GEOLOGICAL SURVEY CIRCULAR 821 

Puerto Rico Seismic Network Data Report of 

Earthquakes located by the Programs HYP071 

and HYPOELLIPSE 

July 1, 1975-December 31, 1977 

Puerto Rico Seismic Network Data Report of 

Earthquakes Located by the Programs HYP071 

and HYPOELLIPSE 

July 1, 1975-December 31, 1977 

By R. L. Dart, A. C. Torr, D. L. Carver, 

and M. K. Wharton 

GEOLOGICAL SURVEY CIRCULAR 821 

1980 
United States Department of the Interior 

CECIL D. ANDRUS, Secretary 

Geological Survey 

H. William Menard, Director 

Free on application to Branch of Distribution, U.S. Geological Survey, 1200 South fads Street, Arlington, VA 22202 
CONTENTS 

Page 

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

Puerto Rico Seismic Program------------------------------------------ 1 

Puerto Rico Seismic Network------------------------------------------ 1 

Seismicity----------------------------------------------------------- 1 

Instrumentation------------------------------------------------------ 1 

Data Analysis-------------------------------------------------------- 1 

Selected and Relocated Earthquakes----------------------------------- 5 

References----------------------------------------------------------- 5 

Figure 1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

ILLUSTRATIONS 

Page 

Puerto Rico Seismic Network------------------------------- 2 

HYP071-located earthquakes-------------------------------- 3 

Depth profile of earthquakes shown in figure 2------------ 4 

HYPOELLIPSE-located earthquakes, 

gap size < 360 degrees------------------------------------ 8 

Depth proJEile of earthquakes shown in figure 4------------ 9 

HYPOELLIPSE-located earthquakes, 

gap size < 270 degrees------------------------------------ 10 

Depth proJEile of earthquakes shown in figure 6------------ 11 

Frequency distribution of earthquake magnitudes----------- 12 

TABLES 

Page 

Table 1. Network Stations------------------------------------------- 2 

2. HYPOELLIPSE catalog, July !-December 31, 1975-------------- 6 

3. References for the 1975 HYPOELLIPSE catalog---------------- 8 

4. Remarks for the 1975 HYPOELLIPSE catalog------------------- 8 

5. HYPOELLIPSE catalog, 1976---------------------------------- 13 

6. References for the 1976 HYPOELLIPSE catalog---------------- 27 

7. Remarks for the 1976 HYPOELLIPSE catalog------------------- 27 

8. HYPOELLIPSE catalog, 1977---------------------------------- 29 

9. References for the 1977 HYPOELLIPSE catalog---------------- 41 

10. Remarks for the 1977 HYPOELLIPSE catalog------------------- 42 

III 

PUERTO RICO SEISMIC NETWORK DATA REPORT OF 

EARTHQUAKES LOCATED BY THE PROGRAMS HYP071 

AND HYPOELLIPSE 

JULY 1, 1975-DECEMBER 31, 1977 

By Richard L. Dart, Arthur C. Tarr, 

David L. Carver, and Mary Kay Wharton 

INTRODUCTION 

This report makes available to interested 

parties preliminary results of analysis of data 

on the best located earthquakes for a 30-month 

period, July 1, 1975, through December 31, 

1977. The overall objective of the Puerto Rico 

Seismic Program, the regional seismicity, 

network instrumentation, data analysis, and 

selected earthquakes are briefly discussed. 

PUERTO RICO SEISMIC PROGRAM 

The Puerto Rico Seismic Program is managed 

by the U.S. Geological Survey, in cooperation 

with the Puerto Rico Water Resources Authority 

(PRWRA). The principal objective of the program 

is the assessment of regional and local 

seismicity of the Puerto Rico region and the 

associated seismic hazard (Tarr and King, 

1976). A number of large, destruct! ve, 

historical earthquakes have occurred in the 

vicinity of Puerto Rico; but, until the program 

began in 1974, little was understood about the 

relationship of the seismicity to known or 

suspected geological structures. Accomplishment 

of the program objective is fundamental to the 

assessment of the earthquake potential and the 

associated seismic risk of Puerto Rico. 

PUERTO RICO SEISMIC NETWORK (PRSN) 

The recording of seismic data began in 

August 1974 with the installation of a threestation temporary network. A permanent network 

of 10 stations began operation in November 

1975. Presently the network consists of 15 

stations (fig. 1). The station configuration is 

designed for detection and location of local and 

near-regional earthquakes. The PRSN is 

presently recording an average of 10 earthquakes 

per day, with an accuracy previously 

unobtainable (Schell and Tarr, 1978) (fig. 2). 

The entire list of stations, past and present, 

is found in table 1. 

SEISMICITY 

The Puerto Rico segment of the Antilles Arc 

is exceedingly complex (Tarr and King, 1976). 

The results from data collected by the PRS?T have 

shed new light on the tectonics of the 

northeastern Caribbean region by firmly 

establishing the existence and configuration of 

the North American lithospheric plate below the 

Puerto Rico-Island block (Schell and Tarr, 

1978). Intermediate-depth earthquakes located 

by PRSN form a prominent inclined siesmic zone 

dipping about 45-60 degrees from the Puerto Rico 

Trench to a depth of about 150 km under the 

island (fig. 3) (Carver and Tarr, 1976). For 

more information, see Donnelly, 1964; Bracey and 

Vogt, 1970; Nagle, 1971; and Malfait and 

Dinkelman, 1972. 

INSTRUMENTATION 

The PRSN currently consists of 19 

seismometers at 15 permanent station sites (15 

vertical and 4 horizontal Geotech S-13 

seismometers). Each station has one or more 

seismometers, an amplifier transmitter package, 

and an antenna tower. All stations transmit 

their data via FM radio telemetry and microwave 

link to the central recording site located at 

the San Juan Geophysical Observatory at Cayey, 

Puerto Rico. A 20-channel Develocorder 

(galvanometric, automatic film-developing 

recording system) at the observatory records all 

19 data channels and WWVB timing onto a 

continuous 16-mm film (Tarr and King, 1976). 

DATA ANALYSIS 

Record interpretation, data processing, and 

collection of hypocenter data and related-event 

parameters were performed by the U.S. Geological 

Survey (Dart and others, 1979). All hypocenter 

data were first computed by the program HYP071 

(Lee and Lahr, 197 5). This program had been 

revised (N. S. Davids, unpub. data, 197~) and 
MONA 

Atlantic 

DESECHEO 

IDE • 

Caribbean 

Ocean 

Sea 

~ 

CULEBRA -LP' y 

~ a-~ 

c:::::::> VIRGIN ISLANDS 

VIEQUES 

~ 

17~&~--------------------------~-------------.r-------------§-------------l§ 

i I 

Central Recording Site (Cayey) e 

Seismographic Station .6. 

Figure !.--Region monitored by the Puerto Rico Seismic Network. 

Station SJGC is located at the central recording site. 

Table !.--Puerto Rico Seismic Network stations 

Code Latitude N. Longitude W. Elevation Dates of operation deg min deg min m 

CAG 18 14.37 66 02.12 350 08/16/74-07/17/75 

DOS 18 19.77 66 40.73 400 08/16/74-07/17/75 

MPR 18 12.77 67 08.36 10 09/--/73-11/14/75 

PON 18 00.20 66 36.83 50 08/16/74-07/17/75 

SJG 18 06.70 66 09.00 457 10/12/74-02/22/76 

SJGC 18 06.70 66 09.00 457 01/22/76-PRESENT 

CYP 18 06.70 66 09.00 457 08/30/76-03/07/77 

APR 18 27.46 66 43.77 53 11/ 14/75-PRESENT 

CSB 18 17.35 66 09.36 480 07/30/75-PRESENT 

CDP 18 10.51 66 35.48 1300 07/30/75-PRESENT 

EYP 18 18.76 65 47.47 1060 07/30/75-08/09/76 

IMR 18 05.30 67 50.83 55 11/14/75-01/10/77 

2 

;i 

I 
Table 1.--Puerto Rico Seismic Network stations--Continued 

Code Latitude N. Longitude W. Elevation Dates of operation 

deg min deg min m 

MCP 18 25.14 67 06.64 250 11/14/7 5-PRESENT 

LSP 18 10.66 67 05.17 390 11/ 14/75-PRESENT 

CPD 18 05.33 65 54.93 370 07/30/75-PRESENT 

PNP 18 03.50 66 41.02 200 07/30/75-PRESENT 

LPR 18 18.53 65 52.18 580 08/10/76-PRESENT 

MGP 18 00.46 67 05.35 60 11/14/75-PRESENT 

CCA 18 04.18 66· 19.58 269 02/15/77-PRESENT 

MOV 18 16.92 66 22.00 485 02/15/77-PRESENT 

LRS 18 17.60 66 50.70 440 02/ 15/77-PRESENT 

IDE 18 23.19 67 29.77 218 02/15/77-PRESENT 

IMO 18 06.69 67 54.51 84 02/15/77-PRESENT 

18.SI'IJ 

0 

0 

Cb 0 0 

0~ 

0 0 0 0 0 0 0 0 0 

0 

0 

17 

.... 

ID 

I 

N 

loloi6IV 0 I 0 0 0 0 

""" 50.0 100.0 150.111 <1.0 OR 7 1.0 2.0 3.0 4-" 

D thCkm) !WMM Mo. nl~uda 

Figure 2.--Earthquakes located within the Puerto Rico Region, July, I, 1975-

December 31, 1977, using the HYP071 program. 

3 

I o] 

5.a 
~ 

CJ.7 .IMI, -66.58) - s N - C.19.5"· -66.58) 

as r----------r----~ 

0 

0 

0 

58.8 

NORTH-SOUP~~N ~~r: PROFILE 0 0 -- . J.IIJ8.II ... 

: ~ ~ 

). 'UEIT 

0 0 0 

oo 

0 ... 1.5atlll 

·- s 

~ ~ 

• ~KI1 

..,.:I i i i ~ ~ EXPLANATION I o I o r· -~--l --<8 o l b . J 

<.UJ OR ? .1.0 2.81 a." ..... 5.0 

Ma.antfuda 

Figure 3.--Depth profile of the earthquakes plotted in figure 2 and within 

the area bounded bv lat 17° and 19.5° N. and bv long 65.5° and 67., 0 w. 

Hypocenters are projected into a north-south plane through long 66.5° w. 

(See map insert.) Depth and horizontal distance are measured in 

kilometers. 
made compatible with the u.s. Geological 

Survey's Honeywell MU1TICS computer. All HYP071 

hypocenter locations were then relocated using 

HYPOE11IPSE (Lahr, 1979) and are listed in 

tables 2, 5, and 8. Duration magnitudes were 

calculated for Puerto Rico earthquakes. The 

earthquake data catalog (tables 2, 5, and 8) for 

the Puerto Rico region (fig. 1) is considered 

complete for magnitudes above 3.1. This 

"completeness threshold" was determined from the 

cumulative frequency-of-occurrences graph (fig. 

8). A b-value (b=1.14+.01) was obtained from a 

fit of a straight line to the incremental curve 

of occurrences using a weighted least squares 

for occurrences and has the equation log 

N = 5. 06-1.14 M. This line was calculated for 

occurrences at 0.10 magnitude intervals (3.3-

3.9). Detection and accurate location of earthquakes become increasingly more difficult for 

events with magnitudes below 3.3. 

SELECTED AND RELOCATED EARTHQUAKES 

The earthquakes listed in this report were 

initially selected on the basis of their 

location using their HYP071 hypocenter 

solutions; the constraints were for no less than 

four station observations and RMS (root-meansquare of the travel-time residuals, in seconds) 

ERR (standard error of the epicenter, in 

kilometers), and ERZ (standard error in depth, 

in kilometers) are constrained to values of less 

than or equal to 0.35 s, 25 km, and 50 km 

respectively. These selected events are plotted 

in figures 2 and 3. The selected earthquakes 

were then relocated using HYPOE11IPSE and the 

resulting data grouped according to the length 

of the maximum axis of the error ellipsoid ((10 

km) and the gap size (270 and (360 degrees). 

Gap size is defined as the largest azimuthal 

separation between stations (Lee and Lahr, 

1975). Groupings of the higher quality 

hypocenters locations are shown in figures 4, 5, 

6, and 7, which illustrate changes within this 

higher quality data set when the gap size is 

controlled. 

REFERENCES CITED 

Bracey, D. R. and Vogt, P. R., 1970, Plate 

tectonics in the Hispaniola area: Geological 

Society of America Bulletin, v. 81, 

P• 1855-2860. 

5 

Carver, D. 1., and Tarr, A. C., 1976, Recent 

seismicity of the Puerto Rico region [Abs.]: 

Geological Society of America Abstracts with 

Programs, v. 8, p. 805. 

Dart, R. 1., Carver, D. 1., Wharton, M. K., and 

Tarr, A. C., 1979, Puerto Rico Seismic Program 

seismological data summary: U.S. Geological 

Survey Open-File Report 79-870, 138 p. 

Davids, N. S., 1977, Seismic network analysis 

and processing system (SNAPS)--A user's guide, 

Honeywell MU1TICS version (unpublished 

data): U.S. Geological Survey, 175 P• 

I 

Donnelly, T. M., 1964, Evolution of the eastern 

greater Antillean Island Arc: A~erican 

Association of Petroleum Geologists Bulletin, 

v. 48, P• 680-696. 

Lahr, J. C., 1979, HYPOE11IPSE--A computer 

program for determining local earthquake 

parameters, magnitude and first motion 

pattern: U.S. Geological Survey Open-File 

Report 79-431, 233 p. 

Lee, W. H. K., and Lahr, J. C., 1975, HYP071 

(Revised)--A computer program for determining 

hypocenter, magnitude, and first motion 

pattern of local earthquakes: U.S. Geological 

Survey Open-File Report 75-311, 113 P• 

Malfait, B. T., and Dinkelman, 

Circum-Caribbean tectonics 

activity and the evolution of 

Plate: Geological Society 

Bulletin, v. 83, p. 251-272. 

M. G., 1972, 

and igneous 

the Caribbean 

of America 

Nagle, F. , 1971, 

Marine Science 

P• 375-449. 

Caribbean geology, 

Bulletin, v. 21, 

1970: 

no. 2, 

Schell, B. A., and Tarr, A. c., 1978, Plate 

tectonics of the northeastern Caribbean Sea 

region: Geologie Mijnbouw, v. 57, p. 319-324. 

Tarr, A. c., and King, K. w., 1976, Puerto Rico 

Seismic Program: u.s. Geological Survey OpenFile Report 76-49, 23 p. 
"' 

Table 2.--Catalog of 1975 earthquakes located by the HYPOELLIPSE program 

[UTC, Coordinated Universal Time; negative latitudes and longitudes are south and west, respectively; M, duration magnitude; 

a, b, and c, principal axes of confidence ellipsoid; Tr, trend of axis in degrees; Pl, plunge of axis in degrees; 

%, confidence level; Rms, root mean square of residuals; No. ob, number of observations used in hypocenter computation; 

Gap, largest azimuthal separation between seismograph stations; DM, distance to third nearest station, in kilometers; 

Q, quality index; Hypo auth, hypocenter authority meaning person or institution responsible for hypocenter determination, 

cited by catalog name and authority number in table 4; *, remarks cited by catalog name and index in table 3; 

leaders ( ••••• ) designate instances when data values are unknown or not computed] 

Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo Name Index yr mo d h min s (deg) (deg) (km) M 

PRN75 1 1975 

2 1975 

3 1975 

4 1975 

5 1975 

6 1975 

7 1975 

8 1975 

9 1975 

10 1975 

11 197 5 

12 1975 

13 1975 

14 1975 

15 1975 

16 1975 

17 1975 

18 1975 

19 1975 

20 1975 

21 1975 

22 1975 

23 1975 

24 1975 

25 1975 

26 1975 

27 1975 

28 1975 

29 1975 

30 1975 

31 1975 

32 1975 

33 1975 

34 1975 

35 1975 

7 30 16 55 7.020E 

8 1 20 2 48.020 

8 4 5 2 37.920 

8 4 7 36 26.970 

8 9 7 18 19.550 

8 14 23 12 45.330 

8 23 17 27 23.070 

8 24 3 24 59.080 

8 25 8 16 51.100 

8 29 13 13 23.470 

9 14 20 19 5.070 

9 15 2 41 7.120E 

9 15 4 22 56.900 

9 15 22 46 50.070 

9 15 23 14 5.600 

9 22 20 16 12.080 

10 1 20 17 25.770 

10 2 20 2 48.390 

10 14 00 33 56.980 

11 15 16 27 1.330E 

11 15 19 27 29.320 

11 15 19 54 4.310 

11 15 21 25 35.140 

11 16 12 51 56.350 

11 17 20 34 43.570 

11 18 19 12 28.170 

11 19 4 32 49.010 

11 19 7 10 2~.690 

11 21 10 58 33.890 

11 22 21 35 38.760 

11 23 12 21 32.160 

11 23 19 36 7.260 

11 24 5 5 15.230 

11 24 8 10 26.480 

11 24 14 50 37.090 

18.333 

18.623 

18.175 

18.853 

18.879 

18.157 

18.601 

18.266 

17.667 

18.815 

19.066 

18.222 

19.099 

19.057 

19.036 

18.256 

18.954 

18.276 

18.086 

18.328 

17.990 

18.ll0 

18.884 

17.850 

18.602 

17.805 

18.002 

18.716 

17.936 

18.889 

18.110 

18.092 

18.139 

18.012 

18.106 

-66.093 

-66.581 

-66.989 

-66.341 

-65. 559 

-67.050 

-66.520 

-66.609 

-66.158 

-65.128 

-65.329 

-67.120 

-67.488 

-65.827 

-65.739 

-66. 5ll 

-65.250 

-66.535 

-66.035 

-66.143 

-66.466 

-65.551 

-65.349 

-67.951 

-67.000 

-66.888 

-66.462 

-67.479 

-66.280 

-66.586 

-66. 734 

-66.541 

-67.041 

-67.087 

-67.112 

1.4 

2.8 

9.2 

16.3 

12.1 

9.8 

8.7 

15.8 

35.1 

23.9 

4.8 

0.4 

18.2 

6.7 

1.1 

8.5 

10.0 

13.3 

25.5 

16.2 

42.9 

8.6 

84.1 

20.1 

15.1 

16.0 

8.8 

7.0 

25.9 

23.1 

16.3 

15.7 

20.2 

19.4 

1.1D 

2.0D 

2. 2D 

1. 4D 

2.4D 

2.7D 

1. 9D 

1. OD 

1. 3D 

3.0D 

2. 7D 

2.6D 

3.1D 

2.4D 

2. 4D 

1.0D 

2. 6D 

0.9D 

2.2D 

l.lD 

2. 7D 

2.2D 

2.3D 

1. 7D 

l.lD 

0.7D 

1. 9D 

1.on 

0.8D 

0.7D 

1. 2D 

O. 7D 

O. 8D 

a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * 

2.6 100 3 

3.3 65 1 

3.2 94 8 

3.2 240 0 

10.5 315 3 

7.2 103 3 

0.8 60 28 

2.8 328 4 

1.9 259 8 

27.1 323 0 

17.3 334 14 

1.8 87 9 

2.3 5 21 

5.5 328 11 

5.1 292 3 

0.4 78 4 

15.1 307 11 

9.9 169 12 

4.3 319 8 

2.5 266 0 

3.5 191 3 

11.6 352 30 

10.5 316 18 

16.5 353 1 

1.5 80 13 

5.7 179 3 

6.6 191 5 

4.3 120 6 

O.R ?.74 0 

1.9 266 0 

2.7 351 0 

1.3 73 21 

36.7 214 21 

2.9 90 34 

1.2 57 32 

7.1 8 19 45.9 198 70 68 0.12 

5.3 335 3 >99.9 174 86 68 0.19 

5.5 186 16 2.0 339 72 68 0.15 

7.4 330 1 >99.9 149 88 68 0.11 

7.0 223 30 51.1 51 59 68 0.16 

23.9 194 19 5.1 4 70 68 0.39 

1.3 309 34 2.3 180 43 68 o.os 

0.8 58 6 27.0 205 82 68 0.06 

3.9 167 13 11.7 20 74 68 0.09 

>99.9 233 8 10.3 53 82 68 0.13 

7.1 234 35 80.6 83 51 68 0.08 

10.9 180 16 5.4 329 71 68 0.27 

11.3 257 39 3.2 117 43 68 0.07 

12.3 64 28 3.7 219 59 68 0.12 

3.4 200 33 >99.9 27 56 68 0.10 

1.9 346 22 12.8 178 67 68 0.04 

5.6 211 30 56.0 55 57 68 0.22 

2.1 73 25 4.6 282 61 68 0.17 

2.2 223 33 3.7 61 55 68 0.09 

4.6 356 0 >99.9 90 90 68 0.28 

1.1 101 8 21.6 301 81 68 0.12 

50.3 103 32 6.6 230 43 68 0.35 

7.3 213 35 60.3 69 49 68 0.30 

3.0 263 30 8.2 85 59 68 0.10 

3.0 345 22 4.5 198 64 68 0.20 

2.1 88 24 2.5 275 65 68 0.22 

2.2 100 8 42.9 312 80 68 0.24 

7.3 211 12 3.1 3 76 68 0.24 

?..Q 1~4 4 11.~ 4 ~~ ~~ 0.oa 

3.3 176 15 29.9 355 75 68 0.10 

0.8 261 14 3.9 81 76 68 o.os 

3.0 179 35 20.1 319 47 68 0.09 

7.9 323 40 4.1 103 42 68 0.28 

5.3 331 35 10.4 209 36 68 0.04 

3.1 301 36 9.8 177 38 68 0.06 

5 258 55 D 

7 300 63 D 

8 330 89 D 

6 311 95 1) 

6 329 •• D 

9 336 96 D 

9 276 67 c 

6 248 78 D 

6 276 71 D 

4 341 •• D 

5 338 •• D 

7 214 •• D 

6 316 •• D 

6 318 •• D 

6 327 •• D 

6 251 67 D 

6 338 •• D 

6 259 71 D 

6 297 69 D 

7 192 SO D 

7 203 47 D 

8 307 63 D 

7 333 •• D 

7 348 •• D 

14 261 48 D 

8 279 46 D 

7 199 45 D 

10 316 89 D 

7 U4 '}~ n 

6 261 95 D 

7 143 38 c 

6 195 46 D 

6 217 48 D 

5 155 43 D 

6 274 56 D 

1 * 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 * 

1 

1 

1 

1 

1 

1 

1 

1 * 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 
Table 2.--Catalog of 1975 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM ~ auth * 

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

PRN75 36 1975 11 27 15 10 28.630 18.829 -67.466 5.6 2. 3D 5.2 132 18 9.3 229 21 3.6 4 61 68 0.16 7 332 99 D 

37 1975 11 28 00 42 42.510 18.036 -67.013 11.4 1. 7D 1.8 3 20 1.0 104 28 2.4 243 54 68 0.16 10 159 35 c 1 

38 1975 11 28 16 38 3.020 18.332 -67.374 14.6 1. 3D 4.8 311 12 3.4 47 27 1.6 200 60 68 0.14 R 2 91 4 7 D 1 

39 1975 11 29 4 50 19.660 18.068 -67.097 7.8 1. 6D 1. 5 338 9 1.7 75 38 3.3 237 50 68 0.22 11 185 39 c 1 

40 1975 11 30 14 5 17.580 17.82 4 -66.767 3.0 1. 5n 1.7 263 0 2.8 173 5 54.~ 352 85 68 0.24 8 226 43 D 1 

41 1975 12 1 11 5 55.960 18.036 -65.536 15.3 1. 4D 4.5 24 0 5.8 294 35 >99.9 114 55 68 0.32 5 312 71 D 

42 1975 12 1 19 44 37.910 18.420 -66.408 15.5 1. 3D 55.4 349 1 2.8 259 6 3.7 89 83 68 •••• 4 262 49 D 

43 1975 12 1 23 28 39.130 18.863 -67.812 16.6 3.2D 2.6 5.'> 14 15.1 150 18 5.9 290 66 68 0.17 11 283 •• D 

44 1975 12 2 11 31 47.800 17.836 -67.167 1.8 1. 6D 3.6 107 4 6.8 200 37 13.9 11 52 68 0.26 8 300 57 D 

45 1975 12 3 14 38 5.300 18.751 -66.829 62.9 1.7D 5.6 271 4 8.5 5 44 44.0 176 45 68 0.17 6 2A3 88 D 

46 1975 12 4 20 28 29.990 18.002 -67.103 16.8 1. 2D 1.7 104 18 2.9 358 40 7.0 212 44 68 0.12 7 277 45 D 

47 1975 12 5 15 10 42.610 18.425 -65.941 15.3 1. 1D 2.3 271 4 10.0 1 5 3.2 142 83 68 0.10 5 252 43 D 

48 1975 12 5 20 40 38.030 17.874 -67.154 13.1 1. 7D 7.5 14 0 2.6 284 29 2.3 104 61 68 0.17 7 297 54 D 

49 1975 12 6 1 2 52.180 18.190 -66.566 14.3 0.8D 7.1 328 15 1. 1 62 16 2.8 197 67 68 0.09 6 197 45 D 1 

50 1975 12 6 4 32 8.000 18.033 -67.111 11.5 0.9D 2.6 305 0 3.8 35 34 11.7 215 56 68 0.24 5 220 43 D 1 

51 1975 12 6 22 26 49.580 19.192 -66.564 15.5 2.3D 3.9 127 19 5.3 224 20 27.6 357 61 68 0.28 11 298 •• D 1 

52 1975 12 7 15 16 52.080 18.831 -66.816 56.1 2.0D 3.9 67 12 6.4 333 18 13.2 188 68 68 0.28 11 276 76 D 1 

53 1975 12 8 3 13 14.660 18.854 -65.347 9.9 3.1D 7. 8 190 14 9.8 288 30 52.6 78 56 68 0.38 11 318 •• D 1 

54 1975 12 8 18 31 1 0. 2 30 17.849 -66.835 8.9 0.9D 1.6 264 1 4. 1 174 7 24.6 3 82 68 0.10 6 267 44 D 1 

55 1975 12 9 1 1 22.830 18.634 -66.816 73.8 1. 8D 4.3 91 7 8.8 182 9 5.8 324 78 68 0.24 10 246 56 D 1 

56 1975 12 9 20 55 39.750 17.998 -66.701 13.5 1. 9D 5.8 270 22 12.2 15 32 2.5 151 49 68 0.22 5 270 66 D 1 

57 1975 12 9 23 5 57.830 18.266 -66.266 10.2 2.1D 2.5 10 5 1.1277 24 3.1 111 65 68 0.24 12 144 36 c 1 

58 1975 12 10 3 41 34.140 17.881 -67.175 5.4 1. 5D 4.4 128 22 19.8 22 34 7.0 244 47 68 0.27 7 284 56 D 1 

59 1975 12 10 17 23 9.990 17.843 -66.763 3.8 1.1D 1.3 266 0 2.6 176 6 37.8 355 84 68 0.11 7 221 41 D 1 

60 1975 12 11 00 36 47.250 18.441 -67.508 10.8 1. 3D 70. 1 112 7 6.5 204 16 4.0 0 72 68 0.13 6 316 65 D 1 

61 1975 12 12 3 20 29.160 17.898 -66.274 1.5 O. 9D 2.4 264 1 5.4 174 1 >99.9 39 88 68 0.18 6 225 46 D 1 

62 1975 12 14 8 40 31.230 18.550 -66.949 17.9 1. 5D 1.5 82 5 3.4 173 17 7.7 337 72 68 0.13 9 239 44 D 1 

63 1975 12 17 22 55 20.480 18.338 -66.294 115.8 2.6D 3.8 270 20 13.4 168 28 7.5 31 '14 68 0.19 9 167 36 D 1 

64 1975 12 21 00 18 32.040 18.069 -67.106 11.5 1. 2D 2.9 83 31 4.4 330 34 5.2 204 40 68 0.21 7 205 45 D 1 

65 1975 12 23 5 22 7.140 18.708 -66.917 72.0 2.0D 4.4 65 23 32.1 176 39 7.4 313 41 68 0.23 8 273 76 D 1 

66 1975 12 23 14 37 41.180 18.811 -64.611 7.0 2. 8D 18.4 331 0 5.3 241 42 33.7 61 48 68 0.25 8 343 •• D 1 

67 1975 12 24 10 6 51.020 18.573 -66.779 77.2 2.5D 1.7 87 6 4.5 178 13 2.8 333 75 68 0.15 13 249 54 D 1 

68 1975 12 27 11 56 43.580 17.997 -66.976 29.3 1.1D 3.0 90 8 12.9 188 44 8.8 352 44 68 0.30 5 198 32 l) 1 

69 1975 12 28 16 45 9.950 17.905 -66.842 12.9 1. 6D 4.9 91 20 23.3 347 33 7.8 206 49 68 0.42 7 212 40 D 1 

70 1975 12 29 5 27 18.670 18.264 -6 7. 635 25.9 2 .OD 19.4 219 10 10.7 121 37 5.4 321 51 68 0.33 5 333 •• D 1 

71 1975 12 29 8 14 31.210 19.173 -66.819 45.5 3.2D 5.4 76 4 39.0, 167 20 29.2 336 69 68 0.24 9 297 •• D 1 

72 1975 12 29 22 32 48.410 18.885 -67.465 30.8 z;on 13.9 102 1 7.1 12 4 >99.9 206 85 68 0.05 5 318 •• D 1 

------------------------------------------------------------------------------------------------------------------------------------
0 

0 

17~~-------------,~------------~~------------~--------------~--------------· 

lo ID 

58.8 1N.8 

0 ihCkm) 

150.0 

I 0 

<.1.111 OR ? 

.J • _ ___, _ __,._____, _ __.I, .... "" 

0 0 0 0 

2.8 a.e 4.8 

Ma !ude 

Figure 4.--Earthquakes located within the Puerto Rico region, July, 1, 1975-

December 31, 1977, using the HYPOELLIPSE program. All earthquakes plotted 

have the maximum axis of the error ellipsoid~ 10 km and a gap size of 

< 360°. ~ 

0 

5Jj 

Table ).--References for catalog of 1975 earthquakes located by the HYPOELLIPSE program 

[Cat, catalog; Auth no., authority number cited in table 2] 

--------------------------------------------------------------------------------------- Cat Auth 

Name no. References 

PRN75 1 u.s. Geological Survey, this report. 

--------------------------------------------------------------------------------~------

Table 4.--Remarks for catalog of 1975 earthquakes located by the HYPOELLIPSE program 

Catalog Remarks 

Name Index 

PRN75 Probable blast attributed to road construction or quarries. 

12 Do. 

20 Do. 

8 
1.0 

C1.7 JJJe, -66.58l • S N • CJ.S.511!11, -66.!5Sl 

ae I I &rae,.~ 0 9.- 0 I ~ I I 

58.0 

JJJe.tlll 

.1!58.11 

288.8 ~ 

0 

; 

0 

0 

0 

i 

0 8 

i N 

EXPLANATION 

[ololojojojoj 

<.1.8 OR ? 1..8 2.8 a.II!JI 4.8 5.8 

Mmanl.ud• 

~ 

Figure 5.--Depth profile of the earthquakes plotted in figure 4 and within 

the area bounded by lat 17° and 19.5° N. and by long 65.5° and 67.5° W. 

Hypocenters are projected into a north-south plane through long 66.5° w. 

(See map insert, fig. 3.) nepth and horizontal distance are measured in 

kilometers. 
0 

D 

0 0 

0 

0 

0 

17~r---------~~--------------~-------------,~------------~------------~ 

Figure 6.--Earthquakes located within the Puerto Rico region, July 1, 197:-

December 31, 1977, using the HYPOELLIPSE program. All earthquakes plotted 

have the maximum axis of the error ellipsoid ~ 10 km and a gap size C'f 

< 270°. 

