect became apparent on the morning of the 28th when vast numbers of 

red snappers, which normally inhabit waters deeper 

than 400 feet in Prince William SounctY, were found 

i/ According to an oral communication from Dr. N.J. 

Willimovsky, there are 26 genera of "red snapper" 

caught in commercial abundance in Prince William 

Sound. He states that of these, only the genera 

Sebastolobus and Sebastodes increase in abundance 

with depth. These two general probably constitute 

most of the "red snapper" population found dead at 

the surface following the earthquake. 
62° 

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EXPL ANAT ION 

0--+ Inferred direc t ion of un usually high waves 

NW1tbered localities are referred to in t ext 

+---25' 

Ap prox ilute highest e I evat ion above nor111a I 

tide I eve\ reached by waves at t i 111e of a rr ival 

XX Areas of mass fish mortalit y 

. 9: 10.4 PM 

Epicenter and ti11e of l arger sub11arine 

aftershocks (11agn i t ude 6 .2~6 .5) during 

period of unusua II y high waves 

.... Submarine .. ndsl ide 

Figure 7. Map showing wave directions, areas of mass fish mortality, submarin e l andslides, and m a jor s ubmarine aft e r shocks. 

' \ / 

\/ 
floating dead on the surface (see fig. 7 for locations). 

The area between Knight Island, Chenega Island, and 

Evans Island was covered with snappers according to 

Cordova Airlines pilot Jim Osborne, who could see the 

red spots clearly from an altitude of 3,000feet. Captain Stewart of the ~ observed that the waters of 

Port Valdez were thick with bloated dead snappers as 

he steamed out of the port on the 28th, and the Brenner 

party reports having seen dead snappers in Port Wells 

at that same time. Everyone who saw the fish remarked on their great size compared to those normally caught by local fisherman; most estimates 

agreed that the largest fish weighed about 30 pounds. 

Unfortunately, none of the fish were submitted to biologists to determine the cause of death. One plausible 

explanation is that the fish, which are extremely sensitive to rapid pressure changes, were forced up off 

the bottom where they normally live by turbidity currents triggered during the seismic shaking. 

The widespread and sudden dumping of sediment over 

large areas of the bottom is confirmed by the great 

number of crab pots that were found buried, or partly 

buried, in Prince William Sound after the earthquake. 

According to Mr. Baxter of the State Department of 

Fish and Game, the crab population was not seriously 

affected and crab catches were approximately the same 

before and after March 27. 

Tectonic uplift during the earthquake left most of 

the extensive razor-clam beds off the mouth of the 

Copper River above the reach of normal tides, thereby resulting in their virtual extinction. 

The potential effect of the land-level changes on 

salmon runs in south-central Alaska is difficult to 

evaluate. There should be little or no effect on upstream migrants. In uplifted areas new intertidal 

spawning grounds may become available, whereas tidal 

spawning ground in subsided areas may be lost. The 

pattern of salmon spawning and fishing in the affected 

areas almost certainly will be changed, although the 

net overall effect of loss and gain in Alaska may balance out. Studies are underway by Federal and State 

agencies concerned with fisheries managment to provide a reliable basis on which to predict possible future 

changes. 

DAMAGE TO CITIES, TRANSPORTATION 

ROUTES, AND INDUSTRIES 

CITIES 

The earthquake caused extensive damage to Anchorage and the port cities of Seward, Whittier, Valdez, 

and Homer. Kodiak was damaged not by the tremor 

but by inundation after the earthquake. 

Anchorage 

The city of Anchorage, about 80 miles west of the 

epicenter, sustained the greatest property damage. 

The Anchorage Daily Times, April 9, 1964, reported 

that the damage amounted to about $200,000,000, that 

215 residential homes were destroyed, and 157 commercial buildings became unusable. Nine people lost 

their lives or are missing in Anchorage. This damage 

was from both seismic shock and from landslides 

triggered by the earthquake, but mostly the latter. 

14 

Seismic shock severely damaged several high-rise 

reinforced concrete structures,and one collapsed. It 

also severely damaged West High School, some cinderblock buildings, and some wooden structures, and 

caused the control tower at International Airport to 

collapse. 

The earthquake triggered lllandslides large enough 

to show on figure 15. Three of these, the Turnagain 

Heights, L Street, and 4th Avenue slides, caused most 

of the casualties and catastrophic damage in Anchorage 

(figs. 17 and 18). A fourth slide destroyed the Government Hill Grammar School. 

The L Street slide, that at 4th Avenue, and the one 

that destroyed the grammar school moved laterally as 

relatively coherent masses (fig. 16). The heads of 

these slides were zones of tension into which strips of 

ground as much as 150 feet wide subsided as much as 

15 feet along near-vertical fractures. Narrow zones 

of compressional buckling at the toes of the slide also 

caused extensive destruction (fig. 18D). 

In contrast, most of the landslide mass at Turnagain 

Heights broke into a chaotic jumble of rotated blocks 

which destroyed almost all structures within the slide 

area (figs. 17 A,B ). An eye-witness account of the 

Turnagain Heights slide was furnished the Geological 

Survey by Mr. E. R. Bush, as reported to him by Mr. 

