Hawaiian Volcano Observatory

1968 Quarterly Administrative reports

Introductory Note By Thomas L. Wright and Jennifer S. Nakata

Compiled By Jennifer S. Nakata

Summary 49

January, February, and March 1968

By Arnold T. Okamura, Robert Y. Koyanagi, and Willie T. Kinoshita

Summary 50

April, May, and June 1968

By Robert Y. Koyanagi, Arnold T. Okamura, and Willie T. Kinoshita

Summary 51

July, August, and September 1968

By Robert Y. Koyanagi, Howard A. Powers, and Willie T. Kinoshita

Summary 52

October, November, and December 1968

By Robert Y. Koyanagi, Howard A. Powers, and Elliot T. Endo

Open-File Report 2007-1328

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia 2007

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INTRODUCTORY NOTE

The Hawaiian Volcano Observatory Summaries have been published in the current format since 1956. The Quarterly 

Summaries (1956 through 1973) and the Annual Summaries (1974 through 1985) were originally published as Administrative Reports. These reports have been compiled and published as U.S. Geological Survey Open-File Reports. 

The quarterly reports have been combined and published as one annual summary. All the summaries from 1956 to 

the present are now available as .pdf files at http://www.usgs.gov/pubprod.

The earthquake summary data are presented as a listing of origin time, depth, magnitude, and other location parameters. Network instrumentation, field station sites, and location algorithms are described. Tilt and other deformation 

data are included until Summary 77, January to December 1977. From 1978, the seismic and deformation data are 

published separately, due to differing schedules of data reduction. 

There are eight quarters—from the fourth quarter of 1959 to the third quarter of 1961—that were never published. 

Two of these (4th quarter 1959, 1st quarter 1960) have now been published, using handwritten notes of Jerry Eaton 

(HVO seismologist at the time) and his colleagues. The seismic records for the remaining six summaries went back to 

California in 1961 with Jerry Eaton. Other responsibilities intervened, and the seismic summaries were never prepared.

Chronology

The following Kïlauea eruption chronology covers the two recent reports and the six missing quarters:

Location Beginning Date Ending Date Comment

Kïlauea Iki crater (Kïlauea’s summit) 11/14/1959 12/20/1959 19 eruptive episodes

Kapoho (lower east rift zone) 1/13/1960 2/18/1960 4 eruption stages

Halemaumau (Kïlauea’s summit) 2/24/1961 2/24/1961 Intermittent activity during 

uninterrupted inflation following the 1960 eruption

Halemaumau (Kïlauea’s summit) 3/22/1961 3/25/1961 Same as above.

Halemaumau (Kïlauea’s summit) 7/10/1961 7/17/1961 Same as above.

Heiheiahulu (middle east rift zone) 9/22/1961 9/25/1961 First historical east rift eruption at this location

The 1959-1960 eruptions were among two of the most spectacular Kïlauea eruptions. The HVO staff was kept busy 

with acquisition of unusually high quantities of instrumental data and observations of the two sequences, which 

were separated by less than one month. Even with a year’s interval before the beginning of the summit-east rift sequence in 1961, the staff never caught up, and the seismic records were set aside for later study. 

A total of 1,672 earthquakes—1,106 for 1960 and 566 for 1961—are part of HVO’s cataloged database. The annual 

listings have been appended to the 1st Quarter Report of 1960 and to the 4th Quarter Report for 1961. The number of 

earthquakes is probably low, biased toward the larger magnitudes. The entire HVO catalog, including 1960 and 1961, 

is accessible from the ANSS CATALOG SEARCH site at http://www.ncedc.org/anss/catalog-search.

 Thomas L. Wright and Jennifer S. Nakata 
UNITED STATES

DEPARTMENT OF THE INTERIOR

GEOLOGICAL .SURVEY

. HAWAIIAN VOLCANO OBSERVATORY

SUMMARY 49

January, February, and March 1968

By Arnold T. Okamura, Robert Y. Koyanagi

and Willie T. Kinoshita

Issued July 1969

OBSERVATORY STAFF

Geology

R. S. Fiske

H. A. Powers (Scientist in Charge)

D. A. Swanson

Geo;ehysics

w. T. Kinoshita

George Koj ima

R. Y. Koyanagi

A. T. Okamura

Geochemistry

R. T. Okamura

T. L. Wright

Support

J. C. Forbes

w. H. Francis

B. J. Loucks

M. K. Sako

M. S. Umezu

Akira Yamamoto

K. M. Yamashita
CONTENTS

Page

Tilting of the ground around Kilauea Caldera -------------------- 1.

Seismic summary ----------------------------~-------------------- 5

Illustrations

Figure 1. Map' of the islan~ of Hawaii showing seismograph

stations and localities mentioned in the text 2

2. Tilting of the ground around Kilauea Caldera between

November 8; 1967, and February 14, 1968 ------------ 4

Tables

Table 1. Tilt coordinates at Uwekahuna 1

2. Tilt coordinates and changes at bases around

Kilauea Caldera ------------------------------------- 3

3. Number of earthquakes and minutes of tremor recorded

on seismographs around Kilauea Caldera -------------- 6

4'. Local earthquakes recorded by seismographs of the

U.S. Geological Survey ------------------------------ 10

5. u.s. Geological Survey'seismograph stations in

Hawaii----------------------------------------------- 17

6. U.S. Geological Survey ti1tmeter stations in Hawaii --- 19

i
Tilting of the ground around Kilauea Caldera

Tilting of the ground around the summit of Kilauea is monitored

daily by a short-base water-tube tiltmeter at Uwekahun.a (table 1), and

at irregular intervals it is measured on a regional scale by means of a

network of' field tilt-bases and a portable water-tube tiltmeter. The

attitude of the ground surface at each tilt-base is reported in terms

of north~south and east-west tilt coordinates. Both coordinates at

each station were arbitrarily set equal to 500 when measurements at that

station were begun. ,Increasing tilt coordinates correspond to northward

and eastward tilting of the earth's surfacej that is, to a relative .

subsidence toward the north and east. A one-unit change in coordinate

corresponds to a tilting of 1 microradian (1 mm per km) in the direction

indicated.

Location of and essential data on each tiltmeter station are listed

in table 6, which is published only in the first qua~ter issue each year.

Table 1.--Tilt coordinates at Uwekahuna

January, February, and March 1968

Date Date

(1968) N-S E-W (1968) N-S E-W

Jan. 7 557 404 Feb. 18 554 402

14 557 403 25 556 404

21 556 403 Mar. 3 555 404

28 . 556 402 10 556 404

Feb. 4 556 401 17 556 402

11 555 ·402 24 556 ·400

31 556 400

1
EXPLANATION

WOj~

Honokaa

'000 0

Paauilo

.• Seismograph Station

Town or locality

5 a 5 10 15 20 25 Kilometer, AHA....--. •

ContOUf interval 1,000 feet

Datu", is ",eon seo ,.".,

Figure l.--Map of the Island of Hawaii showing seismograph stations

operated by the U.S. Geological Survey, principal settlements,

and selected geologic features. Epicenters of local earthquakes

are given in table 4 in terms of geographic coordinates, which

are indicated at the edges of the map.

2
1st Quarter) 1968

Table 2.--Tilt coordinates and changes at bases around Kilauea Caldera

(see fig. 2 and table 6)

( -6 Rate 10 rad/mo) Date of

Tilt base Date Tilt coordinates and direction of last

(locatio~) (1968) tilting since reading

N-S E-W last reading (1968)

Uwekahuna Feb. 13 598.1 395·7 2.8 N. 88.0° w. Nov. 9

(u on fig. 2)

Tree Molds (TM) ,21 481.1 500.2 2.1 N. 31.5° w. 8

Sand Spit (SS) 14 894.3 682.0 6.0 S. 89·2° w. 8

Keamoku (Kea) 14 546.4' 372.0 4.3 S. 20.6° E. 8

Ahua Karnokuko1au 14 400.1 550.8 2.1 S. 67.4 0

w. 8

(Kam)

Kipuka Nene (KN) 14 299·7 308·5 . 0.02 N. 31.3° E. 7

Hilina Pali (HP) 14 455·1 502.6 0.17 S. 48.30

w. June 28

Kapapala Ranch 13 497·6 510.6 . 0·31 N. 56.5 0 E. Nov. 8

(Kap)

Mehena (M) 21 574.8 578.8 1.1 N. 0.60

E. 8

3
J

Kop

,

2000

o

Tilting rate 2.5 x 10-6 radians/month

NOV. 8, 1967 - FEB. 14, 1968

5KM

Figure 2.--Tilting of the ground around Kilauea Caldera between

November 8, 1967, and February 14, 1968. The vector depicting tilting

at a given tilt base points in the direction of maximum relative

subsidence and has a length proportional to the rate of tilting during

the measurement interval. Closed circles represent field tilt bases;

open circle, short-base water-tube tiltmeter. See ~able 2 for

explanation of .abbreviations.

4
Seismic summary

Events recorded by the U.S. Geo'logtcal Survey seismograph network

in Hawaii fall into two categories: Local earthquakes and tremor

originating in the region of the Hawaiian Isla~ds (usually within 100 km

of at least one seismograph), and distant earthquakes originating more·

than 3,000 km from Hawaii. As in index of seismic activity at Hawaiian

volcanoes, daily counts of earthquakes and minutes of tremor recorded·

by seismographs in Hawaii are listed in table 3. The earthquakes are

separated in groups on the basis of region of origin as determined by.

analysis of records obtained daily at the Observatory (U, M, M(2), A,

D, N, WP, :ME', K, 0). Earthquakes of magnitude 2.0 or greater are

generally sufficiently well recorded to be located with greater precision;

they are listed individually' in table 4.

Location of and essential data on each seismograph station are

listed in table 5, which is published only in the first quarter issue

each year.

5
Table 3. - -Number 0 f earthquakes and minutes of tremor recorded on seismographs around Kila

Tremor is separated into three categories: deep, intermediate, and shallow, on the basis of relati

on seismographs in the summit region. Unless ·otherwise stated, tremor is presumed to be associa

movement of magma within the central complex of Kilauea.

Earthquake categories are: Kilauea summit, 30 km earthquakes from a source about 30 kID beneath the 

sUmmit ·region; long-period, earthquakes characterized.by low-frequency waves that originate abou

Kilauea summit; and shallow earthquakes in the Kilauea Caldera region;· shallow earthquakes along 

zone of Kilauea and the adjacent portion of the Kaoiki fault system; earthquakes along the easte

Kilauea'·s east rift zone--detected largely on the Pahoa seismograph; earthquakes from the upper 

zone and the adjacent fault systems of Kilauea's south flank.; and earthquakes from other reg'ions

Mauna. Kea, etc.

Tremor Earthquakes

Date (minutes) Kilauea summit sw. rift Eastern Upper

Inter- Long and east east Koae 

Deep mediate Shallow 30 km period Shallow Kaoiki rift rift

Jan. 1 ---- ------- ------- 4 ------ 115 14 ------ 15 ---- 1 west 

2 18m ------- ------- 13 ------ 150 8 1 10 1 1 Kawa

3 14m ------- ------- 1 ------ 210 9 ------ 12 ---- ------

4 30m -_._---- ------- ----- ------ 105 16 76 ---- ------

5 15m ------- ------- ----- ------ 45 14 ------ 38 ---- -

6 10m ------- '5h ----- ------ 75 21 1 48 ---- ------

7 ---- ------- 12h 1 ------ ------- 13 1 315 16

8 ---- ------- ------- ----- ------ 180 15 ------ 142 3 1 south

9 ---- ------- 6h 2 ------ 60 44 ------ 173 13 

10 ---- ------- ------- 2 ------ 140 31 ------ 27 ---- l·Waik

11 ---- ------- 6h ----- ------ 135 29 ------ 26 l3 1 Kawa

12 ---- ------- 16h 3 ------ 30 21 ------ 11 4 ------

13 ---- ------- 24h 4 --.. ---- ------ 23 ------ 10 2 1 Waip

Hawai
Jan. 14 ---- 24h ------ ------- 17 ------- 17

4

15 -------- 24h

2 ------ ------- 11 ------- 16 -------

16 -------- 24h 1 ------ ------- 18 ------- 16 -------

17 -------- 24h ------ ------- 11 -------

7 --_ ... -------

18 -------- ------- ------ 195 10 ------- 14

3 -------

19 -------- 24h 1 ------ 20 20 ------- 29 1 offsh

20 -------- 24h -----_. ------- 26 ------- 22

6 -------

21 -------- 24h 1 ------ ------- 13 ------- -------22. -------- 24h '1 ------ -------

8 ------- 33 -------

23 -------- 24h ------ ------- 12 ------- 21 1 Kawai

24 -------- 24h 1 ------ -------

8 --_._--- 38-

25 -------- 20h

2 ------ ------- 12 29 -------

26 -------- 24h

4

2

7 ------- 13 1 -------

27 -------- 24h

5 ? ? 5

2

5 ? -------

28 -------- 18h

5 ------ 30

8 1 24

2 west 

29 -------- 22h

4 ------ -------

8 ------- 10 1 -------

30 -------- 24h ------ -------

6 ------- 28

2 1 Naale

-J 31 -------- 24h

2 ------ 75 13 ------- 34

5 --------

Feb. 1 -------- 24h

2 ------ 30 16 ------- 38 1 Keana

2 -------- 24h

2 ------ 90

6 ------- 16

3 -------- 24h ·2 ------ ------ 10 ------- 23

4 -------- 24h

2 ------ 28 13 ------- 27

5 -------

5 ---- -------- 24h

5 ------ 75- 11 ------- 14 3 -------

6 -------- 24h 1 ------ ------ 14 ------- 17 1 Keana

7 7m 24h

5 ------ 30 18 ------- 16 2 1 Waiki

1 Naal

8 -------- 21th 3 ------ 29

9 ------- 39 1 west 

9 -------- 24h 1 ------ 41

9 ------- 15 1 Puu W

10 -------- 24h

2 ------ 41 14 ------- 21 -------

11 34m -------- 24h

4 ------ 45 11 ------- 29 -------

12 -------- 24h

2 ------ 31

9 ------- 25 -------

13 -------- 24h

5 ------ 30 10 . ------- 25

5 -------

14 ---.. _--- 24h 12 ------ 30 23 ------- 62 -------15 -------- 24h 1 ------ 57 14 ------- 48 1 west 
Table 3.--Number a f earthquakes and minutes of tremor recorded on seismographs around Kilauea Ca

-Tremor Earthquakes

Date (minutes) Kilauea sunmiit (196i) sw. rift Eastern Upper Inter- Long and east east Koae O

Deep mediate Shallow 30 kIn period Shallow Kaoiki rift rift

Feb. 16 ---- -------- 24h 5 ------ 45 16 ------- 30 1 1 west H

17 ---- -------- 24h 3 ------ 45 12 ------- 5 ---- -------

18 ---- -------- 24h 3 ------ 45 18 1 19 ---- -------

19 ---- -------- 24h 8 ------ 30 6 ------- 16 - 3 -------

20 ---- -------- 24h 2 ------ 45 12 i 26 2 1 west H

21 ---- -------- 24h 1 ------ 31 12 ------- 31_ ---- --------

22 ---- -------- 24h 2 ------ 45 11 ------- 20 3 1 offsho

23 26rr -------- 24h 5 ------ 45 41- l 48 7 --------

24 ---- -------- 24h 5. ------ 55 57 ------- 21 ---- l'offsho

25 16rr -------- 24h 2 ------ 60 117 ------- 27 6 1 Mahuk

Maui

26 ---- --------- 24h 12 -----.- 37 31

.-

1 36 2 --------

27 IOn: -------- 10h 4 ------ 93 14 ------- 37 2 --------28 -------- 24h 4 ------ 22 10 1 15 1 1 Mokuaw29 ---- -------- 24h 3 ------ 43 10 ------- 20 2 1 Mokuaw

Mar. 1 ---- 6m 24h 3 ------ 36 7 ------- 28 5 1 Mokuaw

2 4n: -------- 24h 1 ------ 19 15 1 25 4 1 Mokuaw

west H

3 ---- -------- 24h 2 ------ 44 13 ------- ? 5 --------

4 ---- -------- 24h 1 ------ 51 16 1 11 6 1 west H

5 ---- -------- 24h 1 ------ 180 16 1 15 ----

6 30m -------- 24h 2 ------ 12 5 -r----- 15 1---- --------

7 ---- -------- 24h 2 ------ 73 7 24 3 --------

8 ---- -------- 24h 2 --.;.--- 25 14 ------- 26 ---- 1 Hilo

9 30m -------- 24h 5 ------ 28 14 ------- 20 ---- I Mokuaw

10 ---- -------- 24h 7 ------ 49 15 ------- 19 ---- I Naaleh11 ---- -------- 24h ----- ------ 47 11 ------- 9 1---- 1 west H
Mar. 12 32m -------- 24h 1 ------- 32 22 ._------- 24

3 ------

13 -------- 24h

4 ------- 51 15 1 18

3 1 west 

14 '24h 3 21

4 12

3 - -- -- 

-------- ------- -------- ------

15 ---- -------- 24h

2 ------- 28 12 -------- 14

8 ------

16 -------- 24h ------- 44

6 -------- 14 12 ------

17 -------- 24h 3 ------- 42

5 -------- 15

9 1 Hilo

18 -------- 24h

7

4 84

9 -------- 10

8 ------

19 --------- 24h 1 ------- 26

9 --------

7 5 ------

20 -------- ------ '3 ------.- 12 11 --------

6

2 1 Kean

21 14m -------- 24h ------ ------- 50 8 --------

4 1 ------

22 -------- 24h

4 ------- 33

6 -------- 16·

3 ------

23 -------- 24h ------ ------- 120 5 --------- 43 2 2 Moku24 -------- 24h

4 ------- 24 12 -------- 33

6 ---.--

25 ---- -------- 24h ------ ------- 48 13 1 27

2 1 Moku

Keana

'26 -------- 24h ------ ------- 94

7 -------- 1.8 1 Naal

27 -------- 24h

2 ------- 45

4 -------- 18 ------

\.0 28 -------- 24h

2 ------- 90 13 -------- 35

5 ------

29 5m -------- 24h 3 ------- 100

9 -------- 12 5

30 -------- 24h 2 ------- 105

9 -------- 15 1

31 -------- 24h ·3 ------- 38 10 -------- 15

4 1 offsh
t-J

o

Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological Surv

January, February, and March 1968

Entries for a given quake are: date, origin time (Hawaiian Standard Time), magnitude, depth, ed

felt report. All earthquakes of magnitude 2.5 and larger, as well as many favorably located 

on or near the island of Hawaii are included in the list. '