10 
,__ 

,__ 

U7 .JJJe, -66.511) • S N• us.511, -66.511) 

11.11 I I ... B&trJO A........ 01 I I 

0 

0 

511.11 

J.IIII.QJ 

0 8 

.1!511.11 

2118.11 :1 ~ ! ! i 

EXPLANATION [o-r ·0---1 ~-~ -o- fO--[-b] 

<.U/J OR ? 1..11 2.11 all 4.11 !5.11 

Mmanl~ud• 

Figure 7.--Depth profile of the earthquake plotted in figure 6 and within 

the area bounded by lat 17° and 19.5° N. and by long 66.5° and 67.5° w. 

Hypocenters are projected into a north-south plane through long 66.5° w. 

(See map insert, fig. 3.) Depth and horizontal distance are measured in 

kilometers. 
1,000 

·. 

100 

"' >oC 

<( 

::> 

Cl 

;= 

"' 

~ 

u. 

0 

"' <Xl 

::!! 

N '"""" 

::> 

z 

10 

1 0. 1. 

1,000 

·· .. 0 0 

·. \ 

0 ·~ CUMULATIVE 

100 

INCREMENTAL 

. "' 

"" .. <( .. . ::> 

Cl . \ . .. • 0 0 . LOG 10 N,•6.98-155 M ~ ~ 

. . 0 .. 

1\ 

LOG ,

0 Nz= 5.06-1.14 M . . . 0 . "' <Xl . ::!! 

::> . z 

\ 10 .. \ 

3. 4. 5. 

0 

.... ----~- 1\ 10 3. 

MAGNITUDE MAGNITUDE 

Figure 8. --Incremental and cumulati:ve frequency distribution for duration 

magnitudes of earthquakes recorded within the Puerto Rico region. Both 

graphs show a straight-line, weighted least-squares fit to the data. 

Slopes were calculated for occurences at 0.10 magnitude intervals. Values 

for b were 1.14 and 1. 55 for incremental and cumulative distributions, 

respectively. 

5. 

I 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program 

[UTC, Coordinated Universal Time; negative latitudes and longitudes are south and west, respectively; M, duration magnitude; 

a, b, and c, principal axes of confidence ellipsoid; Tr, trend of axis in degrees; Pl, plunge of axis in degrees; 

%, confidence level; Rms, root mean square of residuals; No. ob, number of observations used in hypocenter computation; 

Gap, largest azimuthal separation between seismograph stations; DM, distance to third nearest station, in kilometers; 

Q, quality index; Hypo auth, hypocenter authority meaning person or institution responsible for hypocenter determination, 

cited by catalog name and authority number in table 6; *, remarks cited by catalog name and index in table 7; 

leaders ( ••••• )designate instances when data values are unknown or not computed] 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Fypo 

Name Index yr roo d h min s (deg) (deg) (km) M a(kro) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * 

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

PRN76 1 1976 1 3 13 41 20.210 18.499 -65.824 14.8 2.3D 42.8 36 11 5.1 136 41 2.0 295 46 68 0.09 6 275 52 D 

2 1976 1 5 5 11 13.220 17.870 -66. 289 ..... 1. 2D 1.9 267 0 4.1 357 0 >99.9 90 89 68 0.30 8 227 4 7 D 

3 1976 1 5 20 58 39.290 17.874 -66.276 24.5 l.lD 1. 3 2 70 4 3.3 180 8 15.2 27 81 68 0.10 6 280 48 D 

4 1976 1 7 2 3 3.760 18.983 -64.943 17.7 2.9D 26.9 129 19 7.3 232 34 16.6 14 49 68 0.32 8 332 •• D 

5 1976 1 7 3 27 59.550 18.076 -67.060 21.0 l.OD 2.4 0 8 1.5 95 33 4.8 259 55 68 0.14 7 144 40 c 1 

6 1976 1 7 21 32 27.540 18.676 -66.720 25.6 1. 7D 7.2 124 28 5.8 13 34 9.8 243 43 68 0.38 9 271 67 D 1 

7 1976 1 7 23 3 34.600 17.979 -66.883 7.2 2.0D 1. 4 81 4 7.1 347 43 3.6 176 46 68 0.18 8 192 31 D 1 

8 1976 1 7 23 3 45.100 18.283 -66.221 67.7 1.2D 9.0 31 24 2.5 283 33 4.1 150 46 68 0.09 6 191 42 D 1 

9 1976 1 8 11 35 1.070 17.811 -66.809 15.1 O. 8D 3.2 256 9 15.5 350 26 5.9 148 62 68 0.01 5 280 50 D 1 

..... 10 1976 1 9 20 3 9.620 18.439 -66.810 22.1 l.OD 4.4 159 17 >99.9 61 24 12.7 280 59 68 0.10 4 295 •• D 1 w 11 1976 1 11 1 57 45.400 18.591 -65.643 18.9 2. 6D 16.0 228 10 2. 6 320 16 6.8 106 71 68 0.10 8 303 68 D 1 

12 1976 1 12 1 31 53.470 18.062 -66.424 25.2 ... 2.5 83 15 6.2 180 25 16.3 325 60 68 0.11 6 176 38 D 1 

13 1976 1 12 2 59 29.280 18.405 -65.903 15.3 2. 5D 39.2 14 7 10.5 106 19 8.0 265 69 68 0.10 5 246 41 D 1 

14 1976 1 12 18 13 8.690 18.454 -65.705 20.1 2.5D 25.0 48 14 3.5 308 34 7.3 157 52 68 0.13 7 308 51 D 1 

15 1976 1 13 17 12 27.680 18.164 -67.006 16.6 1. 2D 1.8 168 8 0.9 74 23 7.9 275 65 68 0.09 8 161 36 r. 1 

16 1976 1 13 17 18 1.860 17.717 -67.033 0.2 2.7D 2.0 109 5 12.4 16 35 6.5 206 54 68 0.15 8 284 53 D 1 

17 1976 1 14 11 27 50.970 17.921 -66.286 6.6 1. 6D 0.9 265 10 4.4 5 44 2.6 165 44 68 0.09 7 205 43 D 1 

18 1976 1 15 00 45 5.030 18.994 -66.824 50.4 2. 3D 10.0 275 3 17.4 6 21 89.7 177 68 68 0.19 6 301 •• D 1 

19 1976 1 15 9 52 20.070 18.865 -67.309 22.2 2.4D 6.2 145 12 2.7 46 38 11.8 249 49 68 0.11 7 311 •• D 1 

20 1976 1 16 7 55 7.650 17.999 -66.592 16.7 1.6D 1.6 92 13 2.7 191 33 5.1 344 53 68 0.17 9 185 53 D 1 

21 1976 1 17 3 45 22.250 18.361 -66.228 70.2 2.7D 1.127719 4.8 179 21 3.1 46 60 68 0.06 8 239 44 D 1 

22 1976 1 19 20 19 28.580 18.138 -66.540 17.4 0. 9D 1. 1 79 29 9.6 325 37 2.2 196 39 68 0.07 6 141 44 D 1 

23 1976 1 20 3 40 39.490 17.980 -66.594 16.1 1. 7D 1. 1 89 9 7.3 353 29 3.4 194 59 68 0.13 8 189 53 D 1 

24 1976 1 22 18 46 13.350 18.247 -66.474 29.5 l.OD 76.9 335 9 6.6 68 17 17.6 219 70 68 •••• 4 205 34 D 1 

25 1976 1 23 3 33 30.310 18.945 -65.533 9.0 3.1D 2.2 309 3 2.0 217 30 11.9 45 59 68 0.11 8 319 •• D 1 

26 1976 1 25 10 55 5.600 18.165 -67.297 14.3 1. 6D 0.9 353 1 4.1 263 3 1.4 102 86 68 0.04 6 267 34 D 1 

27 1976 1 26 00 3 56.430 18.595 -65.770 13.5 2. 3D 16.1 306 1 >99. 9 37 28 >99.9 215 61 68 0.13 4 309 98 D 1 

28 1976 1 27 11 46 48.050 18.587 -66.480 93.3 2.7D 1.9 275 9 8.1 176 42 6.6 15 46 68 0.15 10 218 63 D 1 

29 1976 1 29 23 24 50.160 18.158 -67.442 37.0 2.4D 4.6 164 13 37.0 261 30 5.9 53 56 68 0.12 7 296 45 D 1 

30 1976 1 31 22 52 57.780 18.219 -66.915 39.0 1. 00 7.7 184 4 2.6 275 8 13.2 67 81 68 0.12 6 141 30 D 1 

31 1976 2 1 6 6 55.430 18.055 -67.102 25.4 O. 7D 14.5 140 8 30.9 236 39 9.4 40 49 68 0.11 5 201 44 D 1 

32 1976 2 1 22 8 11.940 18.486 -67.865 64.5 2.4D 3.0 137 15 24.3 292 41 12.7 30 44 53 0.19 9 333 99 D 

33 1976 2 1 22 58 10.370 18.007 -66.879 3.2 1. 3D 2.0 269 0 6.2 359 0 14.7 90 90 68 0.16 6 182 29 D 1 

34 1976 2 2 1 20 27.640 18.159 -66.946 28.3 ... 10.2 86 20 26.7 344 29 46.6 205 53 68 0.30 5 163 30 D 1 

35 1976 2 5 8 7 36.470 18.048 -67.129 14.6 1. 3D 0.7 350 3 3.4 258 27 0.4 86 62 68 0.03 6 241 47 D 1 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * 

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

PRN76 36 1976 2 5 20 5 4.230 18.359 -66.475 1.1 I. 2D 4.2 264 0 14.6 354 2 >99.9 173 88 68 0.12 5 210 40 D 1 

37 1976 2 6 10 42 5.120 18.441 -66.473 19.5 I.ID 8.8 61 10 22.5 325 30 66.8 168 58 68 0.15 5 269 48 D 1 

38 1976 2 7 6 48 5.450 18.174 -67.024 18.7 2.6D 1.6 346 1 1.4 76 22 6.6 254 67 68 0.14 10 91 29 c 1 

39 1976 2 8 17 38 19.070 18.371 -66.390 35.5 !.3D 6.5 82 6 32.5 350 18 16.8 189 70 68 0.28 6 245 46 D 1 

40 1976 2 8 20 20 29.470 17.964 -65.497 0.2 2.1D 11.0 108 16 20.1 210 34 37.8 358 51 68 0.18 5 337 •• D 1 

41 1976 2 9 2 2 1 6 2 4 • 160 18.085 -66.891 7.5 1. 6D 4.5 357 0 1.8 87 7 6.3 267 83 68 0.32 10 150 23 c 1 

42 1976 2 11 17 45 26.270 17.736 -66.746 14.6 1. 3D 5.1 104 31 11.7 352 32 3.0 227 42 68 0.24 7 264 51 D 1 

43 1976 2 13 2 49 33.700 18.883 -66.505 19.6 2. 5D 10.4 87 4 >99.9 178 20 >99.9 347 69 68 0.01 5 300 79 D 1 

44 1976 2 13 19 44 35.830 18.370 -66.467 10.5 o.9D 4.8 252 6 77.0 157 38 6.8 349 51 68 0.11 5 213 41 D 1 

45 1976 2 15 21 18 14.210 17.821 -66.957 15.4 I. lD 20.8 211 11 7.8 308 30 4.8 103 57 68 0.05 5 278 42 D 1 

46 1976 2 17 2 57 10.950 18.223 -67.412 13.7 I. 2D 12.8 84 2 3. 1 174 4 2.8 328 85 68 0.10 6 291 42 D 1 

47 1976 2 19 13 47 48.290 18.119 -66.908 31.8 1.4D 5.9 75 1 62.0 167 44 26.5 344 45 68 0.04 5 202 34 D 1 

48 1976 2 20 00 12 55.030 18.139 -67.354 31.2 2.0D 6.1 9 27 45.8 260 32 7.1 131 45 68 0.17 7 282 40 D 1 

49 1976 2 20 9 34 45.870 18.328 -66.026 21.1 2.2D 0.4 122 6 3.6 30 17 0.6 230 71 68 0.02 6 258 62 D 1 

50 1976 2 22 20 38 5.830 18.979 -65.863 45.3 2.3D 6.7 304 17 24.3 39 18 61.5 173 64 68 0.29 8 289 •• D 1 

51 1976 2 23 20 13 3.410E 18.323 -66.149 0.8 !.3D I. 2 101 1 2.5 1111 9.0 196 78 68 0.21 7 201 38 D 1 * 

52 1976 2 24 3 48 42.810 17.766 -66.679 6.4 1. 2D 1.1 230 4 3.0 139 7 26.3 349 81 68 0.09 7 258 51 D 1 I-' 

.p... 53 1976 2 24 4 32 44.350 17.769 -66.685 0.4 l.OD 1.2 262 0 2. 7 172 1 >99.9 351 88 68 0.11 8 232 50 D 1 

54 1976 2 28 21 12 15.250 18.000 -65.504 5.0 2.0D 5.4 87 32 6. 1 199 32 10.2 323 41 68 0.28 9 314 70 D 1 

55 1976 2 29 2 23 25.920 17. 769 -66.793 1.6 1. 3D 6.0 231 2 9.1 141 2 >99.9 6 87 68 0.14 5 253 89 D 1 

56 1976 2 29 5 7 26.720 18.562 -66.142 67.9 1. 6D 10.5 283 13 73.5 24 41 62.2 179 46 68 0.04 5 271 63 D 1 

57 1976 3 5 1 12 48.850 17.822 -66.797 2.8 1. 8D 0.9 95 1 3.2 186 2 40.7 339 87 68 0.11 9 228 45 D 1 

58 1976 3 5 15 1 47.140 18.139 -66.006 15.1 2. 4D 3.1 1 14 2.1264 28 4.2 115 58 68 0.27 9 120 23 c 1 

59 1976 3 6 4 55 34.850 18.142 -67.023 20.0 2.5D 3.6 7 19 2.6 106 26 q.8 245 57 68 o.2~ 9 101 32 c 1 

60 1976 3 6 17 10 21.220 18.679 -66.844 15.9 2. OD 1.2 279 0 3.4 9 0 >99.9 90 90 68 0.06 7 290 71 D 1 

61 1976 3 6 22 51 34.350 18.699 -66.802 64.1 2.0D 0.8 83 7 1.9 347 42 4.9 180 47 68 0.05 9 276 72 c 1 

62 1976 3 7 23 11 39.950 18.666 -67.681 5.7 3. 2D 7.9 158 19 1.2 59 25 3.3 281 57 68 0.14 10 268 83 D 1 

63 1976 3 8 1 3 39.260 18.114 -66.019 23.7 O.SD 0.9 307 0 3.2 217 43 2.1 37 4 7 68 o. 04 6 164 24 c 1 

64 1976 3 8 2 32 12.520 18.197 -67.518 62.2 3.2D 8.8 174 6 3.4 82 19 13.5 280 70 68 0.19 9 169 50 D 1 

65 1976 3 8 7 5 21.090 18.090 -67.036 10.6 2.0D 2.0 1 13 1.6 97 27 4.5 248 59 68 0.22 11 120 37 c 1 

66 1976 3 8 12 5 45.050 18.429 -67.554 7.9 1. 7D 20.7 104 14 8.3 1 43 7.9 207 43 68 0.18 6 318 68 D 1 

67 1976 3 8 13 8 25.720 18.080 -66.217 20.3 l.OD 4.1 276 13 17.7 13 28 9.7 163 58 68 0.23 6 169 32 D 1 

68 1976 3 9 22 10 14.690 17.569 -66.507 7.5 I.6D 5. 6 353 13 1.7 259 16 3.5 121 69 68 0.13 8 2 76 71 D 1 

69 1976 3 10 19 20 19.090 19.099 -65.424 10.0 2.8D 4. 4 166 11 2.8 265 38 24.3 62 49 68 0.19 10 317 •• n 1 

70 1976 3 10 23 16 34.090E 18.145 -65.695 0.1 2.5D 5.1 357 5 62.2 266 11 8.7 112 77 68 0.21 7 315 95 D 1 * 

71 1976 3 12 9 52 0.700 18.101 -66.901 24.7 0.8D 1.2 289 4 2.6 20 19 3.9 188 70 68 0.07 6 141 ~1 c 1 

72 1976 3 12 23 29 8.980 18.172 -67.340 5.2 2.6D 14.5 78 4 3.3 168 7 5.4 319 81 68 0.23 9 277 37 D 1 

73 1976 3 13 00 20 25.780 18.019 -67.046 11.9 2.5D 1.8 337 7 I. 3 71 34 5.0 237 55 68 0.14 10 166 39 c 1 

74 1976 3 13 00 59 5.910 17.967 -67.095 18.3 l.ID 1.0 105 23 2.7 212 36 1.5 350 45 68 0.07 7 281 45 D 1 

75 1976 3 13 5 47 5.780 19.748 -66.764 25.8 2.5D 45.3 263 0 >99.9 353 0 >99.9 90 90 68 0.30 5 324 •• D 1 

76 1976 3 13 8 14 13.900 17.975 -67.095 17.5 1. OD 0.8 100 22 3.2 205 33 1.4 343 48 68 0.06 7 280 45 D 1 

77 1976 3 13 8 52 5.740 17.963 -67.109 18.5 O.SD 20.4 245 24 9.5 354 36 7.3 129 44 68 o.os 5 289 46 D 1 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time {UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s {deg) {deg) {km) M a{km) Tr Pl b{km) Tr Pl c{km) Tr Pl % {s) ob Gap DM Q auth * ------------------------------------------------------------------------------------------------------------------------------------

PRN76 78 1976 3 14 10 16 31.110 18.688 -65.564 1.7 z.sn >99.9 221 22 17.4 325 31 27.5 101 so 68 0.08 5 317 89 D 1 

79 1976 3 14 22 43 52.260 17.955 -66.795 4.6 1.3D 1.1 82 1 3.1 173 31 6.7 351 58 68 0.1Q 11 196 32 D 1 

80 1976 3 16 19 36 4. 650 18.513 -67.401 15.8 1. 4D 2.0 245 0 4.0 335 0 >99.9 90 89 68 O.ll 7 3ll 65 D 1 

81 1976 3 17 5 49 38.030 17.816 -66.809 0.2 1. 2D 3.6 274 0 7.2 4 0 >99.9 90 90 68 0.28 7 230 SO D 1 

82 1976 3 17 6 54 59.180 17.839 -66.794 1.4 1.7D 1.3 267 0 3. 7 177 1 75.4 356 88 68 0.14 9 224 43 D 1 

83 1976 3 17 7 53 31.080 18.098 -66.582 20.9 O. 6D 11.7 333 23 5.8 83 38 3.7 220 42 68 0.16 6 183 50 D 1 

84 1976 3 17 8 15 4.490 18.270 -67.366 73.4 1.4D 12.5 197 14 9.9 293 24 6.9 79 61 68 0.28 9 284 41 D 1 

85 1976 3 18 19 3 17.740 18.224 -66.996 25.3 1.1D 1.6 4 5 1.2 95 15 4.5 257 74 68 0.06 6 12 7 26 B 1 

86 1976 3 21 22 59 48.150 19.ll8 -66.821 S. s· 2.9n 30.5 169 7 2.1 75 34 4.1 269 55 68 0.09 7 300 •• D 1 

87 1976 3 22 14 9 28.830 18.688 -66.611 7.8 2.2D 0.7 92 2 2.6 183 36 1.8 0 53 68 0.11 10 252 65 D 1 

88 1976 3 25 16 38 12.860 18.592 -66.629 85.0 2.1D 2.2 285 8 9.0 189 37 3.3 26 51 68 0.16 10 234 59 D 1 

89 1976 3 25 19 1 17.870 18.312 -66.840 1.7 1.4D 4.4 261 0 9.1 171 1 >99.9 350 88 68 0.10 5 156 30 D 1 

90 1976 3 25 22 6 4.870 19.159 -65.747 6.5 2.5D 8.5 120 4 3.1 212 31 54.7 23 58 68 0.17 8 324 •• D 1 

91 1976 3 25 22 30 33.490 18.982 -65.874 2.7 2. 7D 19.3 207 (, 2.4 301 35 6.1 108 54 68 0.13 9 296 •• D 1 

92 1976 3 26 13 37 26.390 18.489 -65.797 104.7 2. 2D 10.6 43 6 31.8 137 35 4.7 305 54 68 0.12 6 291 51 D 1 

93 1976 3 28 13 3 4.030 18.329 -66.509 30.7 O. 8D 60.3 161 6 ll. 0 70 ll 29.6 279 77 68 0.04 5 245 38 D 1 

94 1976 3 28 20 32 49.360 17.970 -66.766 16.2 1.1D 0.6 254 13 3.5 160 18 1.7 19 67 68 o.os 7 235 35 n 1 1-' 95 1976 3 29 5 22 0.230 18.876 -67.557 20.0 3. 3D 3.3 72 16 31.7 167 19 9.6 305 64 68 0.17 7 279 92 n 1 Vl 

96 1976 3 29 5 25 21.250 18.526 -67.248 12.9 1.7D >99.9 304 0 31.5 213 8 10.1 34 81 68 0.16 5 315 79 D 1 

97 1976 3 29 5 33 56.600 18.875 -67.635 4.5 1.9D 37.9 43 3 9.2 310 43 22.1 137 46 68 0.01 s 335 •• n 1 

98 1976 3 29 6 15 50.840 18.461 -65.557 56.3 3.6D 3.8 308 33 7. 8 192 35 27.8 69 38 68 0.16 10 309 66 D 1 

99 1976 3 29 9 12 5.860 18.721 -67.381 15.3 2.1D 6.7 250 0 17.5 340 0 >99.9 90 89 68 0.17 6 255 86 D 1 

100 1976 3 29 20 15 20.010E 18.336 -66.132 ..... 1. 3D 3.2 320 0 12.4 2 30 0 >99.9 270 89 68 0.30 7 269 52 D 1 * 

101 1976 3 30 8 22 2.980 17.951 -67.101 17.4 0. 8D 3.5 230 24 1.8 336 32 1.5 110 48 68 0.10 8 284 46 D 1 

102 1976 3 31 2 19 58.890 18.678 -65.835 17.2 2.2n 3.8 264 2 6. 4 354 10 27.9 162 79 68 0.30 11 286 71 D 1 

103 1976 3 31 2 38 47.550 17.807 -66.783 9.1 LSD 2.2 90 ll 3.9 188 34 11.1 145 53 68 0.22 8 241 46 D 1 

104 1976 3 31 13 39 35.380 18.923 -65.375 31.5 2. SD 16.7 47 2 25.8 317 6 >99.9 156 83 68 0.25 6 335 •• D 1 

105 1976 3 31 16 13 20.050 18.399 -66.429 6.9 1. on 2.0 274 5 3.5 5 7 23.1 148 81 68 0.15 6 201 46 D 1 

106 1976 4 1 22 30 33.080 18.835 -67.026 51.6 1.6D 3.6 319 9 2.7 55 32 8.4 216 56 68 0.19 12 292 73 D 1 

107 1976 4 2 7 2 40.170 18.656 -67.508 9.9 1. 7D 35.0 202 12 20.8 105 31 8.1 310 56 68 0.31 6 326 •• n 1 

108 1976 4 2 22 12 39.160 20.222 -68.699 21.8 3.1D >99.9 232 0 >99.9 322 0 >99.9 90 89 68 0.01 3 355 •• D 1 

109 1976 4 2 22 31 22.370E 18.407 -65.892 0.3 0.9D 9.2 14 0 1. 8 284 1 >99.9 104 89 68 0.13 6 244 43 D 1 * 

llO 1976 4 3 4 40 45.080 18.854 -67.304 24.6 3.1D 5.6 121 5 3.9 215 40 2.4 25 49 68 0.14 11 311 75 D 1 

111 1976 4 3 4 57 4.740 18.379 -67.103 16.0 1. 6D 14.3 214 10 11.4 117 36 >99.9 317 52 68 0.07 5 172 41 n 1 

ll2 1976 4 3 5 55 30.170 18.670 -66.822 19.8 1. 4D 2.5 86 4 6. 1 355 10 9.1 197 79 68 0.24 11 2)3 60 D 1 

ll3 1976 4 3 13 27 34.850 18.174 -66.859 33.1 1. 4D 4.5 355 7 2.8 86 8 10.1 225 79 68 0.28 10 108 28 c 1 

114 1976 4 3 14 26 26.240 17.863 -66.8()3 13.9 1. 4D 5.6 257 5 28.3 165 23 37.0 358 66 68 0.08 5 265 41 D 1 

115 1976 4 5 6 48 53.880 18.281 -67.071 23.2 ... >99.9 269 3 8.9 0 16 10.9 168 73 68 o.os 5 199 30 D 1 

ll6 1976 4 6 17 34 14.510 18.050 -66.957 25.2 0.9D 1.6 98 4 4.2 7 15 6.6 202 74 68 0.12 7 163 29 c 1 

ll7 1976 4 6 19 40 4 7. 530E 18.340 -66.140 0.4 1.1D 1.6 292 0 2.2 22 3 36.3 202 87 68 0.27 8 206 37 D 1 * 

ll8 1976 4 6 20 21 57.590E 18.324 -66.151 0.1 1. OD 1.8 277 0 2.4 7 2 82.3 187 88 68 0.14 6 251 40 D 1 * 

119 1976 4 7 2 12 26.440 18.189 -66.747 ll. 5 0.6D 1.2 259 12 1.9 358 37 3.4 154 so 68 0.09 7 172 36 c 1 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM 0 auth * ------------------------------------------------------------------------------------------------------------------------------------

PRN 7 6 12 0 1 9 7 6 4 7 10 44 0.390 18.341 -65.834 11.0 2. 3D 9.3 33 14 9.7 133 35 3.6 285 51 68 0.34 8 222 34 D 1 

121 1976 4 7 13 22 50.780 18.415 -66.405 1.4 1.2D 6.5 286 0 13.1 16 1 >99.9 196 88 68 0.09 5 208 49 n 1 

122 1976 4 7 16 1 49.730 18.312 -66.861 5.1 0.9D 1.9 179 4 1.3 89 6 4.8 302 82 68 0.15 8 106 29 c 1 

123 1976 4 7 22 50 2.150 18.246 -67.420 8. 1 1. 5D 8.4 176 1 35.0 86 14 19.5 270 75 68 0.01 5 293 44 D 1 

124 1976 4 8 2 30 46.170 18.651 -65. 652 18.8 2.1D 25.9 222 16 3.9 321 29 9.4 106 56 68 0.21 10 301 73 D 1 

125 1976 4 8 10 56 57.570 18. 734 -67.173 17.5 2. 7D 2.5 75 2 6.2 345 11 17.7 176 78 68 0.15 9 250 81 D 1 

126 1976 4 8 20 3 16.740 18.255 -66.253 58.4 l.4D 6. 7 277 3 22.0 185 29 42.7 13 60 68 0.06 5 174 43 D 1 

127 1976 4 9 8 16 15.6 70 18.600 -66.212 81. 1 1. 6D 16.5 274 16 76.9 169 41 >99.9 21 44 68 0.15 5 270 78 D 1 

128 1976 4 9 21 51 17.180 18.490 -66.819 18.5 2. 5D 1.1 266 13 1.7 165 39 5.6 11 48 68 0.11 10 212 42 n 1 

129 1976 4 10 12 41 52.440 18.691 -65.500 16.4 1.9D >99.9 226 13 13.8 320 17 29.5 100 68 68 0.18 6 328 84 D 1 

130 1976 4 11 6 49 53.680 18.751 -67.323 9.2 1. 4D 12.7 214 17 9.9 116 26 4.1 333 58 68 0.15 6 326 86 D 1 

131 1976 4 11 20 2 43.960 17.905 -67.333 18.3 2. 2D >99. 9 57 3 23.2 325 36 16.4 152 53 68 0.01 5 325 71 D 1 

132 1976 4 11 20 29 10.440 18.459 -66.394 95.1 1. 9D 3.6 104 7 8.9 196 16 6.9 352 72 68 0.23 11 223 46 D 1 

133 1976 4 11 23 10 22.660 18.709 -66.780 63.4 1. 9D 2.0 91 6 4.3 355 45 8.6 186 44 68 0.20 14 258 67 D 1 

134 1976 4 13 13 35 21.090E 17.948 -66.152 0.6 2.3D 7. 0 232 0 62.2 322 0 >99.9 90 89 68 0.16 4 283 58 D 1 * 

135 1976 4 13 13 36 2.890 17.797 -65.930 21.9 2.5D 77.8 163 11 13.9 256 16 43.7 39 70 68 0.06 5 286 59 D 1 

136 1976 4 13 21 56 3.410 18.216 -67.056 33.1 0.8D 3.4 10 22 2.3 111 25 9.7 244 55 68 0.09 6 129 23 c 1 ,_. 137 1976 4 13 23 10 9.460 17.984 -66.835 18.1 0.5D 2.0 260 7 10.3 165 39 5.5 358 50 68 0.09 6 213 33 D 1 0\ 138 1976 4 14 7 57 55.380 19.410 -65.026 23.5 3.0D 6.9 315 0 95.8 45 0 >99.9 90 90 68 0.17 9 328 •• D 1 

139 1976 4 14 14 11 13.910 18.028 -67.088 40.3 2. 6D 4. 2 100 14 4.8 3 25 19.4 216 60 68 0.12 6 97 43 c 1 

140 1976 4 16 17 7 6.800 17.966 -66.989 14.4 0.4D 25.4 199 15 4.1 97 38 10.7 306 48 68 0.02 5 221 34 D 1 

141 1976 4 16 19 9 44.480 18.150 -67.202 97.2 2. 2D 1.5 79 19 4.5 338 29 2.6 197 54 68 0.06 9 273 56 D 1 

142 1976 4 17 14 41 23.360 17.990 -6 7. 114 14.2 1.4D 6.4 324 15 10.4 229 20 2.5 89 64 68 0.15 6 287 46 D 1 

143 1976 4 17 16 43 0.350 18.536 -65.573 36.8 1. 2D 13.2 253 18 25.0 148 38 12.8 3 46 68 0.35 7 337 67 D 1 

144 1976 4 18 1 11 35.500 17.994 -68.031 70.0 2.6D 12.9 347 16 38.5 242 42 4.6 93 43 68 0.15 9 333 •• D 1 

145 1976 4 18 14 44 43.880 17.888 -67.148 11.5 l.lD 28.0 247 1 14.9 338 18 10.6 153 71 68 •••• 5 310 67 D 1 

146 1976 4 18 23 51 22.590 18.292 -65.042 98.4 2.1D 8.1 194 24 88.1 83 39 5.6 307 41 68 0.04 6 341 •• D 1 

147 1976 4 19 3 14 38.770 18.690 -65.522 4.8 2.4D 24.5 232 14 5.0 133 32 2.4 342 54 68 0.12 8 311 92 D 1 

148 1976 4 20 7 56 56.600 18.132 -66.090 25.3 1.6D 1.9 127 3 3. 1 36 21 4.9 224 68 68 0.14 8 131 21 c 1 

149 1976 4 20 14 1 26.620 17.911 -66.860 25.4 2.0D 3.7 1 13 1. 1 95 16 2.6 234 69 68 0.10 8 212 38 D 1 

150 1976 4 21 3 8 46.780 19.363 -68.444 90.8 3.4D 5.6 54 7 >99.9 320 33 31.6 155 56 68 0.07 6 320 •• D 1 

151 1976 4 21 18 50 57.510 17.891 -67.178 13.0 1. 7D 20.1 98 1 22.9 8 16 6.8 191 73 68 0.11 5 296 59 D 1 

152 1976 4 21 20 57 31.830 18.655 -65.425 12.6 2.4D >99.9 234 12 27.7 141 15 18.8 2 70 68 0.06 5 329 87 D 1 

153 1976 4.25 17 1 27.820 17.962 -6 7.030 1.2 2.4D 3.1 8 2 1.3 99 6 10.0 260 83 68 0.14 9 223 51 D 1 

154 1976 4 26 17 15 19.930 18.296 -66.117 64.8 1.9D 3.2 355 0 0.9 265 16 1. 8 85 74 68 0.11 11 184 34 D 1 

155 1976 4 27 1 6 20.190 18.938 -67.345 7.2 2.2D 6.6 124 22 12.4 224 23 4.7 356 57 68 0.22 7 321 •• n 1 