Brooke Marston, 1900 Turnagain Parkway, Anchorage, 

Alaska: 

"I was driving my automobile westward on McCallie 

Avenue when the earthquake occurred. I immediately 

stopped my automobile and waited until the quake subsided. It appeared to me that the car was rocking 

from north to south. Itrockedsoviolentlythat I nearly 

became seasick. From my car I could observe an 

earth crack alined north-south and opening and closing 

from east to west. As soon as the quake subsided I 

proceeded to drive westward to the corner of McCollie 

Avenue and Turnagain Parkway. After turning right on 

Turnagain Parkway and driving approximately 180 feet 

north, I realized the bluff was gone north of my driveway, which paralleled the bluff in an east-west direction. I got out of the car, ran northward toward my 

driveway, and then saw that the bluff had broken back 

approximately 300 feet southward from its original 

edge. Additional slumping of the bluff caused me to 

return to my car and back southward approximately 

180 feet to the corner of McCallie and Turnagain 

Parkway. After I stopped at this point, the bluff continued to slowly slide northward as I continued to back 

my auto southward on Turnagain Parkway. The bluff 

slowly broke away until the corner of Turnagain Parkway and McCallie had slumped northward. 

"It is my impression that the Turnagain Bluff area 

slumped northward in segments and that much of the 

southward receding of the bluff occurred after the 

major earthquake had subsided. 

"I was never aware of any unusual noise other than 

the sounds of people calling for help." 

Mr. Milton Norton also was an eyewitness of the 

Turnagain Heights slide. He stated that sliding started 

during the shaking and that the bluff peeled away in 

a succession of narrow slabs. It continued to peel in 

this fashion until the severe shaking stopped, except 

for relatively minor sloughing. 
Mr. Bush also furnished the Geological Survey an 

eye-witness account of the 4th Avenue slide as related 

by Mr. Chancey Croft of Spenard: 

"Mrs. Croft and I weredrivingeastwardon4th Avenue between D and C Streets when the March 27, 1964, 

earthquake occurred. My first impression was that 

either a flat tire or broken wheel was causing unusual 

movements of the car. As we approached C Street, I 

stopped the automobile and we suddenly realized that 

an earthquake was in progress. The car was rocking 

quite a bit in a north-south direction. At this time an 

earth crack alined east-west began to develop near the 

center of 4th Avenue. The crack began to open very 

slowly about a foot from the left edge of our automobile. 

We became concerned that the car might fall into this 

developing chasm and left the car through the right 

front door at a time which we estimate to be approximately 2 minutes after the first earth shocks were felt. 

We proceeded to the south sidewalk of 4th Avenue and 

stood, throughout the remainder of the earthquake, approximately 40 feet west of the corner of 4th and C 

Streets ... 

"While standing on the sidewalk we observed the 

north side of 4th Avenue sinking very slowly for several minutes until it finally came to rest at about the 

time the earth shaking had stopped. We proceeded to 

help people from the sunken buildings and returned to 

our automobile, which was still standing, unharmed, 

about a foot from the edge of the chasm. " 

Mr. George Boney, who was on the second floor of 

the Law Building, stated that the building dropped suddenly about 2 minutes after the initial seismic shock. 

This building, which is at the head of the L Street slide, 

was damaged when the underlying ground failed in 

tension, apparently during the earthquake. A 5-foot 

horizontal displacement was noted on the block in the 

vicinity of lOth Street. 

Numerous cracks were observed in the downtown 

Anchorage area. On April 2, 1964, control points 

were put across some of these cracks (generally less 

than half an inch wide) to determine whether they were 

opening or closing. Observations over several days indicated that there was no significant change. The severe aftershocks of April 3, 1964, did not affect the 

monitored cracks. 

Seward5 

The earthquake was strongly felt at Seward, but damage from ground motion was minor compared to the 

massive destruction and 13 deaths inflicted by submarine landslides and large waves (figs. 8A,B,C). 

Ground motion in Seward during the earthquake 

knocked down some chimneys and damaged a few 

buildings to the extent that they were condemned, but 

reportedly none collapsed from the shaking. The most 

serious result of the ground motion was the almost immediate rupture of large fuel storage tanks on the 

r;J Among the eyewitnesses who furnished data for 

this a c c o u n t were John and Roger Eads, William 

Peterson, Lloyd Heffner, Robert Clark, Harold Drinkall, and Dale Pickett of Seward, and CaptainSolibekke 

of the tanker "Alaska Standard." 

waterfront; these tanks were quickly ignited, spilling 

blazing fuel that was later spread by the waves and 

burned on the water along half a mile of waterfront. 

While the tremors were still strong, and, according to some witnesses, about 30 seconds after they 

had started, 4,000 or more feet of the water-front 

north of Washington Street slid into Resurrection Bay, 

taking with it the dock, warehouse, and many fuel 

storage tanks of the Standard Oil Company and all 

other waterfront installations and industries north 

to the area of the San Juan dock and the small-boat 

harbor (see fig. 9). This submarine landslide, which 

was probably compound, took with it most of the economic base of Seward. The ground that slid was watersaturated alluvium which fronted Resurrection Bay 

with a submarine slope near shore of 30°-35°. This 

very steep slope proved to be unstable under the severe 

shaking of the earthquake. 

The new shoreline has a steep slope formed by the 

main scarp of the submarine landslide, and the water 

off this shore is in consequence fairly deep. Preliminary soundings furnished by the California Shipping 

Company indicate that the submarine slope may still 

be as steep as 30°-35° within the area of the former 

Standard Oil Co. waterfront, and that an area near 

the former dock which was 32 feet deep is now about 

150 or 200 feet deep. Other preliminary soundings are 

reported to indicate that one area in the former smallboat harbor has dropped more than 50 feet, and that 

some former tidelands are now 20 feet deep. 

The ground behind the area which slid is broken 

by many deep open tension cracks which are parallel 

or subparallel to the new shoreline. A sampling of 

these are shown on figure 9. A few of these cracks are 

12 to 18 inches wide, although most are much narrower. 

On a few cracks, vertical displacement of several 

inches, down on the east or bay side, was noted. These 

observations suggest that the entire waterfront area 

with fractures, shown on figure 9, has been extended 

seaward and dropped slightly, and that this area may 

be an incipient landslide. 