Date Time Magni- Dept,h Epicenter 

(1968) tude (kIn) 

h m s Lat N. Long W. Description - - -

Jan. 1 01 02 28.1 2·5 6 19°23.8' 154°55.8' 7kmNE. of Kalapana 

1 05 05 46.1 2.0 3 19°32.5' 156°00.2' 9 km NW •.of Kealakekua 

1 09 50 53·0 2·3 8 19°20.'5' 155°03.2' , 12 kIn ESE. of Makaopuhi seismometer 

1 22 28 19·8 2.4 30 19°21.8 ' 155°16.3' 21anSW. of Ahua seismometer 

2 04 43 37·0 2·5 8 20°05.1 ' 155°48.8 ' 5 ,k.m\ NNE. of Kawaihae 

2 16 32 29·0 2.2 6 19°25.4', 155°25.3' 10 kIn NNW. of Desert seismometer 2 21 13 23·0 2.0 8' 19°20.0' 155°08.8' 4 kIn SEe of Makaopuhi seismometer' 

5 02 58 10·3 2·3 10 19°16.2' 155°07.2' 8 kIn ENE. qf Apua Point 

5 10 47 32·7 2.2 8 19°20.,2' 155°10.1' 3 km south of Makaopuhi seismometer 

6 06 28 41.8 2·7 10 19°15.8' 155'°07.8 ' 7 km. east of Apua Point 

6 12 17 17·5 2.0 10 19°13.7 ' 155°04.1' 14 kIn SE. of Apua Point 

6 18 25 15·0 2.6 40 19°14.0' 155°23.9' 12 km south of Desert seismometer 

6 23 10 22.8 3·0 6 19°U.2' 155°00.0' 22 kIn SEe of Apua Point 

7 04 21 49.4 3·1 26 19°21.1' 155°21.7' 3kInNE. of Desert seismometer 

7 14 24 33·0 2.4 27 19°24.2' 155°16.6' South rim 'of Kilauea Caldera 

7 17 01 36.5 2.1 10 19°18.3' 155°15.1 ' 9kmNW. of Apua Point 7 18 59 11.0 2·3 10 19°19·1' 155°03.3' 16 kIn NE. of Apua Point 7 19 14 41.5 2.0 10 19°18.7 ' 155°08.0' 9k.mNE. of Apua Point 

7 19 19 02·5 2.2 10 19°18.4' 155°13·1' 6kmNW. of Apua Point 

1 19 46 36.5 2.8 9 19°17.4 ' 155°13.0' 4kmNW. of Apua Point 

7 19 57 19·0 2·3 9 19°16.3' 155°13.7' 4 km NW. of Apua Point 

7 22 07 24.3 2.0 3 19°10.2' 25 kIn BE. of Kalapana 

8 00 93 59·0 2.0 8 19°20.1' 155°49.1 1 10 kIn SEe of Hookena 
Jan.

8 06 59 31.2 2.6

9 19°17.5' 155°13.1' 5kmNW. of Apua Point 

8 11 39 56.8 2.0 10 19°18.1' 155°15.8' 9kmNW. of Apua Point 8 11 43 47·5 2.4 10 19°13.8' 155°08.8'

6 krn SE. of Apua Point 

8 13 36 44.0 2.0

8 19°19.5' 155°10.2'

5 km south of Makaopuhi seismometer 

8 21 33 46.2 2.0

9 19°17.8' 155°14.6' 7k.m NW. of Apua Point 

9 02 39 54.2 2.0

9 19°17.7' 155°15.1' 7kmNW. of,Apua Point 

9 08 30 48.3 2.0

5 19°14.8' 155°21.5' 10 k.m SSE. of Desert seismometer 

9 17 55 59·0 2.2

5 19°12.7' 155°21.6' 14 km SSE. of Desert seismometer 

9 18 16 15·9 3·0

7 19°11.8' 155°20.8' 16 k.m SSE. of Desert seismometer 

9 20 24 18.1 3·1

5 19°10.'3' 155°20.8' 11 kIn ENE. of Pa1ima Point 

10 05 33 23·1 2.0

5 19°15.2' 155°22·5' 10 k.m south of Desert seismometer 

10 10 29 36.1 3.6

8 19°11.3' 155°13.6' 8kmsw. of Apua Point 

10 17' 40 06.6 2·3

8 19°07·7' 155°09.8' 15 km south of Apua Point 

10 17 40 57·6 2·3

8 19°09.2' 155°10.'3' 12 km south of Apua Point 

10 18 24 38.5 3·3

8 19°27.5' 155°23.7'

4 km ssw. of Mauna Loa seismometer 

11 04 08 27.6 2.4

6 19°14.5' 155°21.2' 11 k.m SEe of Desert 'seismometer 

11 23 51 11.1 2.0

8 20°06.8' 155°55.4' 13 krn NW. of Kawaihae 

f--J 13 07 43 38.1 2.0

8 19°09·9' 154°54.4' 22 km SSE. of Kalapana 

f--J

13 10 37 38.8 2.5

8 19°22.7' 155°28.8' 11 k.m NW. of Desert seismometer 

13 13 50 21.6 3.2 40 19°37' 156°07' 24 kIn WNW. of Kealakekua 

15 07 10 47·7 3·0 10 19°21.3' 155°08.2'

4 kIn SEe of Makaopuhi seismometer 

15 22 45 21.1 2.6 '5 19°14.7' 155°20.2' 12 SEe of Desert seismometer 

16 02 35 06.7 2.0

6 19°20.0' 155°25.6'

4 km west of Desert seismometer 

16 19 03 10.0 3·5 40 19°16.3' 155°22.2'

7 kIn SSE. of Desert seismometer 

19 17 34 51·5 3·2 13 19°26' 156°21' 45 kIn WSW. of Kealakekua 

19 18 43 30·7 2.2 35 19°23.2' 155°18.0' 3 kIn SW. of Uwekahuna seismometer 

20 01 48 54.2 2.0

5 19°24.8 1 155°26.8 1 11 km SW. of Mauna Loa seismorreter 

20 13 14 25·3 2.0 13 19°19·7' 155°15.6'

5 km south of Ahua seismometer 

20 16 26 33·2 2·5 10 19°21.2 1 155°05.7'

8 kIn ESE. of Makaopuhi seismometer 

21 12 33 11·9 2.2

8 19°13.8 1 155°22.2' 12 km ENE. of Pahala 

22 10 55 46·7 2.4 lQ 19°19.9' 155°09.4' 9k.mNE. of Apua Point 

22 23 55 57·7 2.0

5 19°24.0 1 155°27.4' 10 km NW. of Desert seismometer 

23 09 32 47·8 2.4 13 20°06.4 1 155°54.3' 10 kIn NW. of Kawaihae 23 19 07 .21.1 2·5

9 19°20.7' 155°10 ..0'

2 km south of Makaopuhi seismometer 

23 23 31 22.6 2.1

9 19°21.8 1 155°04.7 1 10 km east of Makaopuhi seismometer 
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geological Surve

January, February, and March 1967--Continued

Date Time Depth Epicenter 

(1968) h tude Lat N. Description 

m s Long w. - - -

Jan. 24 08 57 57·5 2.4 9 19°17.9' 155°16.1' 9kmNW. of Apua Point" 

24 14 48 44.3 3·7 8 19°21.2' 155°01.8' 5 km west of Ka1apana 

24 14 53 31.2 2.2 9 19°21.6' 155°02.3' 6 km west ·'of Kalapana 

24 14 53 56.4 2·3 10 19°21.3 1 155°01.0 1 4 km west of Kalapana 

24 "14 57 15·9 2.5 9 19°19·8' 155°12.3' 5 kIn SW. of Makaopuhi seismometer·

24 16 59 36.1 2.4 5 19°26.2' 155°28.2' 11 km SW.· of Mauna Loa seismometer 

25 06 34 05·9 2.1 9 19°20.2' 155°12.0' ,5kmSW. of Makaopuhi s'eismometer 25 19 14 09·1 2.2 10 19°22.7' 155°03.3' 9kmNW. of Ka1apana' 

27 18 58 52.6 2.2 10 19°19.6' 155°11.9' 8 kID north of Apua Point 

28 17 40 41·7 2.6 5 19°23.8 1 155°25.0 1 7kmNW. of Desert seismometer 

28 18 19 07·5 3·3 30 20°05.1' 155°31.2' 5 km west of Honokaa 

29 08 47 51.2 2.4 28 19°23.2' 155°18.0' 4 kIn south of Uwekahuna seismometer 

30 21 11 00.0 2.0 9 19°20.4' 155°09.1' 3 km SEe of MakaopUhi seismometer 

31 05 28 25.4 2.0 '9 19°20.2' 155°12.3 1 5 kIn,SW. of Makaopuhi seismometer 

31 17 06 56.2 2.0 9 19°20.8' 155°09·7' 2 kIn south of Makaopuhi seismometer 

Feb. 1 09 03 05·5 2.0 5 19°24.1' 155°26.1' 9kmNW. of Desert seismometer 

1. 17 32 36.6 3·5 9 19°20·5' 155°07.5' 5 kIn SEe of Makaopuhi seismometer 

2 02 00 20.4 2.6 3 19°15·9 155°33.1' 11 kIn NW. of Pahala 

2 06 28 36.4 2.6 9 19°20.0' 155°08.6' 5 k.m BE. of Makaopuhi seismometer 

2 07 52 53·6 3·2 9 19°20.2' 155°09.3' 3 kIn SEe of Makaopuhi seismometer 

4 17 47 34.5 2.1 10 19°21.8 1 155°05.2' 9 km east of Makaopuhi seismometer 

5 03 23 23·9 2.0 10 19°23.7 1 155°24.8 1 7kmNW. of Desert seismometer 

6 04 45 43.4 2.0 10 19°19.9' 155°15.4' 5 kIn south of Ahua seismometer 6 04 52 41.3 2·7 8 19°25.0' 155°24.8' 9kmNW. of Desert seismometer 6 06 30 35·1 2.2 10 19°21.8' 155°05.2' 9 kIn ESE. of Makaopuhi seismometer 

6 11 09 23·5 2.0 10 19°25.7' 155° 22 .'9' 8 kIn south of Mauna Loa seismometer 
Feb.

6 16. 22 32·7 2.0 13 19°23.5' 155°27.5' 10 k.m NW. of Desert seismometer 

7 04 41 20·3 3·3

8 19°46.7' 155°40.7' 10 kIn SW. of Waikii 

7 15 40 35·9 2.1 13 19°20' 156°17' 43 krn SW. 'of Kealakekua 

7 21 .24 14.7 2.4

9 19°19.4 ' 155°12.0'

7 km north of Apua Point 

8 13 23 31.6 2.8

0 19°19.3. ' 155°4658' 14 kIn SEe of Hookena 

8 19 20 11·3 2.2

8 19°59.8 ' 155°18.8'

7 km west of Laupahoehoe 

9 07 29 38.0 2·5

0 19°46.$' 155°50.9' Puu WaaWaa 

9 14 34 22.0 2.1

8 19° 2"3.6 1 155°27.4' 10 kIn NW. of Desert seismometer

9 19 06 57·1 2.6 30 19°09.3' 155°25.7 1 7 kIn SE. of Pahala 

10 18 21 06.8 2·3 29 19°20.7' 155°14.6'

4 krn SE of Ahua seismometer 

11 06 17 51·9 2·3 10 19°24.7' 155° 25.2' 9kmNW. o'f Desert 11 14 29 35·1 2.8 40 19°19·1' 154°59.3' 6kmsw. of Ka1apana 

11 14 43 45·7 2·9

8 19°24.9' 155°27.6 1 12 km SW. of Mauna Loa seismometer 

13 21 15 15·7 2·3

9 19°19.7' 155°12.1 1 8 kIn north of Apua Point 

14 00 03 58.1 2.4 10 19°17·9' 155°13.2' ·5krnNW. of Apua Poip.t 

14 15 16 10.4 2.8

9 19°23.2' 155°24.0'

6 k.m NNW. of Desert seismometer 

14 22 37 07·9 2.1

6 19°25.7' 155°26.0' 9krnSW. of Mauna Loa seismometer 

I-' 15 05 07 47.8 3·1 34 19°21.1' 155°18.9'

8 k.m SW. of Uwekahuna seismometer 

\>J 15 12 04 01.4 2·3 10 19°17.7' 155°16.7' 10 kIn WNW. of Apua Point 

15 17 26 33·2 2·7

0 19°34.8' 155°50.9' 10 kIn NE. of Kealakekua 

16 01 58 56.1 2.0

0 19°26' . 2OkmSW. of Kealakekua 

16 19 59 30.4 2.1 10 19°19·2' 155°16.1 1 6 k.m, south of Ahua seismometer 

17 15 54 39.8 2·3 13 19°21.3' 155°07.4'

5 km SEe of Makaopuhi seismometer 

18 21 09 18.8 2.4

9 19°23.2' 155°03.2 1 9k.mNW. of Ka1apana 

19 08 11 47·7 2.8 28 19°23.2' 155°19.2'

5 km SW. of Uwekahuna seismometer 

19 08 52 29·4 3·0

9 19°23.7' 155°26.8' 9k.mNW. of Desert seismometer 

19 20 53 44.7 2.2 29 19°22.0 1 155°18.0'

4 kIn SW. of Ahua seismometer 

20 02 52 50.8 3·3 40 19°08.8' 154°58.8'

5 kID south of Kalapana 

20 10 47 00·3 2.0 3 19°25.2' 155°16.5' Kilauea Caldera 

20 15 06 33·1 2.2

8 19°22.9' 155°00.0' 4kmNW. of Kalapana 

20 20 31 38.9 2.2

3 19°24.2 1 155°47.1 ' 19 kIn SEe of Kealakekua 

21 19 14 54.1 2.0 10 19°20.2' 155°07.4'

5 km BE. of Makaopuhi seismometer 

21 19 17 27·7 2.2

9 19°18.4' 155°13·'4' 6kInNW. of Apua Point 

21 23 39·9 2·3

9 19°19.5' 155°15·7' 10 kIn NW. of Apua Point 
Table 4.--Local earthquakes recorded by seismographs 'of the U.S. Geological Surve

January, February, and March J.969--Continued

Date Time Magni- Depth Epicenter 

(1968) h m s tude (kIn) Lat N. Long W. Description 

Feb. 22 08 13 46.9 2.2 9 19°20.0' 155°08.5' 10 kIn NE. of Apua Point 

22 09 20 40.0 '4.5 8 19°1'5 1 156°19' 43 kIn ENE. of Milo1ii 

22 12 06 4501 2.4 32· 19°18·9' 155°16.0' 7 kIn south of Ahua seismometer 23 04 32 ,46.9 2.4 13 19°19.9' 155°11.2 1 8 kID north of Apua Point 

23 09 24 36.3 3·2 9 19°20.3' 155°08.2' 4 kIn SEe of 1v1akaopuhi seismometer 

23 10 36 37·1 3·0 10 19°18.2 1 155°13·9' 7kmNW. of Desert seismometer 23 20 24 04.3 2·5 10 19° 2,1.0 1 155°03 ..6' 9 kIn west. of Kalapana 

23 23 54 48.4 2.0 10 19°19.0' 155°14.3' 8kmNE. of Apua Point 24 04 44 23·1 2·3 8 19°24.b' 155°25.3' '9krnNW. of Desert seismometer 

24 05 19 28·9 2.0 8 19°25.1 1 155°26.9' 11 kIn NW. of Desert seismometer 

24 05 31 44.1 2.0 5 19°25.0' 155°26.3' 10 km NW. of Desert seismometer 24 05 45 58.8 3·2 7 19°24.7' 155°26·7' 10 krn NW. of Desert seismometer 24 06 41 26.1 2.6 8 19°24.9' 155°25.8' 10 kIn NW. of Desert seismometer 

24 11 31 37.6 3·0 7 19°24.7' 155°26.2' 10 km NW. of Desert seismometer 

25 03 10 22·9 2.8 8 19°24·9' 155?24.9' 9kmNW. of Desert seismometer 25 08 56 07.6 2.0 7 19°15.7' 155°21·9' 9 km'SE. of Desert seismometer 

25 09 11 30·9 3·3 13 20°13' 156°4.7 1 85 kIn SW. of Ha1eaka1a, Maui 

25 10 58 38·9 2.8 3 19°24.8' 155°24.8' 9kmNNW. of Desert seismometer 

25 12 52 54.8 2.2 5 19°14.8 1 155°23.3' 10 km south of Desert seismometer 

25 15 09 35·9 3·1 3 20°13.0' 155°55.8' 4kmNW. of Mahukona 

26 18 00 18.6 2·9 9 19°19.7 1 155°09·2' 9 km NE. of Apua Point 

26 19 10 56.5 2.0 9 19°20.1' 155°15.8' 4 km south of Ahua seismometer 26 23 24 25.1 2.0 6 19°22.6 1 155°26.8 1 8kmNW. of Desert seismoreter 27 06 01 00·9 2.2 6 19°22.3' 155°26.8' 7kmNW. of Desert seismometer 

28 16 53 12·9 2·7 5 19°13.7 1 155°32.7' 8 kIn NW. of Pahala 

28 17 04 40.6 2.4 3 19°14.3' 155°33.8 1 10 km NW. of Pahala 

28 19 56 41.9 2.4 3 19°14.1' 155°36.8' 7kmSW. of Mokuaweoweo Caldera 

29 01 16 59·7 2.4 3 19°23.0 1 155°35.9 1 10 kIn SSW. of Mokuaweoweo Caldera 
Feb. 29 03 08 16.7 2.0

8 19°22.8' 155°03.8' 9kmNW. of Kalapana 

29 03 29 00.2 2.0

8 19°25.9 ' 9kInSW. o.f Mauna Loa seismometer 

29 12 37 07·3 2.1

8 19°20.0' 155°10.7 1 4 km south of Makaopuhi seismomete 

Mar. 1 00 -51 02.4 2.4

2 19°23·3' 155°36.0' 8km south of Mbkuaweoweo Caldera 

2 04 02 59.6 2.4 . 3 19°27 .5. 1 155°46.2' 17 k.m ESE. of Kealakekua 

2 05 00 28.4 2.2

9 19°20.7' 155°03.7 1 9 km west of Kalapana 

2 07 55 24.9 2.8 10 19° 2.4.4 1 155°35.2 1 7 kIn south of Mokuaweoweo Caldera 

2 15 00 14.4 2.0

9 19°18.4' 155°16.3'

7 kIn south of Ahua seismometer 

4· 02 32 -36.9 2.2 O· 19°20.0 1 155°50.7 1 8k.mSE. of Hookena 

4 05 14 55.6 2.0

8 19°25.1' 155°26.21 10 kIn SW. of Mauna Loa seismometer 

5 04 14 20.2 2.4

8 19°25.0' 155°26.5' 10 kIn SW. of Mauna Loa -seismometer 

5 .17 30 54.1 2.2

9 19°20.7' 155°07.21 6 km SEe of Makaopuhi seismometer 

6 04 40 28.9 2.2

8 19°25.7 1 155°25.2'

8 kIn ssw. of Mauna Loa seismometer' 

6 05 04 23·2 2.2

9 19°19.4' 155°11.3 1 5 km SW. of Makaopuhi seismometer 

6 12 29 07·8 2.0 10 19°21.7' 155°06.1'

7 kIn ESE. of Makaopuhi seismometer 

9 01 42 12.8 2.0

0 19°29.0 1 155°36.3' Mokuaweoweo Caldera 

9 13 52 12.4 2·3 31 19°22.0 1 155°14.7 1 3kmSE. of Ahua seismometer 

I-J

9 16 58 09·0 2.1

9 19°19.8 1 155°08.7 1 5 km SEe of Makaopuhi seismometer 

\Jl 10 08 00 32.6 2.2

8 19°12.4 1 155°31.0 1 15 km NE. of Naalehu 

10 ' 12 01 48.5 2.0 10 19°17.7 ' 155°05.3 1 12 kIn NE. of' Apua Point 

12 16 18 32.4 2.0

8 19°16.9 1 155 P 23.1 1 6 kIn south of Desert seismometer 

17 05 17 01.4 2·7

8 19°56.3 1 ,155°28.2 ' 14 kril WNW. of Keanakolu 

17 09 28 58.9 2.2 40 19°39.8' 155°13.7' 16'; km SW. of Hil0 

17 13 49 29.6 2.8

8 19°56.4 1 155°27.4' 13 kIn WNW. of Keanako1u 

17 17 00 03·9 2.0

9 19°22.0' 155°02.8 1 7kmWNW. of Kalapana 

18 01 42 17.2 2.2 29 19°21.7' 155°19.0 ' 6kmsw. of Kilauea Caldera 

19 20 12 15·5 2.0

8 19°16.8' 155°28.2 1 11 kIn SW. of Desert seismometer . 

