From: cowen@jade.ucdavis.edu
Newsgroups: ca.earthquakes,sci.geo.geology
Subject: Caltech Weekly Report, August 27, 1992
Date: 27 Aug 92 22:14:55 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 very lightly, but the information is unaffected.
Weekly Earthquake Report for Southern California, August 20-26, 1992

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, 
August 26, Pacific Daylight Time. Aftershocks of the Landers earthquake
continue, as they will for several months at least. The activity is so 
high that we cannot keep up	with the data processing. The map includes a 
nearly complete set of earthquakes of M2.5 or larger, plus many smaller 
ones that happen to have made it through the system. There are 196 in all.
	The largest quake this week was a M4.1 on Monday morning at the NE end 
of the Big Bear aftershock zone. It was widely felt in the Inland Empire.
	There are two odd observations of probably no significance:
this week's crop of quakes seems to be deficient at the southern end of
the Landers rupture, compared to the northern end, and small quakes have
appeared south of the Mission Creek branch of the San Andreas since about
July 1. This area is usually a reliable source of small quakes; however, 
few were noticed there in the early part of the aftershock sequence.
	It may be of interest to our readers to know that we have recorded more 
than 25,000 earthquakes in the last 2 months, amounting to more than 100
gigabytes of digital seismograms, which could explain why we are so far 
behind. It may be impossible to ever process all of them, at least in any 
kind of a timely fashion.
	We may aim for the top 10,000, say, which ought to be enough data to keep 
most users happy.
	Table 1 lists only earthquakes of M2.5 or larger. Times are local; for 
GMT, add 7 hrs. to the PDT listed.

	Table 1
	-------
	Date  Time     N Lat.   W Long.   Mag

	-------------------------------------------------------------
         8/20 12:14 am  34  1.7  117 32.4  2.6  2 mi. S of the I10/I15

interchange
         8/20 12:15 am  34  7.2  116 55.4  2.8  5 mi. WNW of Mt. San Gorgonio
         8/20  5:37 am  34 57.6  116 56.5  2.7  6 mi. NE of Barstow
         8/20  6:28 am  34  6.5  116 59.1  2.7  9 mi. SE of Running Springs
         8/20  6:30 am  34 35.6  116 36.7  2.5  21 mi. ENE of Lucerne Valley
         8/20  7:15 am  34 23.4  116 27.5  2.7  18 mi. N of Yucca Valley
         8/20  1:18 pm  34 34.9  116 18.6  2.7  32 mi. NNE of Yucca Valley
         8/20  2:59 pm  35  2.3  116 58.7  2.8  10 mi. NNE of Barstow
         8/20  6:28 pm  34 31.1  116 31.4  2.9  28 mi. N of Yucca Valley
         8/21  9:36 am  34  9.9  116 26.1  2.6  3 mi. N of Yucca Valley
         8/21 12:46 pm  34  2.5  116 54.5  2.9  6 mi. SW of Mt. San Gorgonio
         8/21  1:42 pm  35  1.8  116 58.6  2.7  10 mi. NNE of Barstow
         8/21  5:17 pm  34 11.3  116 47.2  2.9  6 mi. NNE of Mt. San Gorgonio
         8/21  6:52 pm  34  6.5  116 59.1  3.4  9 mi. SE of Running Springs
         8/22  6:26 am  35  1.0  116 57.8  2.5  9 mi. NNE of Barstow
         8/22  9:27 am  34  3.4  117  6.5  2.5  3 mi. E of Redlands
         8/22 10:35 am  34 27.0  116 30.1  2.6  23 mi. N of Yucca Valley
         8/22 10:54 am  33 59.6  116 57.8  2.6  4 mi. N of Beaumont
         8/22 12:08 pm  34  6.5  116 59.0  2.6  10 mi. SSW of town of Big 
Bear Lake
         8/22  1:28 pm  34 20.6  116 28.2  2.5  15 mi. N of Yucca Valley
         8/22  4:55 pm  34 23.0  116 27.6  2.5  18 mi. N of Yucca Valley
         8/22  6:17 pm  34 15.8  116 44.1  2.5  6 mi. E of Big Bear City
         8/22  7:55 pm  34 12.9  116 44.2  3.2  7 mi. ESE of Big Bear City
         8/22 10:14 pm  34 56.6  116 46.7  2.8  14 mi. ENE of Barstow
         8/22 10:15 pm  34 56.4  116 46.3  2.9  14 mi. ENE of Barstow
         8/22 10:30 pm  34 13.1  116 46.5  3.3  5 mi. SE of Big Bear City
         8/22 11:36 pm  34 56.6  116 46.7  2.6  14 mi. ENE of Barstow
         8/22 11:40 pm  35  2.0  116 59.4  3.7  10 mi. N of Barstow
         8/23 12:36 am  34  8.5  116 50.3  3.0  2 mi. NNW of Mt. San Gorgonio
         8/23  4:58 am  34 15.3  116 44.1  2.9  6 mi. E of Big Bear City
         8/23  6:46 am  34  6.6  116 59.0  3.2  10 mi. SSW of town of Big 
Bear Lake
         8/23  6:46 am  34  6.7  116 59.3  3.2  9 mi. SE of Running Springs
         8/23  7:10 am  34 56.7  116 45.3  2.7  15 mi. ENE of Barstow
         8/23  8:19 am  35  0.4  116 57.7  2.5  8 mi. NNE of Barstow
         8/23 10:49 am  34  7.3  116 44.1  3.3  5 mi. ENE of Mt. San Gorgonio
         8/23 11:50 am  34  9.6  116 49.1  3.1  4 mi. N of Mt. San Gorgonio
         8/23 12:34 pm  34  8.8  116 26.1  2.6  2 mi. NNE of Yucca Valley
         8/23  2:45 pm  34 38.0  116 30.7  2.8  27 mi. ENE of Lucerne Valley
         8/23  3:33 pm  34 33.3  116 31.7  2.8  24 mi. ENE of Lucerne Valley
         8/23  4:30 pm  34 27.9  116 31.9  2.6  24 mi. NNW of Yucca Valley
         8/23  4:31 pm  34 26.8  116 30.1  2.7  22 mi. N of Yucca Valley
         8/23  8:29 pm  34 26.0  116 27.5  2.8  21 mi. N of Yucca Valley
         8/23 10:47 pm  34 16.2  116 24.3  3.0  10 mi. NNE of Yucca Valley
         8/23 11:33 pm  34  0.9  116 40.8  2.6  8 mi. NE of Cabazon
         8/24 12:44 am  35  0.9  116 58.2  2.7  9 mi. NNE of Barstow
         8/24  1:08 am  34  9.2  116 25.2  2.5  2 mi. NNE of Yucca Valley
         8/24  1:08 am  34  9.1  116 25.0  2.6  	"
         8/24  2:16 am  35  1.0  116 58.2  2.6  9 mi. NNE of Barstow
         8/24  5:43 am  34 56.8  116 46.8  3.4  14 mi. ENE of Barstow
         8/24  5:51 am  34 16.7  116 46.2  2.5  4 mi. E of Big Bear City
         8/24  6:39 am  34 10.3  116 25.9  2.6  3 mi. NNE of Yucca Valley
         8/24  6:51 am  34 16.4  116 46.4  4.1  4 mi. E of Big Bear City; felt
         8/24  7:43 am  34 32.9  116 32.4  2.9  24 mi. ENE of Lucerne 
Valley
         8/24  9:45 am  34 11.0  116 48.5  3.3  5 mi. N of Mt. San Gorgonio
         8/24 11:21 am  34 16.6  116 46.6  3.4  4 mi. E of Big Bear City
         8/24  1:24 pm  34 56.4  116 47.2  3.0  13 mi. ENE of Barstow
         8/24  2:15 pm  34 11.0  116 48.4  3.0  5 mi. N of Mt. San Gorgonio
         8/24  2:57 pm  34 13.6  116 44.8  2.5  6 mi. ESE of Big Bear City
         8/24  3:08 pm  33 59.6  116 57.8  2.8  4 mi. N of Beaumont
         8/24  9:34 pm  35  2.5  118 55.6  2.5  2 mi. NE of the I5/99