The newly formed shoreline at Seward is unstable, 

for it is steep-and the ground behind it contains many 

tension cracks. Until a more stable configuration is 

reached there will be some further retreat of the 

shoreline by erosion, sloughing, and perhaps sliding. 

The possible effects of future great earthquakes on the 

shoreline with its new configuration require careful 

study; the possibility that future large submarine 

landslides may occur there cannot be dismissed 

lightly. 

The submarine landslide drew water from the former 

shoreline and created "boils" of debris -laden muddy 

water at a distance from shore estimated by various 

witnesses to be several hundred feet to a quarter or 

perhaps half a mile (see fig. 10). Some witnesses 

reported two "boils" as shown in figure 10, but possibly both were part of the same large feature. In any 

case, large waves were generated at the 'boil" or 

"boils "and radiated from them at high speed.1f Before 

the shaking stopped, or within a few minutes thereafter, these waves hit the north side of Lowell Point, 

the Seward waterfront, and the north and east sides of 

Resurrection Bay. They caused considerable damage 

15 
railroad yards. Wave height was estimated by John 

and Roger Eads to be about 30 feet at the north side of 

Low~ll Point, where trees behind the beach show 

bruises between 12 and 14 feet above their bases. 

About 30 minutes after the first wave (time estimates 

vary from 15 to 45 minutes) a seismic sea wave 

entered Resurrection Bay, increased in height as it 

entered shoaling water, and inundated the low areas of 

Lowell Point, Seward, and the flats at the head of 

Resurrection Bay. Local splashes from this wave 

reportedly reached 100 feet above water level, but in 

most places its highest trim lines were roughly estimated to be 25 to 35 feet above the water surface, 

which was at low tide at that time. This wave was 

higher and more forceful than the first, locally generated, wave and caused most of the wave damage at 

Seward. lt destroyed The Alaska Railroad docks and 

swept many houses and boats from the vicinity of the 

small boat harbor into the lagoon north of Seward and 

onto the flats at the head of Resurrection Bay. It also 

tossed boxcars, and even a locomotive into windrowlike heaps as shown on figure 9. The path that this 

wave took through Seward is recorded by steel fence 

posts and other objects, which were bent in the direction the water traveled. These are shown by arrows on 

figure 9. Here, as at other places, the fact that the 

tide was low minimized the damage and loss of life. 

The large seismic sea wave was reported by soine 

witnesses to have been followed by large ground swells 

at intervals of about an hour or an hour and a quarter 

until about 4:00 or 5:00 o'clock the next morning, but 

darkness and the demands of self preservation precluded accurate observations of events during the 

night. Reportedly, none of these later waves or swells 

were as large as the first seismic sea wave. The 

passage of what may have been the largest swell was 

reported by John and Robert Eads, who noticed that 

after a full tide at Lowell Point at 9:30p.m., the water 

receded to about 40 feet below low water in the area of 

The Alaska Railroad docks at !O:OOp.m. Others reported that the water subsequently rose, without producing 

a violent wave, to a height estimated to be about 20 

feet above high water at approximately 11:00 p.m. 

According to these estimates, the amplitude of this 

wave was about 70 feet. 

Whittier 

The town of Whittier, where 13 people lost their 

lives or are missing, lies at the head of Passage 

Canal (fig. 19) and is about 40 miles southwest of 

the epicenter. Shaking lasted for approximately 2 

minutes and had a general east-west direction. Residents on bedrock felt a jarring motion; those on fill or 

unconsolidated deposits a rolling or "round-andround" motion. 

Loss of life and most of the damage at Whittier was 

caused by the high water and by the fire that followed 

the earthquake (fig. 8D). Seismic shock was reported 

to have damaged only the Hodge Building and to have 

destroyed one oil tank, the slip tower, and the "old" 

Army dock. 

The following sequence of events is based on interviews with residents of Whittier. 

The tide was about 1 foot and the water "glassy" 

before the earthquake. Mr. Farrian Kolb reported that 

about 2 minutes after the shake started, the water in 

Passage Canal rose rapidly to an elevation of25 to 26 

feet. It was still "glassy" and did not contain any 

debris. Mr. M. J. Dixon also reported that the water 

was "glassy" and estimated that it reached an elevation of 26 feet. The water receded and from 45 seconds 

to 1 minute later a wave came in. The wave was muddy, 

contained much debris, and was about 35 feet high 

when it hit the area of the railroad depot (elevation 

26 feet). Mr. McDonald described the wave as a black 

cloud boiling out of the canal about 50 yards from 

shore. Mrs. Kolb described it as a wall of water about 

30 to 50 feet high that rose about half-way out in the 

bay. She also stated that she had the impression that 

something was exploding underneath the water. This 

wave struck the railroad depot about 8 to 10 feet above 

the ground surface. 

16 

From 30 to 45 seconds after the second rise in sea 

level (the first actual wave) or within 3-3/4 minutes 

after the initial seismic shock, another wave occurred. 

This wave was similar in nature to the one that 

reached about 35 feet but was 4 to 5 feet lower and 

did not contain as much debris. 

Residents believe that most of the damage was 

caused by the first wave (second rise of water level). 

The high water line is shown on figure 19. In the 

northwest part of Passage Canal, in the vicinity of 

the CAA station, gravel was deposited as high as 60 

feet by the waves. A barnacle-covered boulder of 4 

cubic yards was carried about 125 feet by the water 

and deposited on the track near the railroad depot at 

an altitud~ of approximately 26 feet. 