23 05 29 18.0 2.4

5 19°23.21 155°25.7 1 7kmNW. of Desert seisInOreter

23 05 32 03·5 2.0 27 19°23.7' 155°17.6' 2kmSE. of Kilauea Caldera 

23 06 47 11.1 2.5

3 19°30.7 ' 155°42.1 ' 12 kIn WNW. of Mokuaweoweo Caldera 

23 13 57 13·2 2.5 3 19°33.2' 155°42.2 ' 15 kIn WNW. of Mokuaweoweo Caldera 

24 02 45 02.6 2·7

9 19°19.9 1 155°12.7 ' 8kmNNW. of Apua Point 

25 14 50 53·3 2·5 40 19°46.0' 155°19 ..3 ' 25 kIn WNW. of Hilo 25 16 57 36.7 2·3 3 19°23.8' 155°37.4 1 9kmSW. of Mokuaweoweo Caldera 

26 03 27 54.8 2.4

9 19°20.0' 155°10.8'

4 km SW. of Makaopuhi seismometer 
4.--Local earthquakes recorded by seismographs of the U.S. Geological Surve

January, February, and March 1968--Continued

Date Time Magrii Depth Epicenter 

(1968) 11 tude (kIn) Lat N. Long W. Description 

In §.

Mar. 26 09 41 27.6 2., 3 19°13.2' 155°36.3' 17k.mNNW. of Naalehu 

28 00 30 01.6 2.6 10 19°22.7' 155°23.7 ' 5 km north of Desert seismometer 

29 03 51 19·8 2.2 6 19°26.2 1 155°27.1' 9k.mSW. of Mauna Loa seismometer 

29 12 11 40.8 2.0 10 19°21.8' 155°i6.1' 1 km south. of Ahua seismometer 

30 03 37 14.3 2.1 8 19°24.0' 155°26.0' 8k.mNW. of Desert seismo:rreter 

30 ·23 21 18.1 2.0 9 19°20.2' 155°08.0 ' 5 krn SE. of Makaopuhi seismometer 31 00 56 15·0 4.2 13 21°45' 156°56' 60 km of Molokai 

31 01 22 07.8 3·0 13 21°50' . 156°51' 137 kIn NW. of Ha1eakala, Maui 

31 15 00 37·7 2.2 13 19°34.1 1 155°20.0' 10 kIn NE. of Mauna Loa seismometer 

31 20 58 56.1 2.0 13 19°33.21 155°21.3' 7 kIn NE. of Mauna Loa seismometer 
Table 5.--U.S. Geological Survey.seismograph stations in Hawaii

LOn island of Hawaii unless otherwise

Station Location

Uwekahuna

Volcano

Observatory)

Mauna Loa

Ahua

Mauna Loa (2)

Desert

North Pit

West Pit

Makaopuhi

Kealakomo

Outlet

Kipuka Nene

Cone Peak.

Hi10

Kipapa, Oahu

Pahoa

Symbol

U

M

A

M(2)

D

N

WP

MP

K

KN

°

CP

Hi

Kip

Pa

Lat N.

19°29.8'19°22.4'

19°20.21

19°24.9'

19°24.7'

19°21.8 1

19°18.5'

19°23.4 1

19°20.1'

19°23.7 1

19°43.2 1

Long W.

155°23.3'

155°15.9 1

155°20.7'

155°23.3 1

155°17.0'.

155°17.5'

155°10.7'

155°09.6 1

155°16.8'

155°17.4 1

155°19.7 1

155°05·3'

158°00.9 1

154°56.8'

Altitude

(m)

above sea

level

1,240

2,010

1,070

1,475

815

1,115

1,115

885

201

1,084

924

1,038

20

205

Equipment

(Z, vertical; N, north-south; 

Long-period N, 

(Seismometer and galvanomete

l? 90 seconds,

Short-.peri9d, .Sprengnether: E

liVO-I: zY

Short-base liquid-level

Remote recording liVO-2:

Do.

Remote recording 1.0 sec. EV

Do.

Do.Do.

Do.

Do. (installed Sept. 28, 

Do.

Do. (installed Sept. 21, 

Do. (installed Nov. 8, 19

liVO-l: Z

Wood-Anderson: N, E. Opera

Joseph De Mello at St. Josep

HVO-1: Z. Operated by U.S. 

Geodetic Survey.

HVO-l: Z. Operated by KODgo 

Pahoa School.
Table 5.--U.S. Geological Survey seismograph stations in Hawaii--Continued

Station Symbol Location

Lat N. Long W.

Altitude

(m)

above sea

level

Equipment

(Z, vertical; N, 

Haleakala, Maui Ha

Naalehu Na

Kamuela Ka

&; North Bay NB

Kealakekua Ke

2,090

205

740.

4,005

505

HVO-l: Z.

Wood-Anderson: . N, E., Opera

of Haleakala National Park, 

1.0 seG. EV-17 

galvanometer: Z. Operated 

Mrs. E. Elarionoff at Naaleh

1.0.sec. EV-17, 0.286 sec. ga

Operated by Michael Foster a

1.0 sec. EV-17: Z. with heli

Operated by U.S. Weather Bur

1.0 sec. EV-17, 0.286 sec. ga

Z, EW, and NS. Operated by 

Kana County Hospital.

is a moving-coil, hinged, vertical-component seismograph with seismometer and galvan

0.5 second. Overdamping of both seismometer and galvanometer is used to control the strong gal

reaction. This seismograph has a peak magnification of about 20,000 at a period of 0.25 

optical, on photographic paper.

is a moving-coil, vertical-component seismograph with a seismometer period of 0.8 se

signal is transmitted over telephone wires to the Hawaiian Volcano Observatory, where it is rec

smoked-paper recorders.
Table 6.--u.s. Geological Survey'tiltmeter stations in Hawaii

Frequency Base

Station Symbol 'Location of length Description

Lat N. wng W. rea9ing M

Tree Molds TM ' 19°26.3' 155°11.3' Quart~rly 50·79 NS. and EW.

Sand Spit SS 19°24.1' 155°16.8' ---do---- 25.40. Equilateral ',. triangle

Keamoku Kea . 19° 25.1', 155°19.0' ---do---- 41.55 Do'.

Ahua Kamokukolau Karn 19°22.7' 155°16.6' ---do---- 50·19 Do.

Kipuka ,Nene KN 19°19·4' 155°16.1' ---do---- 50·19 Do.

Hi1ina Pa1i HP 19°18.2' 155°18.6' ---do---- 41.13 Do.

Kapapala Ranch Kap 19°20.5' ' 155°23.8' ---do---- 50·19 Do.

Mehana M 19°26.2' 155°14.3' ---do---- 25·00 Do.

Uwekahuna U 19°25.5' 155°17·4' --,-do---- 50·79 Do.

Uwekahuna Vault 19°25.4' 155°17.6 ' Daily 3.48 NS. and EW.

19
UNITED STATES

DEPARTMENT OF THE INTERIOR

GEOLOGICAL SURVEY

HAWAIIAN VOLCANO OBSERVATORY

SUMMARY 50

April, May, and June 1968

By Robert Y. Koyanagi, Arnold .T. Okamura

and Willie T. Kinoshita~/

Issued September 1970

OBSERVATORY STAFF

Geology

H. A. Powers (Scienti~t-in-Charge)

D. A. Swanson

Geophysics

D. B. Jackson

W. T. Kinoshita

George Kojima

R. Y. Koyanagi

A. T. Okamura

Geochemistry

R. T. Okamura

T. L. Wright

Support

J. C.. Forbes

w. H. Francis

B. J. Loucks

S. A. Takeguchi.

M. S. Umezu

Akira Yamamoto

~/National Center of Earthquake Research, Menlo Park,

California.
CONTENTS

Page

Summary of activities ------------------------------ 1

Tilting of the ground around Kilauea caldera ------- 3

Seismic summary ------------------------------------ 6

Illustrations

Figure 1. Map of the island of Hawaii showing seismograph stations and localities mentioned in the text -------------------- 2

2. Tilting of the gr.ound around Kilauea caldera between February 14, 1968 and June

10, 1968 ------------------------------ 5

Tables

Table 1. Tilt coordinates at Uwekahuna Vault ---~-- 3

2. Tilt coordinates and changes at bases

around Kilauea caldera ----------------- 4

'3. Number of earthquakes and minutes of tremor

recorded on seism~graph.s around Kilauea

caldera -----------------------------~-- 7

4. Local earth~uakes recorded by seismographs

of the U.S .. Geological Survey ---------- 11
Summary of activities

Th'e eruption on the summit crater ,continued throughout this quarter except for a 2-hour period on May 5th when

fountaining and tremor ceased. Thi~ short period of ina~tivity separated the 29th and 30th phases. By the' end

of June the depth of new lava to the 1961 floor in

Halemaumau was 360 feet. Levees around the central, active

portion of the lake are 405 to 420 feet above the preeruption floor.

Levels were run on the benchmarks in'the summit area

and the upper east rift in early April and early June.

The leveling generally shows small inflation during the

quarter. In early April the summit benchmarks were still

ab,out,a.l foot below their pre-eruption levels. By June

the summit was at about the pre-eruption level. Inflation

along the upper east rift came into prominence during this,

period as uplift in the Alae,-Makaopuhi crater area nearly

~atched uplift in the summit area in April. In June the

upper east rift area showed slight deflation, but it

still remained at a fairly high level.,

There were slight extensions along all of the geodimeter lines in the summit area when their lengths as measured in May were compared with their October 1968 (preeruption) lengths.

In addition to several bursts of shallow caldera quakes

several tens ,of earthquakes were recorded daily from sources

beneath Kilauea's southwest and southeast flanks. The

largest quake from the shallow caldera source region registered magnitude 4 on May 29. A swarm of several hundred

"30-kmdeep" Kilauea summit quakes occurred in l~te April.

The largest. event, a 4-1/2 magnitude shock at 04 Q'9 m,

Aprii 28,' appeared to have initiated, this deep episode.

1
EXPLANATION

6 Seismooraph Station

o Town or locality

bB::::EH~.-2i::::==::::i====31O===::JlrMile.

5 0 5 10 20 25 Kilometer. HAR e--3 I

Contour interval 1,000 'eet

Datum is mean sea level

TopoQraphr by US GeoIoQical Sune,

laupohoe 01 - 20·

Figure l.--Map of the Island of Hawaii showing seismograph stations

operated by the'U.S. Geological Survey,principal settlements,

and selected geologic features. Epi'centers of local earthquakes

are given in table 4 in terms of geographic coordinates, 'which

a~e indicated at the edges of the map.

2
Tilting of the ground around Kilauea Caldera

Tilting of the ground around the summit of Kilaeua

is monitored daily by a short-base water-tube tiltmeter

in Uwekahuna Vault, and at irregular intervals it is

measured on a regional scale by means of a network of

field tilt-bases and a portable water-tube tiltmeter.

The attitude of the ground surface at each tilt-base is

reported in terms-of north-south and east-west tilt

coordinates. Both coordinates at each station were arbitrarily set equal to 500 when measurements at that station

were begun. Increasing tilt coordinates correspond to

northward and eastward tilting of the earth's surface;

that is, to a relative subsidence toward the north and

east. A one-unit change in coordinate corresponds to a

tilting of 1 microradian (1 mm per km) in the direction

indicated.

Location of and essential data on each tiltmeter

station are listed in table 6, which is published only in

the first quarter issue each year.

Table l.--Tilt coordinates at Uwekahuna vault

April, May, and June 1968

Date N-S E-W Date N-S E-W (1968) (1968)

April 7 556 402 May 19 555 399

14 556 399 26 555 402

21 556 399 June 2 555 402

28 556 398 9 555 402

May 5 555 400 16 556 395

12 556 399 23 55·5 394

30 556 397

3
Table coordinates and changes at bases around Kilauea caldera. (
Q

o

"

9KN

cr

o

2000

2.; x 10-6 radians/month

1968 - JUN~ 10, 1968

N

t

5KM

Figure 2.--Tilting of the ground around Kilauea caldera.

The vecto~ depicting tilting at a given tilt base

points in the direction of maximum relative subsidence

and has a length proportional to the rate of tilting

during the measurement interval. Closed ·circles represent field tilt bases; open circles, short-base

water-tube tiltmeters. See table 2 for explanation

of abbreviations.

5
Seismic summary

Events recorded by the U.S. Geological Survey seismograph network in Hawaii fall into two categories: Local

earthquakes and tremor originating in the region of the

Hawaiian Islands (usually within 100 km of at least one

seismograph), and distant earthquakes originating more

than 3,000 km from Hawaii. As an index of seismic activity at Hawaiian volcanoes, daily counts of earthquakes

and minutes of tremor recorded by seismographs in Hawaii

are listed in table 3. The earthquakes are separated in

groups on the basis of region of origin as determined by

analysis of records obtained daily at the observatory

(U, M, Mx, A, D, N, WP, MP, Kx, 0,). Earthquakes of

magn·itude 2.0 or greater are generally sUfficiently well

recorded to be located with greater precision; they are

listed individually in table 4.

Location of and essential data on each seismograph

station are listed in table 5 in the first-quarter issue

each year.

Acknowledgments

Several people or agencies reported "felt" earthquakes

during the 2nd quarter, 1968. Their assistance ~s gratefully acknowledged.

6
--.;J

Table 3.--Number of earthquakes and minutes of tremor recorded on seismograph

Kilauea Caldera

Tremor is separated into three deep, intermediate, and on th

relative amplitudes on seismographs in the summit region. Unless otherwise stat

is presumed to be associated 'with movement of magma within the central complex o

Earthquake categories are: Kilauea summit, 30 km earthquakes from a source about 

the Kilauea summit region; long-period, earthquakes characterized by low-frequen

originat"e about 5 km beneath Kilauea summit; and shallow earthquakes in the Kila

region; shallow earthquakes along the SW. rift zone of Kilauea and the adjacent 

the Kaoiki fault system; earthquakes along the eastern half of Kilauea's east ri

tected largely on the Pahoa seismograph; earthquakes from the upper east rift zo

adjacent fault systems of Kilauea's south flank; and earthquakes from other regi

Hawaii, Mauna Kea, etc ..

Tremor Earthquakes

(m = minutes Kilauea Summit h = hours)

Date SW rift Eastern U

(1968) Inter- Long and east e

Deep mediate Shallow 30KM Period Shallow Kaoiki rift r

April 1 24h 4 40 8 

2 . 24h 3 80 14 

3 24h 2 325 7 

4 .. 24h 1 60 11 

5 24h 2 105 3 

6 24h instI uments off ---------------- -----------

7 24h 8 120 4 

8 24h 45 8 

9 6m 24h 6 60 7 

10 24h 120 instrl ments off -

II 24h 3 60 4 

12 24h 5 120 9 

I
of earthquakes and minutes of tremor recorded on seismograph

Kilauea Ca1dera--Continued

Tremor Earthquakes

(m = minutes

h = hours) Kilauea Summit

Date SW rift Eastern U

(1968) Inter- Long and east . e

Deep mediate Shallow 30KM Period Shallow Kaoiki rift r

April 13 · · 24h . · 60 9 · 

14 · 24h 2 150 10 

15 · 24h . 45 22 

16 · 24h 2 · 105 9 · 

17 · · 24h 1 45 '7 

18 14m 2 30 5 · 

19 24h 2 45 12 

20 · 24h 120 5 

21 · · 24h · 75 · 22 · 2·4h 2 · 135 8 · 

23 24h · III 4 · 

24 · 24h 4 · 75 13 

25 24h 2 45 11 · 

26 24h 45 11 1 

27 24h 106 120 6 

28 24h 62 · 45 34 29 24h 25 45 8 · 

30 24h 15 9 11 

May 1 · 24h 14 15 10 · 

2 24h 5 1 11 · 

3 24h 3 . 15 1 

4 . 24h 4 4 7 

5 · 22h 3 5 · 

6 24h 7 7 34 1 

7 '24h 5 · 19 
May

8

4 43

9 

9 24h

9 5 '12 

10 24h

4

9 

11 24h .2

7

12 24h

4

7 1 

13 24h 5 21 12

14 24h 3 3 16 1 

15 24h

4 5 14

16 24h 5 24 13 

17 24h 3 5 18 

18 24h 3 22 18 

19 15 122 16 

20 13

6 10 

21 24h

7

4 14 

22 24h

2 23

9 

23

4 15 8 1 

24 53m

9 160

6 

\0 25 65m 24h 5 69

9 

26 20m 24h

6 10

2 

27 24h

2 48

4 

28 19m 24h

7 34 8 

29 24h 1 190

4 1 

30 24h 1 14

6 

31 24h

6

4

9 

June 1 24h

4 28

4 

2 24h

2 16

7 1 

3 24h 5 25

9 1 

'4 24h 43 11 

5 24h 1 36 3 

6 24h 3 21

7 

7 24h

2 58

8 1 

8 24h 1 65 9 

9 24h 2 13 17 

10 10m 24h

7 38 20 

11 24h 2 46 16 

12 24h

6 21 30 

13 24h

2 18 

14 24h 3 48 8 
o

.Table 3.--Number of earthquakes and minutes of tremor recorded on seismograph

Kilauea Ca1dera--Continued

Tremor Earthquakes

(m = minutes

h = hours) Kilauea Summit

Date

(1968) SW rift Eastern U

Inter- Long and east e

Deep medi ate Shallow 30KM Period Shallow Kaoiki rift- r

June 15 24h 1 15 9 -- 

16 42m 3 69' 6 1 

17 24h 10 19 31 

18 24h 12 66 27 

19 . . 24h 2 27 5 1 

20 24h 10 43 45 2

21 24h 6 25 15 22 24h 4 · 150 26 

23 24h 3 · 70 43 

24 24h 3 · 44 28 

25 24h 7 57 20 

26 24h 9 72 23 

27 24h 7 · 35 21 28 30m 11 24 26 29 22m 24h 7 51 

30 18m 24h 8 29 23 
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

April, May, June 1968

Entries for a given quake are: date, origin time (Hawaiian Standard Time), magnit

epicenter, and felt report. All earthquakes of magnitude 2.5 and larger, as wel

located smaller ones, occurring on or near the island of Hawaii are in

the list.

