From: cowen@JADE.UCDAVIS.EDU
Newsgroups: ca.earthquakes,sci.geo.geology
Subject: Caltech Earthquake Reports, December
Date: 4 Jan 93 22:20:11 GMT
Reply-To: cowen@JADE.UCDAVIS.EDU
Followup-To: ca.earthquakes
Organization: Geology Department, University of California, Davis

I have combined the two Caltech weekly reports that covered the Christmas
period. They accompanied postscript maps that I can't or won't re-post 
because they are very big files. 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.

Earthquake Report for Southern California, December 17 - 29, 1992

These documents are 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.
--------------------------------
December 17-21, by Helen Qian, Seismological Laboratory
(kate@bombay.gps.caltech.edu), and Lucy Jones, U.S. Geological Survey
California Institute of Technology

Because of the holiday, this week's report is shorter than usual, covering 
only 5 days. Aftershocks of the Landers earthquake continued from midnight
Thursday morning, December 17, PST, to midnight Monday night, December 21, 
PST, as they will for several years at least. The map includes a virtually
complete set of earthquakes of M2.0 or larger, plus many smaller ones: 324 
in all.

The phrase for the week is "the same ol' thing."  The largest quake was a 
M3.8 southeast of Yucca Valley at 3:44 am on Monday morning, felt by people
living in the area. Another felt event was a M3.4 near Big Bear later that
morning. Both were Landers aftershocks.

December 22 - 29, 1992. By Kate Hutton, Seismological Laboratory
(kate@bombay.gps.caltech.edu), and Lucy Jones, U.S. Geological Survey
California Institute of Technology
--------------------------------
This Report covers 8 days, so is slightly longer than usual. Issues should
revert to their usual Thursday schedule in January.
Aftershocks of the Landers earthquake continued in the time period from

midnight Tuesday morning, December 22, PST, to midnight Tuesday night, 
December 29, PST, as they will for several years at least. The map includes 
a virtually complete set of earthquakes of M2.0 or larger, plus many 
smaller ones: 613 in all.
Very little of note occurred this week. The M3.1 early on Wednesday near
Elizabeth Lake, within a few kilometers of the surface trace of the San 
Andreas Fault, is the most interesting event. The Mojave segment of the 
San Andreas and vicinity are normally very quiet, and this event occurred 
a few kilometers NW of previously seen activity. The focal mechanism
of this quake shows that it resulted from thrust faulting, and therefore 
was probably on one of the many secondary thrust faults that parallel the 
San Andreas.
Several Landers and Big Bear aftershocks were felt, including the week's
largest, a M3.7 on Saturday afternoon.
The table lists  quakes M2.3 or larger. Times are local; for GMT, add 
8 hrs. to the PST listed.

Date  Time      N Lat.   W Long.   Mag

-------------------------------------------------------------
12/17  9:40 am  33 14.9  116  3.9  3.0   6 mi. WSW of Salton City
12/17  7:44 pm  34  6.4  116 56.1  2.4   6 mi. W of Mt. San Gorgonio
12/17  9:59 pm  34 15.1  116 25.7  2.5   9 mi. N of Yucca Valley
12/17 10:42 pm  34 37.8  116 37.6  2.3   22 mi. NE of Lucerne Valley
12/18  1:57 am  34  2.0  117  7.0  2.4   3 mi. ESE of Redlands      
12/18  4:12 am  34 16.4  116 51.3  2.5   Big Bear City   
12/18  5:59 am  35  1.1  116 58.1  2.6   9 mi. NNE of Barstow       
12/18 10:42 am  34 27.3  116 30.6  2.3   23 mi. N of Yucca Valley   
12/18  9:37 pm  34 56.5  116 56.8  2.4   5 mi. NE of Barstow        
12/19  1:04 am  34 37.5  116 34.3  2.4   24 mi. ENE of Lucerne Valley
12/19  8:24 am  34 33.0  116 32.9  3.2   	"
12/19 12:15 pm  34 12.1  116 25.5  2.3   5 mi. NNE of Yucca Valley   
12/19  4:48 pm  33 59.5  116 56.2  2.3   4 mi. NNE of Beaumont       
12/19  4:49 pm  35  2.0  116 57.9  2.7   10 mi. NNE of Barstow       
12/19  5:07 pm  34 36.6  116 37.6  2.6   21 mi. ENE of Lucerne Valley
12/19  6:47 pm  34 32.9  116 33.0  2.7   	"
12/19  7:28 pm  34  9.9  116 25.9  2.4   3 mi. NNE of Yucca Valley   
12/20  2:03 am  34 12.3  116 49.4  2.5   4 mi. SSE of Big Bear City  
12/20  5:17 am  34  0.1  117  5.8  2.7   5 mi. SE of Redlands        
12/20  5:22 am  34 34.0  116 28.6  2.6   30 mi. N of Yucca Valley    
12/20  5:38 am  33 15.4  117 35.9  2.6   11 mi. S of San Clemente    
12/20  7:52 am  34 15.6  116 45.8  2.7   5 mi. E of Big Bear City    
12/20  4:15 pm  34 23.9  116 26.5  2.5   19 mi. N of Yucca Valley    
12/20  5:25 pm  34 32.2  116 32.4  2.7   25 mi. ENE of Lucerne Valley
12/20  6:18 pm  35  2.7  116 58.8  2.3   11 mi. NNE of Barstow       
12/20  7:41 pm  35  2.9  116 59.1  2.4   11 mi. N of Barstow         
12/21  3:44 am  34  5.5  116 24.8  3.8   2 mi. SE of Yucca Valley. Felt

