SOUTHERN CALIFORNIA SEISMOGRAPHIC NETWORK A Cooperative Project of Caltech and the U.S. Geological Survey December 19, 1996 Weekly Earthquake Report for Southern California ------------------------------------------------ December 12 - 18, 1996 Prepared by: Kate Hutton, Seismological Laboratory (kate@bombay.gps.caltech.edu) Lucy Jones, U. S. Geological Survey California Institute of Technology For further information, please contact the authors or the Caltech Public Relations Office at 818-395-6327. For daily updates, call our Earthquake Information Hotline: 818-395-6977. -------------------------------- This week's Report covers the time period from midnight Thursday morning, December 12, Universal Time (ie. GMT), to midnight Wednesday night, December 19, Universal Time. In local time, the period of coverage is from 4 p.m., December 11, Pacific Standard Time, to 4 p.m., December 19, Pacific Standard Time. We detected and processed 475 earthquakes during the seven-day period covered. The seismicity this week was basically a continuation of last week's: more Coso and Ridgecrest quakes. The three largest events, two M3.8's and a M3.6, were all Coso quakes, aftershocks of the November 27, 1996 M5.3. The largest of the Ridgecrest quakes was a M2.9. We did not get any reports that indicated any of these events were felt by the public. No M3+ earthquakes happened anywhere else in our coverage area. Because of the holidays coming up, the next two Weekly Reports will probably be produced from automatically processed data only. This means, in particular, that the total number of events will be lower than it otherwise would be. We hope to get caught up in January and resummarize the late December activity for our readers. Table 1 lists the quakes this week that were M2.0 or larger in the central part of the coverage area. Times are local times; if you want Greenwich Mean Time, add 7 hrs to the Pacific Daylight Time or 8 hrs to the Pacific Standard Time listed. Table 1 ------- Date Time N Lat. W Long. Mag ------------------------------------------------------------- 12/12 2:59 am 36 5.3 117 39.5 2.2 16 mi. ENE of Coso Juction 12/12 7:36 am 34 27.4 120 32.5 2.0 4 mi. W of Pt. Conception 12/12 8:20 am 34 26.3 120 33.5 2.0 " 12/12 8:25 am 36 4.0 117 38.3 2.7 17 mi. E of Coso Junction 12/12 8:34 am 36 5.1 117 39.4 2.1 " 12/12 9:38 am 36 5.2 117 39.1 2.0 " 12/12 11:31 am 36 4.8 117 38.0 2.0 " 12/12 1:14 pm 36 4.1 117 37.9 2.1 " 12/12 1:30 pm 36 5.4 117 39.2 2.0 " 12/12 2:02 pm 36 4.0 117 38.4 2.5 " 12/12 2:36 pm 36 3.9 117 38.8 2.6 " 12/12 6:18 pm 36 5.0 117 39.3 3.0 " 12/12 6:18 pm 36 4.5 117 39.3 2.1 " 12/12 6:28 pm 36 4.8 117 39.4 2.8 " 12/12 7:00 pm 36 5.0 117 39.5 3.8 " 12/12 7:32 pm 33 41.0 117 56.2 2.1 2 mi. SSE of Fountain Valley 12/12 8:18 pm 36 5.1 117 39.7 2.4 17 mi. E of Coso Junction 12/12 8:38 pm 36 4.6 117 38.9 2.2 " 12/12 9:23 pm 34 1.9 117 14.1 2.9 1 mi. SE of Loma Linda 12/12 9:58 pm 33 11.9 115 34.4 2.2 4 mi. SW of Niland 12/12 11:19 pm 36 4.9 117 39.3 2.1 16 mi. E of Coso Juction 12/13 12:29 am 36 3.7 117 38.7 2.2 " 12/13 12:31 am 36 3.8 117 38.6 2.2 " 12/13 1:43 am 36 5.1 117 39.4 2.3 " 12/13 8:31 am 34 20.3 118 28.1 2.2 4 mi. NNW of San Fernando 12/13 9:39 am 34 57.6 116 39.9 2.2 20 mi. ENE of Barstow 12/13 9:54 am 35 