Date Time Magni- Depth Epicenter

tude (km) 

h m s Lat. N. Long. w. Description 

- -

April 1 14-34-22·.7 2.0 9 19°27.2' 155°27.4·' 9 km SW of Mauna Loa

,seismometer

3 15-06-11.1 3.7 8 19°23.1' 155°27.1' 8 km NW of Desert seismo

meter 

4 16-56-16.4 2.5 3 19°33.2' 155°50.8' 9 km NE of Kealakekua

4 18-20-57.7 2.4 28 19°03.8' 155°23.8' 20 km E of Naalehu

4 23-16-53.2 2.0 3 19°23.0' 155°36.1' 10 km S of Mokuaweoweo

Caldera

5 04- 5'8 - 3 3 . 1 2.4 8 19°57.3' 155°29.8' 17 km WNW of Keanakolu5 07-11-40.6 2.0 8 19°25.6' 155°24.3' 8 km SSW of Mauna Loa

seismometer

6 00-30-15.7 2.5 35 19°19.5' 154°59.5' 3 km SW of Ka1apana

6 09-36-22.7 2.7 3 19°13.7' 155°31.0' 5 km NW of Pahala
Table 4.--Loca1 earthquakes !ecorded by seismographs of. the u.s. Geological 

April, May, June 1968

.......

I\)

Date Time Magni- Depth Epicenter 

tude (km) 

.h m L·at. N. Long. w. Description - -

April 7 20-25-15.7 2.0 27 19°22.3' 155°16.8' 2 km W of Ahua s e i smomet e

9 00-38-37.0 2.0 3 19°11.2' 155°39.6' 16 km NW of Naalehu

9 01-14-56.7 2'.6 13 20°00' 156°25' 90 km S of Ha1eaka1a, Mau

10 01-00-24 '.8 3.7 27 19°23.9' 155°16.9' South rim of Kilauea 

Caldera 

10 04-59-48.6 2.0 2 19°25.5' 155°16.9' Kilauea Caldera

10 09-18-17.2 2.1 5 19°25.1' 155°26.0' 10 km SW of Mauna Loa

seismometer

11 14-45-20.9 2.2 9 19°19.5' 155°13.4' 7 km NW of Apua Point

12 20-24-01.8 2.4 45 19°15.6' 155°12.9' 2 km W of Apua Point

13 05-06-05.5 2.1 15 19°27.7' 155°38.8' 5 km SW of Mokuaweoweo

Caldera

13 11-13-00.6 2.4 3 19°43.2' 155°43.8' 30 km NE of Kealakekua

14 08-25-25.1 2.2 9 19°19.0' 155°11.8' 6 km N of Apua, Point

14 10-45-57.3 2.5 0 20°02.1' 155°59.7' 17 km W Kawaihae
Table 4.--Local earthquakes recorded by seismographs of. the u.s. Geological 

April, May, June 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description

- -

April 15 10-30-25.5 3.0 10 19°15.0' 155°25.2' 8 km NE of Pahala 

15 10-53-10.5 2.2 5 19°14.5' 155°27.7' 13 km BW of Desert seismo 

meter

16 20-16-17.0 2.2 35 19°20.1' 155°09.6' 3 km BE of Makaopuhi

seismometer

17 00-39-37.8 2.1 8 19°15.0' 155°26.7' 11 km SW of Desert seis- 

mometer

17 04-58-06.3 2.4 8 19°48.3' 155°37.4' 6 km SE of Waikii

17 12-38-56.5 2.0 8 19°25.3' 155°25.5' 9 km SW of Mauna Loa

seismometer

18 20-09-42.8 3.2 29 19°22.0' 155°16.8' 2 km SW of Ahua seismo- 

meter 

21 08-27-46.4 2.1 9 19°19.8' 155°11.7' 4 km SW of Makaopuhi

seismometer

21 20-27-52.1 2.3 8 19°19.4' 155°10.2' 5 km S of Makaopuhi

seismometer

28 04-08-59.0 4.5 30 19°22.5' 155°17.9' 4 km W of Ahua. seismo- 

meter 
Table 4.--Loca1 earthquakes recorded by seismographs of. the U.S. Geological 

April, May, June 1968

Date Time Magni- Depth Epicenter 

tude (km) 

-h m Lat. N. Long. w. Description - -

April 28 04-16-24.8 2.1 30 19°22.8' 155°17.4' 3 km WNW of Ahua seismo- 

meter 

28 04-52-13.3 3.2 30 19°21.8' 155°18.4' 5 km SW of Ahua seismo- 

meter 

28 05-19-12.8 3.6 30 19°22.5' 155°16.9' 2 km W of Ahua seismomet

28 05-59-13.0 2.2 30 19°22.9' 155°16.2' 1 km NW of Ahua seismometer28 06-44-47.3 2.0 29 19°21.8' 155°17.8' 3 km SW of Ahua seismometer

28 o8 - 3 5- 2'5 . 0 3.4 8 Q-9°24.9' 155°26.8' 11 km SW of Mauna Loa 

seismometer

28 08-39-47.9 2.4 30 19°22.0' 155°17.3' 3 km SW of Ahua seismometer28 08-55-36.8 2.3 31 19°23.2' 155°17.0' 2 km S of Kilauea Calder

28 11-28-25.3 2.5 30 19°22.2' 155°17.2' 3 km W of Ahua seismomet

28 19-45-05.1 2.1 30 19°22.0' 155°17.7' 3 km W of Ahua seismomet
Table 4.--Local earthquakes recorded by seismographs of. the U.S. Geological 

April, May, June 1968

.......

Vl

Date Time Magni- Depth Epicenter 

tude "( km) 

h m .§.. Lat. N. Long. W. Description - -

April 28 21-23-40.4 2.1 8 19°21.8' 155°24.3' 3 km NW of Desert seis- 

mometer

29 02-22-50.0 2.1 30 19°22.8' 155°16.7' 1 km NW of Ahua seismometer

29 05-02-26;9 2.2 8 19°23.1' 155°27.1' 9 km NW of Desert seis- 

mometer

29 08-07-05.9 2.3 31 19°22.5' 155°16.3' 1 km W of Ahua seismomete

29 15-58-52.8 2.8 31 19°23.3' 155°17.0' 3 km NW of Ahua seismometer

29 20-35-29.1 2.6 30 19°23.3' 155°16.2' 2 km NW of Ahua seismometer

29 23-17-21.7 2.3 10 19°11.9' 155°27.7' 2 km E of Pahala

30 01-30-51.6 2.2 3 19°26.9' 155°46.7' 17 km SE of Kealakekua

30 03-21-12.1 2.0 30 19°22.8' 155°17.7' 3 km W of Ahua seismomete

30 08-27-36.7 1.9 30 19°23.3' 155°16.9' 3 km NW of Ahua seismometer

30 12-12-43.5 2.5 8 19°5l.4' 155°33.6' 10 km E of Waikii
Table 4.--Local earthquakes recorded by seismographs of, the U.S. Geological 

April, May, June 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

April 30 19-13-00.0 2.6 30 19°22.3' 155°17.2' 2 km W of Ahua s e i smomete

30 23-27-19.4 2.4 30 19°23.0' 155°16.8' 2 km NW of Ahua seismo- 

meter

May 1 03-33-07.7 2.4 30 19°22.2' 155°17.3' 2 km W of Ahua seismomete

1 11-09-04.3 2.1 8 19°25.7' 155°24.2' '8 km SSW of Mauna Loa

seismometer

3 19-10-14.1 2.6 8 19°25.3' 155°24.8' 9 km SW of Mauna Loa

seismometer

3 19-39-12.0 3.2 30 19°21.7' 155° 1·5 .8' 2 km S of Ahua s e i smomete

6 02-42-49.5 2.5 8 19°54.8' 155°38.8' 6 km N of Waikii

7 12-51-19.6 2.1 31 19°22.9' 155°17.7' 3 km NW of Ahua seismometer

8 o7 - 18 -'0 2 . 5 2.6 32 19°22.8' 155°16.0' 1 km NW of Ahua seismo- 

meter

8 10-01-13.3 2.7 9 19°20.3' 155°06.8' 7 km SE of Makaopuhi

seismometer

10 17-23-39.6 2.0 9 19°19.2' 155°16.2' 6.km S of Ahua s e ismometer
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

April? May, June 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h !!!. L,at. N. Long. w. Description -

May 11 06-23-53.2 2.1 9 19°18.4' 155°16.3' 8 km S of Ahua seismomete

12 04-54-05.1 2.0 8 19°23.0' 155°24.0' 5 km NNW of Desert seismometer

12 10-06-52.9 3.6 0 19°20.2' 155°44.8' 17 km SE of Hookena 

13 14-24-11.2 2.1 9 19°20.5' 155°06.9' 6 km SE of Makaopuhi

seismometer

14 13-21-06.8 2.4 8 19°24.7' 155°26.2' 11 km SW of Mauna Loa

seismometer

14 17-57-39.6 2.0 8 19°25.8' 155°25.5' 8 km SW of Mauna Loa

seismometer

16 09-38-00.9 2.0 9 19°20.3' 155°06.8' 6 km SE of Makaopuhi seismometer

17 21-43-11.0 2.2 7 19°23.8' 155°14.9' 3 km NE of Ahua seismometer

18 19-17-28.4 2.0 9 19°19.0' 155°12,.7' 7 km NW of Apua Point

18 16-18-43.2 2.8 5 19°23.8' 155°23.7' 7 km N of Desert seismometer
Table 4.--Local earthquakes recorded by seismographs of. the U.S. Geological 

April, May, June 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h !!! L·at. N. Long. w. Description -

May 19 06-29-42.6 2.7 5 19°24.5' 155°35.5' 6 km S of Mokuaweoweo

Caldera

19 09-02-13.5 3.0 5 19°23.8' 155°36.5' 6 km SSW of Mokuaweoweo

Caldera

20 01-30-07.' 5 2.0 10 19°21.8' 155°05.9' 8 km E of Makaopuhi

seismometer

21 03-07-29.5 2.7 35 19°21.8' 155°01.9' 6 km WNW of Kalapana

22 17-51-49.4 2.0 10 19°21.2' 155°03.9' 9 km W of Kalapana23 01-58-02.3 2.1 9 19°20.6' 155°06.7' 6 km SE of Makaopuhi

seismometer

23 10-23-43.3 2.4 40 19°15.3' 155°06.4' 9 km E of Apua Point23 19-56-'39.6 2.2 9 19°21.2' 155°00.8' 4 km W of Kalapana23 21-11-52.3 2.3 7 19°23.2' 155°23.8' 6 km N of Desert seismometer

26 04-26-02.3 2.3 30 19°23.0' 155°17.3' 2 km SSW of Kilauea

Caldera

28 04-43-1.3.0 2.0 9 19°19.8' 155°08.5' 5km SE of Makaopuhi

seismometer

.......

OJ
Table 4.--Local earthquakes recorded by seismographs of. the U.S. Geological 

April, May, June 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m s L·at. N. Long. w. Description - - -

May 28 10-23-52.7 2.1 30 19°23.8' 155°14.5' 2 km SE of Kilauea -Calder

28 16-54-40.1 2.3 10 19°15.6' 155°27.0' 11 km SW of Desert seis- 

mometer

29 11-42-34.3 3.7 3 19°25.2' 155°16.3' Kilauea Caldera 

29 21-54-40.1 2.5 9 19°19.7' 155°08.7' 5 km BE of Makaopuhi

seismometer

31 03-08-16.0 2.2 9 19°20.7' 155°08.7' 4 km SE of Makaopuhi

seismometer

31 08-53-18.1 2.5 5 19°29.9' 155°48.8' 12 km ESE of Kealakekua

31 20-28-14.2 2.7 8 19°24.0' 155°46.8' 20 km SE of Kealakekua

June 1 03-04-55.7 2.1 9 19°20.6' 155°07.1' 6 km SE of Makaopuhi

seismometer

2 21-17-25.4 3.1 9 19°20.8' 155°07.2' 6 km SE of Makaopuhi 

seismometer 

2 21-19-43.5 2.3 10 19°20.4' 155°05. 4 ' 8 km SE of Makaopuhi

seismometer
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

April, May, June 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m L.at. N. Long. w. Description - -

June 3 06-29-58.8 2.0 30 19°22.2' 155°17.4' 3 km W of Ahua s e i smomete

3 12-04-02.1 2.0 13 18°44' 155°28' 30 km SE of Kalae Point

3 13-06-39.9 2.4 8 19°21.8' 155°29.0' 10 km WNW of Desert seismometer

6 16-08-57.6 2.4 30 19°23.1' 155°17.2' 2 km S of' Kilauea Caldera

7 04-22-36.3 2.0 5 19°11.8' 155°40.2' 17 km NW of Naalehu

8 04-25-25.6 2.1 8 20°00.0' 155°18.7' 8 km W of Laupahoehoe

8 05-27-58.9 3.0 30 19°22.1' 155°17.8' 4 km SW of Kilauea Calder8 19-08-53.4 2.8 4 19°24.8' 155°16.7' Kilauea Caldera 

9 10-22-58.4 2.1 10 19°18.9' 155°13.3' 7 km NW of Apua Point

10 13-54-53.2 2.3 8 19°25.8' 155°27.2' 10 km SW of Mauna Loa

seismometer

11 11-25-28.5 2.1 5 19°25.3' 155°26.3' 10 km SW of Mauna Loa

seismometer
Table 4.--Local earthquakes recorded by seismographs of. the U.S. Geological 

April, May, June 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description

- -

une 16 17-08-26.5 2.4 10 19°21.7' 155°14.7' 3 km SE of Ahua seismomet

16 22-10-36.6 2.3 10 19°20.5' 155°07.8' 5 km SE of Makaopuhi

seismometer

17 22-33-12.0 2.6 8 19°33.3' 155°48.5' 12 km ENE of Kealakekua

18 14-47-14.6 2.0 10 19°20.8' 155°08.1' 4 km SE of Makaopuhi

seismometer

19 04-36-18.9 3.0 5 19°24.0' 155°17.3' . SW rim of Kilauea Caldera 

19 22-44-57.9 2.0 10 19°19.2' 155°13.3' 8 km NW of Apua Point

20 04-20-09.8 3.0 13 20°44' 157°05' 105 km W of Haleakala,

Maui

20 23-07-57.7 3.1 30 19°22.0' 155°17.0' 2 km SW of Ahua seismomet

21 05-03-29.9 2.0 3 19°22.7' . 155°46.1' 14 km E of Hookena

'21 16-11-02.4 2.3 30 19°22.9' 155°16.7' 2 km NW of Ahua seismometer

21 17-58-44.7 2.6 30 19°22.9' 155°17.0' 2 km S of Kilauea Caldera 

J
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

April! May! June 1968

I\)

I\)

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

June 22 16-08-36.1 2.4 8 19°12.0' 155°33.8' 9 km W of Pahala

23 09-08-51.0 2.5 5 19°21.0' 155°12.3' 4 km SW of Makaopuhi

seismometer

23 10-44-00.9 2.0 8 19°22.2' 155°24.8' 4 km NW of Desert seismometer

24 18-10-19.0 2.7 8 19°25.2' 155°28.1' 11 km SW of Mauna Loa

seismometer

24 20-22-16.4 2.0 10 19°23.0' 155°26.9' 8 km NW of Desert

seismometer

25 02-40-12.0 2.7 5 19°23.2' 155°29.4' 12 km NW of Desert

seismometer

25 15-41-27.1 2.6 9 19°20.7' 155°11.6' 4 km SW of Makaopuhi

seismometer

27 03-28-19.4 2.1 8 19°22.2'. 155°30.4' 13 km NW of Desert

seismometer

28 08-01-18.7 2.1 9 19°19.7' 155°12.7' 8 km NW of Apua Point

29 08-49-41.9 2.4 8 19°12.0' 155°28.7' Pahala
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geological S

April, May, June 1968

I\)

w

Date Time Magni- Depth Epicenter 

tude (km) 

h Lat. N. Long. W. Description

-

June 29 14-13-46.6 2.2 8 19°53.8' 155°44.0' 10 km NW of Waiki i .

