From: cowen@JADE.UCDAVIS.EDU
Newsgroups: ca.earthquakes,sci.geo.geology
Subject: Caltech Weekly Report, 21 January
Date: 26 Jan 93 18:11:19 GMT
Reply-To: cowen@JADE.UCDAVIS.EDU
Followup-To: ca.earthquakes
Organization: Geology Department, University of California, Davis

Here is the text of the Caltech weekly report. It accompanies a postscript
map that I can't or won't re-post because it's a very big file. You can 
ftp the text and map from seismo.gps.caltech.edu under successive
directories pub and ca.earthquakes. 
I've edited the text lightly, but the information is unaffected.

Weekly Earthquake Report for Southern California, January 14 - 20, 1993

Kate Hutton, Seismological Laboratory (kate@bombay.gps.caltech.edu)
Lucy Jones, U.S. Geological Survey
California Institute of Technology

This document is a commentary on current seismic activity. The 
earthquakes discussed have been detected and processed 
automatically. All epicenters and magnitudes have been reviewed 
to exclude obvious blunders; however, they must still be 
considered preliminary.  For further information, please contact 
the authors or the Caltech Public Relations Office at (818) 356-6326.
--------------------------------
This week's Report covers the 7 days to midnight Wednesday night, 
January 20, PST. The map includes a virtually complete set of earthquakes 
of M2.0 or larger, plus many smaller ones: there are only 318 this time.
This week's activity is more of the same, mostly more Landers and Big Bear
aftershocks. These will, as we have said, continue for years to come, 
gradually decreasing in number over time.
The week's largest quake (M3.5) occurred in the wee hours of the morning 
on Monday; it was a Landers aftershock and went unfelt, apparently. 
A M3.2 and a M3.0 were felt at different locations in the Inland Empire 
on Sunday morning. Also Monday morning, a M3.2 was felt near Niland, 
in the northern Imperial Valley.
The small cluster near Niland is interesting, because it is near the 
southward extension of the San Andreas Fault beyond its junction with 
the Brawley Seismic Zone, an amorphous band of seismic activity that 
connects the San Andreas to the Imperial Fault to the south. 
Quakes of this size have occurred near Niland in the past few years, 
but generally after major seismic activity in the Imperial Valley.
The table lists the quakes that were M2.3 or larger. Times are local; 
for GMT, add 8 hrs. to the PST listed.
-------
Date  Time      N Lat.   W Long.   Mag