47.3 117 37.6 2.0 11 mi. N of Ridgecrest 12/13 10:38 am 36 3.7 117 38.8 2.0 16 mi. E of Coso Junction 12/13 1:54 pm 36 3.8 117 38.9 2.0 " 12/13 2:10 pm 33 53.2 116 2.0 2.2 15 mi. NE of Indio 12/13 10:38 pm 36 10.9 117 35.8 2.1 13 mi. SW of Panamint Springs 12/13 10:41 pm 36 5.0 117 39.2 2.0 16 mi. E of Coso Junction 12/14 12:29 am 36 3.8 117 38.8 2.8 " 12/14 12:32 am 36 3.9 117 38.8 2.4 " 12/14 1:55 am 32 8.3 116 41.5 2.7 35 mi. SE of San Ysidro 12/14 4:42 am 36 5.6 117 38.1 2.1 16 mi. E of Coso Juction 12/14 6:23 am 36 5.1 117 39.2 2.2 " 12/14 7:03 am 36 4.2 117 39.3 2.4 " 12/14 8:47 am 36 4.6 117 39.2 2.0 " 12/14 12:00 pm 34 22.8 116 27.9 2.1 18 mi. N of Yucca Valley 12/14 2:57 pm 36 4.7 117 39.5 2.2 16 mi. E of Coso Junction 12/14 9:12 pm 34 9.0 116 26.6 2.3 2 mi. N of Yucca Valley 12/15 12:27 am 36 4.0 117 38.0 2.8 17 mi. E of Coso Junction 12/15 7:10 am 36 4.8 117 39.1 2.4 " 12/15 11:39 am 36 4.6 117 54.0 2.6 3 mi. NE of Coso Junction 12/15 1:34 pm 34 37.3 116 38.0 2.5 21 mi. NE of Lucerne Valley 12/15 2:42 pm 36 3.7 117 38.7 2.7 17 mi. E of Coso Junction 12/15 6:18 pm 33 26.8 116 54.2 2.8 6 mi. NNW of Palomar Observatory 12/15 7:31 pm 36 4.5 117 38.6 2.1 17 mi. E of Coso Junction 12/15 7:53 pm 35 47.8 117 38.2 2.6 12 mi. N of Ridgecrest 12/15 8:06 pm 35 47.7 117 38.3 2.9 " 12/15 8:45 pm 32 21.5 115 6.4 2.6 31 mi. SE of Calexico 12/16 2:30 am 36 5.2 117 39.2 3.6 16 mi. E of Coso Junction 12/16 2:41 am 36 4.6 117 39.3 2.2 " 12/16 2:44 am 36 4.8 117 39.4 2.1 " 12/16 7:05 am 36 3.7 117 37.8 2.2 " 12/16 7:37 am 36 4.6 117 39.3 2.0 " 12/16 9:07 am 36 3.8 117 38.3 2.0 " 12/16 9:14 am 36 4.7 117 39.5 2.1 " 12/16 10:01 am 35 47.7 117 38.3 2.3 12 mi. N of Ridgecrest 12/16 10:49 am 32 28.0 115 15.3 2.4 19 mi. SE of Calexico 12/16 2:05 pm 36 4.1 117 38.1 2.4 17 mi. E of Coso Junction 12/16 3:22 pm 34 13.4 116 27.1 2.0 7 mi. N of Yucca Valley 12/16 7:24 pm 34 34.2 116 34.3 2.3 22 mi. ENE of Lucerne Valley 12/16 8:03 pm 36 5.0 117 39.3 3.8 16 mi. E of Coso Junction 12/16 8:07 pm 36 5.1 117 39.1 2.0 " 12/16 8:10 pm 36 5.1 117 39.2 2.4 " 12/16 8:33 pm 36 5.5 117 39.6 2.7 " 12/16 10:59 pm 36 5.6 117 39.3 2.4 " 12/16 11:11 pm 36 5.4 117 39.4 2.0 " 12/17 12:29 am 36 4.8 117 39.1 2.1 " 12/17 1:27 am 36 4.7 117 39.7 2.9 " 12/17 1:28 am 36 4.7 117 39.4 2.4 " 12/17 1:29 am 36 4.7 117 39.6 2.2 " 12/17 2:30 am 36 4.7 117 39.3 2.4 " 12/17 3:13 am 36 5.7 117 39.4 2.2 " 12/17 3:22 am 36 1.0 117 42.5 2.5 " 12/17 4:22 am 36 0.9 117 42.6 2.0 " 12/17 7:31 am 36 5.0 117 39.3 2.4 " 12/17 8:41 am 36 5.0 117 39.5 3.0 " 12/17 9:08 am 36 3.8 117 38.8 2.6 " 12/17 3:24 pm 36 5.6 117 39.5 2.1 " 12/17 3:32 pm 36 4.3 117 38.7 2.7 " 12/17 4:07 pm 36 3.5 117 38.3 2.1 " 12/17 6:15 pm 36 5.0 117 39.3 2.4 " 12/17 6:28 pm 34 59.6 116 57.3 2.2 8 mi. NNE of Barstow 12/17 9:07 pm 33 13.6 116 2.3 2.4 5 mi. SW of Salton City 12/18 1:04 am 36 4.8 117 39.3 2.7 16 mi. E of Coso Junction 12/18 7:42 am 33 31.6 116 33.3 2.2 7 mi. ESE of Anza 12/18 7:59 am 34 0.5 116 45.7 2.0 6 mi. NNE of Cabazon 12/18 10:38 am 36 3.8 117 38.8 2.1 16 mi. E of Coso Junction 12/18 11:11 am 33 39.3 117 2.9 2.1 7 mi. SW of Hemet 12/18 12:16 pm 36 26.6 117 48.4 2.0 15 mi. NE of Olancha 12/18 3:17 pm 34 20.8 118 18.5 2.2 6 mi. N of Sunland -------------------------------------------------------------