29 18-50-54.5 2.5 9 19°19.7' 155°11.2' 8 km NNE of Apua Point

30 09-05-50.6 2.. 5 8 19°15' 156°23' 54 km WNW of Hookena
UNITED STATES

DEPARTMENT OF THE INTERIOR

GEOLOGICAL SURVEY

HAWAIIAN VOLCANO OBSERVATORY

SUMMARY 51

July, August, and September 1968

By Robert Y. Koyanagi, Howard A. Powers,

and Willie T. Kinoshita~/

Issued September 1970

OBSERVATORY STAFF

Geology

H. A. Powers (Scientist-in-Charge)

D. A. Swanson

Geophysics

D. B. Jackson

George Kojima

R. Y. Koyanagi

Geochemistry

R. T. Okamura

T. L. Wright

Support

J. c. forb e s

w. H. Fran·cis

B. J. Loucks

R. G. Mitchel

M. S. Onouye

S. A. Takeguchi

Akira Yamamo.to

~/National Center of Earthquake Research, Menlo Park,

California.
CONTENTS

Page

Summary of activities ------------------------------ 1

Tilting of the ground around Kilauea caldera ------- 4

Seismic summary ------------------------------------ 7

Illustrations

Figure 1. Map of the island of Hawaii showing

seismograph stations and localities

mentioned in the text ----------------- 2

2. Tilting of the ground around Kilauea

caldera between June 10, 1968 and

September 9, 1968 --------------------- 6

Tables

Table 1. Tilt coordinates at Uwekahuna Vault ----- 4

2. Tilt coordinates and changes at bases·

around Kilauea caldera ---------------- 5

3. Number of earthquakes and minutes of

tremor recorded on seismographs around

Kilauea caldera ----------------------- 8

4. Local earthquakes recorded by seismographs

of the U.S. Geological Survey --------- 12
Summary of activities

The eruption of Halemaumau that began on November 5,

1967, ended on the 13th of July. About 109 x 10 6 cubic

yards of new lava was erupted into the pit during the 31

phases of this eruption. The final depths of filling,

measured from the 1961 floor are: . high lava marks 363-375

feet; inner levee, 420 10 feet; highest cone, 470 feet.

Follaving the end of the eruption, lava drained out of the

inner lake, leaving about a 50 foot depression in the

center.

The volcano, however, did not remain quiet very long

as it began erupting again at 0248 HST on August 22 along

the Upper East Rift. It began erupting at Hiiaka crater,

about 2 miles east of Ahua seismometer, and eventually

extended to fissures up to 10 miles to the east. This

eruption continued until early morning of August 26. An

estimated 130,000 cubic yards of lava was erupted of which

only about 17,500 cubic yards remain on the surface.

The lava erupted from the main fissures in Hiiaka contains only olivine and spinel phenocrysts and so must have

been hot, an interpretation supported by several optical

pyrometer measurements of l145°C. Large olivine phenocrysts

are abundant (8-14 per cent) and commonly occur i~ clots.

Many of the larger olivine crystals are strained. The lava

from the Escape Road is similar to that in Hiiaka lake.

The lava that erupted from the small fissure on the

southwest wall of Hiiaka is much more crystalline, with

numerous aligned plagioclase and clinopyroxene microlites

as well as 10 or so per cent olivine phenocrysts. This

lava flowed slowly and quickly turned into aa, suggesting,

together with its crystallinity, that the lava either was

simply cooler lava of Hiiaka lake-type or that it is a more

viscous, and also cooler., differentiate.

Several new cracks were formed before and during the

erupti~ns along the Hilina Pali, Chain of Craters and Escape

roads where they cross the Koae fault system. Some of these

cracks reached widths of 2 to 3 inches. A few of the cracks

showed right-lateral displacement, but the dominant horizontal

displacement was tensional.

A comparison of the level and tilt data taken at the

end of the Halemaumau eruption and after this eruption shows

summit deflation of a little less than 0.8 foot and inflation

1
EXPLANATION

• Seismograph Station

o Town or locality

5 0 5 10 15 20 25 Kilometers A A R e---3 &+3 i

Figure l.--Map of the Island of Hawaii showing seismograph stations

operated by the U.S. Geological Survey, principal settlements,

and selected geologic features. Epicenters of local earthquakes

are given in table 4 in terms of geographic coordinates, which

are indicated at the edges of the map.

2
near Hiiaka crater of about 0.9 foot. Horizontal distance

changes over roughly the same span of time showed general

contrarition lines in the summit area up to 66 parts per

million and general extension along lines in the Upper East

Rift area up to 130 parts per million.

The count for shallow caldera quakes was low throughout most of the Halemaumau eruption. This was partly due

to the lower gains the seismometers were operated at in the

summit area, necessitated by the continuous harmonic tremor

associated with the fountaining. The count of East Rift

quakes picked up slightly after the end of the Halemaumau

eruption. The August eruption was preceded by a swarm of

several hundred small quakes at or near the site of

eruption.

3
Tilting of the ground around Kilauea caldera

Ti'lting of the ground around the summit of Kilauea is

monitored daily by a short-base water-tube tiltmeter in

Uwekahuna Vault, and at irregular intervals it is meas'ured

on a regional scale by means of a network of field tiltbases and a portable water-tube tiltmeter. The attitude of

the ground surface at each tilt-base is reported in terms of

north-south and east-west tilt coordinates. Both coordinates

at each station were arbitrarily set equal to 500 when

measurements at that station were begun. Increasing t~lt

coordinates correspond to northward and eastward tilting of

the earth's surface; that is, to a relative subsidence toward

the north and east. A one-unit change in coordinate

corresponds to a tilting of 1 microradian (1 mm per km) in

the direction indicated.

Location of and essential data on each tiltmeter station

are listed in table 6, which is published only in the first

quarter issue each year.

Table 1.--Tilt coordinates at Uwekahuna vault,

July, August, and September, 1968.

Date N-S E-W Date N-S E-W (1968) (1968)

July 7 557 395 Aug. 18 559 401

14 558 399 25 542 440

21 558 402 Sept. 1 539 435

28 559 402 8 542 423

Aug. 4 558 401 15 544 417

11 558 402 22 545 414

29 545 408

4
Table 2.--Tilt coordinates and changes at bases around Kilauea caldera. (See 

Rate (10- 6 rad/mo)

and direction of 

Tilt base Date Tilt Coordinates tilting since 

(1968) N-S E-W last reading 

Uwekahuna (U on 28 Aug 572.2 400.6 21.2 S41.5°E 

fig. 2)

Tree Molds (TM) 10 Oct 444.2 511.4 11.5 s14.4°E 

Sand Spit (SS) 9 Sept 893.8 688.6 11.2 S73.00E 

Keamoku (Ke a ) . 2 Sept 544.6 391.2 12.9 s68. 8° E- 

\.n

Ahua Kamokuko1au 6 Sept 449.7 541.7 20.6 N3.1°E 

(Kam) .

Kipuka Nene (KN) 2 Sept 302.8 308.0 1.2 N8.00w 

Hi1ina Pali (HP) 16 Oct 456.1 499.1 0.45 N74.7°W 

Ka.papala Ranch 28 Aug 492.5 509.8 0.01 S31.7°W 

(Kap) .

Mehena (M) 2 Sept 572.5 579.4 2.7 S41.4°w 
cr

o

,I'M

Q

-~ 2000

------.. . 1----1

Tilting rate 5.0 x 10-6 radians/month

JUN. 10, 1968 - SFP. 9, 1968

N

t

5 t< M

Figure 2.--Tilting of the ground around Kilauea caldera.

The vector depicting tilting at a given tilt base

points in the direction of maximum relative subsidence

and has a length proportional to the rate of tilting

during the measurement interval. Closed circles represent field tilt bases; open circles, short-base watertube tiltmeters. See table 2 for explanation of

abbreviations.

6
Seismic summary

.Events recorded by the U.S. Geological Survey seismograph network in Hawaii fall into two categories: Local

earthquakes and tremor originating in the region of the

Hawaiian Islands (usually within 100 km of at least one

seismograph), and distant earthquakes originating more

than 3,000 km from Hawaii. As an index of seismic activity

at Hawaiian volcanoes, daily counts of earthquakes and

minutes of tremor recorded by seismographs in Hawaii are

listed in table 3. The earthquakes are separated in groups

on the basis of region of origin as determined by analysis

of records obtained daily at the observatory (U, M, Mx, A,

D, N, WP, MP, Kx, 0,). Earthquakes of magnitude 2.0 or

greater are generally sufficiently well recorded to be

located with greater precision; they are listed individually

in table 4.

Location of and essential data on each seismograph

station are listed in table 5 in the first-quarter issue

each year.

Acknowledgments

Several people or agencies reported "felt" earthquakes

during the 3rd quarter, 1968. Their assistance is gratefully acknowledged.

7
co

Table 3.--Number of earthquakes and minutes of tremor recorded on seismograph

Kilauea Caldera

Tremor is separated into three categories: deep, intermediate, and shallow, on the 

relative amplitudes on seismographs in the summit region. Unless otherwise state

presumed to be associated with movement of magma within the central complex of K

Earthquake categories are: Kilauea summit, 30 km, earthquakes from a source about 

the Kilauea summit region; long-period, earthquakes characterized by low-frequenc

originate about 5 km beneath Kilauea summit; and shallow earthquakes in Kilau

region; shallow earthquakes along the SW. rift zone of Kilauea and the adjacent p

Kaoiki fault system; earthquakes along the eastern half of Kilauea's east rift z

largely on the Pahoa seismograph; earthquakes from the upper east rift zone and t

fault systems of Kilauea'·s south flank; and earthquakes from other .regions: wes

Mauna Kea, etc.

Tremor Earthquakes

(m = minutes

h hours) Kilauea Summit =

Date SW rift Eastern Up

(1968) Inter- Long and east ea

Deep mediate Shallow 30KM Period Shallow Kaoiki rift rif

July 1 24m 24h 10 9 37 

2 24h 4 5 21 1 

3 24h 2 18 12 

4 24h 2 2 15 . 

5 24h 1 5 10 

6 3m 3 1 7 1 

7 22m 24h 2 5 42 1 

8 2m 2 1 45 2 

9 10 2 36 2 

10 5 41 2 

11 2 1 25 1 

12 3 29 2 

13 9 3 48 4 

14 3 2 41 2 
JUly 15 5 4 22 

16 6m

4 1 5 

17 1 23 17 

18

2 24 11 

19 1 16

4 23 

20 3 38 14 22 

21 8m 3 35 16 21 

22 1 23 15

2 

23 2m 3 39 19

6 

24

2 51 8 1 

25 . 6 48 18 1 

26 38m

4 28 12

5 

27 17m 35 15

4 

28 3 32 12

6 

29 41 10 5 

30 4m 53 16

4 

31 3 39

9 3 

\0

August 1 30m

2 43 18

7 

2 6m 1 56

7 1 

3 5 79 18 

4

2 47 13

2 

5 5m 3 43 18

7 

6 3 94 16

2 

7 2 57 12 3 

8 7m 1 74 21

3 

9 1 39 19 1 

10 38

7

6 

11 1 50 26

7 

12 53 12 3 

13 88 12

4 

14 1 73

9

2 

15 19m

2 83

4

2 

16 30m 8 50 10

7 

17

4 60 16

4 

18 1 102 14 14 

19 2 68 12 3 

20 3m 5 53 25 3 

21 
Table 3.--Number of earthquakes and minutes of tremor recorded on seismograp

Kilauea Caldera--Continued

Tremor Earthquakes

(m = minutes

h hours) Kilauea Summit =

Date SW rift Eastern Up

(1968) Inter- Long and east ea

Deep mediate Shallow 30KM Period Shallow Kaoiki rift ri

August 22

23 24h · 7 

24 24h 4 25 1 

25 24h 4 6 14 20 

26 11m 24h 2 6 14 24

27 33m 24h 4 · 22 17 15 

28 24h 40 28 20

29 5m 1 59 7 36 

30 . 2 · 27 8 31 

31 . 4 21 12 36 

Aug. 2e-26, a small occurred at Hiiaka Crater or th

zone along th Chain cf Cra ers roac. The Ma kaopuhi SE i smograpl lin

obse rvatory w as tempor arily cut by fire from the erupt on.

September 1 2 23 6 27 

2 . 2 100 32 57 

3 2 104 17 32 

4 . 102 20 20 

5 1 57 8 13 

6 . 1 58 13 24 

7 4 55 25 -- 22 

8 4 80 15 -- 38 

9 1m 101 16 -- 37 

10 1 123 9 -- 23 

11 4m 5 122 28 -- 30 

I
September 12 1 67 16 

13 1 49 14 

14 35m

3 75

2 

15 3m

2 31

8 

16 26m 3 91 27 

17

2 66

8 

18 5m 1 50 2 

19

4 67

8 

20 1 104 28 

21

2 166 29 

22

7 127 11 

23

2 102 22 

24 7m

2 67 15 

25

2 101 11 

26

4 76 10 

27 124 21 

28 15m

2 105 18 1 

29

7 94

5 1 

30 4m 3 196 27 
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 1968

Entries for a given quake are: Date, origin tim (Hawaiian Standard Time), magnit

epicenter, and felt report. All earthquakes of magnitude 2.5 and larger, as we

favorably located smaller ones, occurring on or near the island of Hawaii are i

the list.

Date Time Magni- Depth Epicenter 

tude (km) 

h m s Lat. N. Long. w. Description

- -

July 1 02-03-23.4 2.0 30 19°22.7' 155°14.9' 2 km NE of Ahua s e i smomet 

1 16-24-13.7 2.1 30 19°22.0' 155°16.8' 2 km SW of Ahua seismomet

1 20-49-55.5 2.0 8 19°23.1' 155°29.2' 12 km NW of Desert

seismometer

2 04-23-09.4 2.0 8 19°26.2' 155° 25 .2-' 7 km SW of Mauna Loa

seismometer

2 10-55-06.3 3.4 8 20°00.2' 155°49.3' 4 km SSE of Kawaihae 

2 12-11-10.6 3.5 8 20°03.8' 155°50.2' 3 km NW of Kawaihae 

2 12-31-59.0 2.0 20 19°24.8' 155°17.0' Kilauea Caldera

2 12-58-03.7 2.0 10 19°21.8' 155°05.3' 8 km E of Makaopuhi

seismometer

3 00-56-21.5 2.1 10 19°23.1' 155°03.8' 11 km E of Makaopuhi

seismometer
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 1968

selsmometer

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

July 3 02-38-23.1 2.0 33 19°25.2' 155°16.1' Kilauea Caldera

3 20-07-54.2 2.1 10 19°19.9' 155°09.9' 4 km S of Makaopuhi

seismometer

4 05-54-41.1 2.0 5 19°20.3' 155°07.8' 5 km SE of Makaopuhi

seismometer

4 07-34-18.3 2.1 10 19°19.8' 155°12.1' 18 km NNW of Apua Point

5 02-17-21.5 2.7 32 19°23.2' 155°17.1' 2 km S of Kilauea Calde

5 02-21-59.0 2.2 30 19°22.2' 155°17.1' 2 km W of Ahua seismome

6 18-25-32.0 2.6 8 19°25.3' 155°23.1' 8 km S of Mauna Loa 

seismometer

7 18-51-47.4 2.2 8 19°23.2' 155°29.3' 12 km NW of Desert

seismometer

8 04-13-08.8 2.9 13 20°04' 156°16' 45 km W of Kawaihae

8 04-35-40.2 2.3 10 19°23.4' 154°58.7' 4 km N of Ka1apana

8 18-55-40.6 2.1 3 19°24.0' 155°25.2' 7 km NW of Desert

seismometer

8 20-08-50.5 2.1 8 19°23.2' 155°25.0' 6 km NW of Desert
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geologica

July, August, September 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. W. Description - -

July 8 20-23-32.0 2.0 5 19°23.4' 155°25.7' 7 km NW of Desert

seismometer

8 20-59-23.5 2.1 7 19°23.7' 155°25.5' 7 km NW of Desert

seismomete"r

8 2.1 10 19°19.8' 155°13.3' 9 km NW of Apua Point

9 00-40-11.4 2.0 10 19°20.9' 155°07.1' 5 km SE of Makaopuhi

seismometer

9 03-50-51.1 2.5 8 19°55.9' 155°44.0' 11 km SSW of Kamuela

9 19-24-57.3 2.5 30 19°22.3' 155°16.8' 2 km W of Ahua seismome9 21-32-15.2 3.5 13 19°19.2' 155°13.7' 8 km NW of Apua Point 

10 11-14-27.3 2.0 10 19°21.2' 155°06.2' 8 km SE of Makaopuhi

seismometer

10 11-54-51.5 2.0 10 19°21.8' 155°02.8' 7 km NW of Kalapana10 18-45-23.4 3.3 40 18°51.7' 155°08.5' 45 km SSE of Apua Point

10 21-41-23.7 2.0 9 19°22.4' 155°26.9' 8 km NW of Desert

seismometer
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geologica

July, August, September 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m L.at. N. Long. w. Description - -

July 10 22-49-53.2 2.0 8 19°26.2' 155°28.5' 11 km SW of Mauna Loa

seismometer

11 12-57-08.0 2.2 8 19°20.4' 155°09.0' 3 km SE of Makaopuhi

seismometer

12 05-53-55.4 2.0 5 19°24.9' 154°59.0' 10 km SW of Pahoa

12 09-47-07.1 2.7 8 20°10.0' 155°36.2' 5 km NW of Waipio Valley

12 11-00-58.9 2.5 8 20°07.5' 155°34.0' Waipio Valley

12 13-17-56.1 2.0 9 19°20.9' 155°04.9' 9 km SE of Makaopuhi

seismometer

12 20-20-31.2 2.0 10 19°20.0' 155°15.5' 5 km S of Ahua seismome

13 01-32-57.0 2.4 9 19°22.0' 155°06.4' 6 km ESE of Makaopuhi

seismometer

13 15-42-39.5 2.4 20 19°25.1' 155°17.1' Kilauea Caldera

15 13-00-54.2 2.4 8 19°24.7' 155°25.8' 10 km SW of Mauna Loa

seismometer

15 21-58-54.1 2.1 10 19°21.3' 155°06.8' 6 km BE of Makaopuhi

seismometer
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 19·68

Date Time Magni- Depth Epicenter 

tude (km) 

h !!!. Lat. N. Long. W. Description -

July 15 21-59-22.1 2.3 10 19°20.7' 155°07.2' 6 km SE of Makaopuhi 

seismometer

16 04-19-14.4 9 19°18.1' 155°14.2' 7 km NW of Apua Point16 04-20-02.4 2.0 9 19°18.3' 155°14.7' 7 km NW of Apua Point17 05-44-49.0 2.1 8 19°26.9' 155°25.8' 7 km SW of Mauna Loa

seismometer

17 12-34-04.0 2.4 40 19°15.5' 155°06.7' 9 km E of Apua Point

17 16-51-36.2 2.-2 9 19°21.8' 155°05.7' 8 km ESE of Makaopuhi

seismometer

18 07-45-03.4 2.0 15 19°24.5' 155°17.0' Kilauea Caldera

18 16-59-16.6 2.0 10 19°21.4' 155°05.2' 8 km E of Makaopuhi

seismometer

18 23-20-27.2 2.5 9 19°21.2' 155°06.5' 7 km SE of Makaopuhi

seismometer

19 17-38-05.5 2.0 8 19°25.3' 155°24.8' 8 km SW of Mauna Loa

seismometer

20 15-52-42.4 2.1 6 19°28.0' 154°55.2' 4 ·km SE of Pahoa 
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m .§.. Lat. N. Long. W. Description - -