156 1976 4 28 23 52 59.980 18.180 -67.207 6.5 l.lD 3.3 356 4 9.1 ?.n'i t 1 'i.R QQ n ~~ 0.16 6 ?.3'1 ?.8 D 1 

157 1976 4 29 4 34 35.540 18.330 -67.302 18.7 2.4D 13.0 18 7 50.4 285 22 19.0 125 66 68 0.29 6 276 42 D 1 

158 1976 4 29 16 44 29.070 18.043 -67.856 50.3 2 .lD 10.5 351 6 1. 8 86 36 26.3 253 53 68 0.11 8 278 83 D 1 

159 1976 4 30 i4 8 21.480 18.682 -66.417 73.3 1. 9D 0.8 277 7 1. 8 12 39 4.5 178 50 68 0.09 12 233 78 c 1 

160 1976 5 1 3 15 17.900 18.184 -67.127 18.6 1. 7D 2.9 5 19 3.6 108 33 5.2 251 50 68 0.32 10 195 26 D 1 

161 1976 5 1 8 38 8.390 17.973 -66.889 8.6 lolD 8.7 22 8 10.7 115 21 >99.9 273 67 68 •••• 5 306 55 D 1 

162 1976 5 5 18 22 54.160 18.368 -66.829 27.5 l.lD 5.8 111 6 8.6 204 19 29.0 4 69 68 0.22 5 176 34 D 1 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * 

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

PRN76 163 1976 5 6 15 17 2. 720 18.231 -66.952 21.1 1. 4D 0.7 83 6 1.0 352 9 5.0 206 79 68 0.06 7 138 34 c 1 

164 1976 5 6 17 26 59.850 18.356 -66.234 95.7 1. 9D 9.0 196 6 2.4 288 22 4.8 91 67 68 0.18 10 210 49 D 1 

165 1976 5 7 5 37 55.820 18.110 -65.692 23.0 3.5D 1.9 206 4 9.4 114 22 2 .• 2 30 5 6 7 6 8 0 • 1 0 8 277 48 D 1 

166 1976 5 7 18 28 20.330E 18.318 -66.863 1. 0 l.lD 1. 4 2 75 0 3.0 5 0 >99.9 90 90 68 0.14 7 159 33 c 1 * 

167 1976 5 8 3 48 2.940 18.416 -67.098 22.1 2.1D 13.9 205 16 39.5 307 37 6.5 95 48 68 0.17 5 174 45 D 1 

168 1976 5 8 8 53 10.600 17.873 -67.072 1.3 2.3D 5.5 35 6 0.9 127 16 3.5 286 72 68 0.07 8 271 61 D 1 

169 1976 5 8 10 57 4.070 18.572 -66.864 19.7 2.9D 1.2 86 5 4.0 179 24 7.1 346 65 68 0.12 9 236 50 D 1 

170 1976 5 8 14 6 47.550 18.226 -6 7. 211 13.6 2.1D 42.4 264 12 12.7 170 20 9.8 24 66 68 o.os 5 235 27 D 1 

171 1976 5 9 15 4 20.020 17.767 -66.735 15.9 l.OD 10.1 257 0 30.3 347 0 >99.9 90 90 68 0.03 5 287 59 D 1 

172- 1976 5 10 1 56 32.910 17.967 -68.149 152.7 2.5D 74.8 136 27 >99.9 24 35 >99.9 253 42 68 0.07 5 337 •• D 1 

173 1976 5 10 17 23 56.630 18.434 -67.047 86.7 1. 6D 10.7 200 10 4.1 105 30 9.1 306 58 68 0.20 9 189 47 D 1 

174 1976 5 12 2 51 31.410 18.381 -65.856 18.2 2.1D 64 .o 236 0 12.9 326 6 42.7 145 84 68 0.13 5 274 43 D 1 

175 1976 5 12 20 56 32.100E 18.167 -66.934 0.4 o. 7D 5.6 155 6 3.8 64 7 18.6 285 80 68 0.22 5 126 36 D 1 * 

176 1976 5 13 1 51 0.580 18.649 -65.759 4.3 2. 6D 12.1 320 30 >99.9 211 30 24.3 86 45 68 0.04 5 295 72 D 1 

177 1976 5 13 9 52 7.750 18.732 -65.530 38.9 3.1D 8.5 320 17 54.7 56 18 38.5 190 64 68 0.23 7 310 87 D 1 

178 1976 5 13 19 57 16.700E 18.446 -6 7.121 0.2 1. 3D 2.3 52 1 6.8 321 6 47.0 152 83 68 0.31 7 284 49 D 1 * 

179 1976 5 14 16 39 50.330 18.081 -67.326 20.1 1. 5D 11.4 28 0 8. 1 118 23 16.5 298 67 68 0.16 6 319 68 D 1 

..... 180 1976 5 15 2 33 15.390 18.209 -66.118 78.5 1. 6D 8.9 179 10 3.8 83 31 2.6 284 57 68 0.21 12 96 29 c 1 ...... 181 1976 5 15 2 35 17.670 18.659 -66.02 4 64.9 2.7D 4.9 32 13 2.2 296 23 9.0 150 63 68 0.15 11 250 62 D 1 

182 1976 5 15 6 26 39.600 18.292 -66.247 23.2 0. 7D 14.0 159 12 6.1 257 34 28.3 52 53 68 0.02 5 211 53 D 1 

183 1976 5 15 7 5 0.470 18.528 -65.772 23.6 2.6D 22.4 213. 15 6.4 317 41 15.7 107 45 68 0.25 7 279 56 D 1 

184 1976 5 15 10 47 27.020 18.048 -67.069 11.5 1.1D 6.0 122 18 5.1 21 32 21.2 236 52 68 0.09 5 147 41 D 1 

185 1976 5 15 17 36 23.840 18.892 -65.325 26.7 2.8D 13.9 320 0 >99.9 230 0 >99.9 270 89 68 0.30 7 319 •• D 1 * 

186 1976 5 15 22 1 24.750 19.025 -65.197 7.5 3.8D 8.9 329 12 13.1 233 30 38.8 79 57 68 0.27 11 323 •• D 1 * 

187 1976 5 16 4 30 57.560 18.310 -65.884 23.2 2.6D 11.3 188 10 6. 2 285 3 7 16.6 85 51 68 0.39 7 168 30 D 1 * 

188 1976 5 16 4 54 14.140 18.276 -66.245 20.8 o. 7D 13.5 156 24 6.6 258 25 32.7 28 54 68 o. 04 5 199 44 D 1 

189 1976 5 16 10 36 37.920 19.128 -66.810 3Q.9 2.4D 5.8 77 2 36.9 347 12 65.4 177 77 68 0.17 7 300 •• D 1 

190 1976 5 17 3 6 14.010 18.818 -65.448 2.5 3.4D 27.9 224 19 4.9 122 33 2.1 339 50 68 0.12 9 314 •• D 1 

191 1976 5171737 8.690 18.057 -66.264 8.2 2.7D 1.5 258 16 4.2 353 16 4.6 125 67 68 0.20 9 173 37 c 1 

192 1976 5 17 21 30 46.250 18.169 -6 7. 478 8.5 2. 7D 2.9 77 22 4.6 332 33 4.1 194 48 68 0.24 9 157 45 D 1 

193 1976 5 17 22 17 42.360 18.211 -66.552 23.2 1.1D 35.0 328 17 4.0 65 19 9.7 200 63 68 0.18 5 212 43 D 1 

194 1976 5 17 22 53 20.780 18.224 -66.570 73.5 1. 4D 11.0 3 6 3.4 94 10 4.8 243 78 68 0.18 8 176 44 D 1 

195 1976 5 18 6 16 14.620 18.289 -66.393 32.0 1.0D 2.6 76 1 12.1 346 13 8.1 171 76 68 0.20 7 211 32 D 1 

196 1976 5 19 4 7 20.750 18.168 -67.539 126.7 2.1D 7. 3 184 4 3.7 92 23 16.1 283 66 68 0.10 8 164 51 D 1 

197 1976 5 21 22 59 5.840 18.026 -66.788 16.7 o.8n 4.3 258 9 13.8 355 40 34.1 157 48 68 0.02 5 194 32 D 1 

198 1976 5 22 7 11 3.580 18.624 -66.524 11.3 1. 8D 3.9 178 24 1.1 280 25 2.5 50 54 68 0.14 10 244 65 D 1 

199 1976 5 23 8 10 31.940 18.769 -65.327 0.2 2.8D 49.0 236 17 8.7 138 22 3.8 1 61 68 0.20 8 319 •• D 1 

200 1976 5 24 5 7 22.020 18.158 -67.128 10.5 2.0D 2.2 158 25 4.9 262 28 2.5 32 50 68 0.21 10 198 29 D 1 

201 1976 5 24 20 7 1.520 18.151 -66.068 20.9 1. 2D 3.4 299 4 7.2 208 15 10.0 44 74 68 0.23 7 159 20 D 1 

::!02 1975 5 ::!5 7 43 47.970 19.11::! -SS.325 53.5 2. 3D 5.::! 94 4 34.7 351 30 13.9 190 59 59 0.19 9 300 •• D 1 

203 1976 5 25 10 14 26.080 18.138 -67.667 24.7 2.1D 8.5 341 21 2.6 81 25 7.0 216 56 68 0.20 8 168 63 D 1 

204 1976 5 25 12 57 34.370 18.089 -66.833 13.2 o.8n 4.2 259 4 12.1 350 19 50.7 157 70 68 0.03 5 149 29 D 1 

205 1976 5 25 21 37 48.680 17.834 -66.811 9.9 1.1D 1. 0 164 8 0.2 256 14 0.5 45 73 68 0.01 6 271 44 c 1 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

-----------------------------------------------------------------------------------------------~------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * ------------------------------------------------------------------------------------------------------------------------------------ PRN76 206 1976 5 26 5 4 11.150 18.438 -65.726 25.9 2.4D 9.9 193 13 15.4 96 28 2.8 305 58 68 0.25 10 293 49 D 1 

207 1976 5 26 5 20 51.140 17.852 -66.815 10.7 1.1D 0.3 91 16 2.3 349 36 0.6 200 49 68 0.02 6 233 43 c 1 

208 1976 5 27 7 12 20.080 18.569 -67.668 6.2 1.4D 20.1 24 12 >99.9 117 14 9.9 255 71 68 0.09 5 322 87 D 1 

209 1976 5 28 4 28 11.180 17.332 -67.277 17.5 1. 8D 3.7 133 28 10.9 248 38 14.7 17 39 68 0.17 8 307 •• D 1 

210 1976 5 28 14 51 35.640 18.397 -66.396 10.0 1.1D 4.9 274 21 7.5 21 38 60.7 161 44 68 0.19 5 203 48 D 1 

211 1976 5 28 15 56 59.500 18.345 -66.851 24.4 0. 9D 2.8 98 3 7.0 188 4 17.8 332 85 68 0.13 6 183 33 D 1 

212 1976 5 28 18 48 26.460 17.981 -67.086 3.0 1.5D 11.8 220 24 1.9 118 26 3.9 346 53 68 0.16 8 266 43 D 1 

213 1976 5 28 20 55 57.990 18.176 -66.127 20.7 1.0D 0.5 303 5 0.7 210 33 2.0 41 56 68 0.04 7 138 2 7 B 1 

214 1976 5 29 3 7 54.520 17.806 -66.920 0.4 1. 3D 0.8 106 6 2.5 201 41 5.8 9 48 68 0.07 8 245 45 D 1 

215 1976 5 29 9 5 22.770 18.038 -66.938 21.2 O. 7D 6.2 96 3 13.3 5 18 4~.3 195 71 68 0.08 5 173 27 D 1 

216 1976 5 29 21 53 31.100 18.669 -67.001 55.0 1. 2D 8.4 88 27 27.0 339 33 24.8 208 44 68 0.24 6 272 70 D 1 

217 1976 5 30 11 4 2.450 18.257 -67.228 29.5 1.8D 3.7 13 22 16.7 264 38 2.9 126 43 68 0.19 10 243 31 D 1 

218 1976 5 30 11 6 25.290 18.268 -67.161 23.8 1. 6D 2.4 5 5 8.8 272 32 2.0 103 57 68 0.16 9 213 30 D 1 

219 1976 5 31 11 58 10.430 18.262 -67.143 22.0 1.4D 2.7 33 26 2.1 141 33 7.9 273 45 68 0.19 10 203 29 D 1 

220 1976 6 1 1 17 14.160 18.342 -67.238 9.3 1.1D 3.2 191 2 9.8 281 13 5.4 92 76 68 0.30 10 261 40 D 1 

221 1976 6 1 3 15 5.940 17.806 -66.806 0.3 2.8D 1.1 90 1 4.6 181 5 14.1 349 84 68 0.14 10 232 47 D 1 

222 1976 6 1 3 56 5.880 17.823 -66.817 2.4 1.2D 5.3 8 0 1.7 98 1 53.9 278 89 68 0.17 8 229 48 D 1 ....... 

CXl 223 1976 6 1 11 44 17. 650 17.819 -66.814 1. 7 1. 6D 1. 5 280 0 3.8 190 1 63.8 10 88 68 0.17 10 230 46 D 1 

224 1976 6 1 15 58 36.270 18.293 -66.863 5.2 1.4D 0.8 57 7 1.2 149 16 2.6 305 72 68 0.12 10 156 32 c 1 

225 1976 6 1 18 5 10.220 17.979 -67.121 13.7 1.1D 4.9 350 5 14.0 258 21 5.3 93 68 68 0.18 6 282 4 7 D 1 

226 1976 6 2 13 16 18.050 18.924 -64.787 10.4 3.1D 17.5 344 0 13.8 254 43 25.8 74 47 68 0.25 10 333 •• D 1 

227 1976 6 3 21 26 19.550 18.910 -67.399 58.8 3.4D 4.3 62 26 43.7 317 27 10.5 188 50 68 0.16 10 309 88 D 1 

228 1976 6 4 7 28 40.270 18.118 -66.144 13.6 1. OD 1. 6 160 32 2.8 45 34 1.3 281 39 68 0.19 10 114 26 c 1 

229 1976 6 4 16 50 16.490E 18.329 -66.141 ..... 1. 4D 3.0 305 0 5.4 35 0 >99. 9 90 90 68 0.31 6 243 40 D 1 * 230 1976 6 4 20 27 39.250 18.127 -66.488 15.4 0. 7D 14.9 194 18 4.0 89 39 63.8 303 45 68 0.13 5 151 36 D 1 

231 1976 6 4 21 19 30.480 18.131 -67.062 28.2 o. 8D 4.7 2 22 3.8 107 32 14.0 244 49 68 0.24 8 141 32 D 1 

232 "1976 6 5 8 14 29.490 18.972 -66.196 41.4 1. 8D 2.0 289 4 11.9 20 5 16.7 160 83 68 0.11 9 286 95 D 1 

233 1976 6 5 15 2 58.660 18.281 -6 7. 284 32.1 1. OD 3.4 153 23 11.9 261 37 4.6 38 44 68 0.16 8 264 3 7 D 1 

234 1976 6 5 18 7 22.100 17.873 -66.217 0.3 1. 7D 1.4 258 2 3.5 168 3 9.9 22 86 68 0.19 10 219 47 D 1 

235 1976 6 6 5 27 47.230 18.121 -66.996 23.3 1. OD 4.7 181 5 2.4 89 19 7.4 285 70 68 0.18 7 135 34 c 1 

236 1976 6 6 15 7 45.810 18.254 -67.608 10.9 2. 6D >99. 9 93 7 26.2 2 8 18.2 223 79 68 0.11 5 314 61 D 1 

237 1976 6 6 18 9 23.600 18.183 -67.205 27.4 O. 7D 23.3 82 4 8.9 351 7 10.1 201 81 68 0.08 5 233 28 D 1 

238 1976 6 8 17 27 25.020 18.423 -65.413 4.6 2.5D >99.9 245 14 43.6 150 19 23.1 10 66 68 0.02 5 332 85 D 1 

239 1976 6 8 20 27 42.720 18.253 -67.404 12.2 O. 8D 11.0 172 8 30.7 79 21 16.3 281 67 68 0.07 5 290 43 D 1 

240 1976 6 9 8 57 0.610 19.020 -65.535 8.2 2.4D 4.6 306 9 3.0 211 30 23.0 51 58 68 0.18 10 311 •• D 1 

241 1976 6 9 11 15 14.080 U:j. ~00 -nfi.004 20.Q 2.0n 7.t; 12~ a >aa.a 32 2CJ 18.8 ~33 5q 58 o.13 4 255 54 D 

242 1976 6 10 8 7 34.650 18.224 -66.068 83.4 1. 5D 12.6 344 15 4.2 82 26 5.6 228 59 68 0.14 7 194 26 n 1 

243 1976 6 10 20 10 52.440E 18.404 -66.407 0.9 1.4D 3.7 271 0 10.5 1 1 >99.9 181 88 68 0.10 5 204 48 D 1 * 244 1976 6 11 1 58 26.920 18.152 -66.514 12.6 2.4D >99.9 100 9 7.3 8 11 6~8 228 75 68 0.34 5 274 61 D 1 

245 1976 6 13 20 10 54.380 19.040 -67.851 0.3 3. 2D 8.9 150 16 2.2 52 26 4.8 268 58 68 0.24 11 295 •• D 1 * 246 1976 6 13 20 28 56.910 18.421 -67.186 17.1 2.2D 20.7 74 30 >99.9 320 36 9.0 192 39 68 0.26 5 284 4 7 D 1 * 247 1976 6 13 21 13 10.150 18.621 -67.235 23.0 2.1D 33.8 144 12 3.9 46 34 11.0 250 53 68 0.17 7 301 70 D 1 * 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * 

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

PRN76 248 1976 6 13 21 14 15.500 1R.389 -67.114 12.7 ... 14.9 17 5 >99.9 284 29 9.5 116 60 68 0.21 5 190 42 D 1 * 

249 1976 6 13 21 58 47.630 18.557 -67.252 56.2 ... 34.5 67 19 >99.9 321 39 >9Q.9 178 44 68 •••• 4 317 82 D 1 * 

250 1976 6 13 22 10 34.610 18.590 -6 7. 317 26.0 2.1D >99.9 308 6 39.3 216 25 22.2 51 64 68 0.02 4 321 69 D 1 * 

251 1976 6 14 3 22 54.110 19.064 -67.786 19.2 ... 23.9 41 2 >99.9 131 12 14.8 302 77 68 0.24 6 329 •• D 1 * 

252 1976 6 14 4 12 21.700 18.174 -67.229 15.8 O. 8D 8.3 90 10 4.2 189 41 1.9 350 47 o8 0.21 7 244 30 D 1 

253 1976 6 14 4 36 17.110 18.954 -67.512 0.2 2.4D 27.8 138 18 3.9 239 31 1.5 22 53 68 0.07 8 320 •• D 1 * 

254 1976 6 14 4 37 11.170 18.897 -67.818 0.1 3. 6D 16.5 149 15 2.7 51 30 5.3 262 55 68 0.24 11 285 •• D 1 * 

255 1976 6 14 5 51 14.250 18.782 -67.745 4.5 3.3D 13.8 152 16 1. 9 53 30 3.8 266 55 68 0.18 11 276 97 D 1 * 

256 1976 6 15 00 27 33.520 18.882 -67.879 16.8 3.61) 50.3 134 10 11.1 41 17 14.1 253 70 68 0.37 10 288 •• D 1 * 

257 1976 6 15 00 34 10.710 18.361 -67.704 73.4 3.6D 19.1 167 21 11.2 63 32 40.9 284 50 68 0.37 10 237 68 D 1 * 

258 1976 6 16 16 15 51.490 18.024 -66.420 19.7 1.1D 1. 3 97 10 s.o 190 12 15.9 329 74 68 0.16 7 189 40 D 1 

259. 1976 6 16 16 35 31.320 18.751 -67.742 18.8 4. 2D 3.2 58 11 17.9 150 12 8.1 287 73 68 0.24 10 275 •• D 1 * 

260 1976 6 17 12 10 56.630 18.885 -67.850 2.6 3.7D 6.4 236 6 23.7 144 17 4.2 344 71 68 0.24 10 286 •• D 1 * 

261 1976 6 19 19 59 3.820 18.463 -67.444 11.2 1. 7D 4.7 187 11 5.5 280 14 2.4 60 72 68 0.19 9 315 63 D 1 * 

262 1976 6 20 1 5 54.390 17.835 -66.818 14.1 0.6D 6.3 252 2 26.5 161 35 67.6 344 54 68 0.07 5 271 45 D 1 

263 1976 6 20 17 43 4.530 18.621 -65.112 8.7 2. 8D 6.1 333 17 3.2 233 30 19.1 89 54 68 0.26 16 329 •• D 1 

264 1976 6 22 8 9 24.480 18.689 -66.415 24.4 1.4D 1. 1 99 12 2.0 3 27 3.3 210 60 68 0.14 10 256 75 c 1 

265 1976 6 23 7 48 23.120 18.153 -66.986 21.2 1. OD 2.4 1 11 1.5 95 19 6.1 243 67 68 0.19 9 132 32 c 1 ...... 

ID 266 1976 6 23 23 37 32.450 17.999 -67.172 18.2 0.6D 8.1 353 21 17.0 96 29 13.8 233 52 68 0.04 5 301 52 D 1 

267 1976 6 25 00 19 16.960 17.958 -66.484 8.7 1. 3D 0.7 275 0 1..5 185 19 3.1 5 71 68 0.19 18 193 39 c 1 

268 1976 6 25 12 9 46.680 18.201 -66.724 128.8 2. OD 10.6 7 2 2.4 275 34 3.9 100 55 68 0.23 14 140 38 D 1 

269 1976 6 25 14 26 31.060 18.803 -67.445 25.6 2.0D 8.3 45 11 10.3 139 16 3.4 283 70 68 0.07 6 331 96 D 1 

270 1976 6 25 15 28 39.760 18.071 -6 7. 080 13.5 1. 6D 8.9 229 7 1.9 134 32 4.1 329 56 68 0.13 6 263 42 D 1 

271 1976 6 26 2 3 19.360 18.113 -66.618 21.1 1. OD 2.4 328 10 0.9 233 27 1.6 77 60 68 0.06 8 133 50 c 1 

272 1976 6 26 5 37 54.010 18.092 -66.921 24.3 1.0D 6.4 98 3 16.8 189 10 35.5 352 79 68 0.04 5 160 25 D 1 

273 1976 6 27 00 48 4.410 18.283 -67.261 30.5 1. on 12.5 283 20 4.1 182 27 8.0 45 55 68 0.22 7 257 36 D 1 

274 1976 6 27 6 45 0.140 18.565 -67.476 17.7 2.4D 69.7 120 8 6.4 28 13 10.4 240 74 68 0.17 7 312 74 n 1 

275 1976 6 28 5 10 31.190 18.761 -67.133 68.6 2.0D 5.9 304 6 4.1 38 38 8.7 207 51 68 0.29 12 300 65 D 1 

276 1976 6 28 10 28 47.620 18.060 -67.115 24.7 O. 7D 7.7 152 27 17.0 263 35 8.0 33 42 68 0.06 5 219 46 D 1 

277 1976 6 28 12 33 32.430 19.014 -67.434 23.8 3. SD 16.1 142 7 4.0 49 29 6.0 244 60 68 0.17 9 319 •• D 1 

278 1976 6 28 22 25 41.040E 18.216 -66.058 0.2 1.0D 0.8 349 0 2.6 259 0 >99.9 270 89 68 0.06 6 272 57 D 1 * 

279 1976 6 29 2 21 2.970 18.447 -65.621 25.7 1.4D 16.9 84 16 11.3 348 19 33.0 211 64 68 0.04 5 321 •• D 1 

280 1976 6 29 5 10 22.240 18.102 -6 7. 721 57.0 2.4D 5.4 266 5 6.6 174 22 10.3 9 67 68 0.24 13 323 73 D 1 

281 1976 6 29 8 47 38.670 17.783 -66.223 0.1 1. RD 1.7 248 3 5.3 157 3 8.9 23 85 68 0.22 10 236 56 D 1 

282 1976 6 30 2 6 0.390 18.029 -66.655 15.9 1.7D 1.3 90 12 2.6 188 34 2.4 344 53 68 0.20 14 178 46 c 1 

283 1976 6 30 3 25 8.610 18.082 -67.045 16.4 1. OD 9.6 358 7 5.7 91 22 42.2 252 66 68 0.19 5 128 38 l) 1 

284 1976 6 30 19 9 27.490 18.441 -66.583 107.4 2. 2D 7.R 190 4 2.1 99 8 4.7 306 81 68 0.20 15 194 44 D 1 

285 1976 6 30 20 15 37.190 18.388 -66.456 10.1 1.1D 1.8 334 2 3.2 243 25 3.5 69 64 68 0.14 8 184 34 D 1 

286 1976 7 1 6 32 32.680 18. 114 -66.861 10.8 0. 8D 1.2 102 1 4.2 193 31 1.9 10 58 68 0.15 8 136 2 7 c 1 2~f? 1975 : 2 15 42 19.::!20 17.79~ -55.731 1~.0 l.lD 1').~ 140 s 5.3 230 41 11.3 43 43 03 0.02 5 294 58 D 1 

288 1976 7 3 4 44 30.620 17. 774 -66.796 6.5 O. 9D 5.2 275 2 8.o u~s 10 >99.9 17 79 68 0.06 5 289 54 D 1 

289 1976 7 3 9 38 8.380 18.101 -66.106 20.9 0.9D 5.8 142 2 14.9 51 25 21.8 236 64 68 0.02 5 175 21 D 1 

290 1976 7 3 15 8 12.460 19.156 -65.375 0.7 3.2D 3.6 320 11 )6.3 57 34 53.9 215 53 68 0.19 10 319 •• D 1 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr roo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(kro) Tr Pl % (s) ob Gap DM 0 auth * ------------------------------------------------------------------------------------------------------------------------------------

PRN76 291 1976 7 4 18 23 23.420 18.907 -67.832 0.7 3. 8D 40.9 152 20 4.3 49 31 8.8 269 51 68 0.35 10 290 oo D 1 

292 1976 7 5 00 22 40o660 l7o737 -66.711 4o0 1o2D 4o7 229 4 l0o9 139 6 >99o9 352 82 68 Oo23 5 302 63 D 1 

293 1976 7 5 6 40 53o390 18o539 -66.340 100o8 1.6D 3.2 73 14 l4o8 168 19 3o7 309 66 68 Oo22 12 262 51 D 1 

294 1976 7 6 2 18 43o230 18o938 -66o075 47o1 2. 3D 6o3 295 7 60.5 28 19 33o6 186 69 68 Oo31 9 288 92 D 1 

295 1976 7 6 2 46 1o950 18.869 -66o093 44o3 2o 3D 5o5 296 8 41o7 30 29 27.7 193 59 68 Oo27 9 283 84 D 1 

296 1976 7 6 3 31 46o020 19.149 -66o016 19o8 2. 7D 3o1 298 13 8.2 204 16 4o6 66 69 68 Oo18 11 300 o• D 1 

297 1976 7 6 6 54 3o550 18.672 -67.126 31.4 1o 6D 5o4 153 27 6.3 46 30 13o5 276 47 68 Oo16 7 328 74 D 1 

298 1976 7 6 16 1 23.400 17o780 -66o712 18o4 1. 3D 2.3 228 13 6.9 133 18 20o0 351 67 68 OolO 6 286 4 7 D 1 

299 1976 7 6 18 29 7.880 17.843 -66.791 19.1 Oo 9D 2o6 243 13 6.2 142 40 15.4 347 47 68 Oo11 6 270 42 n 1 

300 1976 7 6 19 55 57o130 18.321 -66.862 3o3 Oo9D 1.0 101 6 2o0 10 10 3.8 221 78·68 0.15 9 110 2R C 1 

301 1976 7 9 16 7 44.130 18o344 -66.849 19.1 0 • 0 5o8 279 2 22.6 9 8 58o6 175 81 68 OolO 5 251 36 D 1 

302 1976 7 10 4 9 53.250 18.411 -67.520 7o4 1. lD 14.5 212 6 31o4 303 8 >99o9 85 79 68 0.08 4 314 64 D 1 

303 1976 7 10 18 55 24.400 17.776 -66. 755 6o7 1o OD 2.8 249 4 6.2 158 12 53o5 357 77 68 Oo14 6 246 47 D 1 

304 1976 7 10 23 25 38.650 17 0 772 -66.707 15o4 1. 2D 21.9 144 1 8.9 54 2 7o1 260 87 68 Oo05 5 303 60 D 1 

305 1976 7 11 2 51 53.830 17o982 -65.547 OoO lo4D 11o9 101 27 37o8 352 33 16.8 221 44 68 Oo20 5 336 73 D 1 

306 1976 7 11 11 41 33.000 18.642 -67 0 486 17o0 2o7D 4o8 30 14 6o2 295 21 10o1 152 64 68 Ool8 10 315 82 D 1 

307 1976 7 12 6 00 48o570 17.763 -66o 734 12.7 1o 3D 0.4 345 20 Oo2 244 27 Oo2 107 55 68 0.01 6 296 59 c 1 

308 1976 7 12 6 15 26.270 17o784 -66o748 13o2 l.OD 6o5 233 15 26o6 330 25 15.5 114 60 68 Oo04 5 292 56 D 1 N 309 1976 7 13 20 22 21.620 18.301 -66o871 6o9 1. 3D 1.2 93 3 1o7 183 3 4.5 318 85 68 0.20 12 104 28 c 1 0 

310 1976 7 14 9 40 45o240 18o041 -6 7. 068 12o3 0.3D 2.6 15 23 3o1 119 31 8.5 255 49 68 Oo14 6 142 41 c 1 

311 1976 7 14 19 4 47o020 18.383 -66.850 20o8 0 oo 0.9 269 0 3o6 0 32 7o2 178 57 68 Oo05 6 262 40 D 1 

312 1976 7 16 3 30 35.350 18.620 -65o312 Oo6 3o0D >99o9 256 14 37.4 158 28 9o0 10 58 68 0.32 7 334 oo D 1 

313 1976 7 16 21 5 10o250 18.417 -66.764 14o9 1.4D 0.7 303 18 Oo7 196 42 2.8 51 42 68 Oo16 7 129 37 R 1 

314 1976 7 18 8 1 8.910 18o323 -67.287 Oo1 Oo9D Sol 350 0 17o7 260 0 >99o9 270 90 68 0.25 5 271 41 D 1 

315 1976 7 20 22 43 51ol30E 18.054 -65o798 0.2 2o 2D 5o7 160 3 l2o9 70 7 19.5 273 82 68 Oo20 6 326 85 D 1 * 

316 1976 7 21 4 51 48.200 18o000 -67.098 36o7 1o 7D 3o5 18 16 1.9 114 18 5.8 250 65 68 0.21 13 270 44 D 1 

317 1976 7 21 20 12 57o000E 18. 111 -66o485 0.8 2o OD 1. 4 91 1 5o9 181 1 >99.9 316 88 68 Oo16 7 157 36 D 1 * 