Valdez 

The city of Valdez at the northeastern corner of 

Prince William Sound was severely crippled by the 

earthquake. Thirty lives were lost when the dock area 

disappeared in a sudden submarine landslide during and 

immediately following the earthquake. An estimated 

40 percent of the business district and 10 to 20 percent 

of the residential district were destroyed and the 

sewage and water systems were disrupted. The docks, 

piers, fuel-storage terminal, and small-boat harbor 

are gone. Two fishing boats that were away from port 

during the earthquake are all that remain of the local 

fishing fleet. Photographs of Valdez before and after 

the March 27 earthquake are shown on figure 20. The 

following report is based chiefly on a 1-day reconnaissance examination of earthquake features in the 

Valdez area by Robert M. Chapman, of the U. S. 

Geological Survey. 

Earth tremors rocked Valdez on March 27 for 3 to 

5 minutes. During that time, cracks opened throughout 

town and the adjacent areas; s t r u c t u res heaved, 

settled, and shook violently; and people had great 

difficulty in standing. The most complete destruction 

and tragic loss of life occurred in the dock area, 

where the 10,815-ton M. V. Chena, was unloading. 

Almost as soon as the earthquake tremors were felt, 

the entire dock area, which was crowded with people, 

began to sink into the sea and a great "mound" of 
Figure 8. Photographs of wave and submarine landslide damage at SEWARD and WHITTIER. A, Waterfront at 

SEWARD, showing damage produced by submarine landslides (right side) and large waves (U.S. Army 

Mohawk photograph). B, C, The Alaska Railroad marginal docks at the south end of SEWARD before 

and after they werehitbylargewaves (U.S. Army Mohawk photograph). D, Waterfront at WHITTIER, 

showing area flooded by large waves (U.S. Army Mohawk photograph). · -

17 
.... 

"' 

-----N 

0 200 400 600 800.1000 FEET 

APPROXIMATE SCALE, IN FEET 

.... 

"' 

Base map and photo interpretation 

by W. H. Condon, 1964 

Figure 9. Map of SEWARD showing damage by submarine landslide and large waves. 

18 
9 

\ 

\ 

\ 

\ 

\ 

\ 

\ 

\ 

\ 

\ 

\ 

\ 

\ 

\ 

I 

EXPLANATION 

Highest level reached by waves 

Approximate position of former 

shoreline 

____ .l 

New shoreline 

,, -- tl--7- --- 1 ---- ... - Installations or buildings removed by 

submarine landslides, and large waves 

_. Direction of wave motion as indicated by 

bent posts and displacement of objects 

-----;-rEarth -fractures 

More fractures than are shown occur 

along the water-front between Adams 

and Monroe streets 

Box cars 

FUEL TANKS 

(j) 

Vertical 

[I] 

Topped 

Installations or buildings 

1. Alaska Railroad Transit Sheds (Heavy damage) 

2. Boiler House 

3· Depot 

ij. Power Plant(~urned) 

5. standard oil Docks and 

warehouses (Destroyed) 

6. Engine House 

7. Army Docks and warehouses (Destroyed) 

s. San Juan Dock, cement Plant, 

Marine ways (Destroyed) 

9. Small Boat Harbor, City Dock, 

scow Grid (Destroyed) 

19 
Figure 10. SEWARD and the upper part of RESURRECTION BAY, showing two reported positions of large "boils" of muddy water formed by submarine 

landslides. 

20 
N 

...... 

5 0 5 MILES 

Figure 11. Map of VALDEZ and vicinity. 
N 

N 

~ 30 ~--------------T-------~------~------~--------~--~----~------~~~--~r-------~r-~--~-------.----, 

UJ .,_ f3~:::LL ~~..J l ~ 11 

~ ~ ~ ~ ~ l ,' ~~ ;::~~ ? -~:~ww l ~~~~ ~~..J· j /:. 

ffi 25 >--- "' il ~ ' l-" '~ ~ g ~ A / :-~ ~ , ~/.~ n 

~ 20 - : ! ~A /\ ,\ / \\~wl ~ IV r _j 

~ ~ ~ :: \ : ~ ::~ ~ \/ UJ I 5 1-- ~ ~I \ I \ I ~ 1 .... ·P ... ·P ... : ¥ 

~ ,~~I \ I \ I 

~ Sl \ I \ I 

~ I 0 1- ! @I \ I \ I ~ PREVIbUS H HW ~~ \ I \ I o~ ?t.~\OD OF HIGH 

.!- PRIOR TO '

11 ~~ 1 / \. ! \..t.\J~~ ~ 5 ,__EARTHQUAKE "· 1 Q. 

; 

: ~ 

: ~,ot. c~t.O 

<( 

.... 

C) 

z 

0 - <(~ 

~<( 

~~ ~.., 

a: 

0 -

z 

r? ··?-

I l 

I \ - . ..., 

~ 'r--...._ "" v \.tf ---l'~t<-O' g 1 ~ ~ NEW LLW AFTER EARTHQUAKE 

~ 0 ~-------------T----~~------.. --~~~------~-------.------~-------.------~------~------~--_, 

~ 

w 

(/) 

~ -5 r-

.... 

J: 

(.!) 

-

PREVIOUS LLW PRIOR TO EARTHQUAKE 

w J: -10 ~--------------._------~------_.------~--------~------~------_.------~--------~------~------~--~ 5:00 PM 6:00 PM 7:00PM 8:00PM 9:00PM 10:00 PM 11:00 PM 12:00 PM 1:00AM 2:00AM 3:00AM 

3/27/64 4/28/64 

TIME 

Figure 12. Generalized record of sea-level fluctuations. 
Figure 13. M ap of KODIAK and vicinity. 

23 
muddy turbulent water appeared several hundred yards 

offshore (fig. 11). Within 2 or 3 minutes after the 

tremors began, the ship was lifted about 30 feet above 

the pier on an incoming wave and heeled over landward 

45° - 50° into a "whirlpool" of mud and debris where 

the pier had been. According to Capt. Merrill D. 