July 21 08-29-27.9 2.5 7 19°10.2' 155°37.1' 12 km NW of Naalehu 

21 13-25-27.5 2.2 10 19°24.7' 155°03.3' 13 km NE of Makaopuhi

seismometer

21 16-46-38.4 2.3 6 19°26.8' 154°53.8' 7 km SE of Pahoa

21 21-15-24.0 3.3 10 19°22.8' 155°03.2' 8 km NW of Ka1apana 

22 19-59-14.6 2.0 10 19°19.4' 155°10.9' 8 km NE of Apua Point

23 04-49-31.7 2.0 30 19°23.7' 155°15.8.' 1 km S of Kilauea Calder

23 08-15-02.7 2.5 5 19°27.0' 154°55.7' 5 km SSE of Pahoa

24 15-56-30.5 2.1 10 19°21.3' 155°11.3' 3 km SW of Makaopuhi

seismometer

26 01-53-23.4 2.3 10 19°20.9' 155°08.3' 3 km SE of Makaopuhi

seismometer

26 18-42-45.6 2.1 10 19°25.6' 155°00.0' 8 km NNW of Kalapana 

27 06-58-58.5 2.3 30 19°22.8' 155°17.2' 2 km S of Kilauea Calder
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h !!!. Lat. N. Long. w. Description -

July 28 05-45-51.4 2.5 9 19°19.3' 155°13.3' 7 km NW of Apua Point

29 06-21-11.9 3.3 9 19°23.2' 155°05.6' 8 km ENE of Makaopuhi 

seismometer 

29 06-45-16.0 2.0 9 19°21.1' 155°06.7' 6 km SE of Makaopuhi

29 09-37-47.9 2.0 9 19°20.8' 155°11.7' 4 km SW of Makaopuhi

seismometer

29 19-35-44.7 3.7 10 19°21.0' 155°06.7' 7 km SE of Makaopuhi 

seismometer 

29 19-41-24.9 2.1 10 19°21.0' 155°06.8' 6 km SE of Makaopuhi

seismometer

30 01-06-47.7 2.1 8 19 ° 15 · 9' . 155°29.1' 7 km N of Pahala

30 04-39-35.8 2.0 31 19°24.1' 155°46.0' 14 km ENE of Hookena

30 05-34-33.9 2.4 0 19°25.1' 155°53.6' 4 km NNE of Hookena

30 15-40-55.6 2.0 7 19°28.2' 154°54.2' 4 .km BE of Pahoa
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 1968

t-J

\0

Date Time Magni- Depth Epicenter 

tude (km) 

h Lat. N. Long. w. Description -

July 30 22-34-02.9 3.3 30 19°27.1' 155°31.7' 7 km SE of Mokuaweoweo

Caldera

30 23-57-41.4 2.2 5 19°26.6' 154°53.8' 8 km SE of Pahoa

31 00-39-25.2 2.7 8 20°03.0' 155°45.9' 7 km NW of Kamuela 

31 04-22-50.8 2.3 5 19°27.4' 154°55.8' 5 km SE of Pahoa

31 09-34-58.0 2.0 8 19°22.8' 155°03.0' 8 km NW of Kalapana

31 10-42-59.5 2.3 10 19°20.0' 155°08.7' 3 km SE of Makaopuhi

seismometer

31 14-41-56.0 2.5 5 19°26.9' 154°54.5' 7 km SE of Pahoa

August 1 00-03-57.6 2.0 10 19°24.2' 155°02.7' 9 km NW of Kalapana

1 00-34-37.8 4.0 10 19°20.0' 155°06.8' 7 km SE of Makaopuhi 

seismometer

1 00-47-41.5 2.0 10 19°21.0' 155°06.7' 6 km SE of Makaopuhi

seismometer

1 01-15-29.9 2.3 10 19°20.8' 155°06.9' 6 km SE of Makaopuhi

seismometer

1 01-48-22.4 2.3 8 19°55.7' 155°42.8' 10 km NW of Waikii
Tabl'e 4. --Local earthquakes recorded by seismographs of the U. S. Geological 

July, August, September 1968

f\)

o

Date Time Magni- Depth Epicenter 

tude (km) 

h E! Lat. N. Long. w. Description -

August 1 07-21-22.9 2.2 9 19°28.1' 154°55.2' 4 km SE of Pahoa

1 22-50-14.3 2.0 10 19°19.7' 155°11.7' 5 km sw of Makaopuhi

seismometer

2 12-19-34.6 2.6 20 19°26.0' 154°57.2' 7 km S of Pahoa 2 12-59-17.2 2.7 8 19°23.9' 155°28.8' 12 km NW of Desert

seismometer

2 18-36-55.4 3.8 40 19°51.9' 155°55.1' Kihol0 Bay 

2 18-41-18.8 2.0 10 19°20.3' 155°08.9' 4 km BE of Makaopuhi

seismometer

3 06-32-22.4 2.3 8 19°22.8' 155°23.8' 5 km N of· Desert 

seismometer

3 17-03.-41.1 2.0 9 19°25.1' 155°26.9' 11 km NW of Desert

seismometer

4 05-18-44.1 2.2 9 19°20.0' 155°08.·5' 5 km BE of Makaopuhi

seismometer

5 08-38-09.6 2.6 5 19°26.4-" 154°54.1' 8 km SE of Pahoa
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h Lat. N. Long. W. Description

-

August 5 10-30-38.3 2.0 8 19°25.9' 155°23.1' 7 km S of Mauna Loa seismometer

5 10-37-18.0 3.1 5 19°54.1' 155°53.1' 7 km NE of Kihol0 Bay 

5 17-24-34.6 2.2 9 19°23.2' 155°02.2' 7 km NW of Ka1apana

6 10-39-07.2 2.2 8 19°12.5' 155°33.9' 9 km W of Pahala

6 16-34-42.8 2.0 13 20°09.5' 155°53.5' 3 km SE of Mahukona6 23-14-51.3 3.0 10 .19°19.8' 155°13.1' 9 km NW of Apua Point

7 01-44-08.1 2.3 8 20°02.0' 155°51.0' 2 km SW of Kawaihae

7 09-12-43.6 2.5 5 19°23.0' 155°29.0' 11 km NW of Desert

seismometer

7 10-58-25.0 4.4 3 19°19.1' 155°48.2' 12 km SE of Kookena 7 12-05-01.0 3.7 3 19°23.0' 155°45.2' 15 km E of Hookena

7 23-25-19.4 2.6 8 19°52.1' 155°33.2' 10 km E of Waikii
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 19-68

Date Time Magni- Depth Epicenter 

tude (km) 

h !!! Lat. N. Long. W. Description -

ugust 9 00-06-20.1 2.3 8 20°02.0' 155°51.9' 4 km SW of Kawaihae- 

9 01-04-53.4 3.7 30 0.9°23.4' 155°17.0' 1 km S of Kilauea Caldera 

10 11-09-21.2 2.5 10 0-9°20.4' 155°12.1' 9 km N of Apua Point

10 15-59-43.8 2.6 9 0..9°22.4' 155°03.7' 12 km E of Makaopuhi

seismometer

12 04-07-12.7 3.5 13 119°00' 156°21' 53 km SW of Milolii

12 06-32-23.5 2.0 9 119°20.1' 155°12.8' 6 km SW of Makaopuhi

seismometer

12 06-37-04.9 2.7 5 19°27.4' 154°55.4' 5 km SE of Pahoa

13 17-05-03.7 2.2 5 19°25.2' 155°01.7' 9 km NW of Kalapana

14 04-57-08.9 2.4 10 11.9°26.0' 155°03.5' 12 km NW of Kalapana

14 10-39-23.8 2.4 3 19°27-.-2' 155°48.6' 14 km SE of Kealakekua

15 16-27-34.4 2.3 8 18°59' 156°17' 45 - km SE of Mil_olii

A
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 1968

(\)

w

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

August 15 19-21-21.3 2.2 8 19°25.8' 155°56.0' 10 km S of Kea1akek-ua

16 01-52-49.3 2.2 5 19°23.4' 154°59.5' 4 km N of Ka1apana 

16 02-05-41.6 2.6 5 19°26.3' 155°00.2' 8 km SW of Pahoa

16 12-30-13.9 '2.8 13 20°08.4' 155°53.5' 5 km S of Mahukona16 13-14-00.4 3.2 15 19°24.1' 155°17.0' S rim of Kilauea Caldera 

16 16-23-37.6 4.1 8 19°53.2' 155°22.9' 5 km SW of Keanako1u 

16 16-47-19.9 2.4 8 19°52.4' 155°25.2' 10 km SW of Keanako1u

17 13-15-25.1 2.3 10 19°21.7' 155°05.1' 9 km ESE of Makaopuhi

seismometer

17 22-38-49.6 2.3 10 19°24.2' 155°03.2' 10 km NW of Ka1apana

20 16-29-40.9 3.3 8 19°23.2' 155°25.1' 7 km NW of Desert 

seismometer 

21 11-28-56.2 3.0 8 19°11.2' 155°36.7' 14. km NNW of Naalehu 
Table 4.--Local earthquakes recorded by seismographs of the u.s. Geological 

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

August 21 22-21-57.0 2.7 8 20°01.5' 155°59.6' 17 km W of Kawaihae

22 03-21-59.0 2.5 5 19°22.8' 155°15.3' 1 km NE of Ahua seismometer

22 03-31-02.0 2.6 5 19°22.7' 155°14.2' 3 km E of Ahua s e i smomet e

22 03-57-39.9 2.0 4 19°22.5' 155°14.0' 3 km E of Ahua s e i smomet e

22 04-09-56.0 3.0 4 19°22.4' 155°14.1' 3 km E of Ahua s e i smomet e

22 04-22-29.3 2.0 3 19°22.7' 155°14.6' 3 km E of Ahua s e i smomet e

22 04-46-21.3 3.0 3 19°21.2' 15S013.0' 5 km BE of Ahua

seismometer

2'2 05-06-54.2 3.1 2 19°22.8' 155°14.4' 3 km ENE of Ahua

seismometer

22 05-25-4S.S 2.7 2 19°22.4' 15S014.5' 3 km E of Ahua seismomete

22 05-45-02.0 2.8 2 19°21.7' 15S01S.0' 2 km BE of Ahua

seismometer
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h !!! Lat. N. Long. w. Description -

August 22 05-53-26.4 2.8 4 19°22.3' 155°15.1' 2 km E of Ahua seismomete

22 06-01-07.5 2.7 9 19°20.9' 155°09.4' 2 km SE of Makaopuhi 

seismometer 

22 06-05-35.1 2.1 3 19°22.8' 155°14.7' 3 km NE of Ahua

seismometer

22 06-29-16.6 2.2 3 19°22.7' 155°14.3' 3 km E of Ahua seismomete22 10-07-44.7 2.0 10 19°21.2' 155°07.1' 5 km ESE of Makaopuhi

seismometer

22 16-36-47.0 2.3 30 19°23.2' 155°15.2' 2 km NE of Ahua

seismometer

23 06-37-35.0 2.9 8 19°25.1' 155°25.8' 10 km SW of Mauna Loa

seismometer

23 15-00-27.6 2.6 9 19°21.4' 155°08.8' 2 km SE of Makaopuhi

seismometer

24 14-13-59-5 2.8 8 19°54.8' 155°29.9' 17 km W of Keanakolu

24 19-31-42.4 2.3 10 19°18.2' 155°07.7' 9 km NE of Apua Point

25 10-15-35.2 2.0 10 19°19.8' 155°13.4' 7 .km SW of Makaopuhi

seismometer
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 1968

Date .Time Magni- Depth Epicenter 

tude' (km) 

h' m Lat. N. Long. w. Description - -

ugust 25 20-12-15.7 2.6 34 19°24.8' 155°10.2' 5 km N of Makaopuhi

seismometer

26 05-32-11.2 2.4 8 19°23.1' 155°26.9' 8 km NW of Desert

seismomete'r

26 13-43-28.3 2.2 10 19°20.0' 155°08.7' 4 km SE of Makaopuhi

seismometer

29 22-36-21.6 2.3 9 19°20.1' 155°07.8' 5 km SE of Makaopuhi

seismometer

30 19-09-38.7 2 ..5 8 19°20.8' 155°26.3' 5 km NW of Desert

seismometer

31 08-59-00.5 2.2 10 19°20.6' 155°07.1' 5 km SE of Makaopuhi

seismometer

September 2 04-44-46.9 2.4 10 19°22.3' 155°02.0' 6 km NW of Ka1apana

2 14-5'8- 3.4 3.1 8 19°21.3' 155°27.1' 7 km NW of Desert 

seismometer 

3 10-45-11.5 2.0 8 19°20.7' 155°26.8' 6 km W of Desert

s.e i smomet er

A
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 19.68

Date Time Magni- Depth Epicenter 

tude (km) 

h !!!. Lat. N. Long. w. Description -

September 3 11-29-39.6 2.6 8 19°24.5' 155°28.5' 12 km NW of Desert

seismometer

4 22-58-08.9 2.1 13 20°01.5' 155°17.0' 7 km NW of Laup ahoeh oe

4 23-04-00.5 2.3 8 19°24.0' 155°23.8' 12 km N of Desert

seismometer

5 03-58-06.2 2.2 8 19°59.0' 155°25.0' 12 km NW of Keanako1u

5 03-59-40.2 2.8 8 19°58.1' 155°23.9' 9 km NW of Keanakolu5 06-12-43.7 3.2 8 19°57.8' 155°23.8' 8 km NW of Keanako1u 

6 10-31-52.6 2.0 8 19°58.6' 155°50.2' 7 km S of Kawaihae

7 05-52-45.1 2.1 8 19°22.6' 155°25.0' 5 km NW of Desert

seismometer

7 14-41-20.1 2.1 3 19°18.7' 155°39.7' 20 km SW of Mokuaweoweo

Caldera

7 17-08-44.3 3.7 20 19°26.0' 155°16.7' Kilauea Caldera 

7 17-17-25.9 2.6 20 19°25.3' 155°16.5' Kilauea Caldera
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 19,68

Date Time Magni- Depth Epicenter 

tude (km) 

h E! • Lat. N. Long. w. Description -

September 8 07-59-47.3 2.3 25 19°24.9' 155°15.8' Kilauea Caldera

10 15-22-42.3 2.3 10 20°02.7' 155°34.2' 13 km ENE of Kamuela

10 19-53-28.3 2'00 0 19°28.1' 155°47.9' 14 km SE of' Kealakekua

10 22- 32-0 0'.7 2.5 8 19°25.9' 155°24.1' 7 km S of Mauna Loa 

seismometer 

12 09-12-48.8 2.0 8 19°21.3' 155°24.5' 3 km NW of Desert 

seismometer

21 02-13-34.1 3.0 8 19°13.0' 155°38.1' 17 km NW of Naale.hu

21 20-37-50.5 2.2 8 19°21.1' 155°26.7' 6 km NW of Desert

seismometer

21 23-44-01.9 2.4 50 19°47.8' 156°01.9' 8 km NE of Keahole Point22 14-42-36.8 2.0 3 19°23.2' 155°11.4' 3 km NW of Makaopuhi

seismometer

23 18-11-53.3 4.1 8 20°10.3' 155°48.5' 20 km NW of Kamuela 

I\)

co
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h Lat. N. Long. W. Description -

September 23 18-18-12.2 3.2 30 20°09.2' 155°48.0' 10 km SE of Hawi

23 19-44-29.2 2.5 8 19°25.0' 155°25.5' 9 km NW of Desert

seismometer

24 15-08-48.8 2.3 50 19°53.5' 155°58.0' 5 km NW of Kihol0 Bay

24 "'" )-5- 52 . 3' 2".2 0 19 0 -39 .0' 155°53.9' 10 km E of Kailua

25 05-00-01.8 2.5 8 20°20.9' 155°47.2' 10 km NE of Upolu Point

25 08-01-49.2 2.0 8 19°26.8' 155°26.1' 7 km SW of Mauna Loa

seismometer

25 16-04-54.7 2.0 20 19°25.2' 155°15.9' Kilauea Caldera25 20-49-50.6 2.0 9 19°20.8' 155°07.8' 5 km BE of Makaopuhi

seismometer

26 13-0.1-15 . 2 2.0 9 19°20.2' 155°08.5' 4 km BE of Makaopuhi

seismometer

27 17-40-09.2 2.8 7 19°28.5' 155°46.2' 17 km SE of Kealakekua

28 06-28-53.8 2.9 10 19°18.7' 155°14.4' 8 km NW of Apua Point

28 11-50-08.6 2.3 9 19°17.9' 155°13.1' 5 km NW of Point
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

July, August, September 1968

w

o

Date Time Magni- Depth Epicenter 

tude' (km) 

h Lat. N. Long. w. Description -

September 28 19-12-09.8 2.7 20 19°28.6' 155°15.8' 5 km NE of Kilauea-Calder

29 14-59-43.5 2.1 8 19°54.2' 155°29.0' 9 km N of Mauna Kea

Summit

29 15-31-22.9 2.2 9 19°21.0' 155°08.0' 4 km SE of Makaopuhi

seismometer

30 04-01-12.3 2.3 8 19°22.3' 155°25.8' 6 km NW of Desert 

seismometer

30 12-15-35.4 2.0 30 19°23.2' 155°15.9' 2 km B of Kilauea Caldera

30 13-34-51.2 2.3 45 18°51.9'· 155°17.0' 39 km BE of Naalehu
UNITED STATES

DEPARTMENT OF THE INTERIOR

GEOLOGICAL SURVEY

HAWAIIAN VOLCANO OBSERVATORY

SUMMARY 52

October, November,. and December 1968

By Robert Y. Koyanagi, Howard .A. Powers,

and Elliott T. Endo~/

Issued September 1970

OBSERVATORY STAFF

Geology

H. A. Powers (Scientist-in-Charge)

D. A. Swanson

Geophysics

D. B. Jackson

George Kojima

R. Y. Koyanagi

Geochemistry

R. T. Okamura

T. L. Wright

Support

C. D. Arakaki

J. C. Forbes

w. H. Francis

B. J. Loucks

M. S. Onouye

S. A. Takeguchi

Akira Yamamoto

~6ational Center of Earthquake Research, Menlo Park,

California.
CONTENTS

Page

Summary of activities ------------------------------ 1

Tilting of the ground around Kilauea caldera ------- 4

Seismic summary ------------------------------------ 7

Publications of special interest and HVO contributions, 1968 -------------------------------------- 29

Illustrations

Figure 1. Map of the island of Hawaii showing

seismograph stations and localities

mentioned in th~ text ----------------- 2

2. Titling of the ground around Kilauea

caldera between September 6 and December

2, 1968 ------------------------------- 6

Tables

Table 1. Tilt coordinates at Uwekahuna vault ----- 4

2. Tilt coordinates and changes at bases

around Kilauea caldera ---------------- 5

3. Number of earthquakes and minutes of

tremor recorded on seismographs around

Kilauea caldera ----------------------- 8

4. Local earthquakes recorded by seismographs of the U.S. Geological Survey 12
Summary of activities

After a sharp reinflation at Kilauea summit following

the August eruption a new eruption broke out on the Upper

East Rift at Kilauea. Strong harmonic tremors that began

at 1037 October 7 at the Makaopuhi seismograph was followed

by the sighting of fume clouds at 1435. Although fountaining was not sighted at this time, we believe that this was

the beginning of the eruption. The eruption began at Kane

Hui 0 Hamo, a low cone about 1 mile north of Makaopuhi

seismometer, and eventually erupted from vents up to 3 miles

further to the east. Fountaining continued intermittently

until October 16. On October 22 activity renewed for a

short time but the eruptive activity from this date until

November 19 consisted mostly of low level harmonic tremor,

fuming and occasional bursts of spatter. A downrift migration of vents that occurred during the August eruption,

did not characterize this eruption; eruptive centers shift~d

at random between Napau Crater and 2 miles downrift. About

7 million cubic meters of new lava finally remained on the

surface near and within Napau Crater as a result of the

October eruption.