12/21  4:47 am  35  2.4  116 58.6  2.3   10 mi. NNE of Barstow       
12/21  5:19 am  34  2.0  117  8.5  2.3   2 mi. SE of Redlands        
12/21  5:39 am  34 14.0  116 44.3  3.4   6 mi. ESE of Big Bear City. Felt

12/21  8:18 am  34 20.9  116 53.3  2.3   6 mi. NNW of Big Bear City  
12/21  9:50 am  34 25.8  116 30.7  2.5   21 mi. N of Yucca Valley    
12/21 10:37 am  34 26.7  116 30.3  2.6   	"
12/21 10:49 am  34 29.1  116 27.0  3.0   	"
12/21 12:53 pm  35 42.2  118  5.6  2.4   24 mi. ESE of Lake Isabella
12/21  6:20 pm  35  1.4  116 58.4  3.2   9 mi. NNE of Barstow        
12/21  6:32 pm  34 37.5  116 32.7  2.3   25 mi. ENE of Lucerne Valley
12/21  9:57 pm  34 36.0  116 35.5  2.4   	"
-----------------------------------------------------------
12/22  4:19 am  34 59.5  116 57.0  2.3  8 mi. NNE of Barstow
12/22  5:02 am  34 55.8  116 43.8  3.1  16 mi. E of Barstow
12/22 11:52 am  35 18.9  117 39.4  3.1  21 mi. S of Ridgecrest
12/22  1:20 pm  36  0.4  117 41.2  2.3  14 mi. E of Coso Junction
12/22  3:18 pm  34 11.8  116 50.4  2.5  4 mi. S of Big Bear City
12/22 11:57 pm  36 32.9  117 48.7  2.4  14 mi. ESE of Lone Pine
12/23  1:43 am  36  9.9  118  7.1  2.8  10 mi. SW of Olancha
12/23  1:45 am  34 23.6  116 28.3  2.4  19 mi. N of Yucca Valley
12/23  4:09 am  34 54.8  116 45.3  2.3  15 mi. E of Barstow
12/23  4:38 am  34 40.9  118 28.7  3.1  5 mi. WNW of Elizabeth Lake
12/23  5:59 am  36 54.1  118 34.9  2.4  22 mi. WNW of Independence
12/23  8:35 am  36 33.1  117 49.1  3.1  14 mi. ESE of Lone Pine
12/23  9:49 am  34 35.8  116 38.2  2.8  20 mi. ENE of Lucerne Valley
12/23 12:28 pm  36 32.3  117 48.8  2.3  14 mi. ESE of Lone Pine
12/23  2:19 pm  33 56.8  116 22.3  2.5  7 mi. E of Desert Hot Springs
12/23  2:59 pm  36  5.0  117 41.8  2.3  14 mi. ESE of south end of Haiwee
Reservoir 
12/23  6:40 pm  34 11.7  116 52.4  2.6  3 mi. SSE of town of Big Bear Lake
12/23  8:47 pm  34 20.5  116 53.0  2.3  5 mi. NNW of Big Bear City
12/23  8:47 pm  34 24.4  116 26.3  2.4  19 mi. N of Yucca Valley
12/23  9:00 pm  34 24.5  116 28.9  2.8  	"
12/24  1:25 am  35  1.4  116 55.4  3.3  10 mi. NNE of Barstow
12/24  7:04 am  34  4.7  116 24.7  2.6  3 mi. SE of Yucca Valley
12/24  8:45 am  35 45.4  117 36.1  2.8  9 mi. NNE of Ridgecrest
12/24  8:46 am  35 45.2  117 35.9  2.7  	"
12/24 11:17 am  34  5.6  116 50.4  2.9  Under Mt. San Gorgonio
12/24  3:54 pm  34 10.7  116 25.6  2.5  4 mi. NNE of Yucca Valley
12/24 11:29 pm  34 37.9  116 29.6  2.5  28 mi. ENE of Lucerne Valley
12/25  1:34 am  33 45.2  116  7.8  2.7  5 mi. ENE of Indio