interchange
         8/25 12:58 am  33 59.1  116 17.6  2.5  12 mi. SE of Yucca Valley
         8/25  3:37 am  34 16.6  116 46.4  2.7  4 mi. E of Big Bear City
         8/25 10:08 am  34 35.6  116 32.8  2.5  24 mi. ENE of Lucerne Valley
         8/25 10:24 am  34 56.4  116 47.1  2.8  13 mi. ENE of Barstow
         8/25 12:46 pm  34  9.6  116 26.5  2.7  2 mi. N of Yucca Valley
         8/25  9:59 pm  35  0.4  116 57.6  2.5  8 mi. NNE of Barstow
         8/25 10:48 pm  35  2.2  116 59.9  2.7  10 mi. N of Barstow
         8/26  1:11 am  34 14.9  116 26.0  2.7  9 mi. N of Yucca Valley
         8/26  1:55 am  34  8.7  116 25.6  2.9  2 mi. NNE of Yucca Valley
         8/26  3:58 am  35 56.3  117 44.9  2.8  13 mi. ESE of Coso Junction
         8/26  5:25 am  34  6.7  116 58.9  2.9  9 mi. SSW of town of Big 
Bear Lake
         8/26  6:21 am  34  3.6  116 22.0  3.6  6 mi. SE of Yucca Valley
         8/26  6:31 am  35 31.0  117 28.1  2.6  13 mi. ESE of Ridgecrest
         8/26  6:50 am  34  6.3  116 59.0  3.4  9 mi. SE of Running Springs
         8/26  8:36 am  34 16.8  116 44.2  2.5  6 mi. E of Big Bear City
         8/26  8:50 am  34 16.6  116 44.4  2.7  	"
         8/26  9:28 am  34 18.6  116 26.2  2.7  13 mi. N of Yucca Valley
         8/26  1:29 pm  34 56.4  116 47.2  2.9  13 mi. ENE of Barstow
         8/26  5:11 pm  34 16.6  116 46.7  2.8  4 mi. ENE of Big Bear City
         8/26  6:44 pm  34 56.5  116 47.4  3.4  13 mi. ENE of Barstow
         8/26  7:53 pm  34 58.6  116 58.3  3.5  6 mi. NNE of Barstow
	-------------------------------------------------------------
Newsgroups: ca.earthquakes