Stewart, "the ship was slammed on the bottom and 

rolled wildly from side to side like a rag doll" by a 

rapid succession of waves before it finally slithered 

off the mud bottom through wreckage of docks and a 

cannery to reach the safety of deep water. Approximately 3 hours after the earthquake, fire broke out 

in fuel storage tanks 0.3 mile southeast of town, 

throwing flames hundreds of feet into the air; miraculously, no fires broke out in town. 

The initial wave that lifted the Chena devastated 

what remained of the Valdez waterfront within two 

blocks of shore. During the general confusion that 

prevailed about 15 minutes after the earthquake began, 

a smaller wave reportedly inundated the waterfront 

area, adding to the damage. A third wave followed 

several hours later at about 11:00 p.m., and the last 

and highest wave, between 1:00 and 2:00a.m., flooded 

the low-lying portions of the city to limits shown on 

figure 11. The earthquake occurred approximately at 

low tide and the last wave coincided closely with the 

high tide. It is not known whether any of the waves 

that reached Valdez was the one that left high trim 

lines at the Cliff mine and Jackson Point (fig. 11), 

but it could have been the wave that arrived at Valdez 

almost unnoticed about 15 minutes after the earthquake began. The high-water waves that flooded the 

lower part of town at 11:00 p.m. and between 1:00 

and 2:00 a.m. were probably tsunami waves generated 

in the Gulf of Alaska. 

The city of Valdez is situated on an alluvial fan of 

unconsolidated sediments that is built out into the head 

of the deep, steep-sided fiord of Port Valdez. Prior 

to the earthquake, the seaward slope of the alluvial 

fan was approximately 15° near the shoreline. The 

shaking apparently induced precipitous failure of the 

unstable, water-saturated alluvium, and a slice 4,000 

feet long and 600 feet wide that included the dock area 

slid seaward. The motion of this large block resulted 

in the violent upwelling in the middle of the bay, 

which in turn caused the destructive wall of water 

that caught the Chena in the first wave. Preliminary 

soundings along the shoreline by the U.S. Army Corps 

of Engineers show profound changes in the bottom 

configuration. At the dock site where there formerly 

was 35 feet of water there now is 110 feet of water. 

An area at the small boat harbor that had formerly 

been exposed at low tide is now covered with water 

70 feet deep. 

Mr. Ralph Migliaccio, a geologist who examined the 

upper part of the submarine slide with skin-diving 

gear, reported that its topography was hummocky, 

chaotic, and typical of landslides. 

Structural damage to buildings was greatest where 

cracks extended beneath or close to them. Substantial 

buildings that stood on uncracked ground, such as the 

electric generating plant and portions of the mental 

hospital were essentially intact; however' a part of 

the mental hospital was severely damaged where 

ground cracks intersected it. 

24 

The nature and pattern of cracks observed in the 

outwash gravel on which the entire town is situated, 

and subsidence observed in the central part of town 

all suggest seaward extension and the possibility that 

a large segment of the town site may be on incipient 

landslide blocks. 

Homer 

Homer, about 160 miles southeast of the epicenter, 

was shaken violently by the earthquake. Mr. Ralph 

Cowles stated that the total time of the tremor was 

from 2 to 27.2 minutes and that its motion was "wavy" 

and east-west. 

Local moderate damage was done in downtown 

Homer. Homer Spit, a sand bar that extends 5 miles 

into Kachemak Bay, also suffered damage. During the 

earthquake, southeast-northwest trending fractures 

developed throughout much of the spit. Mr. Glen 

Sewell heard and saw a fracture, 12 to 18 inches wide, 

coming toward him from the southeast. The fracture 

passed between his legs, through a building, and continued on into Kachemak Bay. Many of the fractures 

had vertical displacement, some as much as 8 inches, 

with the downdropped side toward the coast. 

One of the most spectacular and awesome events, 

as reported by Mr. Dick Hoffer and Mr. Sewell was 

the disappearance of the small boat harbor on Homer 

Spit. Within 17.2 to 2 minutes after the tremor started, 

the harbor disappeared into a "funnel-shaped" pool. 

A lighthouse once on the harbor breakwater is now 

40 to 50 feet below sea level. 

Homer Spit has subsided 4 to 6 feet. This subsidence 

consists of both regional subsidence and local compaction of the unconcolidated sediments that underlie 

the spit, as shown on figure 6. 

TRANSPORTATION ROUTES 

The Alaska Railroad 

The Alaska Railroad was extensively damaged by the 

earthquake. Damage was caused by (1) seismic shock, 

(2) landslides, (3) subsidence, (4) fractures through 

right-of-way, bridges, and buildings, (5) wave action, 

(6) fire, and (7) inundation of subsided area during 

high tide. 

Damage was severe to railroad bridges from 

Matanuska south to Seward (fig. 2 ). Most of the 

bridges in this 185-mile stretch of the railroad are 

cambered from compression. At the head ofKnik Arm, 

there was horizontal and vertical displacement of piles 

and subsidence and shearing of piers. At Portage, 

20-Mile Bridge failed due to compression and subsidence (fig. 14B). 

Northward from Matanuska to Hurricane, which is 

half way between Anchorage and Fairbanks, steel 

jammed tight in most of the bridges. Damage ranged 

from moderate near Matanuska to slight at Hurricane; 

north of Hurricane no report of damage has been 

received. 

Large areas subsided at Knik Arm and in the Portage 

area at the head of Turnagain Arm. In the Portage 

area, unconsolidated sediments underlying about 4 or 
5 miles of the right-of-way subsided due to a combination of compaction of the unconsolidated sediments 

and regional subsidence. The amount of subsidence 

(regional and compaction combined) is unknown, but 

locally may be as much as 7 feet. During the high 

tides of April 13 to 14, 1964, much of the right-of-way 

was inundated as well as the town ofPortage. Erosion 

during these high tides washed out some of the railroad. 