318 1976 7 23 17 1 35.810E 18.236 -66.063 Oo6 Oo4D 4o6 144 1 6o9 54 1 >99.9 279 88 68 ooOO 5 204 27 D 1 * 

319 1976 7 23 21 33 20.110 17o963 -66o064 2.6 Oo8D Oo8 274 3 1.9 184 5 14o8 35 84 68 0.06 6 231 37 D 1 

320 1976 7 24 8 29 39.320 18.213 -67o162 27.3 Oo6D 6.0 169 16 13o0 68 35 27o0 279 50 68 0.08 5 212 24 D 1 

321 1976 7 24 13 26 8o030 17.955 -65.906 13.3 1.3D 20.9 17 22 6.7 118 24 3.9 250 56 68 Oo19 6 284 45 D 1 

322 1976 7 27 21 53 53.970 18ol39 -67o463 11.3 2.0D 3.7 291 5 1. 8 23 21 1o4 189 68 68 0.09 8 300 48 D 1 

323 1976 7 27 22 53 7o120 1 7. 62 8 -65.979 16.0 3. 4D 2o 3 243 2 9.7 153 8 15.9 346 81 68 Oo15 10 281 76 D 1 

324 1976 7 28 1 39 31o150 17.638 -65o 949 20o4 1. 8D 2o1 242 11 3.0 149 16 7o2 6 70 68 0.10 9 306 90 D 1 

325 1976 7 29 1 23 40.530 18.828 -65.399 0.1 2.1D 6.2 237 0 4o9 147 10 2.6 326 80 68 0.09 6 332 oo D 1 

326 1976 7 29 6 26 51.220 l8o745 -65.380 0.7 2o0D >99.9 227 17 28.4 126 31 17.5 341 53 68 0.08 4 335 oo D 1 

327 1976 8 1 21 48 16.600 18o 726 -67.747 7o3 3o0D 18.4 323 5 2.7 56 30 8.3 225 59 68 Oo15 7 277 92 D 1 

328 1976 8 1 22 33 59o340 18.513 -67.421 46.2 3.3D 20.8 304 15 6.4 41 23 8.7 184 61 68 0.26 9 307 66 D 1 

329 1976 8 2 5 34 ooOOoo 18o285 -66o042 125.1 1o 7D 14o 1 185 4 10.8 93 31 4o8 281 58 68 0.24 9 286 72 D 1 

330 1976 8 5 00 20 3.100 l8o239 -66.173 70.0 1o 3D 33.3 36 14 12.6 292 42 15.1 141 44 68 0.27 5 129 58 D 1 

331 1976 8 5 2 32 33.340 18.085 -67o096 11.6 0.8D 4.8 176 7 7.4 81 36 18o0 275 53 68 0.11 5 182 37 D 1 

332 1976 8 5 2 32 56.920 18.086 -6 7. 073 9.0 1. 7D 1o5 18 15 1. 7 117 30 4o5 265 55 68 0.22 12 162 37 c 1 

333 1976 8 5 3 4 28.090 18o069 -67.139 17o3 2.1D 2.1 348 16 2o5 92 39 7.5 241 46 68 Oo21 11 222 39 D 1 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr roo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * ------------------------------------------------------------------------------------------------------------------------------------ PRN76 334 1976 8 5 7 26 23.990 18.654 -66.121 71.8 1. 8D 2.6 299 20 5.6 44 36 9.3 186 47 68 0.18 11 266 68 D 1 

335 1976 8 5 22 46 51.490 18.069 -67.100 14.7 0.7D 8.4 163 11 40.4 258 26 4.3 52 61 68 0.02 5 197 44 D 1 

336 1976 8 6 9 15 22.260 18.309 -67.161 15.3 l.lD 7.3 276 16 1.3 175 34 2.1 28 51 68 0.09 6 216 34 D 1 

337 1976 8 6 16 46 24.040 18.424 -66.295 ..... 1.2D 3.0 277 0 10.6 7 0 >99.9 90 90 68 0.14 6 267 42 D 1 

338 1976 8 8 00 41 38.600 18.068 -67.150 17.3 0.6D 26.9 248 23 5.8 350 25 17.9 121 54 68 •••• 5 230 39 D 1 

339 1976 8 8 11 3 0.310 18.066 -67.173 15.3 1.6D 9.0 241 10 3.1 146 22 1.8 353 65 68 0.26 10 244 40 D 1 

340 1976 8 8 22 58 16.040 17.62 7 -65.993 14.4 3.4D 3.3 244 0 14.1 154 1 >99.9 333 88 68 0.18 9 280 75 D 1 

341 1976 8 8 23 2 13.380 17.994 -66.734 14.5 0.8D s.s 254 17 21.9 150 38 16.6 4 46 68 0.02 5 262 42 D 1 

342 1976 8 8 23 21 9.740 18.794 -66.089 50.6 1. 7D 3. 3 285 6 4.3 18 26 37.7 183 63 68 0.20 9 291 87 D 1 

343 1976 8 11 21 29 53.570 18.676 -66.887 15.8 1.5D 2.0 280 0 3.0 10 0 >99.9 90 90 68 0.13 8 310 72 D 1 

344 1976 8 12 7 58 55.510 19.385 -6 7. 242 14.5 3.8D 3.9 60 9 46.4 157 39 18.1 320 49 68 0.15 10 315 •• D 1 

345 1976 8 12 8 46 17.530 19.288 -67.196 10.5 2.SD 2.7 195 23 4.5 92 26 28.7 320 53 68 0.15 10 312 •• D 1 

346 1976 8 12 18 50 10.990 18.299 -66.853 3.3 ... 1.4 357 13 0.8 91 16 3.9 230 69 68 0.08 7 153 32 c 1 

347 1976 8 13 20 15 17.770 18.213 -66.177 8.2 1. 2D 4. 7 178 11 26.1 272 20 19.1 60 66 68 0.07 5 209 34 D 1 

348 1976 8 13 21 48 39.940 18.526 -65.851 24.0 2.7D 14.2 98 32 20.6 211 32 4.6 335 41 68 0.25 8 309 93 D 1 

349 1976 8 14 4 22 53.120 17.987 -67.009 13.0 1. lD 3. 1 346 11 2.4 82 28 8.2 237 59 68 0.11 6 207 35 D 1 

350 1976 8 14 13 21 54.560 17.653 -65.976 18.5 1. 3D 4.7 135 2 2. 2 225 3 42.2 11 86 68 0.18 9 292 73 D 1 

N 351 1976 8 15 8 36 6.510 19.075 -66.590 44.5 ... 28.0 3 0 2.9 93 3 12.6 273 87 68 0.10 7 295 98 D 1 

352 1976 8 15 13 8 45.460 18.043 -66.807 13.2 2. 3D 0.6 83 19 1.1 191 42 1.6 335 41 68 0.09 10 179 30 c 1 

353 1976 8 15 15 19 12.110 19.135 -66.510 37.1 2.4D 6.3 295 3 9.4 25 10 37.7 189 79 68 0.28 10 300 •• D 1 

354 1976 8 16 4 15 49.760 18.568 -66.750 18.3 2.SD 1.3 86 6 2.8 177 11 3.2 328 77 68 0.14 12 230 47 D 1 

355 1976 8 16 4 58 33.490 18.913 -66.441 70.8 1. 9D 7.2 261 2 9.8 353 42 75.6 168 47 68 0.23 6 297 98 D 1 

356 1976 8 16 11 29 15.270 18.098 -65.750 8.4 1. 8D 6.5 117 15 8.4 214 25 4.1 359 60 68 0.24 8 313 48 D 1 

357 1976 8 16 12 3 17.840 17.832 -67.169 6.5 1. 2D 7.2 178 4 22.3 268 7 49.2 58 81 68 0.07 5 309 57 D 1 

358 1976 8 17 18 15 52.100 17.979 -67.070 16.2 0.7D s.s 141 7 5.8 45 42 15.5 238 47 68 0.22 6 249 42 D 1 

359 1976 8 18 00 25 2.730 17.396 -67.780 0.6 0.8D 40.2 so 18 4.4 311 24 3.5 173 59 68 0.05 6 322 <1 D 1 

360 1976 8 18 19 17 11.420 18.309 -66.926 17.0 1. 2D 3. 2 176 5 1.8 85 10 16.3 292 78 68.0.15 7 148 38 c 1 

361 1976 8 21 18 33 16.540 18.569 -66.905 19.6 2.1D 1.7 86 8 4.4 182 39 5.9 347 49 68 0.18 11 239 47 D 1 

362 1976 8 21 23 21 18.780 18.257 -66.305 19.2 2.1D 2.5 190 5 1. 0 280 8 4.5 68 80 68 0.20 14 141 32 c 1 * 

363 1976 8 21 23 51 11.250 18.280 -66.307 20.2 0.9D 1.3 269 2 3.2 359 5 4.6 157 84 68 0.19 10 197 32 D 1 * 

364 1976 8 22 2 16 27.580 18.243 -66.302 19.1 0. 8D 5.3 352 0 2.9 262 12 7.6 82 78 68 0.28 9 175 32 D 1 * 

365 1976 8 22 4 57 9.280 18.283 -66.295 64.1 1.4D 9. 7 189 3 2.6 280 16 4.9 88 73 68 0.24 11 168 34 D 1 

366 1976 8 22 5 55 43.210 19.007 -65.231 16.0 2. 7D 46.3 312 0 >99.9 42 0 >99.9 90 90 68 0.12 4 343 •• D 1 

367 1976 8 22 11 46 40.660 19.019 -65.577 26.5 3. 3D 2.5 307 0 20.9 37 0 >99.9 90 90 68 0.08 9 311 •• D 1 

368 1976 8 22 13 26 8.410 17.460 -67.340 7.9 2.1D 11.9 26 20 5.9 131 35 7.2 273 48 68 0.35 10 255 88 D 1 

369 1976 8 22 21 17 5.370 18.362 -65.835 16.8 2. 4D 49.6 47 27 4.2 295 37 5.4 164 41 68 0.20 7 292 37 D 1 

370 1976 8 23 16 18 23.840 18.033 -66.188 0.4 0.4D 3.9 280 0 9.8 10 0 >99.9 90 90 68 0.11 5 202 45 D 1 

371 1976 8 23 21 5 11.410 18.240 -67.047 22.3 o. 8D 5.1 157 15 9.6 61 21 28.3 279 63 68 0.02 5 136 26 D 1 

37 'Z 1'P6 8 'Z~ 10 40 11.'Z10 18. 'Z'Z4 -1)1).101 'Z').7 -z.on 1.1 ?.~n 1?. 4.1 1M ~?. 4.fi ?.R ~5 fi8 0.29 12 128 28 C 1 

373 1976 8 26 2 1 29.280 18.235 -66.929 15.1 0. 8D 8.5 22 3 5.2 112 5 19.7 262 84 68 0.26 6 170 30 D 1 

374 1976 8 26 9 13 16.250 18.278 -66.253 53.0 1. 3D 1.9 285 6 5.2 191 31 4.7 25 58 68 0.22 10 152 41 D 1 

375 1976 8 27 7 1 8.080 18.091 -66.236 15.5 o. 7D 1.1 357 4 2.4 266 12 0.6 106 77 68 0.06 7 281 34 D 1 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * 

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

PRN76 376 1976 8 27 8 2 50.540 18.456 -65.498 17.8 3. 2D 62.5 242 16 5.3 347 41 10.7 135 44 68 0.23 9 314 72 D 1 

377 1976 8 27 10 34 4.310 18.505 -66.647 15.0 2. 9D 4.3 182 7 1. 4 86 40 2.3 280 49 68 0.18 10 206 50 D 1 

378 1976 8 27 14 4 34.590 18.409 -65.924 5.1 0.4D 5.4 290 6 22.8 198 10 38.6 51 78 68 0.01 5 263 41 D 1 

379 1976 8 28 2 47 58.400 17.816 -66.957 10.1 1.1D 3.0 16 16 0.5 116 31 48.2 263 54 68 0.03 6 249 69 D 1 

380 1976 8 28 18 59 41.110 18.157 -66.813 11.4 1. 2D 0.4 85 9 1.2 352 18 o.~ 200 69 68 o.o6 9 143 34 c 1 

381 1976 8 29 1 22 43.110 18.554 -65.639 36.5 1. 5D 22.7 318 9 63.5 224 25 28.0 67 63 68 0.11 5 325 64 D 1 

382 1976 8 30 1 00 11.640 17.957 -65.444 0.5 1. 8D 3.2 86 16 6.5 341 42 3.9 191 43 68 0.07 6 329 77 D 1 

383 1976 8 30 9 15 22.130 18.020 -65.609 14.6 1.on 8.8 195 7 16.6 288 26 7.3 91 62 68 0.08 5 314 65 D 1 

384 1976 9 1 17 18 27.070 18.308 -66.854 1.7 o.8n 3.6 87 1 15.7 357 1 >99.9 221 88 68 0.06 5 227 33 D 1 

385 1976 9 1 22 47 49.120 17.864 -66.130 7.1 1. 2D 1.2 266 3 2.8 175 11 12.0 12 78 68 0.13 9 240 47 D 1 

386 1976 9 2 11 48 21. 250 17.914 -66.264 ..... 1. 7D 0.9 264 0 3.0 354 0 >99.9 90 89 68 0.17 11 207 43 D 1 

387 1976 9 3 7 56 42.690 18.148 -67.368 16.1 ... 12.7 214 4 16.1 304 4 >99.9 78 84 68 0 .• 10 5 285 41 D 1 

388 1976 9 3 10 8 28.070 18.922 -67.010 21.5 2. 2D 3.1 69 25 43.4 175 31 9.7 308 48 68 0.15 8 297 94 D 1 

389 1976 9 5 7 1 49.440 18.320 -67.048 12.'2 1.0D 8.8 236 10 3.2 143 15 23.4 358 71 68 0.01 5 158 48 D 1 

390 1976 9 6 8 44 3 7.190 17.799 -66.163 14.2 1.3D 1.7 132 17 1.2 26 42 0.7 238 43 68 0.10 11 239 54 c 1 

391 1976 9 7 20 57 20.760 17.803 -66.864 10.0 1.1D 4.7 86 4 13.9 177 16 >99.9 343 73 68 0.21 5 278 50 D 1 

392 1976 9 8 22 2 5.040 18.842 -68.093 7.2 2.on 17.1 143 26 53.1 38 28 >99.9 268 50 68 0.10 5 343 •• n 1 

N 393 1976 9 10 3 22 38.600 18.347 -66.195 19.7 O. 9D 1.3 206 15 2.6 302 23 1. 0 85 62 68 0.03 6 287 35 D 1 N 394 1976 9 12 2 48 13.610 17.961 -67.109 14.7 1.3D 2.8 208 13 1.5 304 24 0.5 91 62 68 0.04 6 283 51 D 1 

395 1976 9 13 23 30 35.350 18.027 -66.562 13.6 1. 7D 1.7 0 16 1.0 256 42 0.9 107 43 68 0.11 10 179 45 c 1 

396 1976 9 14 00 41 59.820 18.609 -66.111 77.5 1. 7D 11.8 173 22 3.1 276 28 4.9 50 52 68 0.20 10 265 55 D 1 

397 1976 9 14 6 15 10.730 19.243 -65.700 0.7 3. 2D 29.9 214 13 5.1 115 34 2.0 321 52 68 0.11 9 311 •• D 1 

398 1976 9 14 22 57 43.080 17.925 -67.011 13.9 o.m 10.4 14 14 5.2 110 22 19.3 255 63 68 0.01 5 251 38 D 1 

399 1976 9 15 2 39 44.370 17.953 -66.981 9.4 1. 2D 2.5 359 14 0.8 93 15 3.7 228 69 68 0.11 9 228 34 D 1 

400 1976 9 15 12 31 32.470 18.480 -65.989 121.7 1. 9D 16.8 175 20 5.3 281 37 13.0 62 46 68 0.28 11 240 44 D 1 

401 1976 9 15 14 49 31.520 18.104 -67.200 19.3 1.0D 3.7 32 2 4.2 124 45 7.7 301 44 68 0.11 6 283 55 D 1 

402 1976 9 17 20 6 11.640 18.098 -66.479 1. 6 1.3D 1.0 91 1 2.8 181 4 36.5 347 85 68 0.20 10 162 35 c 1 

403 1976 9 17 20 40 18.860 18.072 -66.588 8.2 0.7D 4.7 219 4 9.4 127 25 22.8 317 64 68 0.15 5 177 47 D 1 

404 1976 9 17 21 40 44.340 18.132 -66.472 14.3 0.4D 3.8 88 15 10.7 186 28 27.7 333 57 68 0.10 5 156 34 D 1 

405 1976 9 18 3 51 32.930 19.150 -65.790 19.8 1.8D >99.9 201 10 22.5 104 36 15.0 304 52 68 0.25 6 327 •• D 1 

406 1976 9 18 12 16 56.400 18.171 -66.844 10.0 o.sn 2.4 269 1 9.0 179 41 4.9 1 48 68 0.26 7 170 27 D 1 

407 1976 9 18 14 30 16.490 17.831 -66.786 7.0 1. 6D 1. 3 100 13 2.5 201 40 4.6 356 47 68 0.18 11 225 43 D 1 

408 1976 9 21 15 36 35.460 18.058 -66.940 23.2 O. 9D 1.4 96 11 2.9 0 27 7.4 206 60 68 0.07 6 161 27 c 1 

409 1976 9 22 2 39 36.290 18.126 -66.524 54.5 1. 3D 3.1 84 4 8.9 175 19 5.7 343 70 68 0.23 10 179 43 D 1 

410 1976 9 22 13 46 51.810 17. 377 -66.843 42.6 ... 4.5 105 12 23.9 200 21 62.5 348 65 68 0.10 6 286 •• D 1 

411 1976 9 23 3 44 16.550 18.122 -67.015 8.7 1.4D 3.7 356 3 1. 6 88 38 6.6 263 51 68 0.32 12 110 34 c 1 ~12 19~~ 9 23 7 4S 24.010 18.84 7 -66.245 25.3 1. 6D 22.5 184 5 5.4 278 37 10.0 87 52 68 0.15 6 298 82 D 1 

413 1976 9 24 1 40 22.670 18.117 -67.067 ..... 1.4D 1.8 26 1 2.0 116 3 8.4 278 86 68 0.18 8 153 34 c 1 

414 1976 9 26 5 25 24.200 18.757 -66.543 52.9 1. 9D 1.9 267 1 2.7 358 33 10.7 175 56 68 0.22 15 263 66 D 1 

415 1976 9 26 14 42 7.290 18.237 -67.066 15.1 0.4D 25.3 308 22 16.6 206 27 3.4 72 53 68 0.29 6 259 45 D 1 

416 1976 9 26 22 41 36.790 18.269 -66.264 65.4 2.0D 2.5 280 13 6.4 185 19 4.2 43 66 68 0.22 11 146 36 D 1 

417 1976 9 27 5 57 59.200 19.268 -66.087 10.0 ... 18.3 281 5 90.9 15 39 >99.9 185 50 68 0.12 5 323 •• D 1 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * ------------------------------------------------------------------------------------------------------------------------------------

PRN76 418 1976 9 27 7 12 32.310 19.145 -66.638 31.0 2.3D 3.6 85 1 5.6 355 8 58.6 182 81 68 0.23 11 295 •• D 1 

419 1976 9 30 20 5 31.720 18.105 -66.485 1. 1 1. 4D 1.4 91 1 4.4 181 2 72.4 335 87 68 0.27 10 159 35 c 1 

420 1976 9 30 22 7 48.050 18.092 -66.455 0.3 o. 8D 1.6 273 0 4.6 183 1 >99.9 3 88 68 0.26 9 165 32 c 1 

421 1976 10 1 9 6 5.270 18.885 -65.709 16.3 2. 2D 26.2 206 24 1.6 310 28 6.6 81 51 68 0.06 7 311 96 D 1 

422 1976 10 2 1 45 2.490 17.885 -65.550 31.5 l.lD 49.7 195 18 16.0 98 21 33.5 322 61 68 0.39 6 327 68 D 1 

423 1976 10 3 3 46 23.470 19.094 -66.103 18.3 3.0D 1.8 283 11 15.5 189 18 5.4 43 68 68 0.10 9 299 97 D 1 

424 1976 10 3 10 4 8.240 18.141 -66.047 33.0 1. 2D 1.6 263 1 1. 9 353 6 3.0 163 83 68 0.10 8 124 20 B 1 

425 1976 10 4 22 55 11.680 17.773 -66.732 0.7 ... 6.3 238 0 22.8 148 1 >99.9 327 88 68 0.05 5 286 58 D 1 

426 1·976 10 5 4 40 12.910 18.928 -66.426 22.9 1. 8D 5.3 31 6 2.6 298 22 9.1 136 67 68 0.20 9 279 95 D 1 

427 1976 10 6 8 19 44.550 17.894 -65.986 9.7 1. OD 0.6 103 2 1. 0 193 8 2.1 0 81 68 0.02 6 299 4 7 c 1 

428 1976 10 6 8 21 7.790 17.881 -65.984 10.6 0. 3D 0.6 264 9 1.0 167 35 2.5 7 53 68 0.02 6 303 49 c 1 

429 1976 10 7 6 4 3.880 18.22 7 -67.161 16.1 3.3D 7.3 267 24 3.0 14 32 3.2 147 47 68 0.33 12 211 22 D 1 

430 1976 10 7 6 12 54.760 18.249 -67.221 28.4 l.lD 2.8 176 8 8.5 267 8 7.3 41 78 68 0.24 8 239 30 D 1 

431 1976 10 7 6 27 46.630 18.237 -67.165 22.0 1.5D . 0.9 170 7 2.9 265 37 2.0 70 52 68 0.10 10 214 27 D 1 

432 1976 10 7 23 16 35.850 18.227 -67.179 22.0 2. 5D 1.2 85 5 1.6 353 32 1.5 182 57 68 0.14 12 121 22 B 

433 1976 10 8 19 31 34.370 18.65 7 -66.902 18.6 1. 7D 9.1 349 1 4.5 79 5 54.6 248 84 68 0.32 8 250 70 D 

434 1976 10 8 22 18 43.220 17.892 -65.983 11.5 0. SD 6.7 268 16 12.1 167 34 43.2 20 51 68 0.03 5 300 48 D 

435 1976 10 9 3 7 48.300 17.882 -65.989 9.2 0.4D 5.6 262 8 11.3 168 28 32.8 7 60 68 •••• 5 302 49 D N 436 1976 10 9 21 27 38.070 18.983 -65.426 8.9 2.3D 15.3 313 16 7. 1 213 30 73.0 68 55 68 0.17 6 321 •• D 1 (.;..) 

437 1976 10 10 4 18 9.340 17.878 -65.988 9.6 0.2D 0.6 264 8 1. 2 169 31 3.2 7 57 68 0.03 6 303 49 c 1 

438 1976 10 10 12 45 4.040 18.227 -67.174 21.2 3.0D 2.0 170 4 1.7 79 15 2.7 274 74 68 0.21 14 120 22 c 1 * 

439 1976 10 11 23 38 26.070 18.233 -67.181 20.9 2.5D 1.7 6 24 3.9 258 36 1.5 123 44 68 0.21 18 221 22 D 1 

440 1976 10 12 4 46 30.710 18.584 -67.441 12.4 2. 9D 4.8 136 8 2.3 44 13 1.4 256 74 68 0.10 11 311 74 D 1 

441 1976 10 12 8 7 56.760 17.442 -66.169 11.7 2. 9D 2.1 255 1 10.3 165 2 46.6 12 87 68 0.13 10 281 87 D 1 

442 1976 10 13 16 13 48.240 18.544 -67.084 7.9 1.5D 25.1 305 16 1 o. 3 47 35 30.7 195 so 68 •••• 5 297 59 D 1 

443 1976 10 14 9 36 45.000 18.490 -66.724 121.3 2.0D 2.0 264 0 9.6 174 18 2.9 353 72 68 0.20 15 235 52 D 1 

444 1976 10 14 10 51 3.340 17.940 -66.997 9.7 0.8D 3.5 5 2 1.0 95 11 4.7 265 78 68 0.07 6 239 36 D 1 

445 1976 10 14 13 23 30.150 18.280 -65.815 12.0 2.4D 3.7 159 2 11.0 69 17 2.4 255 72 68 0.16 7 263 36 n 1 

446 1976 10 15 9 48 4 7.180 18.812 -64.917 10.0 2.5D 43.3 336 23 15.3 229 34 >99.9 93 46 68 0.25 5 345 •• D 1 

447 1976 10 15 15 54 38.920E 18.454 -6 7. 118 0.1 1. lD 10.8 34 1 15.2 304 1 >99.9 169 88 68 0.34 531749D 1 * 

448 1976 10 15 16 45 15.980 17.970 -67.127 15.4 1. 3D 1.2 326 8 2.6 234 13 0.7 87 74 68 0.10 9 284 48 D 1 

449 1976 10 16 00 41 9.580 18.008 -65.392 9.7 1.5D 20.6 346 5 10.6 77 8 8.1 225 80 68 0.01 5 330 81 D 1 

450 1976 10 16 18 24 58.640 18.508 -66.278 82.1 2.0D 2.6 277 5 8. 2 182 40 5.4 13 49 68 0.17 10 214 48 D 1 

451 1976 10 17 19 2 41.840 17.757 -66.734 10.3 0.6D 5.6 232 9 21.6 140 10 73.4 4 76 68 0.08 5 297 49 D 1 

452 1976 10 18 23 30 21.790 17.954 -66.776 15.9 0. 7D 15.4 176 '3 5.2 267 16 43.9 75 73 68 0.05 5 240 41 D 1 

453 1976 10 19 1 41 18.240 18.618 -67.507 10.6 1.8D 6.6 52 7 10.9 145 27 3.4 309 62 68 0.24 9 315 81 D 1 

454 1976 10 19 14 53 5.510 18.329 -65.895 36.3 1. 6D 2.7 274 15 7.1 12 30 4.8 160 55 68 0.16 8 229 32 D 1 

455 1976 10 19 20 9 26.650E 18.325 -66.144 ..... 1. OD 1.7 246 0 3.6 336 0 >99.9 90 89 68 0.24 7 211 29 D 1 * 

456 1976 10 20 2 46 11.320 18.777 -66.729 27.4 1. 5D 2.4 247 0 9.8 337 0 >99.9 90 89 68 0.14 6 270 81 D 1 

457 1976 10 21 17 26 28.490 18.230 -67.035 25.3 l.DD 5.5 359 3 >'}').') ~57 15 29.9 115 72 5g o.os s ?.1'~ ~ '5 n 1 

458 1976 10 23 2 57 50.530 17.989 -65.381 8.6 1.4D 17.2 216 4 33.3 307 16 9.9 112 73 68 0.02 5 331 83 D 1 

459 1976 10 23 4 52 6. 700 18.000 -65.404 6.7 1.4D 6.9 57 16 10.3 159 37 12.7 308 48 68 0.15 6 330 80 D 1 

460 1976 10 24 2 00 38.970 17.785 -66.782 3.3 1.4D 5.3 253 2 3.6 162 20 9.1 348 69 68 0.24 8 262 54 D 1 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr rna d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(krn) Tr Pl % (s) ob Gap DM Q auth * ------------------------------------------------------------------------------------------------------------------------------------

PRN76 461 1976 10 26 4 38 47.250 18.987 -66.247 19.6 2.5D 1.328017 3.2 181 26 4.1 40 58 68 0.12 13 277 97 D 

462 1976 10 27 51311.110 18.603 -66.375 104.2 1. 8D 3.7 280 12 15.3 183 31 5.4 29 56 68 0.24 11 226 59 D 

463 1976 10 27 5 17 13.240 17.846 -65.571 0.4 1.2D 3.2 27 0 1.5 117 1 >99.9 297 89 68 o.os 6 327 68 D 

464 1976 10 27 21 24 5.600 18.580 -66.390 90.5 2.1D 2.4 271 1 10.0 180 21 4.6 4 68 68 0.21 12 222 58 D 1 

465 1976 10 27 22 27 5.650 18.391 -66.451 103.6 LSD 2.2 272 4 8.4 179 33 5.8 9 56 68 0.16 11 186 44 D 1 

466 1976 10 29 3 8 49.410 17.980 -66.452 15.8 0.9D 2.9 8 0 0.9 98 1 >99.9 278 89 68 0.12 9 206 35 D 1 

467 1976 10 29 5 53 38.400 17.999 -66.459 21.8 ... 5.4 92 12 19.5 186 14 44.3 324 71 68 0.02 5 216 35 D 1 

468 1976 10 29 16 29 55.940 19.358 -67.238 0.2 3.4D 14.1 148 9 4.4 53 31 6.6 252 57 68 0.22 12 314 •• D 1 

469 1976 10 30 6 20 33.590 18.514 -65.405 12.4 2.0D 8.2 156 3 48.9 246 12 4.3 52 77 68 0.22 9 319 83 D 1 

470 1976 10 30 11 17 53.040 18.692 -66.487 59.2 LSD 3.2 278 5 5.6 11 31 9.2 179 58 68 0.20 10 238 58 D 1· 

471 1976 10 30 21 36 43.420 18.188 -6 7.113 14.0 L4D 0.9 345 3 2.1 77 38 3.3 252 51 68 0.05 6 188 26 c 1 

472 1976 10 31 13 30 33.850 17.991 -67.020 14.4 0. 8D 2.5 87 18 13.6 184 20 8.1 319 62 68 0.03 5 206 36 D 1 

473 1976 10 31 22 10 20.800 18.155 -67.330 11.0 2.0D 7.4 140 1 4.6 230 9 2.8 43 80 68 0.25 9 321 69 D 1 

474 1976 11 2 12 12 13.770 19.074 -66.530 10.5 2.1D 4.711918 6.7 218 24 62.1 357 59 68 0.26 8 290 •• D 1 

475 1976 11 2 15 16 10.470 18.605 -66. 948 13.6 o. 8D 5.5 185 2 1.3 93 45 4.8 276 44 68 0.10 7 282 61 D 1 

4 76 1976 11 3 00 47 45.030 18.222 -66.438 69.0 1. 2D 10.6 180 11 3.3 272 13 6.4 50 72 68 0.24 10 149 32 D 1 

477 1976 11 3 7 17 59.070 18.131 -67.607 37.1 2.0D 4.2 167 10 41.9 261 21 6.9 53 66 68 0.13 9 315 61 D 1 

N 478 1976 11 3 10 12 57.880 17.986 -65.413 15.5 1. 3D 19.4 211 6 19.8 305 33 >99.9 111 56 68 0.20 5 330 86 D 1 .p.. 479 1976 11 3 19 32 14.400 18.711 -65.760 27.2 2. 5D 4.0 14 18 5.9 116 34 1.7 261 50 68 0.15 11 311 76 D 1 

480 1976 11 3 23 36 49.640 18.056 -66.218 10.5 0.9D 1. 2 272 1 1.8 181 8 4.5 10 81 68 0.18 11 177 32 c 1 

481 1976 11 6 11 41 58.250 18.334 -65.950 7.6 1. 8D 18.0 5 10 4.9 270 28 11.9 113 60 68 0.13 5 211 32 D 1 

482 1976 11 6 19 36 54.000 18.127 -66.041 23.3 O. 7D 0.6 313 13 1.2 51 34 2.5 206 53 68 0.03 6 135 22 c 1 

483 1976 11 8 12 28 13.310 18.545 -6 7. 542 17.5 2.0D 3.8 217 3 s.o 307 3 58.8 81 85 68 0.14 8 326 76 D 1 