The volume of lava above ground may be higher than the

guess given here, for we suspect the average thickness of

new lava outside of Napau has been underestimated,. The

amount of lava that was erupted to the surface but drained

back may be as much as 50% of the amount remaining on the

surface.

Levels were run in the summit and Upper East Rift

area on October 9-10 and again on November 25-26. A comparison with the August 25-26 (Post August eruption) level

data shows that the summit area subsided about 0.4 feet

and the Upper East Rift area near Makaopuhi seismometer

showed an uplift of about 0.6 feet. Most of this deformation

probably took place in the earliest stages of the eruption,

judging from the behavior of'the tiltmeter in Uwekahuna vault;

it showed sharp deflation tilt beginning at about 1130 October

7 and leveling out about 1300 October 9.

Although intermittent eruptive activity continued until

October 22 and harmonic tremor and dense fumes continued

until November 19, the tilt evidence shows that reinflation

began a few days after the start of the eruption. By

November 25-26 the summit had uplifted about 0.2 foot above

its October 9-10 level. The Upper East Rift area uplifted

an additional 0.13 foot above its October 9-10 level.

1
EXPLANATION

• Seismograph Station

a Town or locality

5EHCEH3::EH3:0====:::i:====31O===:jlr Mil..

5 0 5 10 15 20 25 Kilometers ASH e-==3 I

Figure l.--Map of the Island of Hawaii showing seismograph stations

operated by the U.S. Geological Survey, principal settlements,

and selected geologic features. Epicenters of local earthquakes

are given in table 4 in terms of geographic coordinates, 'which

are indicated at the edges of the map.

2
Tilt was measured at the summit stations 6 times

between the August and October eruptions. The total tilt

for the period covered by the leveling verified the level

data except at outlet vault a tilt direction almost 180 0

opposite from the direction that was inferred from the

leveling. The reason for this is unknown.

The short bas,e water tube tiltmeter in Uwekahuna

vault showed rapic inflation beginning on August 25. It

showed an inflation direction and it averaged about 1.13

x 10- 6 radians/day until October 2nd, when inflation

ceased abruptly. Between October 2nd and the beginning

of the eruption there was little or not tilt change.

Distance measurements between stations in the summit

and Upper East Rift areas showed contraction strains at

the summit and slight extension along the Upper East Rift.

The maximum linear strain occurred along east-west lines

just south of Ha1emaumau; they were as high as 7.4 x 10- 5

in the August-October (after eruption) period.

Seismic activity associated with the October Upper

East Rift eruption started at 1037, October 7. Harmonic

tremor and large numbers of south flank and summit earthquakes characterized the early period followed by weak

harmonic tremor and moderate numbers of quakes for the

remainder of the month. During October 7-10, more than

3,000 quakes were recorded; 300 of these events between

0.5 to 3.0 magnitude were read and located.

3
Tilting.of the Ground Around Kilauea Caldera

Tilting of the ground around the summit of Kilauea is

monitored daily by a short-base water-tube tiltmeter in

Uwekahuna Vault, and at irregular intervals it is measured

on a regional scale by means of a network of field tiltbases and a portable water-tube ti1tmeter. The attitude

of the ground surface at each tilt-base is reported in

terms of north-south and east-west tilt coordinates. Both

coordinates at each station were arbitrarily set equal to

500 when measurements at that station were begun. Increas-.

ing tilt coordinates correspond to northward and eastward

tilting -of the earth's surface; that is, to a relative

subsidence toward the north and east. A one-unit change

in coordinate corresponds to a tilting of 1 microradian

(.1 mm per km) in the direction indicated.

Location of and essential data on each tiltmeter

station are listed in table 6, which is published only

in the first quarter issue each year.

Table 1.--Ti1t coordinates at Uwekahuna vault,

October, November, and December, 1968

Date N-S E-W Date N-S E-W (1968) (1968)

Oct. 6 539 421 Nov. 17 523 427

13 517 454 24 524 423

20 516 452 Dec. 1 524 421

27 516 440 8 520 423

Nov. 3 519 436 15 520 420

10 520 432 22 521 418

29 524 417

4
Table coordinates and changes at bases around Kilauea caldera. (Se

Rate (10- 6 rad/mo)

Tilt base Date Tilt Coordinates and direction of 

(1968) N-S E-W tilting since 

last reading 

Uwekahuna (U on 3 Dec. 558.2 399.5 4.3 s4.6°w 

fig. 2)

Tree Molds (TM) 3 Dec. 460.6 503.7 10.1 N25.2°W 

Sand Spit (SS) 27 Nov. 866.8 701.2 11.5 S25.0oE 

Vl Keamoku (Kea) . 2 Dec. 521.5 412.5 '10.4 S42.7°E 

Ahua Kamokukolau 27 Nov. 493.1 531.9 16.3 N12.7°W 

(Kam) .

Kipuka Nene (KN) 5 Dec. 305.0 308.5 0.7 NIl.BoE 

Hilina Pa1i (HP) N/D

Kapapala Ranch N/D

(Kap) .

Mehena (M) 2 Dec. 569.6 576.8 1.3 S42.0oW 
0° ~o

.J

Kop

•

2000

o

t----I

TILTING RATE 5.0 X 10- 6 RADIANS/ MONTH

SEP 6,1968- DEC 2 J 1968

5 I< M

cr

o

Figure 2.--Tilting of the ground around Kilauea Caldera

between September 6, 1968, and December 2, 1968. The

vector depicting tilting at a given tilt base points

in the direction of maximum relative subsidence and

has a length proportional to the rate of tilting

during the measurement interval. Closed circles

represent field tilt bases; open circle, short-base

water-tube tiltmeters. See table 2 for explanation

of abbreviations.

6
Seismic summary

Events recorded by the U.S. Geological Survey seismograph. network in Hawaii fall into two categories: Local

earthquakes and tremor originating in the region of the

Hawaiian Islands (usually within 100 km of at least one

seismograph), and distant earthquakes originating more

than 3,000 km from Hawaii. As an index of seismic activity

at Hawaiian volcanoes, daily counts of earthquakes and

minutes of tremor recorded by seismographs in Hawaii are

listed in table 3. The earthquakes are separated in groups

on the basis of region of origin as determined by analysis

of records obtained daily at the observatory (U, M, Mx, A, D,

N, WP, MP, Kx, 0,). Earthquakes of magnitude 2.0 or greater

are generally sufficiently well recorded to be located with

g r e at.e r pre cision; the y are listed i n d i vi du allyin tab1 e 4.

Location of and essential data on each seismograph

station are listed in table 5 in the first-quarter issue

each year.

Acknowledgments

Several people or agencies reported "felt" earthquakes

during the 4th quarter, 1968. Their assistance is gratefully acknowledged.

7
Table 3.--Number of earthquakes and minutes of tremor recorded on seismograph

Kilauea Caldera

Tremor is separated into three categories: deep, intermediate, and shallow, on the 

relative amplitudes on seismographs in the summit region. Unless otherwise state

presumed to be associated with movement of magma within the central complex of K

Earthquake categories are: Kilauea summit, 30 km, earthquakes from a source about 

the Kilauea summit region; long-period, earthquakes characterized by low-frequenc

originate about 5 km beneath Kilauea summit; and shallow earthquakes in the. Kilau

region; shallow earthquakes along the SW. rift zone of Kilauea and the adjacent p

the Kaoiki fault system; earthquakes along the eastern half of Kilauea's east rif

tected largely on·the Pahoa seismograph; earthquakes from the upper east rift zon

adjacent fault systems of' Kilauea's south flank; and earthquakes from other regio

Hawaii, Mauna Kea, etc.

Tremor Earthquakes

(m = minutes

h hours) Kilauea Summit =

Date SW rift Eastern U

(1968) Inter- Long and east e

Deep mediate Shallow 30KM Period Shallow Kaoiki rift ri

Oct ober 1 4m 4 107 9 1 

2 3 175 27 

3 7m 1 98 7 

4 5m 1 84 12 

5 34m .. 2 77 17 

6 2m 2 87 14 

7 . --

8 24h --

9 24h 19 11 -- 22

10 24h 2 10 2 --

II 24h --

12 .24h --

13 24h 19 

I
October 14 24h 22 

15 3 24h 27 

16 24h 13 

17 12m 24h 20 1 

18 24h 1 15 

19 24h 30 

20 24h 15 

21 24h 24 

22 25m 

23 24h 30 24 24h

4 64 5 

25 20m 24h 53 16 

26 24h 1 35 25 

27 6m 24h

4 45 23 

28 13m 24h

2 29 12 

29 3m 24h 3 26

5 

30 6m 24h

2 35 34 

\0 31 24h 15 lO 22 

Oct. -21, volc nic ac ivity etween

K e Nui

0 ama and ap

Wea harmoni tremor c ntinue to re ard for several we s after th

sur ace acti ity.

November 1 24h

4 19 42 

2 24h

5 22 12 

3 2m 24h

4 16 10 

4 24h

2 11 9 

5 24h

2

4 32 6 

6 24h 1 14 13 18 

7 24h 8 75 21 22 

8 24h 3 31 143 14 

9 24h 25 172 20 

10 24h 1 26 165 23 

11 33m 24h

4 139 12 1 

12 14m 24h 3 90 10 

13 13m 24h 6 189 16 

14 26m 9 265

2 

15 17m 182 9 

16 15m 205 10 
Table 3.--Number of earthquakes and minutes·of tremor recorded on seismographs 

Kilauea Caldera--Continued

Tremor Earthquakes

(m = minutes Kilauea Summit h = hours)

Date SW rift Eastern Upp

(1968) Inter- Long and east eas

Deep mediate Shallow 30KM Period Shallow Kaoiki rift rif

November 17 10m 3 195 14 15 

18 34m 1 132 18 1 13 

19 31m 14 148 27 1 10 

20 37m 2 113 34 12 

21 13m 8 120 16 7 22 65m 3 94 33 15 

23 18m 1 108 29 11 

24 2m 6 169 22 14 

25 12m 2 74 18 24 

26 40m 1 75 41 31 

27 24m 5 90 51 25 

28 18m 65 18 27 

29 26m 2 5 81 18 20 

30 2 3 81 13 16 

December 1 3m . 5 4 95 14 18 

2 14 85 13 2 14 

3 6 10 14 

4 2 102 12 14 

5 2 154 18 11 

6 6 124 24 28 

7 68 6 17 

8 4 3 64 12 1 22 

9 3 105 36 24 

10 5 149 25 1 22 11 21m 5 149 28 22 
December 12 3 III 13

7

13 3 127 . 27 24 

14 1 106 36 18

15 59 13 12 

16 99 7 117 

17 60m 87 8 31 

18 1 91

7 15

19 3 82

9 1 42 

20 79 13 25

21 87 43 16 

22 1 129 39 28

23 1 70 36 33 

24 3m 8 96 54 23

25

6 123 33 19 

26 1 81 40 23 

27 6m 121 17 17 

28 6m

5

2 104 18 10

f-J 29

2 13 117 33 1 43 

f-J 30 2m 13m

2

2 145 31 32

31 8m 1 123 30 29 
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geologi

October, November, December 1968

......

I\)

Entries for a given quake are: Date, origin time (Hawaiian Standard Time), magni

epi'center, and felt report. All earthquakes of magnitude 2.5 and larger, as we

located smaller ones, occurring on or near the island of Hawaii are in

the list.

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

October 1 13-56-24.5 2.4 8 19°21.2' 155°01.7' 5 km W W of Ka1apana

1 19-11-10.7 2.1 30 19°22.7' 155°18.4' 4 km W of Ahua seismomet

1 19-46-17.0 2.0 8 19°17.4' 155°11.1' 4 km NE of Apua Point

2 02-10-04.8 3.3 '8 19°18' 156°46' 93 km WSW of Kealakekua

2 12-59-38.5 2.0 5 19°25.0' 155°25.8' 10 km NW of Desert

seismometer

2 21-54-30.4 2.0 0 19°21.1' 155°44.7' 17 km ESE of Hookena

3 18-26-54.4 2.5 8 19°25.5' 155°25.2' 10 km NW of Desert

seismometer

4 20-40-28.5 2.5 9 19°20.8' 155°06.3' 7 km BE of Makaopuhi

seismometer

4 22-32-56.6 2.5 15 19°24.8' 155°17.7' Kilauea Caldera

6 08-29-01.8 2.4 30 19°22.2' 155°17.1' 2 km W of Ahua seismometE
Table 4.--Local earthquakes recorded by seismographs of. the U.S. Geologica

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

October 6 11-59-51.8 2.0 10 19°21.2' 155°08.8' 3 km SE of Makaopuhi

seismometer

7 11-00-59.7 2.2 3 19°22.5' 155°11.3' 3 km NW of Makaopuhi

seismometer

7 11-04-59.3 2.2 4 19°22.5' 155°11.0' 2 km NW of Makaopuhi

seismometer

7 11-36-21.2 2.3 5 19°21.9' 155°12.3' 4 km W of Makaopuhi

seismometer

7 11-57-14.8 2.1 5 19°22.1' 155°12.6' 5 km W of Makaopuhi

seismometer

7 13-52-26.7 2.1 5 19°22.7' 155°08.3' 4 km NE of Makaopuhi

seismometer

7 14-24-43.2 2.2 4 19°22.7' 155°09.0' 2 km NE of Makaopuhi

seismometer

7 14-36-31.3 2.7 6 19°21.4' 155°10.9' 2 km SW of Makaopuhi

seismometer

7 16-27-54.0 2.7 7 19°22.7' 155°10.4' 2 km NW of Makaopuhi

seismometer

7 18-25-09.0 2.2 2 19°23.3' 155°08.1' 4 km NE of Makaopuhi

selsmometer
Table 4.--Local earthquakes recorded by seismographs of .the U.S. Geological 

October, November, December 1968

Date Time Magni- Depth Epicenter 

"tude (km) 

h !!!. Lat. N. Long. w. Description -

October 7 18-40-26.6 2.0 2 19°23.8' 155°08.3' 5 km NE of Makaopuhi

seismometer

7 19-00-29.2 2.5 2 19°23.7' 155°07.3' 6 km NE of Makaopuhi

seismometer

7 19-04-06.1 2.5 1 19°24.7' 155°08.8' 6 km NE of Makaopuhi

'seismometer

7 19-12-41.4 2.7 5 19°23.3' 155°08.5' 4 km NE of Makaopuhi

seismometer

7 19-21-29.7 2.4 0 19°21.2' 155°09.0' 2 km BE of Makaopuhi

seismometer

7 19-54-26.0 2.1 3 19°23.7' 155°07.8' 5 km NE of Makaopuhi

seismometer

7 20-00-55.6 2.2 4 19°23.1' 155°08.0' 5 km NE of Makaopuhi

seismometer

7 20-29-12.1 2.0 3 19°23.2' 155°07.7' 5 km NE of Makaopuhi

seismometer

7 20-46-19.0 2.1 5 19°22.8' 155°09.0' 3 km NE of Makaopuhi

seismometer

7 22-18-22.0 2.2 4 19°24.8' 155°16.9' Kilauea Caldera
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geologica

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

October 8 00-10-10.8 2.0 4 19°22.8' 155°07.3' 5 km NE of Makaopuhi

seismometer

8 00-28-25.5 2.1 3 19°24.8' 155°17.4' Kilauea Caldera

8 01-14-22.5 2.4 4 19°23.4' 155°07.3' 5 km NE of Makaopuhi

seismometer

8 01-36-51.1 2.7 5 19°23.2' 155°08.6' 3 km NE of Makaopuhi

seismometer

8 01-39-55.2 2.7 4 19°23.0' 155°07.9' 4 km NE of Makaopuhi

seismometer

8 01-46-42.7 2.1 5 19°22.8' 155°08.8' 3 km NE of Makaopuhi

seismometer

8 03-20-25.9 2.1 6 19°23.3' 155°08.7' 3 km NE of Makaopuhi

seismometer

8 03-41-38.4 2.0 5 19°23.2' 155°08.3' 4 km NE of Makaopuhi

seismometer

8 04-10-41.8 2.2 5 19°22.8' 155°08.2' 3 km NE of Makaopuhi

seismometer

8 04-10-43.0 2.0 3 19°23.0' 155°08.3' 3 .km NE of Makaopuhi

seismometer
I-'

0\

Table 4.--Local earthquakes recorded by seismographs of, the U.S. Geological 

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h !!! Lat. N. Long. w. Description -