Extensive landslide damage occurred along the railroad at Potter (fig. 4B), about 9 miles south of 

Anchorage, and near the southeast edge of Kenai Lake. 

The longest slide near Potter is about 1,500 feet long. 

Additional damage was done by avalanches (fig. 4C). 

The Alaska Railroad facilities at Portage, Whittier, 

Seward, and Anchorage also were damaged--those at 

Portage by fractures; those at Seward by submarine 

landsliding and large waves; and those at Whittier by 

wave action and fire. The railroad shops at Anchorage 

were damaged chiefly by small landslides. 

The railroad spur from Portage to Whittier was 

severely damaged between Portage and the tunnel, 

but neither the tunnel nor the mile-long section 

between the tunnel and Whittier were harmed. 

Highway routes 

Severe damage to the highway system, as to The 

Alaska Railroad, resulted chiefly from destruction of 

bridges (figs. 14B and 14C) by seismic shock and 

subsidence of foundations, 

The Seward Highway suffered the severest damage, 

particularly between Potter and Portage, where the 

Department of Highways reported that 22 bridges 

were destroyed, apparently by compression followed 

by collapse. In addition to collapsed bridges, numerous 

snowslides crossed the highway between Potter and 

Seward (fig. 4C). As on the railroad, compaction and 

subsidence occurred in the Portage area. 

Damage to the Glenn Highway between Anchorage 

and Glennallen was minor except at the head of Knik 

Arm, where the bridge piers were damaged. In addition, two snowslides were triggered south of the 

bridge crossing Knik Arm. 

The Sterling Highway between Moose Pass and 

Homer underwent minor cracking and settling offills. 

The highway bridge crossing the outlet of Kenai Lake 

was destroyed, however. 

The Richardson Highway between Glennallen and 

Valdez was little damaged, although the Department 

of Highways reports that part of the road between 

Valdez and Keystone Canyon, about 20 miles east of 

Valdez, is "wavy." 

Some sections of the highways near Kodiak were 

severely damaged by both seismic shaking and seismic 

sea waves. 

On the Copper River Highway, damage was severe. 

The Cordova Times (April 2, 1964) reported that between Eyak River (4 or 5 miles east of Cordova) and 

Mile 13 there were "cracks 6 to 8 inches wide across 

the road at intervals of about 75 feet." Locally, some 

spots sank several feet and "most of the roadway sank 

about 2 feet, leaving all bridges that amount higher than 

the roadway." The Times also states that a Depart25 

ment of Highways Engineer, Mr. Arlan Davis, reported 

that "it appears that serious damage was inflicted on 

every bridge, including the famous M i 11 ion Dollar 

Bridge, which has one end of the northern span in the 

river [Copper River]." The abandoned railroad bridge 

near Abercombie Rapids on the Copper River, about 

15 miles north of the Million Dollar Bridge, has been 

damaged (fig. 14C). This bridge was to be part of 

the highway system. 

OIL, GAS, AND COAL INDUSTRIES 

The petroleum industry, Alaska's largest mineral 

industry, is centered on the Kenai lowland, within the 

area of damage delimited on figure 1. The oil refinery, 

tanks, and docks at Nikiski sustained some damage, 

but there was no important delay in production. The 

wells in the Swanson River oil field and the Kenai gas 

field were reportedly not damaged, although some leaks 

and breaks occurred in pipelines. 

Coal mines, both those in the Matanuska Valley at the 

fringe of the area with significant damage and those in 

the Alaska Range beyond the area with significant damage, escaped injury during the earthquake, and production was not interrupted. However, rail transportation 

from the mines to Anchorage was disrupted for several 

days. 

AREAS DAMAGED BY SEISMIC SEA WAVES OF 

UNKNOWN ORIGIN 

In Alaska extensive damage from seismic sea waves 

generated by the March 27 earthquake, and possibly 

by its early aftershocks, was confined to communities 

on Prince William Sound and the southeast coast of the 

Kodiak Islands; those on the Alaska Peninsula and in 

southern Alaska east of the Copper River delta escaped 

injury. These waves also caused casualties and major 

damage in British Colombia and California. 

Especially hard hit in the Prince William Sound area 

were Valdez, Seward, and Whittier, discussed above 

(fig. 4D). Chenega, a native village of 76 people of 

whom 25 were drowned, was hit by a large wave of 

unknown origin, and large waves destroyed property 

at a number of other localities on Prince William 

Sound and killed a total of six people at Port Nellie 

Juan, Port Ashton, Point Nowell, and Whitshed. An 

abandoned cannery was destroyed in Port Graham, 

near Cape Elizabeth. 

ln the Kodiak Islands, the city of Kodiak and Kodiak 

Naval Base as well as several small outlying communities on the southeast side of these islands were 

severely damaged by seismic sea waves, and 19 people 

are reported dead, or are missing and presumed dead. 

The native village of Kaguyak was almost completely 

destroyed, and that of Old Harbor will require extensive reconstruction. Especially serious to all of the 

damaged communities is the loss of many fishing boats, 

sea-food processing plants, and other waterfront installations which are the mainstay of their economy 

(fig. 14D). 

GEOLOGIC FACTORS INFLUENCING 

EARTHQUAKE DAMAGE 

Geologic factors played the chief role in determining 

the distribution of damage from the earthquake. They 
controlled the distribution of fracturing, compaction, 

lurching, and landslides, and thereby the distribution 

of damage to structures. Where these factors are 

taken into account in locating and designing buildings 

and structures, the damage wrought by large earthquakes will be greatly reduced. For example, fractures or cracks developed chiefly in the unconsolidated deposits, and structures on such deposits also 

suffered more damage from shaking because ground 

motion in unconsolidated deposits is greater than in 

bedrock. 