484 1976 11 9 15 50 57.430 18.807 -66.080 48.8 2.1D 4.2 287 10 8.8 20 17 24.4 167 70 68 0.31 10 270 87 D 1 

485 1976 11 9 21 20 41.970 17.972 -66.590 10.7 0. 7D 3.3 219 18 14.2 325 40 6.4 110 44 68 0.15 6 275 53 D 1 

486 1976 11 10 5 7 3.840 17.779 -66. 771 8.7 1.2D 1.5 258 3 2.9 167 13 17.8 1 76 68 0.08 6 290 55 D 1 

487 1976 11 11 00 20 56.030 18.198 -67.218 13.7 0.4D 8.4 80 5 3.1 349 18 3.8 185 71 68 0.17 6 238 27 D 1 

488 1976 11 11 7 9 50.950 17.786 -65.829 16.2 1.2D 21.6 274 0 35.8 4 1 >99.9 184 89 68 0.09 5 321 58 D 1 

489 1976 11 12 20 11 26.340 18.318 -66.139 o.o 1. 8D 0.6 260 0 1.5 350 0 >99.9 90 90 68 0.15 8 176 39 c 1 

490 1976 11 13 3 43 12.520 17. 780 -66.747 9.9 1.1D 11.4 249 5 26.2 157 19 >99.9 353 70 68 0.07 5 292 57 D 1 

491 1976 11 13 23 8 48.260 19.017 -65.899 21.6 2.2D 3.3 315 18 7.4 208 41 5.4 63 43 68 0.20 9 295 •• D 1 

492 1976 11 14 8 57 15.340 17.815 -66.783 16.2 0.6D 5.9 252 3 17.0 162 4 >99.9 19 85 68 0.08 5 282 51 D 1 

493 1976 11 14 9 6 24.710 18.781 -66.230 21.6 1. 8D 2.5 281 5 4.0 1111 35.8 166 77 68 0.10 7 293 75 D 1 

494 1976 11 14 12 12 55.570 18.463 -65.479 85.9 1. 8D 13.8 186 23 7.1 291 31 5.2 66 49 68 0.24 10 316 74 D 1 

495 1976 11 15 4 9 55.210 19.190 -66.492 29.9 2. 6D 3.6 271 0 8.4 1 3 >99.9 181 87 68 0.27 13 289 •• D 1 

496 1976 11 20 9 17 1.960 18.601 -67.002 24.6 2. 2D 2.4 327 25 1.0 73 31 2.7 206 48 68 0.17 16 255 48 D 1 

497 1976 11 20 14 41 28.650 18.708 -67.398 26.9 2. 3D 7.5 205 13 5.6 109 22 2.8 323 61 68 0.?.4 1n 1n8 84 n 1 

498 1976 11 21 2 45 17.750 18.454 -65.887 20.3 2.5D 48.4 30 17 7.1 288 34 22.3 143 50 68 0.29 6 285 46 D 1 

499 1976 11 22 10 40 41.030 18.655 -65.769 49.4 3.1D 3.7 295 25 26.8 41 30 11.3 172 48 68 0.19 10 293 70 D 1 

500 1976 11 22 22 55 19.780 18.313 -67.076 27.2 0.8D 1.5 163 14 1. 8 64 31 3.2 274 55 68 0.15 10 158 34 c 1 

501 1976 11 23 1 29 0.960 18.635 -66.45 7 88.2 1. 6D 1. 8 65 22 12.5 169 30 3.1 305 51 68 0.18 12 256 66 D 1 

502 1976 11 24 14 9 57.530 17.623 -65.979 26.4 1. 7D 9.9 134 10 4.8 231 31 5.6 28 56 68 0.21 7 305 77 D 1 

503 1976 11 24 20 27 30.680 18.592 -66.448 14.1 1. 5D 25.6 341 2 6.0 249 42 >99.9 74 47 68 0.16 4 294 64 D 1 
Table 5.--Cata~og of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ~----------- Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * 

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

PRN76 504 1976 11 26 6 43 6.260 17.737 -66.947 40.7 1. 2D 0.4 98 12 2.3 359 34 0.6 204 53 68 0.01 6 272 51 c 1 

505 1976 11 26 12 46 30.440 18.123 -68.008 114.7 3.1D 15.9 338 24 4.6 82 30 14.8 216 so 68 0.21 9 328 98 n 1 

506 1976 11 26 15 42 27.370E 18.284 -66.131 0.2 1. SD 1. 0 87 1 4. 8 177 8 87.8 350 81 68 0.13 7 163 so c 1 * 

507 1976 11 26 16 59 8.150 18.312 -67.243 18.7 1.1D 3.2 282 13 1.3 188 17 5.1 48 68 68 0.08 7 256 3 7 D 1 

508 1976 11 27 16 55 15.020 18.536 -65.327 11.6 3.7D 4.6 339 7 14.7 76 44 79.5 242 45 68 0.19 10 322 92 D 1 

509 1976 11 27 18 35 24.400 17.985 -67.049 6.1 1.7D 1.6 88 19 3.3 348 27 11.8 208 56 68 0.10 6 222 39 D 1 

510 1976 11 27 19 42 7.360 17.789 -66.806 9.1 1. 3D 2.5 239 8 6.1 146 17 31.6 353 71 68 0.19 7 281 48 D 1 

511 1976 11 28 6 8 24.700 17.621 -65.963 23.7 1. 3D 2.8 96 3 2.3 186 14 11.5 355 75 68 0.07 7 333 77 D 1 

512 1976 11 28 17 so 5.610 19.331 -64.558 17.1 3.5D 40.3 322 0 >99.9 232 0 >99.9 270 90 68 0.32 8 336 •• D 1 * 

513 1976 11 29 21 35 21.020 19.060 -65.490 16.6 2. 9D 10.4 7 14 5.8 265 40 20.9 113 46 68 0.32 11 314 •• D 1 * 

514 1976 11 30 3 52 5.580 19.098 -65.589 s.o 3.4D 3.5 309 5 19.1 42 30 49.9 211 59 68 0.15 10 311 •• D 1 * 

515 1976 11 30 4 53 22.790 18.767 -66.532 65.9 2.0D 2.6 84 4 5. 7 351 39 18.0 179 50 68 0.27 12 264 83 D 1 * 

516 1976 11 30 7 7 36.470 18.069 -65.682 20.0 2.4D 6.3 189 10 9.9 284 24 >99.9 78 63 68 0.28 4 360 56 D 1 * 

517 1976 11 30 18 32 24.170 19.065 -66.415 5.7 2.5D 1.8 107 11 2.8 203 30 21.2 0 57 68 0.21 14 290 •• D 1 

518 1976 12 1 11 27 59.130 19.070 -65.586 4.4 2.5D 4.3 26 11 10.0 120 21 2.3 270 66 68 0.14 8 323 •• D 1 * 

519 1976 12 1 22 13 5.990 18.589 -65.613 42.7 1.6D 16.5 309 0 9.8 39 45 23.2 219 45 68 0.26 6 328 69 D 1 * 

520 1976 12 2 20 34 58.510 18.079 -66.472 5.6 l.lD 0.9 94 7 1.8 185 12 19.4 335 76 68 0.11 7 170 34 c 1 

N 521 1976 12 3 4 3 56.290 17.778 -66.015 12.7 1.1D 14.8 267 24 11. 8 155 40 25.7 20 40 68 0.02 5 319 59 D 1 VI 522 1976 12 3 17 51 21.900 18.337 -66.835 17.5 1.5D 4.2 127 2 8.3 217 4 43.5 10 85 68 0.19 6 225 35 D 1 

52-3 1976 12 4 1 0 57 51 • 3 90 18.388 -66.337 43.4 1. 4D 2.4 78 2 6.1 168 15 4.1 341 74 68 0.24 12 231 36 D 1 

524 1976 12 4 16 1 59.410 18.387 -65.932 6.2 1. 6D 1.7 278 16 5.3 174 41 4.6 25 44 68 0.20 9 251 38 D 1 

525 1976 12 5 7 58 15.610 17. 827 -6 7. 012 15.5 1. 3D 29.7 198 3 12.8 290 39 5.6 104 so 68 0.12 5 284 43 D 1 

526 1976 12 5 11 24 22.050 17.796 -66.923 7.4 0. 9D 4.4 97 4 12.2 188 18 75.3 355 71 68 o.os 5 282 46 D 1 

527 1976 12 6 1 14 23.610 17.806 -67.043 43.0 1. 2D 17.6 199 9 3. 4 104 29 12.5 304 59 68 0.17 7 270 4 7 D 1 

528 1976 12 6 6 11 48.470 18.727 -66.933 63.9 1. 8D 2.8 81 19 6.9 184 34 4.4 327 49 68 0.27 15 263 63 D 1 

529 1976 12 6 7 24 30.050 18.118 -67.016 24.2 0.8D 9.5 158 24 10.2 so 35 25.6 274 45 68 0.10 5 149 36 D 1 

530 1976 12 6 8 4 48.850 18.125 -66.999 19.9 0. 9D 2.9 348 6 1. 9 81 24 10.1 245 65 68 0.18 8 114 34 c 1 

531 1976 12 6 19 1 9 14. 060 18.760 -65.324 27.5 2.4D 6.5 326 0 57.4 236 0 >99.9 270 89 68 0.16 7 319 •• D 1 

532 1976 12 7 9 21 11.260E 18.253 -66.099 3.9 2.3D 1.6 193 3 1.0 283 4 3.0 66 85 68 0.15 10 132 25 B 1 * 

533 1976 12 7 17 54 53.910 18.306 -66.861 2.2 0.9D 1. 0 97 6 2.0 6 15 4.2 208 73 68 0.14 9 154 32 c 1 

534 1976 12 7 21 11 17.720 18.156 -67.137 18.6 0.4D 11.2 46 0 23.5 315 33 7.6 136 56 68 0.04 5 263 49 D 1 

535 1976 12 8 9 39 3.690 18.068 -67.264 15.4 ... 21.6 239 3 10.6 149 8 6.1 349 81 68 0.02 5 307 61 D 1 

536 1976 12 8 17 20 48.270E 18.192 -67.147 0.8 o. 8D 7.3 238 5 18.2 329 7 86.5 112 81 68 0.20 4 301 51 D 1 * 

537 1976 12 8 18 38 29.880 18.357 -66.832 28.2 ... 2. 3 110 1 5.6 200 5 15.2 8 84 68 0.16 7 205 33 D 1 

538 1976 12 8 23 21 41.580 19.217 -67.214 18.1 2. 8D 9.8 162 6 3.5 68 30 6.6 262 59 68 0.20 11 311 •• D 1 

539 1976 12 9 19 22 0.210 17.997 -67.130 19.1 l.OD 3.7 233 21 2.5 131 29 1.5 353 53 68 0.06 6 291 48 D 1 

540 1976 12 11 6 5 39.230 18.139 -66.048 23.6 1.8D 4.3 66 8 6. 2 335 9 21.7 197 77 68 0.06 5 131 27 D 1 

541 1976 12 11 6 41 8.310 18.252 -66.610 4.3 1. 6D 0.7 77 2 1.7 347 12 7.3 177 77 68 0.13 12 156 51 c 1 

542 1976 12 12 1 24 35.830 19.305 -66.298 22.5 2. SD 16.6 277 0 >99.9 7 0 >99.9 90 90 68 0.03 5 304 •• D 1 

543 1976 12 12 6 32 29.970 18.492 -67.100 21.6 1. SD 2.4 45 28 7.3 295 33 13.1 167 44 68 0.15 7 23::> 04 D 1 

544 1976 12 12 6 58 s. 710 17.908 -65.658 21.8 1.3D 10.5 85 17 21.0 186 32 34.6 332 52 68 0.07 5 320 57 D 1 

545 1976 12 13 1 30 49.940 17.986 -66.739 u. 9 2.0D 6.0 343 33 1.2 100 35 1.9 223 37 68 0.19 11 188 37 D 1 

546 1976 12 13 7 28 38.810 18.030 -65.576 12.9 1. 2D 1.1 303 11 1. 0 37 21 0.6 187 66 68 0.03 6 317 61 c 1 
Table 5.--Catalog of 1976 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap nM 0 auth * ------------------------------------------------------------------------------------------------------------------------------------

PRN76 547 1976 12 13 7 30 48.070 18.277 -66.196 4.9 2.6D 0.8 274 13 1.5 8 19 3.1 151 66 68 0.12 10 181 40 c 1 

548 1976 12 13 17 3 21.590 17.895 -66.590 14.1 O. 8D 27.8 116 12 17.7 15 41 4.6 218 46 68 0.05 5 283 54 D 1 

549 1976 12 13 21 00 36.440 18.110 -66.481 12.0 o. 7D 1.2 93 17 4.6 353 29 3.4 209 55 68 0.13 7 158 35 c 1 

550 1976 12 14 3 25 25.590 18.131 -66.056 29.6 O. 9D 1.2 63 11 1.8 330 14 2.8 189 72 68 0.05 6 14 7 28 c 1 

551 1976 12 14 12 27 42.720 18.445 -65.630 22.5 2. 8D 5.1 56 6 2.9 149 23 1.3 313 66 68 0.06 8 315 66 D 1 

552 1976 12 16 8 10 49.310 18.733 -66.267 60.7 3.3D 2.4 270 8 11.9 173 42 14.1 9 46 68 0.12 8 264 70 D 1 

553 1976 12 16 19 19 50.530 18.835 -65.597 11.1 3. 4D 4. 8 311 3 29.9 43 27 82.1 216 62 68 0.11 7 310 94 D 1 

554 1976 12 16 21 10 8.970 19.014 -65.880 8.1 2.5D 3.9 154 3 6.4 63 27 2.9 249 62 68 0.13 8 305 •• D 1 

555 1976 12 17 18 8 39. 820E 18.366 -66.473 1. 1 1.1D 4.0 262 0 13.6 352 1 >99.9 171 89 68 0.08 5 212 41 D 1 * 

556 1976 12 17 22 16 18.340 17.942 -66.904 12.3 0.5D 4.0 89 9 19.5 354 29 31.7 194 59 68 0.31 5 229 32 D 1 

557 1976 12 18 00 12 21.910 18.791 -65.583 13.0 2.4D 2.8 316 5 13.7 49 34 63.6 219 55 68 0.11 8 316 90 D 1 

558 1976 12 18 12 41 13.320 17.888 -66.919 15.6 ... 33.0 186 4 5.2 94 25 7.0 284 64 68 0.15 5 253 37 D 1 

559 1976 12 19 4 27 52.350 18.412 -65.900 11.1 2.1D 17.4 199 1 5.4 290 39 13.9 107 50 68 0.23 6 274 41 D 1 

560 1976 12 20 3 4 4.390 18.194 -67.300 23.1 1.0D 7.1 207 19 10.1 101 38 6.4 317 45 68 0.16 6 322 67 D 1 

561 1976 12 21 20 9 14.700 18.396 -66.019 11.0 1.1D 3.9 269 3 30.0 176 41 14.0 3 48 68 0.04 5 251 41 D 1 

562 1976 12 23 20 4 9.650 18.550 -66.778 18.5 2.1D 0.7 102 2 1. 4 12 4 5.7 218 85 68 0.11 13 218 46 D 1 

563 1976 12 24 11 29 25.280 18.810 -65.540 26.0 2.0D 7.1 292 13 4.1 196 25 13.5 48 61 68 0.21 9 327 94 D 1 

N 564 1976 12 24 20 49 40.370 18.197 -67.530 8.0 1. 4D 5.3 323 9 8.5 230 20 9.4 77 67 68 0.27 7 307 51 D 1 V" 565 1976 12 24 23 23 51.380 18.969 -65.042 16.7 2. 6D 13.7 131 16 3.2 234 38 8.6 22 47 68 0.20 10 340 •• D 1 

566 1976 12 25 9 00 24.870 19.022 -66.908 44.6 2.9D 4.0 76 7 18.9 344 18 13.5 186 70 68 0.18 10 288 95 D 1 

567 1976 12 25 21 1 51.980 18.322 -65.746 18.7 2.0D 24.2 64 16 7.3 162 27 6.1 307 58 68 0.29 9 291 43 D 1 

568 1976 12 26 00 18 38.070 17.819 -66.759 3.1 2.8D 0.8 95 3 2.3 186 9 4.6 347 80 68 0.10 10 226 43 c 1 

569 1976 12 26 4 6 55.580 18.158 -67.254 o.o 1. 2D 3.1 355 1 10.6 264 19 8.4 88 70 68 0.33 10 254 33 D 1 

570 1976 12 26 7 58 18.690 18.353 -67.218 20.7 1. 5D 11.5 291 26 4.6 37 31 3.0 168 47 68 0.29 11 257 41 D 1 

571 1976 12 26 11 25 3.070 18.373 -67.278 19.5 0. 9D 7.0 100 5 2. 8 192 22 4.3 358 67 68 0.25 11 280 45 D 1 

572 1976 12 26 17 37 26.740 18.632 -65.587 14.3 2.1D 3.1 318 2 19.0 50 39 61.6 226 50 68 0.13 7 321 74 D 1 

573 1976 12 27 7 4 7.580 19.127 -66.262 0.7 2.1D 7.0 13 8 5.4 109 39 3.0 274 49 68 0.23 10 296 •• D 1 

574 1976 12 28 00 15 39.900 18.562 -6 7. 233 52.4 1. 6D 2.7 290 21 1. 9 39 40 10.1 179 42 68 0.15 12 295 80 D 1 

575 1976 12 28 1 51 11.090 18.130 -66.095 31.6 o. 8D 11.2 233 7 5.9 325 22 20.5 126 66 68 0.07 5 222 31 D 1 

576 1976 12 29 9 53 48.860 18.155 -66.176 17.6 1.3D 1.7 260 3 2.5 168 30 7.1 355 59 68 0.25 10 144 37 c 1 

577 1976 12 30 00 29 5.930 18.029 -65. 122 57.1 2.0D 25.5 10 1 14.3 100 30 >99.9 279 59 68 0.01 5 339 •• D 1 

578 1976 12 30 2 40 5.140 18.009 -67.215 13.3 1. 3D 11.6 340 1 23.1 250 18 4.8 74 71 68 0.12 5 306 57 D 1 

579 1976 12 30 4 10 41.480 18.154 -66.159 14.3 0.6D 0.8 340 2 1. 0 71 26 2.1 246 63 68 0.08 8 193 29 c 1 

580 1976 12 30 10 8 6.690 17.830 -66.761 4.1 1.6D 1. 6 91 6 4.0 184 23 7.2 348 66 68 0.18 9 224 42 D 1 

581 1976 12 30 11 33 11.200 17.784 -66.729 13.1 1. 3D 18.5 335 9 4.8 241 21 9.7 87 66 68 0.06 s 284 46 n 1 

582 1976 12 30 13 22 27.480 18.82 3 -67.191 26.3 2.0D ll.7 320 16 4. 7 224 21 8.8 AS 63 6R 0.27 9 299 91 D 1 

583 1976 12 30 14 26 52.440 18.367 -65.855 15.6 2.6'0 29.8 44 16 4.3 139 19 1.3 277 64 68 0.12 6 295 37 n 1 

584 1976 12 31 10 4 19.320 17. 790 -66.786 9.4 1.1D 6.2 2.55 2 31.6 165 3 84.5 19 86 68 0.01 5 281 4 7 D 1 

585 1976 12 31 14 1 42.950 18.154 -66.178 17.9 2.0D 1.1 270 1 1.6 0 2 2.2 153 87 68 0.09 8 111 31 B 1 

--------------------------------------------------------------------------------------------------------------------------------
Table 6.--References for catalog of 1976 earthquakes located by the HYPOELLIPSE program 

[Cat, catalog; Auth no., authority number cited in table 5] 

----------------------------------------------------------------------------------------~ 

Cat Auth 

Name no. References 

-----------------------------------------~----------------------------------------------~ 

PRN76 1 u.s. Geological Survey, this report. 

----------------------------------------------------------------------------------------~ 

Table 7.--Remarks for catalog of 1976 earthquakes located by the HYPOELLIPSE program 

Catalog Remarks 

Name Index 

PRN76 51 

70 

100 

109 

117 

118 

134 

166 

175 

176 

177 

178 

185 

186 

187 

229 

243 

245 

246 

247 

248 

249 

250 

251 

253 

254 

255 

256 

257 

259 

260 

261 

278 

315 

317 

318 

434 

435 

436 

Probable blast attributed to road construction or quarries. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

One of a large swarm of earthquakes that occurred between 05/12/76 and 05/16/76 in 

the Puerto Rico Trench, north of the Virgin Islands. 

Do. 

Probable blast attributed to road construction or quarries. 

One of a large swarm of earthquakes that occurred between 05/12/76 and 05/16/76 in 

the Puerto Rico Trench, north of the Virgin Islands. 

Do. 

Do. 

Probable blast attributed to road construction or quarries. 

Do. 

One of several hundred aftershocks that were recorded following a magnitude 4.6 earthquake 

northwest of Puerto Rico in the Puerto Rico Trench. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Probable blast attributed to road construction or quarries. 

Do. 

Do. 

Do. 

One of a small swarm of earthquakes that were located north of the town of Barranquitas in 

northeast Puerto Rico. 

Do. 

Do. 

27 
Table 7.--Remarks for catalog of 1976 earthquakes located by the BYPOELLIPSE program--Continued 

Catalog Remarks 

Name Index 

PRN76 437 One of a small swarm of earthquakes that were located north of the town of B~rranquitas in 

northeast Puerto Rico. 

438 A large earthquake, magnitude 3.0, that was felt at Mayaguez and orginated ir the Mona 

Passage. 

447 Probable blast attributed to road construction or quarries. 

455 Do. 

489 Do. 

506 Do. 

512 One of a swarm of several dozen earthquakes that originated in the Puerto Rico Trench, 

north of the Virgin Islands. 

513 Do. 

514 Do. 

515 An aftershock of a large earthquake that occurred on 11/30/76, north of Puerto Rico in 

the Puerto Rico Trench. 

516 One of a swarm of several dozen earthquakes that originated in the Puerto Rico Trench, 

north of the Virgin Islands. 

518 Do. 

519 Do. 

536 Probable blast attributed to road construction or quarries. 

555 Do. 

28 
Table 8.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program 

[UTC, Coordinated Universal Time; negative latitudes and longitudes are south and west, respectively; M, duration magnitude; 

a, b, and c, principal axes of confidence ellipsoid; Tr, trend of axis in degrees; Pl, plunge of axis in degrees; 

%, confidence level; Rms, root mean square of residuals; No. ob, number of observations used in hypocenter computation; 

Gap, largest azimuthal separation between seismograph stations; DM, distance to third nearest station, in kilometers; 

Q, quality index; Hypo auth, hypocenter authority meaning person or institution responsible for hypocenter determination, 

cited by catalog name and authority number in table 9; *, remarks cited by catalog name and index in table 10; 

leaders ( ••••• ) designate instances when data values are unknown or not computed] 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * 

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

PRN77 1 1977 1 1 7 49 11.940 17.740 -66.770 10.8 1. 3D 1.7 232 8 5.1 140 19 32.1 343 69 68 0.12 6 290 52 D 1 

2 1977 1 1 7 49 48.360 17.765 -66.783 12.3 1. 2D 0.8 240 8 2.9 147 15 8.7 357 72 68 0.09 6 286 50 D 1 

3 1977 1 1 8 43 26.520 18.928 -66.370 42.5 2.0D 1.5 288 6 4.2 19 12 10.4 171 76 68 0.20 15 280 87 D 1 

4 1977 1 1 10 00 20.410 18.631 -65.543 15.4 2. 5D 5.5 323 5 25.9 56 34 >99.9 226 55 68 0.16 8 318 6 D 1 

5 1977 1 1 13 8 40.490 18.902 -67.210 14.1 3.4D 2.3 56 3 18.0 323 42 36.2 150 47 68 0.13 9 302 •• D 1 

6 1977 1 1 13 34 39.680 18.856 -67.247 26.5 2.8D 3.8 235 0 26.7 325 0 >99.9 90 89 68 0.16 9 303 95 D 1 

7 1977 1 2 00 5 51.050 18.853 -66.116 38.4 2.0D 2.2 273 $ 3.8 5 17 16.1 158 71 68 0.20 13 283 82 D 1 

8 1977 1 2 2 14 20.840 17.980 -67.052 4.9 2.1D 3.2 359 19 0.9 101 31 2.1 243 52 68 0.16 11 221 40 n 1 

9 1977 1 2 8 8 48.960 17.970 -66.512 12.1 0.9D 0.6 112 28 1.2 219 29 2.0 347 47 68 0.09 10 208 41 c 1 

10 1977 1 2 8 9 40.180 17 0 95 7 -66.512 11.3 1.1D 0.7 107 8 2.6 9 43 1.3 205 45 68 0.13 12 210 42 D 1 N 11 1977 1 2 11 22 55.270 19.451 -66.735 28.3 2.6D 7.0 292 0 20.5 22 0 >99.9 90 89 68 0.26 6 320 •• D 1 1.0 

12 1977 1 2 17 3 39.110 18.069 -67.168 23.0 0.8D 32.3 252 27 16.6 2 34 11.1 132 43 68 0.04 .5 267 51 D 1 

13 1977 1 2 23 5 10.550 18.240 -66.306 15.2 1. 5D 4.5 357 14 1.5 261 24 2.5 115 61 68 0.27 11 133 31 c 1 

14 1977 1 3 3 31 18. 540E 18.027 -67.082 0.4 1.3D 1. 9 131 8 0.9 40 9 5.1 262 77 68 0.10 7 157 42 c 1 * 

15 1977 1 3 6 3 52.870 19.076 -66.087 48.0 1.9D 3.0 302 16 4.1 37 16 29.5 169 67 68 0.26 12 298 •• D 1 

16 1977 1 3 8 7 16.440 18.387 -65 0 702 16.1 2.1D 42.0 237 2 6.7 327 21 9.0 141 68 68 0.20 7 309 49 D 1 

17 1977 1 3 9 4 43.580 18. 740 -67.205 49.6 1.6D 7.2 59 10 20.0 327 11 21.9 190 75 68 0.35 10 297 82 D 1 

18 1977 1 3 17 11 18.620 17.828 -66.814 12.5 0. 8D 1.6 264 1 7.0 174 21 13.2 356 68 68 0.08 6 273 45 D 1 

19 1977 1 3 22 40 6.440 18.601 -66.990 78.9 0 0 0 3.6 198 17 1.6 92 41 1.9 305 43 68 0.06 8 286 63 D 1 

20 1977 1 4 18 39 31.570 17.870 -65.590 9.7 1. 8J) 5.6 8 10 4.0 272 30 2.6 115 58 68 0.17 8 319 65 D 1 

21 1977 1 5 6 3 54.920 18.654 -66.311 31.1 1. 5D 3.0 78 1 6.1 348 23 15.7 171 66 68 0.24 8 280 61 D 1 

22 1977 1 5 8 51 27.850 17.846 -65.604 10.9 1. 4D 0.6 286 15 0.7 21 1.5 0.4 153 68 68 0.02 6 332 76 c 1 

23 1977 1 5 12 59 45.540 18.573 -66.967 76.9 1. 4D 30.5 311 11 46.0 212 42 11.6 53 46 68 0.22 5 281 64 D 1 

24 1977 1 5 18 33 21.110 18.145 -66.176 16.2 1.5D 1.1 103 7 1.5 195 12 4.4 344 75 68 0.13 9 161 37 c 1 

25 1977 1 6 10 45 29.990 18.239 -67.078 41.5 1. OD 8.4 98 21 18.4 204 36 12.4 345 46 68 0.23 6 288 46 D 1 

26 1977 1 7 21 52 37.300 18.111 -66.006 17.8 1.3D 1. 0 28 6 o. 7 297 11 2.5 147 77 68 0.09 10 140 25 c 1 

27 1977 1 8 1 3 16.140 18.457 -65.994 20.9 3.1D >99.9 256 6 12.4 165 7 12.8 27 80 68 0.20 6 329 85 D 1 

28 1977 1 8 6 8 39.130 18.089 -66.021 17 0 9 0. 7D 2.0 32 7 1. 1 301 9 4.1 160 78 68 0.16 10 163 26 c 1 

29 1977 1 8 11 11 32. 800E 18.105 -66.267 0.3 l.lD 8.2 334 0 11.3 244 0 >99.9 270 90 68 0.27 5 289 48 D 1 * 

30 1977 1 8 17 12 50 0 92 0 17 0 805 -66.928 0.2 1.9D 1.3 94 3 2.8 184 13 7.9 352 76 68 0.20 10 246 45 D 1 

31 1977 1 8 19 53 57.330 18.160 -67.462 2.2 1. 2D 12.6 342 2 8. 1 252 3 >99.9 106 86 68 0.11 5 334 83 D 1 

32 197 7 1 8 22 36 43.660 18.948 -67.212 9.7 2. 8D 38.5 144 11 6.2 48 27 13.4 254 60 68 0.33 10 304 86 D 1 

33 1977 1 9 5 49 24.340 17.789 -66.763 11.3 2.9D 4.6 359 23 1. 3 1;)3 29 2.7 237 51 53 0.15 10 232 ~5 D 1 

34 1977 1 9 23 53 26.560 18.523 -65.512 15.5 2.4D 9.7 324 0 >99.9 234 0 >99.9 270 89 68 0.16 5 327 73 D 1 

35 1977 1 10 7 8 10.090 17.998 -65.576 16.4 1. 2D 1. 9 43 2 2.8 134 2 54.0 269 87 68 0.10 7 319 62 D 1 
Table 8.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * 

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

PRN77 36 197 7 1 10 7 40 27.110 17.780 -66.723 16.1 LID 10.5 255 1 20.2 165 3 >99.9 4 86 68 0.15 5 295 59 D 1 

37 1977 1 10 12 44 58.480 18.152 -66.951 18.7 0. 5D 11.6 196 8 3.5 104 11 18.9 321 76 68 0.27 6 189 30 D 1 

38 1977 1 11 14 12 56.780 18.140 -67.790 62.5 2. 3D 3.3 286 18 6.4 183 36 10.1 38 48 68 0.20 12 326 78 n 1 

39 1977 1 12 6 44 2.260 18.469 -67.461 10.1 1.8D 5.6 161 3 11.6 253 29 2.7 65 60 68 0.28 9 316 64 D 1 

40 1977 1 12 7 11 11.5 70 17.905 -66.986 8.6 1.2D 23.6 18 3 4.1 108 18 20.9 279 71 68 0.01 5 254 36 D 1 

41 1977 1 12 15 30 47.110 18.395 -66.409 6.6 ... 4.7 266 4 17.1 356 9 >99.9 152 80 68 0.15 5 222 47 D 1 

42 1977 1 12 19 32 40.660E 18.346 -66.065 0.1 1.4D 4.1 263 0 13.2 353 0 >99.9 90 90 68 0.19 5 210 27 n 1 * 

43 1977 1 13 18 39 4.200 18.698 -66. 733 79.9 1.6D 1. 0 86 8 4.R 178 15 2.7 329 72 68 0.06 7 243 85 D 1 

44 1977 1 13 19 14 57.150 18.111 -65.755 o.o 2. 6D 2.5 16 1 10.7 286 2 6.1 133 87 68 0.30 9 274 42 D 1 

45 1977 1 13 22 26 9.880 18.514 -66.203 26.3 l.OD u. 8 43 30 51.0 153 31 6.5 279 44 68 0.11 5 258 45 D 1 

46 1977 1 14 4 26 14.110 18.189 -67.253 110.3 1. 8D 3.5 216 18 5.5 322 41 1.8 107 43 68 0.10 11 251 30 D 1 

47 1977 1 14 11 35 39.620 17. 95 6 -66.517 8.1 1. 3D 1. 1 96 13 2. 1 l<H 18 4.2 333 67 68 0.13 8 194 53 c 1 