October 8 04-18-43.0 2.0 3 19°23.0' 155°08.3' 3 km NE of Makaopuhi

seismometer

8 04-57-49.1 2.5 5 19°22.9' 155°07.5' 5 km NE of Makaopuhi

seismometer

8 05-19-55.'5 2.2 2 19°23.3' 155°06.9' 6 km NE of Makaopuhi

seismometer

8 05-39-05.6 2.1 5 19°22.3' 155°08.0' 4 km NE of Makaopuhi

seismometer

8 06-14-38.0 2.4 3 19°23.1' 155°06.9' 6 km NE of Makaopuhi

seismometer

8 07-06-25.6 2.6 9 19°18.8' 155°07.8' 9 km NE of Apua Point

8 07-20-31.5 2.1 2 19°23.1' 155°07.8' 5 km NE of Makaopuhi

seismometer

8 07-40-24.8 2.1 2 19°23.2' 155°06.2' 7 km NE of Makaopuhi

seismometer

8 07-46-35.1 2.4 4 19°22.8' 155°07.7' 5 km NE of Makaopuhi

seismometer

8 08-23-03.5 2.5 6 19°22.9' 155°07'.5' 5 ,km NE of Makaopuhi

seismometer
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude' (km) 

h m Lat. N. Long. w. Description - -

October 8 08-49-22.7 2.1 5 19°23.1' 155°08.3' 4 km NE of Makaopuhi

seismometer

8 08-54-44.4 2.1 5 19°23.0' 155°07.8' 5 km NE of Makaopuhi

seismometer

8 2.1 5 19°22.8' 155°08.8' 3 km NE of Makaopuhi

seismometer

8 11-02-39.3 2.1 4 19°23.0' 155°07.7' 5 km NE of Makaopuhi

seismometer

8 11-31-39.2 2.0 4 19°22.9' 155°08"0' 4 km NE of Makaopuhi

seismometer

8 12-31-52.5 2.4 3 19°23.2' 155°07.2' 5 km NE of Makaopuhi

seismometer

8 12-39-05.8 2.5 6 19°22.7' 155°08.4' 3 km NE of Makaopuhi

seismometer

8 12-45-57.3 2.0 3 19°22.9' 155°08.6' 3 km NE of Makaopuhi

seismometer

8 17-24-09.6 2.1 4 19°22.9' 155°08.0' 4 km NE of Makaopuhi

seismometer

8 17-40-55.4 2.0 3 19°23.1' 155°07.8' 5 km NE of Makaopuhi

seismometer
Table 4.--Local earthquakes recorded by seismographs of. the U.S. Geological 

October, November, December 19·68

Date Time Magni- Depth Epicenter 

tude (km) 

h Lat. N. Long. w. Description -

October 8 22-07-17.1 2.1 4 19°23.2' 155°07.8' 5 km NE of Makaopuhi

seismometer

9 06-31-50.4 2.0 2 19°22.7' 155°08.0' 4 km NE of Makaopuhi

seismometer

9 13-39-57 .'5 2.4 30 19°23.3' 155°16.2' 2 km S of Kilauea Calder

9 22-32-40.2 2.7 10 19°13.0' 155°06.9' 10 km SE of Apua Point

9 23-27-55.8 2.2 3 19°20.4' 155°17.8' 5 km SW of Ahua

seismometer

9 23-30-58.8 2.0 3 19°20.8' 155°17.8' 5 km SW of Ahua

seismometer

10 17-34-17.1 3.3 9 19°13.9' 155°05.9' 10 km SE of Apua Point

14 06-09-54.0 2.0 8 19°24.0' 155°24.3' 7 km NW of Desert 

seismometer

15 12-05-03.7 2.5 0 19°30.3' 155°48.0' 13 km ESE of Kealakekua

17 11-41-52.3 2.5 10 19°22.1' 155°01.0' 5 km NW of Kalapana

17 20-06-39.6 2.5 10 19°21.2' 155°06.6' 6 km E of Makaopuhi

s'eismometer
Table 4.--Local earthquakes recorded by seismographs of. the U.S. Geological 

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h Lat. N. Long. W. Description -

October 17 22-51-20.1 2.7 3 19°45.1' 155°44.2' 10 km ESE of Puu Waawaa

18 17-23-38.8 2.4 30 19°23.0' 155°16.9' 2 km S of Kilauea Calder

21 09-53-42.7 2.3 9 19°19.8' 155°08.3' 5 km SE of Makaopuhi

seismometer

22 11-58-27.1 2.0 5 19°09.4' 155°03.3' 18 km SE of Apua Point

\0

25 14-47-09.9 3.7 8 19°19.9' 155°30.6' 5 km SW of Pahala 

25 21-13-38.6 2.4 10 19°16.3' 155°10.8' 2 km NE of Apua Point

26 15-20-36.7 2.4 7 19°23.9' 155°26.1 8 km NW of Desert

seismometer

26 16-22-03.2 2.5 9 19°20.0' 155°08.4' 5 km SE of Makaopuhi

seismometer

26 16-31-57.0 2.0 3 19°36.4' 156°06.0' 21 km NW of Kealakekua

27 13-50-27.3 2.3 3 19°22.3' 155°00.4' 4 km NW o:f Kalapana

27 22-00-07.6 2.3 10 19°49.2' 155°26.9' Near Mauna Kea Summit

28 14-58-53.0 2.0 0 19°27.2' 155°47.9' 15 km SE of Kealakekua
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h E! L.at. N. Long. W. Description -

October 28 21-39-08.7 2.1 10 tl9°19.0' 155°13.0' 7 km NW of Apua Point

29 05-10-01.2 2.5 6 19°24.4' 155°27.0' 10 km NW of Desert

seismometer

November 2 07-31-24.4 2.0 8 19°22.9' 155°27.8' 9 km NW of Desert

seismometer

2 09-03-20.6 2.0 9 19°19.0' 155°13.7' 8 km NW of Apua Point

2 15-39-54.8 2.6 13 19°55' 156°20' 35 km NW of Keahole Po·in

3 06-53-27.2 2.0 8 19°26.3' 155°24.7' 6 km SW of Mauna Loa

seismometer

3 10-02-42.3 2.3 9 19°19.8' 155°09.0' 4 km SE of Makaopuhi

seismometer

3 20-29-28.8 2.1 30 tL9°23.0' 155°16.7' 2 km S of Kilauea Calder

5 09-41-19.5 2.6 0 tL9°28.2' 155°50.5' 10 km SE of Kealakekua

10 10-28-45.4 3.3 7 0.9°24.5' 155°29.4' 13 km NW of Desert 

seismometer

10 20-53-42.1 2.0 20 155°17.0' Kilauea Caldera
Table 4.--Loca1 earthquakes recorded by seismographs of. the U.S. Geological 

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h !!! Lat. N. Long. W. Description -

November 11 05-33-54.9 2.2 8 19°12.3' 155°27.8' 2 km NE of P ahala

11 10-39-23.2 2.5 8 19°11.9' 155°27.1' 3 km E of Pahala

11 11-11-22.8 2.2 9 19°22.4' 155°06.1' 7 km E of Makaopuhi

seismometer

11 14-34-20.9 2.9 10 19°20.5' 155°02.5' 7 km SW of Kalapana

12 14-45-23.5 2.7 8 19°25.8' 155°24.0' 7 km S of Mauna Loa

seismometer

14 00-27-44.1 2.0 9 19°21.8' 155°04.1' 9 km WNW of Kalapana

15 00-41-14.7 2.6 10 19°11.2' 155°26.8' 4 km SE of Pahala

15 14-16-44.5 2.5 8 19°23.2' 155°25.7' 7 km NW of Desert 

seismometer

16 04-05--40.1 2.6 0 19°30.3' 155°46.9' 13 km E of Kealakekua

18 02-03-37.8 2.9 0 19°13.3' 155°36.6' 14 km NW of Pahala

18 19-34-21.8 2.4 9 19°22.7' 155°03.7' 9 km NW of Kalapana

18 21-06-41.2 2.0 8 20°48' 155°09' 85 km NE of Honokaa

18 23-52-59.0 4.3 7 19°13.3' 154°58.0' 15 km S of Kalapana 
Table 4.--Loca1 earthquakes recorded by seismographs of. the U.S. Geological 

October, November, December

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

November 18 23-56-52.3 2.3 7 ,19°12.7' 154°58.1' 16 km S of Kalapana

19 20-43-21.1 3.7 30 19°22.8' 155°18.0' 3 km SW of Kilauea Calder

19 21-17-21.1 2.4 0 19°22.1' 155°47.6' 12 km ESE of Hookena 

19 21-21-31.'7 2.5 30 19°22.8' 155°17.8' 3 km BE of Kilauea Calder

19 22-21-32.6 2.8 9 19°12.0' 154°58.9' 17 km S of Ka1apana

20 09-08-36.9 2.8 35 19°04.7' 155°28.8' 12 km E of Naalehu

20 11-04-03.2 2.5 3 19°33.6' 155°44.8' 19 km ENE of Kealakekua

21 01-36-19.4 2.2 8 19°13.9' 155°00.3' 14 km SW of Ka1apana

22 07-03-12.1 .. 2.4 9 19°19.1' 155°02.3' 9 km SW of Ka1apana22 13-46-26.6 2.5 8 19°26.4' 155°25.5' 7 km SW of Mauna Loa

seismometer

25 05-20-41.8 2.8 8 19°55.0' 155°37.0' 8 km NE of Waikii

25 16-46-00.4 2.9 8 19°12.0' 154°58.0' 18 km S of Kalapana

26 02-41-15.5 2.3 8 19°13.1' 155°33.9' 10 km NW of Pahala
Table 4.--Local earthquakes recorded by seismographs of. the U.S. Geological 

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

November 26 19-40-59.3 2.7 5 19°22.7' 155°26.7' 7 km NW of Desert

seismometer

27 02-29-06.1 2.5 10 19°20.0' 155°08.7' 4 km SE of Makaopuhi

seismometer

28 01-36-16"0 2.'5 7 19°14.5' 155°34.4' 11 km NW of Pahala28 02-37-34.2 2.3 9 19°21.7' 155°04.3' 10 km E of Makaopuhi

seismometer

28 06-42-03.3 2.3 8 19°22.0' 155°24.5' 4 km NW of Desert

seismometer

28 15-40-18.8 2.0 8 19°25.6' 155°24.7' 8 km SW of Mauna Loa

seismometer

28 21-25-41.3 2.1 9 19°19.4' 155°11.7' 7 km N of Apua Point

29 03-11-33.9 2.2 8 19°24.5' 155°26.0' 9 km NW of Desert

seismometer

29 10-11-40.5 2.3 8 19°36.7' 156°05.0' 10 km SW of Kailua

29 13-30-06.6 2.4 30 19°21.8' 155°16.9' 2 km SW of Ahua

seismometer

29 20-11-46.6 2.1 7 19°23.3' 155°22.8' 6 km NE of Desert

seismometer
Table 4.--Loca1 earthquakes recorded by seismographs of the U.S. Geological 

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h !!! Lat. N. Long. w. Description -

November 30 08-44-37.8 2.0 10 19°19.2' 155°13.0' 7 km NW of Apua Point

30 18-19-42.4 2.4 30 19°24.1' 155°14.9' SE rim of Kilauea Calder

30 19-16-31.4 2.2 0 19°26.6' 155°47.2' 16 km SE of Kealakekua

December 2 2.3 3 19°31.8' 155°05.3' 4 km SE of Mountain View

2 10-38-33.5 30 19°23.2' 155°16.8' 2 km S of Kilauea Calder

2 10-41-47.8 2.1 30 19°23.2' 155°16.8' 2 km S of Kilauea Calder

2 21-47-38.6 2.-6 30 19°22.7' 155°17.8' 3 km SW- of Kilauea Calde

3 06-01-49.9 2.0 8 19°20.8' 155°11.2' 3 km SW of Makaopuhi

seismometer

3 13-10-31.7 2.4 3 19°11.8' 155°35.1' 11 km W of Pahala

4 11-17-30.7 2.4 8 19°26.1' 155°28.0' 11 km SW of Mauna Loa

seismometer

6 19-38-24.5 2.9 8 19°55.3' 155°28.8' 19 km SW of Paauilo

7 04-09-37.9 2.2 10 19°19.3' 155°13.0' 8 km NW of Apua Point

7 10-11-29.1 2.0 10 19°19.9' 155°11.8' 8 ·km N of Apua. Point
Table 4.--Local earthquakes recorded by seismographs of the U.S. Geological 

October, November, December 1968

Date Time Magni- Depth

t-----------+ t u d e ( km )

h m Lat. N.

Epicenter

Long. W. Description

f\)

\Jl

December 8

8

10

10

10

10

11

12

13

13

13

14

05-09-40.2

06-51-00.801-55-18.9

13-07-02.9

19-40-53.4

20-11-01.2

14-08-13.5

05-30-02.6

06-38-54.5

15-25-29.6

19-30-48.8

03-00-18.3

2.8

2.3

2.0

2.0

2.7

2.2

2.0

2.0

3.3

2.0

2.1

10 19°21.6' 155°04.8' 9 km E of Makaopuhi

seismometer

10 19°21.7' 155°04.6' 10 km E of Makaopuhi

seismometer

13 19°47' 156°09' 10 km NW of Keahole Poin

40 19°30.5' 155°16.4' 9 km N of Kilauea Calder

9 19°21.1' 155°05.7' 8 km BE of Makaopuhi

seismometer

45 19°10.1' 155°23.2' 7 km NE of Pa1ima Point

8 19°25.5' 155°30.8' 15 km SW of Mauna Loa

seismometer

9 19°18.9' 155°14.8' 8 km NW of Apua Point

8 20°47' 156°57' 55 km W of Ha1eakala, Ma

o 19°21.3' 155°48.5' 10 km BE of Hookena

13 19°38' 156°29' 60 km WNW of Kealakekua
4.--Local earthquakes recorded by seismographs of. the u.s. Geological 

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

December 15 00-07-12.1 2.7 9 19°14.6' 155°11.8' 2 km S of Apua Point

16 16-33-03.5 4.7 10 19°19.9' 155°12.3' 5 km SW of Makaopuhi 

seismometer

19 00-41-13.6 2.7 8 19°26.1' 155°24.6' 8 km SSW of Mauna Loa

seismometer

19 22-16-11.1 3.5 9 19°20.2' 155°06.8' 7 km SE of Makaopuhi 

seismometer 

20 01-42-02.6 2.3 9 19°19.8' 155°11.9' 5 km SW of Makaopuhi

seismometer

20 15-26-59.2 2.6 8 19°22.8' 155°26.7' 8 km NW of Desert

seismometer

22 00-39-54.7 2.3 0 19°48.0' 156°06.0' 8 km NW of Keahole Point

22 23-28-29.2 2.1 7 19°25.2' 155°25.9' 11 km NW of Desert

seismometer

23 01-09-16.6 2.3 8 19°26.2' 155°24.4' 7 km SSW of Mauna Loa

seismometer

23 03-37-45.8 2.4 9 19°20.0' 155°07.7' 5 km SE of Makaopuhi

seismometer
Table 4.--Loca1 earthquakes recorded by seismographs of.the U.S. Geological 

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h !!'! Lat. N. Long. w. Description -

December 23 12-09-58.2 2.4 0 19°40.0' 156°01.8' 5 km NW of Kailua

23 16-03-01.1 2.1 35 19°24.3' 155°07.6' 6 km NE of Makaopuhi

seismometer

23 16-49-24.1 2.0 8 19°23.9' 155°28.1' 11 km NW of Desert

seismometer

24 17-44-35.2 2.2 8 19°24.3' 155°25.2' 8 km NW of Desert

seismometer

24 20-32-12.0 2.3 0 19°26.8' 155°48.0' 15 km SE of Kealakekua

25 04-28-04.7 2.0 8 19°26.0' 155°24.7' 7 km SW of Mauna Loa

seismometer

27 2.3 8 20°04.5' 155°44.0' 6 km NW of Kamuela

27 17-12-32.2 3.1 3 19°53.0' 155°38.9' 3 km N of Waikii

27 23-13-45.5 2.3 3 19°47.9' 155°42.0' 8 km SW of Waikii

29 07-50-55.5 2.7 8 19°49.2' 155°43.9' 10 km SW of Waikii

29 17-58-11.7 2.0 8 19°50' 156°10' 15 km NW of Keahole Poin

30 10-17-11.2 2.6 9 19°21.4' 155°05.7' 8 .km E of Makaqpuhi

seismometer
Table 4.--Local earthquakes recorded by seismographs of. the U.S. Geological 

October, November, December 1968

Date Time Magni- Depth Epicenter 

tude (km) 

h m Lat. N. Long. w. Description - -

December 31 09-35-38.0 3.2 13 20°17'.5" 156°-00. )t 15 km WNW of" Upo1u.Point
Publications of Special Interest

and HVO Contributions, 1968.

Dalrymple, G. B., and Moore, J. G., 1968, Argon-40: Excess

in Submarine Pillow Basalts from Kilauea Volcano, Hawaii:

Science, v. ,161, p. 1132-1135.

Decker, R. W., and Peck, D. L., 1968, Infrared radiation from

Alae Lava Lake, Hawaii: Geo1. Survey Res. 1967, u.s.

Geol. Survey Prof. Paper 575-D, p. 169-175.

Desborough, G. A., Anderson, A. T., and Wright, T. L., 1968,

Mineralogy of Sulfides from certain Hawaiian Basalts:

Econ. Geology, v. 63, p. 636-644.

Fiske, R. S., and Koyanagi, R. Y., 1968, The December 1965

Eruption of Kilauea Volcano, Hawaii: U.S. Geol. Survey'

Prof. Paper 607, p. 1-21.

Koyanagi, R. Y., 1968, Earthquakes from common sources beneath

Kilauea and Mauna Loa volcanoes in Hawaii from 1962 to

1965: u.s. Geol. Survey Prof. Paper 6oo-c, p. 120-125.

Macdonald, G. A., and Powers, H. A., 1968, A Further Contribution to the Petrology of Haleakala Volcano, Hawaii:

Geo1. Soc. America Bull., v. 79, p. 886-888.

Peck, D. L., and Minakami, T., 1968, The Formation of Columnar

J,oin t s ·i n the Upper Part of Ki laue an Lava Lake s, Hawai i :

Geol. Soc. America Bull., v. 79, p. 1151-1166.

Ryall, A. and Bennett, Dale L., 1968, Crustal Structure of

Southern Hawaii Related to Volcanic Processes in the

Upper Mantle: Jour. Geophys. Res., v. 73, no. 14,

p. 4561-4582.

Shaw, H. R., Peck, D. L., Wright, T. L., and Okamura, R. T.,

1968, The viscosity of basaltic magma: An analysis of

field measurements in Makaopuhi lava lake, Hawaii: Am.

Jour. Sci., v. 266, P·. 225-264.

Wright, T. L., Kinoshita, W. T., and Peck, D. L.~ 1968, March

1965 Eruption of Kilauea Volcano and the formation of

Makaopuhi lava lake: Jour. Geophys. Res., v. 73, no. 10,

p. 3181-3205.

29