Compaction 

Extensive areas of unconsolidated deposits were 

compacted by the seismic shock. Although compaction 

of the sediments is widespread, time permitted a 

study only of Homer Spit and the Portage area. 

Homer Spit, extensively used for recreational and 

business purposes, has subsided to the extent that 

much of the spit is now inundated during high tides. 

According to Mr. H. A. Thorne of Homer, who was 

drilling a water well about 100 yards from the continuous -recording tide gauge at the end of Homer Spit, 

the spit is underlain by the following unconsolidated 

deposits: 

0 to 200 feet --- silt, sand, and gravel 

200 to 289 feet --- sand 

289 to 321 feet --- marine sand and clay 

321 to 462 feet--- soft clay, locally mushy 

462 to 468 feet --- hard clay 

468 to 477+ feet --Kenai(?) Formation 

The total subsidence indicated by the tide gauge is 

from 4.5 to 6 feet. For purposes of illustration, the 

conservative figure of 4.5 feet was used in figure 6. 

Based on pre-earthquake and post-earthquake conditions at the water well, the unconsolidated sediments 

compacted about 2.5 feet. The remaining 2 to 3.5 feet 

of subsidence is regional. 

The total amount of subsidence at Portage has not 

been clearly established. However, on the basis of the 

meager information available, there has been some 

compaction. The following unconsolidated deposits 

underlie Portage, as shown in the log of a water well 

at the Union Oil Station: 

0 to 20 feet --- sand and gravel 

20 to 425 feet --- clay 

425 to 426 feet--- sand 

426 to 600 feet --- clay 

The maximum total subsidence in the Portage area 

may be as much as 7 to 8 feet, half of which is probably due to compaction of the unconsolidated deposits. 

The railroad's 20-Mile Bridge rests on piles about 60 

feet deep. The right-of-way to the bridge approaches 

has subsided from 1 to 11/2 feet more than the bridge 

(fig. 14B). Thus, the top 50 to 60 feet of the unconsolidated material has compacted relatively more than 

the material below the piers. This is probably due to 

loss of volume by the extrusion of water during the 

seismic shaking. 

Lurching 

Lurching in the unconsolidated material displaced 

the highway 3 feet in the Portage area and at Knik Arm 

26 

displaced several piles as much as 10 feet horizontally. No such displacement was observed in bedrock. 

Landslides 

Most, if not all, of the destructive landslides were 

restricted to unconsolidated deposits. These include 

the landslides in Anchorage and the railroad landslide 

at Potter. The landslide crossing the railroad at Kenai 

Lake was not observed on the ground so it is not known 

whether the slide is in bedrock or in unconsolidated 

material. Locally in the Portage area the unconsolidated sand, silt, and clay underlying the railroad bed 

flowed and failed completely. 

The Bootlegger Cove Clay (Pleistocene) underlies 

Turnagain Heights, L Street, 4th Avenue, Government 

Hill, Alaska Native Hospital (fig. 19B) and other areas 

in Anchorage where landslides occur. This clay formation failed in the Turnagain Heights, L Street, and 

4th Avenue slides and it probably failed in the other 

landslide areas as well. 

Miller and Dobrovolny (1959) describe the Bootlegger Cove Clay as a" .. light-gray to dark-greenish-gray 

silty clay that contains layers or lenses of medium 

sand." The clay has thin laminations ranging in thickness from 0.25 to 1.0 mm. Over 80 percent of the 

grains that make up the Bootlegger Cove Clay are 

smaller than fine-sand size. A single, apparently typical, grab sample of the Bootlegger Cove Clay taken 

from the Turnagain Heights slide during the present 

study contained 61 percent silt, 25 percent clay, and 

14 percent very fine sand. The clay fraction was found 

by x-ray diffraction analysis to be dominated by chlorite, illite, and fine grained quartz and feldspar, and 

to closely resemble many samples of glacial rock 

flour from south-central Alaska. 

The railroad landslide at Potter was in glacial 

ground moraine consisting of gravel, with pebbles 

generally less than three-fourths of an inch in diameter, overlying an older ground moraine consisting 

predominantly of silt and clay. Failure occurred 

chiefly in the finer grained moraine. Numerous seeps 

were noticed near the base of the coarse-grained till 

several days after the earthquake. 

Damage to structures 

The type and thickness of the underlying deposits 

was, in large part, responsible for the different degrees of damage suffered by many of the structures 

during the earthquake. In the Anchorage area structures that are underlain by a thin layer of glacial 

outwash gravel overlying the Bootlegger Cove Clay or 

underlain by silt were more severly damaged than 

those underlain by a thicker layer of gravel. 

Structures on bedrock were damaged less than those 

on u nco n so 1 ida ted deposits. For example, large 

concrete buildings at Whittier:· built on bedrock, received less damage although closer to the epicenter, 

than the concrete structures of Anchorage which were 

built on outwash gravel and clay. 

All structures in Anchorage were subjected to intense seismic shaking during the earthquake. Many 

of the steel and concrete structures were severely 

damaged and one co 11 apse d (fig. 18D). Some 
Figure 14. Photographs of damage to transportation routes and effects of 

large sea waves. A, Wave trim-line on north-facing bluffs of 

CULROSS ISLAND.-B, Damage to railroad and highway bridge 

areas, 20-MILE RIVER. C, Damage to steel bridge crossing 

COPPER RIVER near Miles Glacier. D, Seismic sea wave 

damage at SEWARD. -

27 
EXPLANATION 

d\) 

--- -1 ·- -1 

lands I ide, arrows show direction of movement 

Dotted where inferred; qu eried where dou btful 

Fractures 

Ba r and ball on downthrown s ide 

"1(/l'l!(l'' "'''''' 

Top of blu ff 

Man y scarp lets , ... ~~ 1 , _ -1 -- ·;:- ? .... .... -"" _, .... _ 

- -

.' ·-- .. -- --

HEIGHTS 

"f Turn agai n 

School 

- '- J. Inlet View ~ ... ,, 11,..,,, •• Sc hpol "t ~ 

'"""'~ ...J ..... :.. 