48 1977 1 15 8 53 56.580 17.961 -66.285 7.0 1. 4D 0.9 261 5 4.5 356 44 2.7 165 45 68 0.24 13 196 40 D 1 

49 1977 1 15 15 36 6.850 18.088 -66.344 52.8 1. 9D 32.3 316 8 16.6 222 29 39.1 60 59 68 0.03 5 327 56 D 1 

50 1977 1 15 15 49 11.660 18.092 -6 7. 205 24.5 LOD 3.5 318 1 5.2 49 37 10.9 227 52 6P 0.14 6 248 38 D 1 

51 1977 1 17 16 00 4.380 18.115 -66.995 24.6 LOD 5.9 197 14 2.9 101 23 10.2 315 62 68 0.18 6 155 34 D 1 

52 1977 1 17 18 55 32.590 17.945 -66.297 1.9 2.1D 0.9 266 1 2.9 176 3 62.5 15 86 68 0.11 8 199 41 n 1 

w 53 1977 1 18 4 19 20.240 18.168 -66.16 7 17.0 1.3D 2.0 353 0 2.2 83 14 2.6 263 76 68 0.26 11 94 30 c 1 0 54 1977 1 18 20 6 58.380 18.222 -67.273 9.5 1.4D 9.3 59 4 23.9 150 9 35.1 306 80 68 0.19 5 313 65 n 1 

55 1977 1 18 21 15 0.850 17.977 -66.266 17.8 o. 8D 4.5 262 12 11.0 163 35 57.7 8 52 68 •••• 5 202 41 D 1 

56 1977 1 18 23 15 45.810 18.103 -66.954 18.8 O. 6D 5.0 99 9 8.0 6 17 38.8 215 70 68 0.04 5 134 29 D 1 

57 1977 1 20 17 45 14.960 18.299 -65.887 11.6 2.2D 7.8 356 4 12.2 89 35 3.2 261 54 68 0.36 8 139 29 D 1 

58 1977 1 20 19 16 36.020 18.304 -66.868 4.9 1. 3D 1.4 85 5 3.6 353 23 5.3 186 66 68 0.17 8 155 33 c 1 

59 1977 1 20 21 28 49.230E 18.119 -66.482 0.8 1. 3D 0.4 89 1 1.2 179 2 20.5 333 87 68 0.33 10 154 35 c 1 * 

60 1977 1 20 22 39 45.420 18.270 -66.041 5.7 1.1D 0.9 260 3 4.3 169 24 11.7 356 65 68 0.15 8 156 29 c 1 

61 1977 1 21 00 1 7.970 18.823 -6 7. 249 26.2 2.1D 14.1 142 10 3.6 44 38 5.4 244 50 68 0.21 10 302 92 D 1 

62 1977 1 21 3 32 34.010 18.729 -66.259 60.4 2.9D 1.5 280 6 5.7 188 14 8.1 33 74 68 0.14 12 249 62 D 1 

63 1977 1 21 4 2 5.950 17.948 -66.293 12.2 l.OD 1.3 91 8 5.0 357 27 3.9 196 61 68 0.19 9 210 40 D 1 

64 1977 1 21 4 58 36.470 17.804 -66.800 0.2 l.OD 2.3 90 9 5.3 186 33 13.7 347 55 68 0.17 7 243 47 D 1 

65 1977 1 21 16 52 16.840 18.083 -67.019 11.9 0.8D 2. 1 34 7 6 1.6 79 19 5.8 241 70 68 0.19 8 128 36 c 1 

66 1977 1 21 22 41 54.250 18.000 -65.846 9.2 1. 3D 8.9 307 1 4.5 37 10 3.4 212 79 68 0.18 7 278 34 D 1 

67 1977 1 22 6 54 14.900 18.611 -67.300 104.1 1. 9D 10.0 175 19 4.3 75 26 40.2 296 56 68 0.11 7 3()1 70 D 1 

68 1977 1 22 12 36 47.770 18.553 -65.490 15.3 2.9D 5.2 331 3 24.8 63 30 63.9 236 59 68 0.20 10 313 76 1) 1 

69 1977 1 22 22 19 47.230 17.760 -66.767 13.5 1.4D 0.5 248 10 1.7 343 26 1.1 138 61 68 ().02 6 294 50 c 1 

70 1977 1 24 00 19 21.840 17.922 -65.744 12.3 1.4D 5.2 21 7 4.5 290 12 2.1 141 76 68 0.21 9 296 60 D 1 

71 1977 1 24 1 48 26.140 17.907 -65.774 9.4 1. 3D 6.0 83 26 7.6 336 31 3.2 205 47 68 0.17 7 293 58 D 1 

72 1977 1 24 6 21 55.090 l7.7lfi -fifi.7')~ a.a l.lD 1). 4 250 4 12.5 159 15 >?9.~ 353 73 03 D.ll 5 301 62 D 1 

73 1977 1 24 21 49 2. 330 18.447 -6 7. 442 9.0 1. 4D 4.7 43 4 12.5 134 21 3.6 303 68 68 0.31 11 307 61 D 1 

74 1977 1 25 20 46 26.240 18.845 -65.857 11.9 2.3D 29.0 213 4 3.5 306 43 7.4 118 46 68 0.15 7 291 87 D 1 

75 1977 1 25 22 6 25.160 19.144 -65.922 18.1 2.1D 10.1 36 3 6.0 304 3R 24.7 130 51 68 0.19 7 323 •• D 1 

76 1977 1 25 22 51 21.360 18.772 -65.804 73.0 1.7D 43.9 193 24 15.3 84 35 6.9 309 45 68 0.27 7 304 82 D 

77 1977 1 26 2 32 17.070 17.842 -66. 799 3.0 1.2D 0.6 96 1 1. 9 187 4 23.6 353 85 68 0.05 7 224 43 D 

78 1977 1 26 2 59 46.540 17.900 -66.221 13.3 o. 7D 2.0 274 1 7.9 4 3 3.q 165 86 68 0.17 7 243 44 D 
Table 8.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Bypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl r, (s) ob r.ap DM 0 auth * 

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

PRN77 79 1977 1 26 8 56 37.930 19.192 -66.466 7.3 1.9D 2.3 272 0 13.7 2 0 >99.9 90 90 68 0.13 9 289 •• D 

80 1977 1 28 14 41 32.860 18.448 -65.926 10.9 1. 9D 4.9 283 13 19.9 16 14 13.0 151 70 68 0.03 5 277 45 D 1 

81 1977 1 29 11 22 44.630 17.960 -66.527 12.7 l.lD 6.8 252 27 23.3 5 37 4.5 135 40 68 0.04 5 210 64 1) 1 

82 197"1 1 30 11 18 22.640 18.035 -67.143 16.1 O. 7D 1.0 354 3 2.5 261 40 1.5 88 49 68 0.04 6 263 49 D 1 

83 1977 1 30 17 6 17.380 18.457 -66.535 90.6 1. 7D 6.5 3 0 2.3 93 3 3.7 273 87 68 0.22 14 193 44 D 1 

84 1977 2 1 4 21 33.200E 18.034 -67.142 0.5 0.6D 18.5 59 2 3.8 329 3 >99.9 182 86 68 0.17 5 24 7 43 D 1 * 

85 1977 2 1 6 00 48.660 19.019 -65.440 4.6 2.8D 13.0 241 2 7.5 149 39 4.2 333 50 68 0.25 11 315 •• D 

86 1977 2 2 10 26 39.250 18.111 -67.447 11.8 1. lD 6.6 165 5 11.7 71 41 3.8 260 48 68 0.19 6 299 49 D 

87 1977 2 2 14 28 52.460 18.462 -65.890 9.7 1. 4D 7.7 272 0 20.3 2 1 45.1 182 89 68 •••• 5 297 47 D 

88 1977 2 3 14 16 38.460 17.951 -66.302 6.6 1. 2D 1.1 269 0 3.3 359 1 20.5 178 89 68 0.14 8 210 42 D 

89 1977 2 3 18 3 38.100 18.306 -66.853 15.6 ... 4.4 115 21 14.1 12 31 6.3 233 51 68 0.05 5 183 31 D 

90 1977 2 4 12 26 11.350 18.125 -67.259 20.8 ... 8.3 346 1 19.4 77 33 11.9 255 56 68 0.27 5 260 36 n 

91 1977 2 4 20 14 11.080 18.098 -66.484 ..... 1.1D 1.4 266 0 4.7 356 0 >99.9 90 90 68 0.27 9 171 35 c 

92 1977 2 4 20 40 36.060 17.967 -66.664 38.9 o. 6n 8.8 252 23 28.8 353 25 43.8 124 54 68 0.04 5 257 45 D 

93 1977 2 5 1 53 58.850 18.195 -67.254 14.2 • •• D 6.8 348 6 17.9 82 33 9.3 249 56 68 o.o1 5 252 29 D 

94 1977 2 5 8 6 24.510 18.266 -67.175 22.9 1.1n 3.0 1 1 10.3 270 29 2.6 93 60 68 0.26 11 220 30 D 

95 1977 2 5 9 24 10.760 18.696 -67.448 11.9 2.0D 3.8 186 18 5.8 89 20 2.1 314 62 68 0.23 12 311 80 n L..l 96 1977 2 5 14 11 7.230 18.668 -66.726 15.9 1. 8D 0.9 89 1 2.1 359 13 8.7 183 76 68 0.19 17 238 66 D 1 

97 1977 2 5 20 50 59.320 18.010 -66.858 9.7 0. 6D 0.4 260 7 1. 2 352 16 2.8 147 72 68 0.03 6 196 51 c 1 

98 1977 2 6 2 47 6. 300 18.715 -67.490 8.2 2.0D 3.5 94 3 5.7 186 24 2.1 358 65 68 0.19 12 313 85 D 1 

99 1977 2 6 15 38 16.720 18.190 -67.093 16.9 o.6n 19.5 263 7 6.3 355 16 8.7 150 72 68 0.08 5177 25n 1 

100 1977 2 6 22 1 12.880 17."35 -66.403 23.4 1. OD 1.2 95 3 3.0 186 25 7.9 359 64 68 0.15 10 209 3R n 

101 1977 2 6 23 50 44.530 1H.246 -67.437 74.2 1.7D 3.4 2 3 2.1 95 41 2.6 269 4R 68 0.10 12 295 45 n 

102 1977 2 7 1 15 11.540 18.188 -67.299 31.5 2.0D 30.2 272 30 6.2 159 34 3.8 33 41 68 0.18 9 292 67 n 

103 1977 2 7 6 37 14.590 18. 6 7.: -65.403 19.5 2 • 3D >9 9 • 9 2 30 1 3 17.4 131 35 7.7 337 52 68 0.23 8 325 90 D 

104 1977 2 8 00 48 33.390 18.412. -67.425 20.2 1.4D 4.9 317 2 5.1 227 5 13.9 69 84 68 0.15 7 307 57 n 

105 1977 2 8 21 54 40.080 18.410 -67.383 23.2 1. 3D 2.8 342 2 4.3 250 39 11.7 75 50 68 0.13 7 303 54 D 

106 1977 2 12 1 53 10.500 18.099 -67.073 22.1 1.1D 5.8 343 21 3.2 82 22 13.5 214 58 ~8 0.32 8 162 36 D 

107 1977 2 12 22 23 3. 930 18.242 -66.618 15. 1 1.5n 1. 4 164 6 2.8 259 40 0.6 66 49 6R 0.17 14 135 27 C 

108 1977 2 13 6 18 52.980 17.928 -65.842 16.9 1.1D 5.7 316 12 11.7 51 23 3.5 201 63 68 0.21 8 311 52 n 

109 1977 2 13 8 29 1.190 17.783 -66.750 0.1 1.1D 1. 8 89 1 3.7 180 3 13.3 341 86 68 0.26 11 232 46 n 

110 1977 2 14 5 3 54.600 18.142 -67.414 48.2 1. 3D 2.9 91 2 6.5 1Rl 15 3.8 354 74 68 0.13 9 330 78 D 

111 1977 2 14 5 28 26.740 18.067 -67.114 11.7 1. 3D 1.6 357 23 2.1~ 108 40 5.2 246 41 ~~ 0.12 7 203 39 n 

112 1977 2 14 17 46 29.230 18.040 -67.150 18.5 l.lD 8.9 3151 29 15.6 104 35 19.9 232 41 68 •••• 5 265 49 n 1 

113 1977 2 16 1 4 13.160 18.039 -65.508 12.2 1. 8D 2.2 25 5 2.4 293 18 1.5 130 71 68 0.12 8 322 ~8 D 1 

114 1977 2 16 8 20 6.400 17.910 -67.072 10.1 1.3D 3.7 28 16 2.1 123 18 11.2 259 65 68 0.09 6 282 44 n 1 

115 1977 2 16 11 49 3.230 17.981 -67.420 37.4 2.9D 1. 8 125 14 7. 8 22 () 2 3 5.9 5 62 68 0.14 11 264 45 n 1 

116 1977 2 16 12 13 16.320 18.010 -67.403 38.3 2.4D 2. 3 128 15 9.0 231 41 5.3 22 45 68 0.15 11 259 43 n 1 

117 1977 2 17 11 19 3.980 18.333 -65.891 48.5 2.sn 2.6 261 25 10.1 153 33 14.1 21 46 68 0.08 6 239 33 D 1 

118 1977 2 17 16 52 6.330E 18.407 -66.024 0.2 1.1D 9.0 346 0 32.0 256 1 >99.9 76 88 68 0.22 5 315 65 D 1 * 

119 1977 2 19 00 4 47.910 17.744 -66.781 5.5 1.1D 2.0 239 4 4.9 148 7 44.0 358 81 68 0.13 6 289 52 D 1 

120 1977 2 19 7 53 39.190 17.684 -67.838 5.0 3.5D 8.4 342 9 43.7 74 16 1.9 224 71 68 0.10 9 336 •• D 1 
Table 8.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) rlorth East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo Name Index yr roo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * ------------------------------------------------------------------------------------------------------------------------------------ PRN77 121 1977 2 19 10 48 44.790 18.754 -65.572 16.5 3. 3D 2.0 319 5 14.6 228 10 7.5 76 78 68 0.07 8 310 94 D 1 

122 1977 2 19 14 11 37.540 18.736 -65.476 17. 1 2.m 26.3 313 1 >99.9 43 28 >99.9 222 61 68 0.04 5 336 90 D 1 

123 1977 2 19 15 8 27.360 18.995 -65.245 7. 8 2. 2D 42.3 318 8 >99.9 223 35 >99.9 60 53 68 0.03 5 343 •• D 1 

124 1977 2 19 23 8 18.010 18.559 -65.633 23.8 2.4D 18.3 225 3 1.6 318 40 2.6 131 49 68 0.03 6 320 65 D 1 

125 1977 2 20 10 4 47.960 18.409 -66.029 67.6 1.4D 13.9 174 20 8.0 274 23 11.3 47 58 68 0.31 8 243 35 D 

126 1977 2 20 23 59 46.980 18.364 -66.210 20.0 1. 7D 6.1 275 13 >99.9 10 21 14.5 155 64 68 0.28 l+ 257 48 D 

127 1977 2 21 5 19 15.110 17.987 -66.880 9.6 0.9D 1.1 83 5 5.6 352 12 3.1 195 76 68 0.16 8 207 30 D 1 

128 1977 2 21 6 18 3. 760 18.146 -66.306 18.5 1.2D 0.7 264 4 2.0 355 4 3.0 129 84 68 0.09 8 150 30 c 1 

129 1977 2 21 10 8 31.130 18.490 -66.474 117.3 2.1D 1.9 86 5 7.4 177 13 4.1 336 76 68 0.12 11 204 45 D 1 

130 1977 2 23 3 21 5.170 Ul.013 -65.793 9.6 1. 7D 1.5 50 8 2.6 316 26 4.8 156 62 68 0.12 10 290 39 D 1 

131 1977 2 23 6 47 1.940 18.051 -65.540 13.1 1. 4D 2.6 70 1 2.1 339 32 1.2 162 57 68 0.13 9 319 6'5 D 1 

132 1977 2 23 13 32 13.770 19.951 -64.336 80.7 2.8D >99.9 312 3 >99.9 42 9 >99.9 204 80 68 0.13 5 349 •• D 1 

133 1977 2 25 2 31 54.370 18.438 -66.087 19.2 1. 7D 9.3 76 7 >99.9 340 40 18.1 175 49 68 0.13 4 278 37 n 1 

134 1977 2 25 5 7 10.830 18.681 -65.513 13.9 2.3D 5.0 319 1 39.3 49 25 >99.9 227 64 68 0.14 8 319 83 D 1 

135 1977 2 25 5 18 36.510 18.988 -65.163 3.7 2.3n 1.4 321 5 0.5 228 31 3.3 60 58 68 0.12 7 339 •• c 1 

136 1977 2 25 15 21 48.700 17.920 -66.653 22.0 1.0D 2. 4 109 2 7 5.4 219 34 14.4 350 43 68 0~16 7 280 38 D 1 

137 1977 2 25 22 59 7.410 18.177 -66.494 94.4 1. 5D 10.3 3 3 4.1 94 25 11.1 267 64 68 0.12 8 145 21 D 1 w 138 1977 2 25 23 11 3.390 18.165 -65.977 77.6 1. 2D 10.5 148 12 7.3 54 21 5.4 266 65 68 0.21 8 119 20 c 1 N 

139 1977 2 26 00 53 21.020 17.698 -65.978 11.0 1. 3D 6.7 350 10 3.() 255 29 2.0 98 59 68 o. 07 6 308 55 D 1 

140 1977 2 27 5 38 33.990 18.831 -66.844 25.8 1.8D 2.2 227 6 2. 7 134 20 33.2 332 68 68 0.15 10 280 94 D 1 

141 1977 2 27 12 7 10.260 19.012 -65.373 4.4 3. OD 17.2 76 4 9.8 168 34 4.8 341 5'5 68 0.32 13 318 •• D 1 

142 1977 3 2 21 9 0.140 17.960 -66.410 9.8 2.1D 1.1 262 20 4.7 4 30 2.6 143 52 6R 0.22 14 194 31 D 1 

143 1977 3 3 4 16 9.260 18.193 -66.084 35.0 l.lD 1.5 2R1 3 2.1 191 9 2.8 30 RO 68 0.13 10 96 25 c 1 

144 1977 3 3 8 41 46.840 18.989 -67.204 11.5 2.1D 2.0 238 0 4.7 148 39 16.5 327 51 68 0.14 13 304 91 D 1 

145 1977 3 3 18 3 7 57 • 4 90 E 1R.299 -66.858 0.3 1. 4D 1.0 272 2 1. 9 2 2 10.R 137 87 68 0.35 14 101 28 C 1 * 

146 1977 3 7 6 25 54.530 18.674 -66.289 31.5 1. 4D 2.2 271 10 2.4 4 16 7.q 150 70 68 0.09 8 309 64 D 1 

147 1977 3 9 6 18 4.080 18.146 -66.016 18.0 1.4D 1.9 298 3 2.5 29 4 6.4 171 84 68 0.21 9 117 22 c 1 

148 1977 3 10 1 35 30.480 18.284 -66.392 40.3 1. 2n 2.7 30 31 4.2 276 35 8.8 151 39 68 0.14 8 284 32 D 1 

149 1977 3 10 4 38 56.960 19.012 -65.152 7.1 2.1D 16.8 314 10 6.7 218 31 39.5 60 57 68 0.20 8 344 •• D 1 

150 1977 3 13 8 43 32.770 18.683 -65.668 21.7 2.sn 34.2 213 20 4.2 317 34 11.4 98 49 68 0.17 9 303 76 D 1 * 

151 1977 3 13 8 46 47.790 18.963 -65.489 8.7 3. 3D 3.1 320 7 16.0 57 41 38.3 223 48 68 0.15 13 311 •• D 1 * 

152 1977 3 13 12 29 12.820 19.053 -6.'5.336 5.6 2.6n 18.0 311 4 11.9 219 31 80.6 48 58 68 0.23 7 336 •• D 1 * 

153 1977 3 13 18 31 31.900 18.039 -65.525 9.9 1. 4D 6.9 183 11 4.4 281 36 2.3 78 51 68 0.17 8 321 67 D 1 

154 1977 3 14 7 14 38.560 18.508 -67.388 12.4 1. 6D 17.5 162 1 7.3 254 44 3.1 70 45 68 0.33 10 239 62 D 1 

155 1977 3 15 1 23 55.090 18.291 -67.427 84.8 1. 7D 6.2 7 17 2.7 109 34 3.9 255 50 68 0.18 13 201 48 D 1 

156 1977 3 15 1 44 27.600 18.802 -66.177 32.5 1.5D 1.3 281 9 2.6 13 12 9.4 155 74 68 0.08 10 296 76 D 1 

157 1977 3 15 5 35 55.690 18.661 -66.924 tt:;.q ... 1.1 340 () 2.1 259 0 >99.9 270 R9 53 O.OS "? 31 :-t 91 D 1 

158 1977 3 16 18 21 53.850 18.102 -66.460 14.7 0.6D 1.7 275 4 5.6 182 36 8.9 11 53 68 0.12 6 164 24 D 1 

159 1977 3 19 8 45 12.330 18.548 -65.418 13.2 2. 9D 4.7 330 4 65.4 237 43 16.6 65 46 68 0.14 9 326 83 D 1 

160 1977 3 21 00 27 10.850 17.927 -66.719 12.4 1. 3D 3.0 358 27 0.9 106 31 1.5 216 46 68 0.13 12 201 40 D 1 

161 1977 3 21 1 48 42.940 18.872 -66.354 46.3 1. 7D 3.1 283 12 4.1 17 18 16.2 161 68 68 0.13 9 300 87 D 1 

162 1977 3 22 14 49 47.910 19.057 -66.014 27.5 2.4D 6.8 283 0 36.5 13 0 >99.9 90 90 68 0.20 7 300 •• D 1 

1:63 1977 3 22 21 4 34.480 18.033 -67.109 5.4 1. 8D 1.6 354 26 18.1 250 28 2.8 121 50 68 0.10 6 217 43 D 1 
Table 8.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes. 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * 

------------------------------------------------------------------------------------------------------------------------------------ PRN77 164 1977 3 23 15 54 50.480 17.832 -66.604 7.4 1.3D 1. 0 94 9 1.9 1R9 32 3.6 351 56 68 0.13 12 250 39 c 1 

165 1977 3 23 17 5 8.970E 18.326 -66.136 0.1 0.6D 4.9 240 0 29.2 330 3 >99.9 149 ~7 68 0.20 5 239 28 n 1 * 

166 1977 3 24 16 41 1.110 17.904 -67.010 2.1 1.8D 1.5 116 12 4.3 215 39 7. 1 12 48 68 0.29 11 234 47 D 1 

167 1977 3 24 20 11 52.900 18.854 -66.321 48.1 1. 6D 2.1 281 7 3.1 13 23 11.4 175 65 68 o.16 12 298 son 1 

168 1977 3 25 3 36 37.780 19.304 -65.528 2.0 2. 5D 5.9 295 19 2.4 194 29 27.0 54 54 68 0.1~ 8 323 •• n 1 

169 1977 3 25 5 51 28.160 18.068 -65.543 13.1 1.3D 2.3 29 15 3.3 292 25 1.5 148 60 68 0.09 7 318 64 D 1 

170 1977 3 25 20 00 58.900 18. 221 -66.129 7.7 o. 5n 2.9 179 9 5.9 88 11 9.5 307 75 68 0.28 7 108 27 c 1 

171 1977 3 25 20 3 7.300 18.073 -66.490 10.4 o. 8D 1.3 99 1 3.1 q 9 4.0 195 80 68 0.17 9 172 21 c 1 

172 1977 3 27 3 5 57.420 18.301 -66.150 59.9 1. 2D 4.0 5 5 2.5 273 19 3.2 110 70 68 0.17 12 183 23 D 1 

173 1977 4 1 8 6 46.540 18.182 -66.149 63.3 1. 2D 15.1 140 22 3.5 242 26 8.2 15 54 68 0.10 6 120 22 c 1 

174 1977 4 1 9 5 29.560 18.493 -66.432 44.4 1.4D 15.5 53 4 70.8 145 26 29.1 315 63 68 0.05 5 302 52 D 1 

175 1977 4 1 17 6 14.050E 18.351 -66.152 o.o 0.9D 3.8 231 0 u.s 321 0 >99.9 90 90 68 0.?.3 5 248 30 D 1 * 

176 1977 4 1 23 2 18.320 17.661 -65.719 4.2 1. 7D 22.2 236 2 >99.9 146 8 >99.9 339 81 68 0.08 5 318 74 D 1 

177 1977 4 1 23 5 0.690 18.789 -66.379 57.5 1. 9D 1. 1 284 7 2.9 16 20 8.0 175 68 68 0.10 12 253 71 D 1 

178 1977 4 2 3 56 0.090 17.998 -65.542 13.2 1. 3D 3.2 220 6 4.4 312 14 1.8 107 74 68 0.12 8 321 66 D 1 

179 1977 4 2 8 41 16.120 18.008 -66.662 32.3 0.9D 1.8 355 ll 0.8 92 33 6.8 250 54 68 0.02 6 259 36 D 1 

180 1977 4 2 10 59 26.010 18.104 -66.094 29.2 1. lD 1. 0 280 0 1.3 10 23 2.0 190 67 68 0.09 10 150 22 c 1 

w 181 1977 4 5 13 2 1 41. 7 50 18.825 -65.318 3.3 3. OD 4.8 330 8 18.8 67 40 55.9 231 48 68 0.18 10 319 •• D 1 w 182 1977 4 7 11 51 23.030 18.786 -65.567 30.4 1. 9D 4.5 291 4 3.2 21 7 18.8 171 81 68 0.19 11 327 91 D 1 

183 1977 4 7 22 39 14.780 17.939 -66.261 8.9 2.4D 1.1 272 3 2.8 180 31 5.6 7 58 68 0.19 13 202 38 D 1 * 

184 1977 4 7 2 2 43 16. 44 0 17.921 -66.249 12.3 o.5n 7. 1 357 4 2.4 90 36 3.6 262 53 68 0.18 7 264 38 D 1 * 

185 1977 4 7 22 45 46.280 17.918 -66.254 8.5 0.7D 1. 3 102 4 2. 4 193 19 8.5 0 70 68 0.06 6 266 38 D 1 * 

186 1977 4 8 2 6 23.280 17.914 -66.258 7.3 o.5n 5.9 94 1 12. 7 185 15 87.5 0 74 68 0.01 5 268 39 D 1 * 

187 1977 4 8 4 15 33.500 18.685 -65.411 69.3 2.on 3.9 306 17 2.5 46 30 8.8 191 54 68 0.16 12 331 90 D 1 

188 1977 4 8 9 37 29.500 17.952 -66.252 11.3 1. OD 1.8 100 4 3.8 191 9 7.7 347 80 68 0.21 9 254 37 D 1 * 

189 1977 4 8 10 13 0.020 17.935 -66.251 13.0 1.1D 0.8 263 1 2.3 353 22 1.6 170 67 68 0.13 11 215 37 c 1 * 

190 1977 4 9 16 18 4.410 18.759 -66.390 12.6 1. 4D 2.0 321 4 3.1 229 26 0.9 60 63 68 o. 05 7 337 74 D 1 

191 1977 4 10 9 19 34.010 17.929 -66.251 11.0 0.9D 0.8 94 11 1.7 188 22 3.7 340 65 68 0.08 9 262 38 c 1 

192 1977 4 10 9 20 4.840 17.927 -66.252 9.1 1.1D 0.6 103 11 1.4 196 20 3.1 346 67 68 0.05 8 263 38 c 1 

193 1977 4 10 9 51 37.710 17.927 -66.249 9.8 O. 7D 0.9 85 3 1.7 176 24 4.6 349 65 68 0.10 10 217 37 c 1 

194 1977 4 14 19 00 35.870 18.707 -66.394 60.2 2.1D 2.1 99 2 4.2 7 41 10.4 191 48 68 0.18 12 259 53 D 1 

195 1977 4 16 7 9 20.760 18.745 -65.241 68.0 2.1D 6. 0 142 4 1.9 49 40 7.1 236 49 68 0.12 11 329 •• D 1 

196 1977 4 20 23 54 19.450 17.937 -66.165 14.4 o. AT.> 0.6 280 0 1.7 10 25 1.2 100 65 68 0.10 12 233 29 C 1 

197 1977 4 23 19 2 38.580E 18.298 -66.199 0.2 2.2D 1.0 279 0 2.0 9 0 69.6 90 90 68 0.16 10 161 21 c 1 * 

198 1977 4 25 20 56 4. 410 18.605 -66.334 49.8 2.9D 2.5 103 4 6.2 194 16 12.3 0 73 68 0.14 9 235 45 D 1 

199 1977 4 26 20 45 18.920 18.331 -66.142 2.5 1. 7n 1.1 281 4 1.8 12 20 4.8 181 69 68 0.18 6 198 24 c 1 

200 197 7 4 27 13 13 41.310 18.604 -66.185 14.0 2.9D 10.2 175 4 1.6 268 26 2.3 76 63 68 0.10 7 273 47 D 1 

201 1977 4 28 23 34 58.060 18.516 -67.368 6.6 2.5D 7.0 179 29 4.4 290 32 2.2 56 43 68 0.34 18 236 48 n 1 

202 1977 4 29 21 28 21.430 18.197 -66.099 65.6 1. 4D 20.3 347 16 5.6 246 33 13.2 99 52 68 0.25 7 108 27 c 1 

?.03 1077 4 10 11 ~1 ?.l.nlO 18.511 -67.193 14.8 2.5n 6.8 173 11 2.3 73 44 5.1 273 44 68 o.33 14 217 41 n 1 

204 1977 5 2 2 44 17.570 18.115 -65.940 59.6 3.0D 2.9 5 7 1.6 272 26 7.0 109 62 68 0.07 8 144 23 c 1 

205 1977 5 2 16 00 56.360 19.113 -67.404 18.4 4.5D 2.2 72 15 ll.3 168 19 5.0 307 65 68 0.20 15 273 •• D 1 * 

206 1977 5 4 10 1 22.110 19.223 -67.450 15.7 3. 2D 2.9 81 16 6.5 181 31 15.3 328 54 68 0.20 12 280 •• D 1 * 
Table B.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * ------------------------------------------------------------------------------------------------------------------------------------ PRN77 207 1977 5 7 19 24 47.150 17.994 -66. 738 8.3 2.on 0.8 92 7 1.5 189 44 2.3 355 45 68 0.20 22 186 35 c 1 

208 1977 5 8 13 43 54.640 17.839 -66.837 9.2 1.8D 4.7 4 21 1.3 105 26 2.3 241 55 6R 0.20 13 247 45 D 1 

209 1977 5 9 4 46 38.840 18.020 -66.762 11.1 l.ln 11.2 303 9 5.5 36 22 2.8 193 66 68 0.23 8 327 46 D 1 

210 1977 5 9 6 59 59.020 17.940 -66.733 8.4 1. 2D 4.9 262 14 7.9 5 40 2.0 156 46 68 0.25 11 299 45 D 1 

211 1977 5 9 8 4 11.630 17.892 -66.021 9.0 1. 7D 0.9 258 6 2.2 167 8 4.7 25 79 68 0.09 10 250 38 c 1 

212 1977 5 9 8 53 17.950 17.799 -66.787 2.1 1.6D 1. 1 98 3 2.4 189 11 5.2 353 78 68 0.20 15 232 47 D 1 

213 1977 5 9 11 28 43.140 17.899 -66.031 6.0 1.6D 1.6 259 7 6.7 168 7 14.0 34 80 68 0.09 6 263 3 7 D 1 

214 1977 5 9 11 30 34.350 17.894 -66.025 4.4 !.3D 1.6 64 1 2.7 154 9 35.1 328 80 68 0.11 7 282 46 D 1 

215 1977 5 10 1 22 37.150 18.156 -66.124 81.5 1.3D 8.6 352 14 5.2 91 31 4.1 241 55 68 0.23 11 89 23 c 1 216 1977 5 10 5 14 24.650 18.569 -66.576 83.5 1. 9D 2.2 89 3 8.1 180 31 3.5 355 58 68 0.08 8 240 54 D 1 