-------------------------------------------------------------
1/14 12:19 am  34 22.8  116 26.7  2.3  18 mi. N of Yucca Valley
1/14  1:48 am  33 12.3  115 35.2  2.6  4 mi. WSW of Niland
1/14  2:55 am  33 53.6  120 20.6  2.9  9 mi. S of San Miguel Is.
1/14  5:38 am  34 30.6  116 30.7  2.6  27 mi. N of Yucca Valley
1/14  7:27 am  34 33.4  116 30.0  2.5  30 mi. N of Yucca Valley
1/14 11:02 am  34 37.1  116 34.8  2.4  24 mi. ENE of Lucerne Valley
1/14 11:23 am  33 57.7  116 18.0  2.7  11 mi. E of Desert Hot Springs
1/14  7:27 pm  34 37.9  116 39.3  2.3  21 mi. NE of Lucerne Valley
1/14  7:44 pm  34 19.8  116 27.6  2.9  14 mi. N of Yucca Valley
1/14  8:47 pm  34 23.4  116 27.0  2.3  18 mi. N of Yucca Valley
1/14 10:50 pm  34 30.8  116 31.1  2.4  27 mi. N of Yucca Valley
1/15  2:31 am  34  9.7  116 25.5  2.5  3 mi. NNE of Yucca Valley
1/15  4:43 am  34  9.1  116 25.1  2.6  2 mi. NNE of Yucca Valley
1/15  5:35 am  34 11.2  116 24.5  2.3  5 mi. NNE of Yucca Valley
1/15  6:55 am  34 20.8  116 53.3  2.4  5 mi. NNW of Big Bear City
1/15 11:26 am  35  2.9  116 58.7  2.4  11 mi. NNE of Barstow
1/15  1:03 pm  34 14.9  116 45.0  2.6  6 mi. E of Big Bear City
1/15  2:05 pm  35 40.9  117 36.1  2.6  5 mi. NE of Ridgecrest
1/15  7:17 pm  34  5.1  116 25.1  2.6  2 mi. SSE of Yucca Valley
1/16  1:25 am  35  0.9  116 58.1  2.5  9 mi. NNE of Barstow
1/16  8:00 am  35  3.0  116 58.9  2.3  11 mi. NNE of Barstow
1/16  8:33 am  34  9.4  116 24.6  2.5  3 mi. NE of Yucca Valley
1/16 11:24 am  34 11.1  116 51.3  2.4  5 mi. S of Big Bear City
1/16 11:45 am  34 55.9  116 55.7  2.7  6 mi. ENE of Barstow
1/16  3:31 pm  34 58.7  116 56.7  2.3  7 mi. NE of Barstow
1/16  6:22 pm  34 13.5  116 51.1  2.3  2 mi. S of Big Bear City
1/17 12:06 am  34 29.4  116 26.8  2.5  25 mi. N of Yucca Valley
1/17 12:57 am  34 16.5  116 44.4  2.9  6 mi. E of Big Bear City
1/17  5:56 am  34 14.4  117 26.4  3.2  1 mi. NW of the I15/I215 
interchange, Cajon Pass; Felt
1/17  9:53 am  34  3.3  117 14.9  3.0  2 mi. E of the I10/I215 interchange,
Redlands Felt
1/17  4:04 pm  34 33.5  116 31.7  2.5  25 mi. ENE of Lucerne Valley
1/17  4:15 pm  35  1.4  116 58.4  2.3  9 mi. NNE of Barstow
1/17  6:14 pm  34 16.7  116 44.3  2.4  6 mi. E of Big Bear City
1/17  7:54 pm  33 59.8  116 21.2  2.5  8 mi. ENE of Desert Hot Springs
1/17 10:24 pm  34 19.9  116 28.4  2.4  14 mi. N of Yucca Valley
1/18  1:30 am  34 36.8  116 38.0  3.4  21 mi. ENE of Lucerne Valley
1/18  2:32 am  32 42.7  118 36.6  2.4  17 mi. WSW of SE tip of San Clemente Is.
1/18  3:55 am  34 36.6  116 38.1  3.5  21 mi. ENE of Lucerne Valley
1/18  6:59 am  33 12.0  115 35.8  3.2  5 mi. WSW of Niland  Felt
1/18  8:29 am  36 10.5  118  2.1  3.0  5 mi. WNW of south end of Haiwee
Reservoir
1/18  9:24 am  33 45.1  116  8.2  2.4  5 mi. ENE of Indio
1/18 11:25 am  33 45.4  116  7.8  2.3  "
1/18  3:50 pm  33 13.5  116 20.1  2.5  3 mi. SE of Borrego Springs
1/19  3:55 am  33 41.2  116 46.8  2.7  5 mi. SW of Idyllwild
1/19  3:55 am  34 59.7  116 57.1  2.7  8 mi. NNE of Barstow
1/19  1:33 pm  34 39.2  116 30.8  2.7  28 mi. ENE of Lucerne Valley
1/19  4:17 pm  32 31.2  115 31.8  2.6  10 mi. SSW of Calexico
1/20  3:16 am  35  2.7  116 58.7  2.5  11 mi. NNE of Barstow
1/20  9:32 am  34  7.9  116 23.5  2.8  3 mi. ENE of Yucca Valley
1/20 10:25 am  34 22.3  116 27.6  2.3  17 mi. N of Yucca Valley
1/20 11:21 am  34 36.9  116 39.5  2.7  20 mi. NE of Lucerne Valley
-------------------------------------------------------------