......., Dena! i 

School 

Central 

..;JJr. High School 

""'* Aurora \ School _I--~~-

E 5TH AVE 

Fairview 

&.School DE BARR AVE 

~ W 15TH AVE 

'1.,,~ ...... ,,,..,111'''"'' ''' ... -· 

E 15TH AVE \~ 

~0{ 

'

Airport Heights 

School 

,,, 

"\ North Star 

l Schoo l 

NORTHERN 

l LIGHTS ~ BLVD 

1 Ml LE 

We ndel l Jr. Hi gh School "" 0 

-;,. Lake 

Ot 's ' lake Otis ,. School 

f ork 

Figure 15. Map showing landslides and related fractures in the ANCHORAGE area. 
----

Because of weakness of thin toe, 

many pressure r-idges and i rregu lar cracks form 

l STREET 

TURNAGAIN HEIGHTS 

Providence 

Hospital 

Bootlegger Cove 

Clay Sea level 

Potential slip surface before 

earthquake shock 

f::J~!~a~ef t;~~p:r;10~1~c;0 s~~~~ni~ ~~it: fa.shion 

.. o. ·., 0 . 

-~·~ ~~;_ ~:~-i~·_:--

Sea level 

Graben forms as block 

drops to fill tension crack 

.o . . o. • •

0 ·.e. 

aootlegger Cove 

Clay 

·. · .. ~.· .. : :"· 

Sea level 

Sea level 

Figure 16. Diagrammatic sections showing probable development of L-Street 

and Turnagain Heights landslides in ANCHORAGE. 

29 
Figure 17. Photographs of destructive landslides in ANCHORAGE. A, Subsidence in the graben at the head of the Fourth Avenue slide. 

B, Landslide near Alaska Nature Hospital. C, D, East and west 

parts of the Turnagain slide. - -

30 
Figure 18. Photographs of destructive landslides and damage in ANCHORAGE. 

A, B, Graben at head of L Street landslide. C, Compressional 

ridge formed at toe of L Street landslide. D, Destruction by 

seismic shock of a partially complete concrete structure on 

unconsolidated deposits. 

31 

Figure 19. Aerial photographs of WHITTIER and vicinity. A, 1948. B, April 

3, 1964. Note destruction of pier facilities. Dashed line shows 

high-water line. (U. S. Coast and Geodetic Survey photographs.) 

33 

concrete-block structures were also damaged, a few 

severely. In contrast, wood-frame structures were 

generally much less damaged, or were unharmed. 

SUBMARINE LANDSLIDES IN FIORD DELTAS 

Submarine landsliding in fiord delta deposits was a 

major geologic side effect of the March 27 earthquake, 

and it seems likely that if Prince William Sound had 

been heavily populated, this phenomenon would have 

been observed even more widely than it was. The susceptibility of the submarine slopes on fiord deltas to 

slide (or fail) under the influence of strong seismic 

shocks of long duration should be carefully studied 

before large buildings or other large structures are 

planned near the shorelines of such deposits. 

LAND-LEVEL CHANGES 

Land-level changes over at least 34,000 square miles 

of south-central Alaska have rendered obsolete all 

nautical charts and primary triangulation survey nets in 

the area. Shorelines that are lowered with respect 

to sea level were especially hard hit by the earthquake-generated waves of March 27 and 28, whereas 

the destructiveness of the waves in uplifted areas was 

substantially less. Regional subsidence has resulted 

in widespread inundation of low-lying coastal property 

and has jeopardized the safety of docking facilities, 

canneries, and other shoreline structures on Kodiak 

Island and the Kenai Peninsula. On the other hand, 

the uplifted areas, particularly Prince William Sound 

and Controller Bay, have had the usefulness of their 

harbors, channels, and shoreline installations seriously impaired by the relatively lowered water levels. 

REFERENCES 

Condon, W. H., and Cass, J. T., 1958,Map of a part of 

the Prince William Sound area, Alaska, showing 

linear geologic features as shown on areal photographs: U. S. Geol. Survey Misc. Geol. Inv. Map 

I-273, scale 1:125,000. 

Davis, T. N., 1960, A fieldreportonthe Alaska earthquake of April 7, 1958: Seismol. Soc. America 

Bull., v. 50, p. 489-510. 

Gutenberg, Beno, and Richter, C. F., 1954,Seismicity 

of the earth and associated phenomena, 2d ed.: 

Princeton, N. J., Princeton Univ. Press, 310 p. 

Miller, R. D., and Dobrovolny, Ernest, 1959,Surficial 

geology of Anchorage and vicinity, Alaska: U.S. 

Geol. Survey Bull. 1093, 128 p. 

U. S. Coast and Geodetic Survey, 1964, Preliminary 

report Prince William Sound, A 1 ask an earthquakes, March-April 1964: Washington, D. C., 

U~ S. Dept. Commerce, 100 p. 

Figure 20. Aerial photographs of Valdez before and after the earthquake. b 

1954. ~ April4, 1964. Note the complete destruction on shoreline, harbor, and pier facilities. (U. S. Coast and Geodetic 

Survey photographs.) 

35 


ALASKA'S GOOD FRIDAY EARTHQUAKE, MARCH 

/