217 1977 5 10 6 13 31.240 17.981 -66.598 14.2 2.3D 4.7 359 15 1.5 96 26 2.0 242 59 68 0.24 13 188 30 D 1 

218 1977 5 10 20 13 47.350 18.102 -66.496 9.2 o.sn 3.2 89 1 16.2 358 3 25.7 197 86 68 0.26 6 155 20 D 1 

219 1977 5 13 00 55 38.700 18.419 -66.769 13.0 1.9D 1.8 189 1 1. 0 99 18 1.1 282 71 68 0.22 18 134 33 B 1 

220 1977 5 13 9 51 17.740 19.028 -65.116 20.0 2.5D 58.2 135 4 >99.9 225 11 44.2 25 78 68 0.09 4 344 •• D 1 

221 1977 5 14 19 13 44.290 18.006 -65.629 12.9 l.lD ll.4 2R3 5 9.2 15 19 5.9 178 70 68 0.30 6 314 56 D 1 

222 1977 5 20 16 54 55.210 18.426 -66.069 89.0 1.4D 64.6 180 5 29.7 88 22 16.3 282 67 68 0.12 5 270 46 D 1 

223 1977 5 22 2 55 0.700 18.155 -66.693 54.3 2. 5D 0.6 96 9 1.7 0 33 2.3 199 55 68 0.06 13 82 22 R 1 

w 224 1977 5 23 22 47 24.880 18.695 -65.654 67.2 1. 9D 7.8 273 4 7.3 181 37 2.6 9 52 68 0.10 7 331 78 D 1 ~ 225 1977 5 26 2 7 22.610 18.698 -66.119 76.6 1.5D 8.2 169 19 3.7 268 26 4.7 46 57 68 0.06 6 311 73 D 1 

226 1977 5 26 15 55 16.080 19.161 -66.399 18.3 2. 2D 2.3 301 0 3.1 31 11 4.2 211 79 68 0.14 11 305 •• D 1 

227 1977 5 27 17 40 42.520 18 978 -66.750 31.5 2.1D 2.6 95 1 6.8 5 8 28.3 192 81 68 0.27 15 259 87 D 1 

228 1977 5 29 10 31 58.240 18.664 -66.875 17.2 !.3D 1.8 259 0 2.0 349 2 59.5 168 R8 68 0.06 10 315 70 D 1 

229 1977 5 29 16 19 2.550 1B.010 -65.564 7.6 1.5D >99.9 296 12 23.6 36 40 10.6 193 47 68 •••• 4 319 63 D 1 

230 1977 5 29 22 30 58.500 17.917 -65.833 13.6 o.sn 4.3 331 17 1.9 68 21 0.9 206 62 68 0.05 6 293 44 D 1 

231 1977 5 31 7 11 2.930 18.443 -67.573 6.6 2.8D 11.0 335 4 3.1 67 19 4.0 234 70 68 0.23 11 225 89 D 1 

232 1977 6 1 21 36 54.900 17.467 -67.572 21.8 2.4n 1.2 119 18 6.1 18 29 4.0 236 54 68 0.13 11 263 94 n 1 

233 1977 6 3 00 50 29.830 17.980 -66.408 13.0 1.5D 4.0 359 0 1. 4 89 16 2.4 269 74 68 0.18 10 204 30 D 1 

234 1977 6 3 18 41 31.330 17. 986 -67.307 1. 4 2. 5D 0.6 85 1 1.5 176 25 2.0 353 64 fi8 0.10 R 197 6S C 1 

235 1977 6 4 18 54 52.420 18.336 -65.715 1'5.9 3.4D 3.6 137 1 13.2 47 15 5.8 230 74 68 0.18 9 308 52 D 1 

236 1977 6 4 22 49 35.350 18.606 -65.230 25.8 3. 2D 8.2 15 5 5.7 107 16 4.0 269 73 fi8 0.10 7 325 •• D 1 

237 1977 6 7 8 42 19.870 18.512 -68.005 25.5 2.9D 10.6 129 1 3.5 39 38 77.8 220 51 68 o.oq 4 304 •• D 1 

238 1977 6 7 16 7 22.600 18.788 -68.868 33.6 3.50 9.2 274 2 52.1 4 2 >99.9 139 R7 68 0.26 7 347 •• D 1 

239 1977 6 7 23 28 13.720 1~.984 -65.815 2 7. 5 2.4D 1. 4 339 0 1.9 249 0 >99.9 270 89 68 0.06 9 322 97 D 1 

240 1977 6 8 16 21 30.790 18.446 -67.338 40.9 2. 2D 13.2 352 9 1.1 85 14 1.7 231 73 68 0.08 7 211 71 D 1 

241 1977 6 8 23 29 20.040 18.885 -65.493 18.5 2. 7D 2.5 273 4 2.0 4 19 4.3 171 70 68 0.08 9 312 •• D 1 

242 1977 6 9 7 42 18.940 18.372 -67.710 .51.0 2.6D 0.9 71 29 2. 8 183 34 5.0 311 42 68 0.11 13 229 64 D 1 

241 lQ77 6 10 2 2q q.l50 19.223 -57.523 41.7 2. 8D 2.9 4S 10 9.0 313 12 29.4 175 74 6R 0.17 8 303 •• D 1 

244 1977 6 10 9 11 36.700 18.435 -65.654 51.7 1. 9D 3.6 80 3 2.7 172 33 1.7 346 56 68 0.06 8 315 55 D 1 * 245 1977 6 12 1 36 6. 220 18.576 -65.690 22.0 2. 8D 2.1 282 7 2.7 18 41 7.6 185 48 68 0.09 8 306 64 D 1 * 246 1977 6 12 3 19 39.730 18. 783 -65.550 10.0 2. 5D 3.3 26 6 6.6 118 23 1.9 283 66 6~ 0.05 6 324 98 D 1 * 247 1977 6 12 14 34 22.620 18.744 -65.344 22.1 2.6D 1.0 234 3 4.0 324 3 1.2 98 85 68 0.05 8 349 •• D 1 * 248 1977 6 12 14 54 34.450 18.716 -65.569 17.6 2. 7D 3.5 49 15 4.2 308 33 16.4 160 52 68 0.07 6 324 91 D 1 * 249 1977 6 12 19 27 54.840 18.955 -65.351 3.7 3.3D 5.8 81 12 6.5 178 29 1.9 332 58 68 0.10 9 323 •• D 1 * 
w 

Vl 

Table 8.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. ~ypo Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM 0 auth * 

PRN77 250 1977 

251 1977 

252 1977 

253 1977 

254 1977 

255 1977 

256 19i7 

257 1977 

258 1977 

259 1977 

260 1977 

261 1977 

262 1977 

263 1977 

264 1977 

265 1977 

266 1977 

267 1977 

268 1977 

269 1977 

270 1977 

271 1977 

272 1977 

273 1g77 

274 1977 

275 1977 

276 1977 

277 1977 

2 78 1977 

279 1977 

280 1977 

281 1977 

282 1977 

283 1977 

284 1977 

285 1977 

286 1977 

287 1977 

288 1977 

L.89 1977 

290 1977 

291 1977 

292 1977 

6 12 19 29 44.110 

6 12 19 32 53.080 

6 12 19 50 45.230 

6 12 19 56 11.850 

6 13 17 00 54.370E 

6 13 17 30 40.420 , ~ 1 ~ ~e 1n n~n 0 1'+ I J.l .l:J•:JJIJ 

6 17 4 17 34.840 

6 18 12 26 43.300 

6 18 13 35 41.390 

6 23 1 52 35.640 

6 23 6 5 18.310 

6 24 14 8 54.920 

6 25 7 59 27.130 

6 26 10 16 5.560 

6 26 13 21 32.400 

6 27 17 17 11.)30 

6 29 5 51 20.970 

6 29 14 8 15.020 

7 3 1 1 2.940 

7 3 15 58 42.960 

7 5 4 54 6.600 

7 6 00 9 41.970 

7 6 8 32 24.030 

7 8 20 53 47.350 

7 8 23 12 46.120 

7 9 5 37 23.360 

7 11 9 51 59.260 

7 11 18 49 41.960 

7 11 23 18 22.710 

7 12 7 13 23.860 

7 12 12 20 44.200 

7 13 9 10 2.710 

7 13 12 6 46.130 

7 13 14 44 56.320 

7 15 00 11 29.520 

7 15 4 22 45.910 

7 15 5 9 28.510 

7 15 6 3 41.310 

7 15 n 6 3.)10 

7 15 10 57 10.620 

7 18 2 29 13.440 

7 19 1 21 51.940 

18.764 

18.852 

18.399 

18.2!39 

18.232 

lfl.l68 

l~.R73 

18.310 

18.681 

18.631 

19.050 

u~. 039 

18.708 

17.962 

18.884 

19.013 

18.090 

18.241 

18.672 

18.R35 

18.145 

18.729 

18.515 

18.726 

18.338 

18.276 

18.42 2 

18. 158 

18.345 

17.881 

18.121 

18.042 

18.703 

17.972 

18.533 

18.768 

17.906 

17.92() 

18.942 

18.010 

17.958 

17.796 

18.574 

-65.580 

-65.320 

-65.1328 

-65.241 

-65.831 

-67.149 

~65.333 

-65.794 

-66.524 

-67.938 

-67.923 

-66.832 

-65.399 

-67.386 

-67.301 

-67.931 

-65.811 

-67.816 

-68.045 

-65.342 

-65.993 

-65.714 

-66.895 

-65.64 7 

-67.451 

-65.996 

-67.493 

-65.959 

-65.895 

-66.548 

-65.996 

-66.818 

-66.664 

-65.556 

-68.328 

-65.043 

-115.411 

-65.413 

-64.673 

-65.586 

-65.512 

-68.085 

-66.478 

17.0 

6.4 

15.5 

16.5 

0.6 

34.0 

11.0 

27.0 

25.5 

14.9 

58.9 

14.3 

19.4 

32.8 

2.8 

1. 0 

/11.8 

26.6 

1. 7 

27.5 

15.7 

19.3 

17.5 

20.6 

33.1 

123.3 

17.2 

26.7 

16.6 

0.4 

2 7. 6 

12. 1 

10.0 

1. 1 

22. ~~ 

20.0 

7.0 

8.3 

51.9 

16.8 

7.0 

42.4 

80.8 

2. 7D 

3.2D 

2.7D 

2.5D 

2. )D 

2.5D 

2. 6D 

2.6n 

2. 2D 

3. 2D 

2.7D 

1.4D 

2. 6D 

2.5D 

3. 7D 

3.7n 

1.9D 

3.4n 

3.ln 

2. 5D 

2. 6D 

2. SD 

2.:m 

2. 9D 

3. 2D 

1. 8D 

2. 9D 

1. 7D 

2. 8D 

1. 8D 

1. 51) 

1. 7D 

2.0D 

3.1D 

2. 9D 

3.1D 

2.0D 

2.0D 

2. 7D 

2.0D 

2.1D 

2. 9D 

1. 6D 

3.5 265 21 2.2 4 22 18.2 135 58 68 0.05 6 313 •• D 

6.8 65 9 10.7 159 25 2.8 317 63 68 0.17 9 328 •• D 

16.5 7 1 10.6 97 27 2.5 276 62 68 0.02 5 313 47 n 

2.3 258 o 6.2 168 1 >99.9 347 88 68 o.o9 7 346 98 n 

1.0 190 1 2.8 280 1 40.9 54 88 68 0.12 7 274 35 D 

1.9 105 15 4.1 11 16 7.1 236 67 68 0.22 12 144 35 c 

4.5 310 1 2.4 218 32 >99.9 45 57 68 0.09 7 335 •• D 

3.2 64 15 1.8 320 43 2.6 169 43 68 0.12 9 294 3R D 

1.1 76 23 2.0 330 33 3.0 194 47 68 0.10 11 260 56 c 

3.9 217 11 10.9 120 35 38.3 321 52 68 0.15 5 282 •• D 

4.3 311 12 2.5 45 18 68.5 190 68 68 0.13 7 295 •• D 

0.6 93 28 1.1 202 31 1.4 330 45 68 0.10 10 176 54 c 

4.9 136 15 2.6 235 31 3.6 23·54 68 0.09 R 331 92 D 

2.0 106 7 4.0 198 15 7.9 352 73 68 0.10 6 205 58 D 

65.6 25 8 >99.9 120 35 58.6 284 53 fi8 0.01 4 354 •• D 

3.2 157 14 19.2 253 21 2.4 35 64 68 0.15 10 324 •• n 

5.9 316 5 15.8 48 21 8.6 214 68 68 o.o6 5 302 ss n 

5.4 326 17 1.3 71 40 2.0 219 45 6~ 0.13 9 211 77 D 

3.2 24 28 10.9 130 28 52.5 257 48 68 0.18 5 301 •• D 

1.5 242 0 3.9 332 0 >99.9 90 90 68 0.03 5 340 •• D 

4.6 14 9 5.9 112 43 2.2 275 45 68 0.27 8 112 22 c 

2.4 303 4 26.0 35 24 21.0 205 65 68 o.o9 6 321 79 n 

1.0 268 1 2.2 178 1 4.6 43 88 68 0.1~ 11 213 ~5 c 

4.6 266 19 2.8 4 23 10.9 140 59 68 0.11 8 318 86 n 

1.9 84 11 10.4 346 36 4.6 188 51 68 0.14 7 1,0 55 D 

9.7 343 4 4.1 252 10 2.~ 95 79 68 0.11 R 163 24 D 

1.7 77 10 10.5 343 21 3.9 190 66 ry8 0.11 6 297 99 D 

3.0 45 9 1.6 312 16 4.1 164 71 68 0.08 6 131 25 c 

1.1 273 21 1.8 174 22 3.1 43 5R 68 o.o5 6 245 34 c 

2.6 272 0 13.6 182 1 >99.9 2 88 68 0.08 5 265 49 D 

1.4 195 3 1.2 285 18 2.9 95 71 68 0.07 7 124 25 B 

0.8 103 10 1.3 8 27 1.1 211 ~0 68 0.10 10 176 29 c 

3.3 167 7 1.1 73 28 2.6 269 60 68 0.15 10 267 71 n 

1.7 314 R 1.4 48 24 0.7 207 64 68 0.05 11 316 65 C 

2.4 115 26 1.5 7 33 4.3 235 45 68 o.os 6 323 •• n 

22.5 328 0 >99.9 23R 0 >99.9 270 89 68 0.05 4 340 •• D 

3.5 32 11 4.3 292 43 2.1 134 44 68 0.10 7 328 82 D 

2.0 306 17 3.o 46 25 1.2 1R6 59 68 n.o5 6 328 89 n 

37.7 149 11 9.5 56 14 >9q.q 275 72 68 0.10 5 352 •• D 

7.0 340 0 6.0 70 4 53.8 250 86 68 0.18 6 317 61 D 

0.8 293 7 1.0 29 36 0.6 194 52 68 0.03 8 322 70 c 

4.6 247 14 2.0 145 42 54.9 351 44 68 0.19 7 305 •• n 

z.s 271 14 6.2 173 32 l.R 22 54 68 0.10 9 279 46 n 

1 * 

1 * 

1 * 

1 * 

1 * 

1 

1 * 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 
Table B.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr rna d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob r,ap DM 0 autb * ------------------------------------------------------------------------------------------------------------------------------------

PRN77 293 1977 7 19 4 13 54.900 18.766 -66.124 16.0 1. 3D 0.5 261 0 0.7 351 0 71.2 90 90 6R O.Oo 7 306 72 n 

294 1977 7 19 23 22 3. 220 19.414 -67.436 50.0 2. 6D 9.0 72 9 85.2 340 9 >99.0 205 77 68 0.01 4 310 •• D 

295 1977 7 20 7 41 15.660 18.021 -66.776 16.6 1.1D 3.4 351 0 1.8 R1 2 97.5 261 88 68 0.21 R 1 R4 49 D 

296 1977 7 20 15 34 57.840 18.719 -67.297 21.7 2. 3D 2.0 65 28 4.4 316 30 11.1 188 4~ 68 0.22 9 264 •• D 

297 1977 7 21 2 47 40.120 17.505 -67.890 3.1 3.4D 6.8 34R 5 37.9 254 41 4.0 84 48 68 0.10 5 291 •• n 

298 1977 7 21 20 6 48.980 18.030 -66.206 15.9 1.8D 0.7 97 10 1.2 4 19 2.3 213 68 68 0.08 Q 201 29 c 

299 1977 7 21 20 46 46.670 18.2Rl -66.249 30.4 2.1D 3.1 244 3 8.2 153 27 5.0 339 62 68 0.07 5 1 q3 3 8 D 

300 1977 7 22 11 12 1. 670 17.889 -68.692 48.0 3.4D 2.1 246 25 14.2 350 27 5.1 119 51 68 0.07 7 348 •• D 

301 1977 7 23 8 39 49.450 18.681 -68.377 0.3 3.2D 11.4 256 21 4.8 355 22 ?..7 126 5~ 68 0.07 5 323 •• D 

302 1977 7 25 7 2 7 31.280 18. 113 -6 7. 733 46.1 3.1D 7.9 181 11 2.8 87 21 14.9 2q7 66 68 o.15 7 176 74 D 

303 1977 7 26 00 23 19.830 18.198 -66.163 78.0 1.6D 8.3 347 23 4.4 94 35 3.2 231 46 68 0.10 7 134 22 c 

304 1977 7 26 16 32 53.380 18.013 -65.731 9.3 2.9D 3.2 125 12 1.7 32 14 1.1 254 71 68 0.05 6 303 46 D 

305 1977 7 28 00 3 33.000 17.517 -65.758 29.7 1. 7D 5. 3 109 5 4.6 199 7 39.0 344 81 6R 0.11 6 323 88 D 

306 1977 7 28 19 37 24.780 18.420 -66.222 62.4 1.3D 15.8 359 0 8.8 88 11 6.6 269 78 68 0.14 5 314 53 D 

307 1977 7 29 14 40 1. 920 18.828 -65.329 19.1 2. 8D >99. 9 69 11 8.5 329 40 54.1 172 47 68 0.15 4 319 •• D 

308 1977 7 30 16 20 0.190 17.905 -67.322 34.2 2. 6D 2.4 93 4 4. 7 185 18 58.9 351 71 68 0.15 o 211 611 n 

309 1977 7 31 4 50 26.240 18.810 -65.818 106.3 2. 3D 30.7 110 15 18.3 20R 29 6.7 356 56 68 0.07 5 341 86 D 1 

310 1977 8 6 11 33 49.990 17.913 -6 7. 786 78.1 3.0D 8.4 4 8 2. 1 99 31 6.5 262 57 68 0.13 8 247 91 D 1 (.;..) 311 1977 8 6 16 41 32.680 18.610 -67.644 26.5 3.61) >99.9 145 4 3.0 53 28 7.7 242 61 68 0.07 5 320 •• D 1 0\ 

312 1977 8 7 5 4 17.260 17.887 -66.260 20.9 1. 4D 2.3 103 4 4.5 194 11 7.9 354 78 68 0.22 10 276 40 D 1 

313 1977 8 7 10 54 27.920 18.123 -65.934 42.9 1. 8D 3.9 239 7 17.3 331 19 9.3 129 69 68 •••• 5 249 30 D 1 

314 1977 8 8 14 33 2.880 18.374 -65.946 2.4 1. 2D 10.5 7 2 2.0 276 4 20.1 124 85 68 0.03 5 262 37 D 1 

315 1977 8 8 2 0 1 6 1 0 • 84 0 18.135 -68.089 11.7 2. 2D 28.6 201 29 >99.9 91 32 >99.9 323 44 68 •••• 4 349 •• D 1 

316 1977 8 9 7 9 27.660 19.077 -66.381 2.1 1. 8D 1.3 299 34 2.5 55 34 1.9 177 3R 6R 0.08 8 312 •• D 1 

317 1977 8 9 9 25 28.800 19.124 -66.389 2 7.1 1. 8D 2.7 97 7 2. 3 190 22 55.8 351 66 68 0.13 10 317 •• D 1 

318 1977 8 9 18 13 32.990 18.585 -66.127 74.9 2.0D 2.4 88 5 7.4 182 34 3.4 351 55 68 0.12 8 2 71 42 D 1 

319 1977 8 9 18 3 5 59 • 0 50 18.698 -67.716 26.6 3.3D 13.2 163 7 4.2 71 15 7.1 277 73 68 0.26 R 268 71 D 1 

320 1977 8 9 20 22 51.880 18.099 -66.497 12.0 l.lD 1.2 99 19 3.3 354 37 2.5 210 46 68 0.15 8 161 20 c 1 

321 1977 8 10 11 37 4.680 17.234 -67.585 17.7 2. 8D 6.3 24 1 3.3 114 22 49.8 292 67 68 0.15 6 277 •• I' 1 

322 1977 8 13 11 19 11.110 17.914 -65.959 17.5 2.4D 3.5 237 11 1).9 336 37 44.7 133 50 68 0.25 4 275 43 D 1 

323 1977 8 13 12 13 49.610 18.905 -65.345 19.3 3.0D >99.9 228 10 22.5 136 12 9.4 356 74 68 0.04 5 343 •• 1) 1 

324 1977 8 12 6 29 17.420 18.412 -66.149 88.7 2. 9D 1.6 281 0 5.0 191 11 3. 1 11 79 68 0.11 10 201 42 D 1 

325 1977 8 14 15 53 9.560 18.714 -68.446 12.7 3. 9D 3.5 28 8 22.9 126 43 17.0 290 45 6R 0.10 7 32 3 •• D 1 

326 1977 8 14 16 14 9.430 18.015 -65.505 9.3 1.5D 1.7 308 6 2.0 39 13 1.2 194 75 68 0.09 9 323 69 n 1 

327 1977 8 15 10 8 15.320 18.025 -65.514 8.4 1. 5D 1.5 281 18 2.1 23 34 1.2 167 50 6~ 0.08 9 322 68 D 1 

328 1977 8 16 3 15 27.260 17.818 -66.252 11.9 1. 6D 3.3 347 17 1.3 83 19 2.3 219 64 68 0.15 10 263 43 D 1 

32') 1 ')77 3 15 10 s 33.550 13.35:> -o 7. 642 47.4 2.8D 3.6 73 6 7.0 338 41 21.4 170 48 68 0.37 11 284 88 D 1 

330 1977 8 16 22 5 8.660 19.277 -67.226 22.8 2. 7D 2.1 115 13 2.7 209 16 42.2 348 69 68 0.09 8 299 .~ D 1 

331 1977 8 17 20 5 42.160 18.170 -68.220 19.7 2. 8n 5.0 12 3 2.7-279 45 7.8 105 44 68 0.14 7 343 •• D 1 

332 1977 8 18 9 49 31.620 19.073 -64.839 19.4 2.9D 38.5 318 0 8.5 227 22 >99.9 48 67 68 0.22 5 350 •• D 1 

333 1977 8 19 4 21 2. 800 17.865 -66.868 8.5 1. 6D 0.4 269 5 2.2 2 37 0.7 172 52 6R 0.06 10 233 45 C 1 

334 1977 8 19 19 5 12.180 18.612 -66.748 19.0 2.4D 1. 6 84 4 2.4 353 21 3.9 184 68 68 0.18 12 229 51 D 1 

335 1977 8 21 8 13 57.660 18.517 -65.632 15.8 2.4D 12.0 329 0 >99.9 239 0 >99.9 270 89 68 0.07 '> 336 71 D 1 
Table 8.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) ~ a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * ------------------------------------------------------------------------------------------------------------------------------------

PRN77 336 1977 8 22 12 16 4.040 18.862 -6 7.113 17.0 2.1D 2.7 63 1 4.1 333 2 >99.9 180 87 68 0.18 8 317 69 D 1 

337 1977 8 23 20 4 26.280E 18.082 -66.485 o.o 1. 7D 0.8 276 0 2.1 6 0 >99.9 90 90 68 0.25 10 168 21 c 1 * 

338 1977 8 24 16 34 19.870 18.811 -67.847 5.8 2. 9D 15.6 144 26 3.3 39 29 11.6 268 49 68 0.34 9 280 89 D 1 

339 1977 8 25 3 17 20.060 18.122 -66.336 22.2 0.9D 2.6 310 24 1. 9 56 32 6.2 191 48 68 0.13 7 180 20 D 1 

340 1977 8 25 9 51 3.300 18.424 -68.439 28.1 2. 9D 3.4 69 2 7.0 339 4 >99.9 185 85 68 0.13 8 331 •• D 1 

341 1977 8 26 15 17 20.690 18.184 -67.580 55.7 2. 2D 1. 7 90 15 4.9 193 40 9.3 344 46 68 0.19 12 162 56 n 1 

342 1977 8 26 17 16 27.460 18.352 -66.142 1.7 o. 7D 1.2 258 0 3.6 348 0 53.9 90 89 68 0.11 6 208 3 7 D 1 

343 1977 8 27 00 23 13.730E 18.240 -66.072 0.8 2.3D 2.3 254 5 3.3 346 22 7.0 151 67 68 0.30 9 290 32 D 1 * 

344 1977 8 27 15 12 43.870 19.143 -66.472 8.3 2. 7D 1.8 284 0 9.2 14 0 >99.9 90 89 68 0.09 9 289 •• D 1 

345 1977 8 27 15 15 0.380 19.062 -66.425 65.6 2.0D 3.3 294 21 3.6 33 24 35.3 167 57 68 0.11 7 315 •• D 1 

346 1977 8 28 8 34 8.300 18.116 -65.523 9.5 2.1D 7.6 256 22 11.9 2 34 4.6 139 47 6~ 0.02 5 326 70 D 1 

347 1977 8 29 7 38 39.190 18.681 -65.460 22.4 3.0D 3.0 22 33 3.8 264 35 9.3 142 37 68 0.18 13 329 •• D 1 

348 1977 8 30 3 40 23.820 19.252 -66.368 26.8 2.3D 7. 2 230 14 4.1 136 17 85.6 357 67 68 0.20 8 308 •• D 1 

349 1977 8 30 9 29 21.750 18.101 -66.881 14.9 1. 2D o.s 204 13 0.4 105 34 0.5 311 52 68 0.04 8 151 24 H 1 

350 1977 8 31 6 29 50.210 18.035 -65.686 13.7 1.4D 2.7 301 8 1.6 35 21 1.1 192 67 68 0.09 8 304 50 D 1 

351 1977 8 31 17 7 55.270 19.057 -65.347 1.3 3.m 2.7 357 24 4.5 100 27 1.9 232 52 68 0.14 12 316 •• D 1 

352 1977 8 31 20 14 8.990 18.201 -66.046 24.5 1.1D 1.5 239 2 17.0 148 12 4.4 338 77 68 0.10 6 173 33 n 1 

w 353 1977 9 2 3 58 32.070 19.135 -66.830 13.6 2.4D 2.9 109 11 4.1 204 26 22.6 359 61 68 0.18 9 282 •• D 1 -...) 354 1977 9 2 9 34 31.700 18.161 -66.155 32.2 0.9D 1.0 81 6 1. 5 350 9 2.0 204 79 68 0.11 11 66 21 B 1 

355 1977 9 2 16 52 3.670 18.405 -66.172 13.5 0. 8D 2.2 262 3 7.4 171 6 18.6 19 83 68 0.10 5 232 34 D 1 

"56 1977 9 4 3 19 2.630 18.427 -66.548 84.3 2.6D 5.5 180 4 1. 4 89 5 3.2 308 83 68 0.14 13 204 43 D 1 

357 1977 9 5 3 00 10.930 17.988 -66.751 106.0 1. 9D 5. 4 100 7 15.4 8 18 29.3 210 70 68 0.02 5 187 36 D 1 

358 1977 9 6 19 23 41.760 18.185 -66.863 16.0 1.9D 0.7 101 4 1.5 192 10 3.5 350 79 68 0.11 10 128 31 B 1 

359 1977 9 8 2 48 12.900 17.970 -65.379 10.1 2.1D 2.6 148 11 3.8 54 18 1.3 267 68 68 0.05 6 330 83 D 1 

360 1977 9 8 5 35 10.240 18.033 -65.404 11.1 1.9D 4.9 249 8 12.8 341 12 4.0 126 75 68 0.08 5 331 79 D 1 

361 1977 9 8 8 4 11.090 18.292 -67.881 22.2 3.8D 9.7 313 13 2.6 52 36 s.s 207 51 68 0.19 9 248 83 D 1 

362 1977 9 11 7 13 0.740 17.874 -66.139 13.6 1. 1D 3. 4 330 18 1. 7 230 29 1. 1 88 55 68 0.08 7 320 46 D 1 

363 1977 9 11 19 45 35.030 17.874 -68.359 12.5 3.1D 3.1 337 9 1.3 72 32 0.6 234 56 68 0.04 8 333 •• n 1 

364 1977 9 12 21 58 2.380 18.167 -66.203 40.3 0.8D 2.4 76 15 3.8 176 33 4.9 326 52 68 0.13 7 169 17 c 1 

365 1977 9 12 23 17 59.070 18.795 -65.129 4.9 3. 8D 6.5 181 10 4.4 280 42 25.3 80 46 68 0.28 12 325 •• D 1 

366 1977 9 13 1 2 49.610 18.923 -64.991 20.0 2.9D 26.2 325 1 >99.9 234 11 12.9 61 78 68 0.07 4 341 •• n 1 

367 1977 9 13 8 31 41.990 17.295 -65.078 4.2 2.7D 4.4 201 19 1.3 304 33 9.5 86 so 68 o. 07 8 340 •• D 1 

368 1977 9 14 12 46 18.140 18.089 -66.066 26.3 1. 5D 0.7 81 3 1. 0 350 8 1.6 191 81 68 0.08 10 156 24 c 1 

369 1977 9 14 14 19 24.180 18.187 -67.351 14.1 2. SD 5.9 227 9 1.7133 21 2.9 338 66 68 0.25 10 203 34 D 1 

370 1977 9 14 17 27 56.750 18.138 -65.300 3.5 2. OD 1. 2 200 13 0.9 104 28 1.7 312 58 68 0.02 6 333 92 c 1 

371 1977 9 16 7 47 16.220 18.072 -66.355 57.5 1. 6D 2.6 4 14 1.7 99 21 1.9 243 64 68 0.11 12 262 23 D 1 

372 1977 9 17 19 36 48.780 18.343 -66.142 66.7 2 .m 6.0 179 28 3.1 289 33 3.8 57 44 68 0.18 9 176 29 D 1 

373 1977 9 18 11 45 4.470 18.702 -67.103 83.5 2.3D 18.3 197 25 2.4 94 27 3.9 323 51 68 0.17 9 302 53 D 1 

374 1977 9 20 16 21 10.210 18.033 -65.506 5.6 2.7D 5.1 183 15 3.3 88 19 6.0 308 65 68 0.19 9 322 69 D 1 

375 1977 9 20 19 37 ~3.330 19.651 -65.925 70.5 z.on 5.5 1% 33 ?..~ 60 3'5 ?..4 30~ 11 ~~ o.na R 101 F-.4 n 1 

376 1977 9 22 9 15 36.540 18.618 -67.006 27.3 2. 4D 1.8 324 3 4.3 233 34 1.0 59 55 68 0.07 8 311 •• D 1 

377 1977 9 22 15 8 59.730 18.240 -6 7.192 21.7 1. 9D 2.8 268 22 1.0 18 39 1.1 156 42 68 0.10 9 22 7 28 D 1 
Table B.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM 0 auth * ------------------------------------------------------------------------------------------------------------------------------------