12/25  8:05 am  34 33.2  116 33.1  2.3  23 mi. ENE of Lucerne Valley
12/25  8:59 am  34 30.7  116 31.3  2.4  27 mi. N of Yucca Valley
12/25 10:26 am  34 55.1  116 54.5  2.7  6 mi. ENE of Barstow
12/25  2:00 pm  35 41.1  117 36.3  2.6  5 mi. NE of Ridgecrest
12/25  2:15 pm  33 57.6  116 19.8  3.1  9 mi. E of Desert Hot Springs
12/25  7:01 pm  34 36.0  116 38.3  2.3  20 mi. ENE of Lucerne Valley
12/25  7:54 pm  34 30.5  116 30.7  2.5  27 mi. N of Yucca Valley
12/25  8:23 pm  34 54.1  119 32.8  2.5  17 mi. SSW of Taft
12/26 10:24 am  34 24.0  116 56.3  2.5  3 mi. S of Lucerne Valley
12/26  2:45 pm  34  0.7  116 19.1  2.3  10 mi. SE of Yucca Valley
12/26  4:18 pm  34 21.1  116 53.6  3.7  6 mi. NNW of Big Bear City. Felt
12/26  7:00 pm  34 35.1  120 40.4  2.6  1 mi. WNW of Pt. Arguello
12/26  7:07 pm  34 57.0  116 55.6  2.8  6 mi. NE of Barstow
12/26 10:03 pm  34  7.8  117 45.3  2.5  2 mi. NW of Claremont Colleges
12/27  5:10 am  33 57.4  116 19.2  2.3  10 mi. E of Desert Hot  Springs
12/27 12:45 pm  34 16.0  116 27.4  3.0  10 mi. N of Yucca Valley. Felt
12/27  6:50 pm  33 56.8  116 18.1  2.5  11 mi. E of Desert Hot Springs
12/27  6:50 pm  33 56.8  116 18.5  2.4  	"
12/28 12:13 am  34 57.0  116 55.8  2.7  6 mi. NE of Barstow
12/28  5:20 am  33 41.8  118 11.2  2.6  5 mi. SSW of downtown Long Beach
12/28  9:42 am  34 12.1  116 26.1  2.9  5 mi. N of Yucca Valley
12/28  9:45 am  34 11.1  116 25.6  2.3  4 mi. NNE of Yucca Valley
12/28  9:51 am  33 56.8  116 18.4  3.2  11 mi. E of Desert Hot Springs;Felt
12/28 10:00 am  33 56.7  116 18.3  3.6  	"   Felt?
12/28  3:05 pm  35 22.1  119  4.4  2.3  3 mi. WSW of downtown  Bakersfield
12/28 11:10 pm  34 21.3  116 27.7  2.4  16 mi. N of Yucca Valley
12/29 12:19 am  34 22.8  116 27.3  2.4  18 mi. N of Yucca Valley
12/29  4:39 am  34  3.7  116 22.2  2.4  5 mi. SE  of Yucca Valley
12/29  6:19 am  34 11.0  116 24.3  2.7  5 mi. NNE of Yucca Valley
12/29  6:24 am  35  6.3  118 31.4  2.6  4 mi. WSW of Tehachapi
12/29  6:24 am  34 11.0  116 24.3  2.7  4 mi. NNE of Yucca Valley
12/29  7:11 am  34 18.8  116 55.7  2.3  4 mi. NNW of town of Big Bear Lake
12/29  9:09 am  35 19.6  117 39.2  2.5  20 mi. S of Ridgecrest
12/29  9:36 am  33 57.3  116 18.8  2.4  10 mi. E of Desert Hot Springs
12/29  7:30 pm  34  5.3  116 22.5  2.9  4 mi. ESE of Yucca Valley. Felt
12/29 10:17 pm  34 21.5  116 28.2  2.4  16 mi. N of Yucca Valley
12/29 10:20 pm  35  0.5  116 58.1  2.3  8 mi. NNE of Barstow
-------------------------------------------------------------