PRN77 378 1977 9 23 14 59 26.310 18.606 -65.433 21.5 3.8D >99.9 243 8 18.8 151 17 8.1 357 71 68 0.04 5 337 93 D 1 

379 1977 9 25 22 9 5.700 18.996 -66.044 56.6 2. 6D 11.8 52 18 6.7 313 26 58.4 173 57 68 0.18 6 299 •• D 1 

380 1977 9 27 4 16 38.580 18.219 -65.892 16.1 2.0D 0.4 150 4 0.2 242 27 1.8 52 62 68 0.01 6 233 30 c 1 

381 1977 9 27 17 17 40.430 18.235 -65.865 15.0 1. 7D 3.9 87 26 1.5 333 38 1.2 201 40 68 0.07 6 197 31 n 1 

382 1977 9 27 19 54 23.320 18.084 -66.480 8.5 1. 9D 1. 0 98 2 2.5 8 5 4.3 209 84 68 0.16 10 167 22 c 1 

?83 1977 9 28 5 25 15.510 18.636 -65.511 30.1 3.5D >99.9 64 15 11.7 328 19 33.4 189 65 68 0.11 5 331 •• D 1 

384 1977 9 28 7 36 11.140 18.026 -66.435 19.9, 2.0D 0.7 261 1 1. 6 351 2 2.6 144 87 68 0.10 11 205 29 c 1 

385 1977 9 29 16 9 43.790E 18.328 -66.163 0.3 1. 9D 2.1 272 1 3.5 2 3 75.4 163 86 68 0.12 5 280 24 D 1 * 

386 1977 9 29 17 1 35.350E 18.351 -66.177 1. 4 1. 4D 2.7 48 4 5.9 317 13 36.7 155 76 6R 0.06 5 284 33 D 1 * 387 1977 9 30 1 17 43.920 18.684 -66.118 75.4 2. 2D 2.5 289 27 2.8 42 36 8.8 172 41 68 0.16 12 267 52 D 1 

388 1977 9 30 11 48 2.990 18.399 -67.347 11.0 2. 9D 2.6 178 2 1.1 268 3 1. 6 54 86 68 0.19 13 180 37 c 1 

389 1977 9 30 13 28 22.140 18.533 -64.974 17.2 2. 6D 4.7 80 12 86.0 347 14 7.3 209 71 68 0.13 6 354 •• D 1 

390 1977 10 1 6 24 18.010 18.583 -66.243 35.8 2.6D 1.7 276 2 3.4 6 13 7.1 177 76 6R 0.21 14 22~ 51 D 1 

391 1977 10 5 10 56 17.760 18.639 -67.487 9.9 3. 7D 2.3 67 1 12.7 157 15 4.0 334 74 68 0.18 7 251 •• D 

392 1977 10 5 12 16 28.590 18.228 -67.579 15.9 2. 7D 1. 6 80 1 3.1 170 21 7.8 348 68 68 0.24 10 198 52 D 

391 1977 10 6 18 29 44.030 18.006 -65.558 6.6 2.5D 0.9 356 1 0.5 87 21 0.6 264 68 68 0.03 9 320 71 c 1 

394 1977 10 6 18 39 55.840 17.713 -65.576 38.2 2.4D 2.7 137 13 3.7 231 16 >99.9 9 69 68 0.16 6 332 •• n 1 w 395 1977 10 6 21 26 27.020 17.981 -65.271 7.8 3.3D 13.5 118 18 38.9 19 27 6.9 237 56 68 0.22 6 335 •• D 1 00 396 1977 10 6 23 21 36.540 18.101 -67.444 22.2 2. 4D 7.9 228 11 2.0 134 19 4.1 346 67 68 0.21 8 248 •• D 1 

397 1977 10 7 00 39 50.530 17.913 -66.535 10.9 2. 5D 11.6 2 2 2.6 93 15 4.0 265 74 68 0.19 7 260 53 D 1 

398 1977 10 7 16 24 59.300 17.809 -67.990 19.3 3.3D 27.2 37 13 2. 7 136 33 8.8 289 53 68 0.16 8 294 •• D 1 

399 1977 10 8 12 00 27.630 18.451 -66.230 102.2 3. 2D 1.7 93 9 7. 8 185 17 4.3 337 70 68 0.13 10 205 41 D 1 

400 1977 10 11 17 9 32.220 18. 110 -65.983 15.8 1. 5D 3.9 15 5 6.6 283 19 12.1 120 70 68 0.03 5 306 37 D 1 

401 1977 10 11 19 27 5.350 18.284 -66.436 37.5 1. 7D 1.6 274 5 3.2 6 24 4.7 172 65 68 0.13 8 14 7 36 c 1 

402 1977 10 11 20 7 17.030 18.124 -65.993 27.5 2. 2D 1. 0 2 38 3 8. 7 329 13 2.9 135 76 68 0.06 6 228 36 D 1 

403 1977 10 12 15 9 54.730 19.220 -67.257 11.4 3.8D 3.6 85 13 6. 1 180 20 20.3 325 65 68 0.20 11 297 •• D 1 

404 1977 10 12 20 32 38.010 18.064 -66.486 5.8 2.1D 1.2 93 2 2.7 183 4 7.9 337 85 68 0.14 7 181 21 n 1 

405 1977 10 13 6 31 50.230 18.597 -65.554 37.6 2.5D 88.1 142 13 6.7 44 31 11.8 251 55 68 0.01 5 352 •• D 1 

406 1977 10 13 10 13 5.070 17.861 -66.161 14.7 2 .lD 7. 7 347 11 9.9 248 41 2.2 90 47 68 0.09 5 291 58 D 1 

407 1977 10 14 14 43 35.580 19.242 -66.405 20.0 3.3D 6.3 273 0 44.6 3 0 >99.9 90 90 68 0.08 5 300 •• D 1 

408 1977 10 14 20 53 52.420 17.874 -65.945 13.9 1.7n 2.8 63 1 6. 7 153 19 93.2 331 70 68 0.04 5 289 49 n 1 

409 1977 10 15 7 4 52.640 18.889 -66.776 28.5 2. 2D 5.8 61 1 6.7 331 1 >99.9 195 88 68 0.09 5 318 •• D 1 

410 1977 10 16 15 27 7. 900 17.655 -67.500 10.8 3.3D 4.5 288 2 5.6 19 23 42.4 194 66 68 0.34 8 249 94 D 1 

411 1977 10 17 21 19 47.300 18.743 -65.020 21.0 2.9D 15.5 152 4 3.3 243 19 4.2 so 70 n8 0.15 R 349 •• D 1 

412 1977 10 18 21 10 40.350 19.020 -65.244 0.5 4.1D 15.2 121 19 6.5 23 21 3.9 249 60 68 0.17 7 329 •• D 1 411 1Q77 10 10 q q '•0.110 lg.395 -67.2S2 7.') 2. SD 3.1 3.J7 1 1.3 R7 6 3.4 258 83 68 0.1P. 9 174 32 r, 1 

414 1977 10 19 20 10 47.170E 18.354 -66.153 1.3 2.1D 1.2 68 1 2.1 338 5 16.9 170 84 68 0.16 8 209 27 D 1 * 415 1977 10 22 15 29 51.340 19.159 -65.389 56.5 2.9D 7.6 291 3 2.9 22 23 21.4 194 66 68 0.06 6 337 •• n 1 

616 1977 10 22 19 39 19.330 19.026 -68.505 4.7 3. 2D 2.9 35 13 >99.9 299 23 49.2 153 63 6R 0.09 7 320 •• n 1 

417 1977 10 23 2 23 39.540 18.383 -65.919 41.3 1. 6D o.R 258 1s 1.2 157 34 1. 1 8 51 68 0.05 10 260 38 c 1 

418 1977 10 23 16 5 2 7.070 18.285 -66.302 22.7 1. 7D 1.0 90 5 1. 9 1 R2 23 2.6 349 66 6R 0.17 13 181 24 C 1 

419 1977 10 23 20 24 35.640 18.791 -65.354 18.8 3. 4D 4.0 354 26 10.9 106 38 3.R 239 41 68 0.17 9 318 •• n 
w 

\0 

Table 8.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) 

Name Index yr mo d h min s 

North East Focal 

latitude longitude depth 

(deg) (deg) (km) 

Error ellipsoid axes 

------------ ------------ ------------ Rms No. Hypo ~1 a (krn) Tr Pl b(km) Tr Pl c(km) Tr Pl ~~ (s) ob Gap DH () auth * 

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

PRN77 420 1977 10 23 22 44 19.370 

421 1977 10 24 22 15 0.350 

422 1977 10 25 4 00 41.020 

423 1977 10 26 12 58 35.780 

424 1977 10 27 17 28 6.200 

425 1977 10 29 2 36 13.160 

426 1977 10 30 4 48 15.450 

427 1977 10 30 ~ 31 51.630 

428 1977 10 31 20 26 48.820 

429 1977 11 1 12 42 24.690 

430 1977 11 2 4 55 34.400 

431 1977 11 2 5 12 47.350 

432 1977 11 2 7 32 21.550 

433 1977 11 2 9 10 50.820 

434 1977 11 2 11 40 3.950 

435 1977 11 2 13 51 42.530 

436 1977 11 2 16 38 48.040 

437 1977 11 2 23 7 25.530 

438 1977 11 2 23 23 5.320 

439 1977 11 2 23 45 44.930 

440 1977 11 3 2 43 14.400 

441 1977 11 3 4 37 7.830 

442 1977 11 3 5 2 27.130 

443 1977 11 3 5 5 37.390 

444 1977 11 3 6 27 13.210 

445 1977 11 3 8 1 59.200 

446 1977 11 3 8 18 35.740 

447 1977 11 3 9 14 50.720 

448 1977 11 4 3 25 2.910 

449 1977 11 5 19 17 34.130 

450 1977 11 6 2 00 53.890 

451 1977 11 6 3 7 45.620 

452 1977 11 7 20 3 13.950E 

453 1977 11 8 20 2 53.100 

454 1977 11 8 23 40 39.220 

455 1977 11 9 20 14 50.280 

456 1977 11 14 20 45 26.170 

457 1977 11 16 4 41 41.550 

458 1977 11 16 13 38 28.520 

459 1977 11 1S 4 35 59.140 

460 1977 11 18 4 39 32.070 

461 1977 11 19 1 8 40.640 

18.706 

18.598 

18.609 

17.892 

18.743 

18.551 

18.574 

18.735 

18.557 

1~.321 

19.166 

19.104 

19.045 

19.128 

19.116 

19.113 

18.958 

19.207 

19.108 

19.109 

19.057 

18.758 

19. 2 34 

19.105 

18.123 

19.129 

19.118 

19.103 

19.366 

18.173 

19.186 

18.316 

18.379 

18.342 

19.206 

18.828 

19.085 

18.031 

18.057 

17.~92 

18.530 

18.780 

-65.214 

-64.380 

-67.568 

-66.921 

-65.669 

-66.504 

-66. 807 

-67.040 

-65.403 

-66.173 

-66.506 

-66.513 

-66.495 

-66.550 

-66.505 

-66.494 

-66.274 

-66.523 

-66.513 

-66.533 

-66.564 

-66.638 

-66.515 

-66.514 

-66.958 

-66.539 

-66.406 

-66.517 

-66.519 

-67.685 

-67.866 

-65.942 

-66.123 

-66.160 

-6 7. 464 

-65.041 

-66.440 

-67.001 

-66.797 

-fi5.013 

-66.269 

-6 7. 211 

6.7 3.3D 

3. 9 3. 4D 

2 7. 4 2. 7D 

11.0 1. 9D 

73.6 2.8D 

65.4 3. 8D 

14. 9 2. SD 

O. 1 2. 6D 

25.5 3.0D 

62.6 3.sn 

7.5 2.9n 

17.0 2.8D 

27.5 2.8D 

36.5 2.6D 

15.9 2.5D 

17.1 2.8n 

53.9 2. 6D 

43.9 3.3D 

16.3 3.2n 

27.0 2.7D 

42.3 2. 6D 

6 7. 2 3. 5n 

1. 9 1. 2n 

1').8 3.1D 

14.3 2.4n 

19. A 2. 8D 

1. 9 2. 7D 

16.1 3. OD 

27. 1 2. 5n 

13.0 3.8D 

87. 7 3. 4D 

l~9. 8 2. 2D 

0.2 2.1D 

21.1 2.1D 

13.9 3. 4D 

20.0 3.0D 

20.n 2.RD 

32.9 2.6D 

12.4 3.0D 

11.5 1.5D 

103.8 2. 3D 

26.4 3.1D 

6.3 110 12 

51.0 344 0 

7.6 282 0 

0.4 93 18 

3.5 73 11 

1.8 276 1 

2.9 339 19 

1.4 90 3 

14.0 326 0 

1. 3 280 7 

1.8 275 0 

1.2 283 2 

1.5 279 0 

2.6 301 5 

0.7 286 0 

1.3 50 1 

5.2 71 5 

3.2 86 5 

0.8 291 0 

6.9 234 5 

4.3 78 2 

1.8 283 0 

1.6 27n o 

1.3 284 0 

1.7 22 12 

O.fi 72 1 

3.5 2 32 

1.8 267 () 

5.3 243 5 

5.0 230 2 

6. 1 300 19 

13.11 205 32 

3. 7 32l~ 0 

2.5 54 3 

3.8 206 18 

25.8 325 3 

4.2 297 3 

'i.8 165 8 

1.3 271 5 

1.5 ~52 10 

3.4 88 2 

1.9 70 31 

3.9 17 16 2.8 235 69 68 0.21 1') 324 •• n 

>99.9 254 0 >99.9 270 90 68 0.11 4 349 •• p 

35.2 12 o >99.9 90 90 68 0.26 n 349 •• n 

2.8 350 36 o.s 204 48 68 0.14 6 233 47 n 

2.8 335 36 11.3 178 51 6R 0.16 12 302 R2 n 

4.3 6 7 6.7 177 82 68 0.16 12 228 46 D 

1.0 84 35 5.6 227 48 6R 0.13 8 233 SOD 

2.6 359 13 4.7 192 76 68 o.o8 6 248 87 n 

>99.9 236 0 >99.9 270 89 68 0.12 4 334 93 D 

2.9 14 29 3.6 177 59 68 0.14 13 168 41 c 

7.7 5 0 >99.9 90 90 68 0.12 11 275 •• D 

1.7 13 8 4.6 179 81 68 0.13 16 270 9R r, 

1.0 9 o >99.9 90 90 6r 0.14 12 266 91 n 

5.1 32 9 >99.9 183 79 68 0.10 6 317 •• D 

1.0 16 o >99.9 90 90 68 o.oR 14 271 99 n 

2.0 320 1 >99.9 184 88 68 0.08 9 101 •• D 

5.0 337 35 29.6 169 54 68 0.10 6 326 84 n 

4.7 355 18 31.7 191 71 68 0.22 11 290 •• D 

1.3 21 0 >99.9 90 89 68 0.11 16 271 98 D 

3.6 141 22 >99.9 336 67 68 0.11 6 347 •• D 

2.9 347 14 29.9 176 75 68 0.10 7 332 •• D 

8.2 193 37 3.4 13 51 68 0.13 9 259 62 D 

8.1 n o >99.9 90 90 68 0.12 12 279 •• n 

2.4 14 o >99.9 90 89 n8 0.16 17 270 96 n 

1.2 283 39 0.7 126 4~ 68 0.12 13 230 37 c 

0.9 342 3 >99.9 1~0 R6 68 0.02 6 303 •• D 

9.0 24R 34 7.3 124 39 68 0.12 6 330 •• D 

2.3 357 0 >99.9 90 89 6R 0.15 13 270 98 D 

3.1 1~1 22 >99.9 345 67 ~R 0.14 9 326 •• n 

9.8 321 37 2.3 137 52 68 0.20 11 306 90 n 

18.9 40 26 92.7 178 56 68 0.19 7 346 •• D 

5.9 321 34 82.3 84 39 6R n.44 4 322 32 n 

11.0 234 0 >99.9 270 89 68 0.20 5 298 30 D 

7.R 322 34 >99.9 149 55 68 0.08 5 279 3'i D 

2.2 103 34 19.8 31? 50 6R 0.22 16 300 •• D 

>99.9 234 10 11.5 72 79 68 0.06 5 343 •• D 

5.4 27 1 >99.9 162 85 6P 0.16 7 332 •• P 

2.5 256 10 3.8 36 77 6R 0.18 14 341 72 n 

3.1 2 17 2.1 165 72 68 0.26 15 169 31 c 

3.3 159 15 5.9 13 70 sq o.1s 9 258 39 n 

9.3 179 25 2.9 354 64 68 0.16 11 233 49 D 

6.3 185 35 4.1 311 39 6R 0.26 15 257 66 D 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 * 

1 

1 

1 

1 

1 

1 

1 

1 

1 
Table 8.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

------------------------------------------------------------------------------------------------------------------------------------ Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ----------------------- latitude longitude depth ------------ ------------ ------------ Rms No. Hypo 

Name Index yr mo d h min s (deg) (deg) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * ------------------------------------------------------------------------------------------------------------------------------------ PRN77 462 1977 11 20 1 51 0.260 18.849 -66.068 39.8 2.3D 2.9 55 9 2. 2 320 28 13.5 162 60 68 0.05 6 323 82 D 1 

463 1977 11 20 19 5 22.320 18.036 -66.819 6.7 1. 8D 1.3 132 11 2.1 228 29 3.9 23 58 68 0.12 9 269 52 c 1 

464 1977 11 22 2 52 47.630 18.542 -66.538 22.0 2.4D 2.9 91 5 9.4 0 1P 26.0 207 78 68 0.21 7 255 49 D 1 

465 1977 11 27 18 29 50.600 18.872 -64.788 22.6 3.2D 80.5 331 1 9.8 240 22 >99.9 64 67 68 0.18 5 354 •• D 1 

466 1977 11 28 18 16 8.190 18.444 -68.045 72.3 3.2D 3.8 80 16 13.1 176 23 8.2 318 61 68 0.29 13 293 99 D 1 

467 1977 12 1 6 17 24.830 17.874 -67.618 20.0 3.3D 30.4 346 0 >99.9 256 0 >99.9 270 90 68 0.15 5 350 •• D 1 

468 1977 12 1 19 36 51.320 18.353 -66.151 11.9 1. 7D 2.0 257 3 3.7 347 9 14.9 148 80 68 0.13 6 208 30 D 1 

469 1977 12 1 19 47 22.520 19.126 -66.127 16.4 2.7D 2.4 302 0 3.3 32 0 >99.9 90 90 68 0.24 7 335 •• D 1 

470 1977 12 1 21 22 2. 920 19.224 -66.135 15.9 2.8D 5.3 335 0 6.0 245 0 >99.9 270 89 68 0.26 9 322 •• J) 1 

471 1977 12 1 22 56 7.780 19.201 -66.091 14.9 2.6D 4. 4 2 70 1 2.7 179 33 >99.9 2 56 68 0.17 8 331 •• D 1 

472 1977 12 1 23 43 44.380 19.048 -66.486 4.1 2.7D 14.3 205 5 8.2 299 31 5.3 106 58 68 0.06 5 330 •• D 1 

473 1977 12 2 00 34 23.150 18.918 -65.314 44.5 3.1D 7.1 49 19 21.6 306 33 85.6 164 50 ~8 0.10 5 352 •• D 1 

474 1977 12 2 00 45 9. 710 19.113 -66.447 2.9 2.6D 3.2 168 4 5.7 258 6 2.9 44 82 68 0.09 6 341 •• D 1 

475 1977 12 2 1 6 4.170 19.106 -66.517 7.9 3. 3D 1. 7 264 9 2.8 169 28 19.4 11 60 68 0.17 12 270 98 D 1 

476 1977 12 2 1 7 53.010 19.150 -66.441 40.3 2.7D 4.9 251 2 3.3 341 12 48.7 151 77 68 o.os 6 333 •• D 1 

477 1977 12 2 1 41 13.780 17.617 -66.450 81.8 2. 3D 16.9 104 20 7.2 211 40 >99.9 354 43 68 0.15 4 344 •• D 1 

47.8 1977 12 2 1 58 22.260 18.382 -66.230 3.4 2.6D 3.5 257 10 6. 2 350 13 41.3 130 73 68 0.08 5 306 36 D 1 

479 1977 12 2 3 A4 53.170 19.189 -66.494 31.0 3.0D 5.4 290 1 10.6 20 2 >99.9 173 87 68 0.24 7 289 •• D 1 .j::-

0 480 1977 12 2 4 00 2.390 18.150 -6 7. 344 1).5 3.0D 2.4 185 7 1.7 94 8 6.3 315 79 ~8 0.18 7 168 60 c 1 

481 1977 12 2 20 12 15.490E 18.340 -66.140 1. 3 1. 9D 1. 5 72 2 3.1 342 10 17.2 174 79 68 0.17 7 202 25 D 1 * 

482 1977 12 2 20 26 36. 720E 18.096 -66.489 1.1 1. 9D 2. 3 187 1 1. 0 97 2 48.7 303 87 68 0.21 10 159 21 c 1 * 

483 1977 12 3 2 52 41.730 17.957 -66.228 7.1 1. 8D 3.6 192 3 1.7 101 5 11.1 312 84 68 0.20 8 245 34 D 1 

484 1977 12 3 3 41 49.850 19.124 -66.484 18.9 2. 6D 16.1 27 1 7.3 297 2 >99.9 144 87 68 0.04 5 332 •• D 1 

485 1977 12 3 5 00 46.610 19.058 -66.953 34.1 3.1D 1.1 83 5 2.5 352 14 26.9 192 75 68 0.19 11 269 93 D 1 

486 1977 12 3 11 2 10.820 19.180 -66.533 2 7. 7 2.8D 4.6 319 0 9.0 229 0 >99.9 270 89 68 0.10 6 334 •• D 1 

487 1977 12 3 12 35 58.920 18.790 -68.385 19.6 4.2D 12.9 136 11 3.8 39 35 9.2 240 52 68 0.13 7 321 •• D 1 

488 1977 12 3 14 15 41.580 19.144 -66.513 6.7 3.5D 2.1 260 11 4. 2 164 2 7 23.1 11 60 68 0.18 10 273 •• D 1 

489 1977 12 3 16 33 55.790 18.521 -67.539 19.2 3. 3D 2.1 71 9 4.5 333 44 6.5 171 44 68 0.36 17 234 60 D 1 

490 1977 12 3 16 39 5.380 18.714 -67.568 5.0 2. 7D 1.9 65 19 4.6 170 36 3.8 313 47 68 0.26 11 259 76 D 1 

491 1977 12 4 8 42 26.820 19.177 -66.507 14.8 3.1D 1.6 109 10 4.1 206 33 15.4 4 55 68 0.14 11 275 •• D 1 

492 1977 12 4 11 51 33.950 18.970 -67.667 3.6 2.9D 18.4 140 20 5.1 242 30 8.7 21 52 68 0.23 6 280 98 D 1 

493 1977 12 6 5 31 40.990 18.971 -65.745 20.0 2.8D 4.4 18 4 8.2 288 4 >99.9 153 84 68 0.15 7 339 •• D 1 

494 1977 12 7 8 38 9.760 18.318 -66.079 14.4 1. 8D 0.8 257 1 1.5 166 4 2.1 1 85 68 0.12 10 190 24 c 1 

495 1977 12 7 8 41 30.110 18.106 -66.083 26.2 1. 5D 1. 0 80 1 1.4 350 2 2.8 196 87 68 0.10 9 148 22 c 1 

'•Y6 1977 12 

~ ~ ;~ ~t:661 18.930 -66.674 42.5 2.6D 1.4 92 2 2.8 0 27 11.6 185 62 68 0.15 14 283 79 D 1 

497 1977 12 17.979 -66.244 6.7 2.2D 6.9 12 4 3.0 103 6 26.0 249 82 68 0.18 6 240 35 D 1 

498 1977 l2 ~ Q 32 113. ?40 I:. 999 -57.173 12.1 2.4D 2.6 240 34 1.1 121 36 5.1 359 35 68 0.23 14 238 48 D 1 

499 1977 12 8 10 34 37.540 18.914 -66.702 25.2 2.7D 4.3 176 18 2.1 76 28 8.7 294 55 6R 0.22 10 269 90 D 1 

500 1977 12 8 13 7 38.630 18.037 -66.175 14.1 2.6D 0.5 78 4 0.9 168 4 1.8 303 84 68 0.05 8 236 28 c 1 

501 1977 12 8 16 59 25.760 18.268 -66.085 20.5 1.5D 2.5 243 9 79.1 145 40 12.0 343 48 68 •••• 4 209 34 D 1 

502 1977 12 11 1 so 14.170 18.841 -65.515 u.o 3.2D 3.4 316 3 2.5 224 31 19.6 51 58 68 0.12 9 319 98 D 1 

503 1977 12 11 2 00 5.440 17.787 -65.548 17.0 2.8D 5.3 170 1 16.1 260 1 >99.9 34 88 68 o.o1 4 351 85 D 1 

504 1977 12 11 3 30 52.020 18.822 -66.332 17.9 2.2D 2.1 57 1 2.8 327 2 66.9 174 87 68 0.13 8 316 75 D 1 
~ 

f--

Table 8.--Catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

-------------------------------------------------------------------------------------------------------------------------------------- Catalog Origin time (UTC) North East Focal Error ellipsoid axes 

---------- ---------------------- latitude ------------- ----------- ----------- Rms No. Hypo longitude depth 

Name Index yr mo d h min s (de g) (de g) (km) M a(km) Tr Pl b(km) Tr Pl c(km) Tr Pl % (s) ob Gap DM Q auth * --------------------------------------------------------------------------------------------------------------------------------------

PRN77 505 1977 12 11 9 6 24.400 19.210 -66.420 35.7 2.8D 3.3 47 5 4.4 317 6 61.4 177 82 68 0.20 9 333 •• D 1 

506 1977 12 11 14 42 57.990 18.715 -65.057 5.1 3.0D 54.0 330 3 5.8 238 32 >99.9 65 57 68 0.11 5 354 •• D 1 

507 1977 12 12 5 9 0.350 18.072 -66.207 15.3 2.3D 5. 0 162 6 1.5 254 20 1. 2 56 69 68 0.12 7 215 25 D 1 

508 1977 12 12 5 50 14.590 18.865 -65.266 5.9 3.3D 7.4 333 7 2.5 239 31 38.4 75 58 68 0.12 8 330 •• D 1 

509 1977 12 14 2 6 1.670 17.922 -66.277 7.1 1. 6D 1.6 97 4 2.1 188 13 5.7 351 76 68 0.10 8 310 41 D 1 

510 1977 12 14 14 34 19.660 17.800 -65.136 42.2 2. 9D 15.9 201 4 7. 6 110 9 48.9 314 80 68 0.20 7 337 •• D 1 

511 1977 12 15 19 4 12.340 18.169 -,68. 069 107.5 3.5D 12.4 180 5 6. 1 273 36 4.1 83 53 68 0.23 11 318 •• D 1 

512 1977 12 16 20 13 49.760 18.341 -66.150 1. 4 1.7D 1.5 74 1 3.0 344 10 17.6 170 79 68 0.13 6 203 25 D 1 

513 1977 12 18 18 46 12.530 18.458 -66.087 109.8 2. 2D 7.3 182 27 3.1 290 32 2.1 60 45 68 0.10 10 246 35 D 1 

514 1977 12 20 7 58 25.010 18.858 -67.333 4.8 2.5D 3.9 66 30 11.2 182 37 4.7 309 38 68 0.23 8 285 81 D 1 

515 1977 12 20 13 1 18.090 18.172 -67.946 53.7 2.8D s.s 317 30 9.4 206 32 ?..9 80 43 68 0.17 8 275 91 D 1 

516 1977 12 20 13 30 2.040E 18.134 -66.524 o.s 2.SD 0.8 284 0 2.7 14 0 >99.9 90 89 68 0.15 9 188 40 D 1 * 

517 1977 12 20 13 46 24.240 18.768 -67.420 1o.q 2.6'0 1.3 61 34 3.5 178 34 1.6 300 37 68 0.15 11 252 74 D 1 

518 1977 12 20 15 1 3.020 18.417 -66.108 83.6 2. 7D 1.1 295 9 5.0 201 19 7.3 49 68 68 0.03 6 240 4 7 n 1 

519 1977 12 21 2 36 39.890 17.765 -66.701 9.4 2.1n 2.0 41 9 2.3 303 39 1.2 142 49 68 0.14 11 307 52 D 1 

520 1977 12 23 2 11 9. 770 17.931 -67.223 20.8 3.1D 21.3 344 3 >99.9 74 q 9.0 236 80 68 0.06 5 346 •• D 1 

521 1977 12 24 2 59 37.640 18.828 -66.491 25.8 2.1D 80. 1 151 6 9. 2 243 20 6.1 45 69 68 0.02 5 323 86 D 1 

522 1977 12 25 12 14 21.960 18.193 -66.071 13.5 1. 9D 0.8 91 1 1.1 1 1 2.6 226 88 68 0.15 12 99 24 B 1 

523 1977 12 26 18 3 49.610 18.101 -64.966 15.9 2. 8D 4. 2 277 0 9.2 7 ('l >99.9 90 90 68 0.20 7 343 •• D 1 

524 1977 12 27 5 42 39.750 17.790 -66.648 11.5 2.3D 1.0 233 25 1.5 343 36 0.6 116 43 68 o.os 8 297 46 c 1 

525 1977 12 31 23 2 1. 050 18.970 -66.275 20.6 2. 7D 2.4 278 0 3.5 8 4 52.2 188 86 68 0.22 12 290 85 D 1 

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

Table 9.--References for catalog of 1'977 earthquakes located by the HYPOELLIPSE program 

[Cat, catalog; Auth no., authority number cited in table 8] 

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

Cat Auth 

Name no. References 

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

PRN77 1 u.s. Geological Survey, this report. 

-----------------------------------------------------------------------------------------
Catalog 

Name Index 

PRN77 14 

29 

42 

59 

84 

118 

145 

150 

151 

152 

165 

175 

183 

184 

185 

.J::... 186 (',) 188 

189 

197 

205 

206 

244 

245 

246 

247 

248 

249 

250 

251 

252 

253 

254 

256 

337 

343 

385 

386 

414 

Table 10.--Remarks for catalog of 1977 earthquakes located by the HYPOELLIPSE program 

Remarks 

Probable blast attributed to road construction or quarries. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

One of a 12-earthquake swarm that occurred north of the Virgin Islands in the Puerto Rico 

Trench. 

Do. 

Do. 

Probable blast attributed to road construction or quarries. 

Do. 

One of a small swarm of earthquakes that were located on the south coast of Puerto Rico near the 

town of Central Aguirre. 

Do. 

Do. 

Do • 

Do. 

Do. 

Probable blast attributed to road construction or quarries. 

A large earthquake, magnitude 4.5, that originated in the Puerto Rico Trench, northeast of 

Puerto Rico. 

An aftershock of the magnitude 4.5 earthquake. 

One of a small swarm of earthquakes that were located in the Puerto Rico Trench, northeast of 

Puerto Rico. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Do. 

Probable blast 

One of a swarm 

Probable blast 

Do. 

Do. 

Do. 

Do. 

attributed to road construction or quarries. 

of earthquakes that were located in the Puerto Rico Trench, northeast of Puerto Rico. 

attributed to road construction or quarries. 
p.. 

w 

Table 10.--Remarks for catalog of 1977 earthquakes located by the HYPOELLIPSE program--Continued 

----------------------------------------------------------------------------------------------------------------------------~---------

Catalog 

Name Index 

PRN77 452 Do. 

481 Do. 

482 Do. 

516 Do. 

Remarks 

-----------------------------------------------~==~--------------------------------------------------------------------------------

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