SOUTHERN CALIFORNIA SEISMOGRAPHIC NETWORK A Cooperative Project of Caltech and the U.S. Geological Survey October 19, 1995 Weekly Earthquake Report for Southern California ------------------------------------------------ October 12 - 18, 1995 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 818-395-6326. For daily updates, call our Earthquake Information Hotline: 818-395-6977. -------------------------------- This week's Report covers the time period from midnight Thursday morning, October 12, Pacific Daylight Time, to midnight Wednesday night, October 18, 1995, Pacific Daylight Time. We timed 460 earthquakes during the 7-day period covered. Due to the Ridgecrest activity, computer problems, and some staffing problems, there are about 400 smaller ones yet to be processed. The only activity of particular interest this week was the brief swarm of Ridgecrest activity on Wednesday morning. The largest was M4.2, and there were six in the M3 range. Almost all the activity took place in about a four hour period, peaking just before 6 am. We got "felt" inquiries about all the events above M3. This higher awareness may be because the events were in the southern end of the sequence near the city of Ridgecrest. However, it is getting more difficult to distinquish between an inquiry about an earthquake that was felt and one that was "felt" on the Internet! The table 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 ------------------------------------------------------------- 10/12 12:29 am 35 46.5 117 39.2 2.6 10 mi. N of Ridgecrest 10/12 12:54 am 35 44.3 117 38.0 2.2 8 mi. NNE of Ridgecrest 10/12 6:11 am 33 10.0 115 38.9 2.0 Under Obsidian Butte 10/12 8:13 am 35 47.3 117 39.0 2.2 11 mi. N of Ridgecrest 10/12 1:30 pm 34 24.9 116 28.9 2.0 20 mi. N of Yucca Valley 10/12 1:31 pm 32 40.3 115 55.1 2.0 6 mi. SE of Ocotillo 10/12 4:01 pm 34 34.0 116 34.6 2.0 22 mi. ENE of Lucerne Valley 10/13 12:12 am 33 45.1 120 7.1 2.0 13 mi. S of Santa Rosa Is. 10/13 4:20 am 34 23.1 118 35.6 2.2 1 mi. WSW of Valencia 10/13 6:29 am 35 48.8 117 38.9 2.7 13 mi. N of Ridgecrest 10/13 6:45 am 35 48.8 117 38.5 2.4 " 10/13 6:58 am 35 48.9 117 38.5 2.0 " 10/14 5:30 am 35 45.1 117 39.1 2.4 9 mi. N of Ridgecrest 10/14 9:57 am 35 44.2 117 37.5 2.3 8 mi. NNE of Ridgecrest 10/14 9:57 am 33 51.8 118 36.9 2.2 12 mi. SSE of Malibu 10/14 3:03 pm 34 37.6 116 40.4 2.2 19 mi. NE of Lucerne Valley 10/14 3:20 pm 35 46.3 117 39.2 2.0 10 mi. N of Ridgecrest 10/14 7:52 pm 35 45.8 117 38.9 2.2 9 mi. N of Ridgecrest 10/14 8:10 pm 34 21.4 117 36.9 2.2 Under Wrightwood 10/14 9:53 pm 34 11.7 118 38.2 2.6 1 mi. WSW of Canoga Park 10/14 10:07 pm 32 40.4 115 54.7 2.3 6 mi. SE of Ocotillo 10/15 2:32 pm 35 44.2 117 37.8 2.3 8 mi. NNE of Ridgecrest 10/15 10:43 pm 34 22.2 118 41.6 2.3 6 mi. N of Simi Valley 10/16 2:35 am 34 35.2 116 36.3 2.1 21 mi. ENE of Lucerne Valley 10/16 6:31 am 35 44.3 117 37.5 2.3 8 mi. NNE of Ridgecrest 10/16 7:38 am 35 58.8 120 28.9 2.4 6 mi. NNW of Parkfield 10/16 3:46 pm 33 58.2 116 48.9 2.2 3 mi. NNW of Cabazon 10/16 7:24 pm 34 20.1 118 30.7 2.1 3 mi. SSE of Newhall 10/16 9:17 pm 35 46.5 117 39.3 2.7 10 mi. N of Ridgecrest 10/17 4:05 am 35 46.3 117 39.2 2.0 " 10/17 4:33 am 34 15.4 118 35.5 2.0 Under Chatsworth 10/17 7:57 am 35 45.4 117 38.4 2.4 9 mi. N of Ridgecrest 10/17 8:32 am 35 47.5 117 39.3 2.4 11 mi. N of Ridgecrest 10/17 12:01 pm 34 1.8 117 15.4 2.0 1 mi. S of Loma Linda 10/17 6:49 pm 35 44.2 117 37.7 2.1 8 mi. NNE of Ridgecrest 10/17 9:08 pm 34 19.9 118 28.6 2.1 3 mi. NW of San Fernando 10/17 9:42 pm 35 44.6 117 40.5 2.2 8 mi. N of Ridgecrest 10/18 1:58 am 35 44.6 117 40.3 2.0 " 10/18 4:37 am 35 44.5 117 37.7 3.1 8 mi. NNE of Ridgecrest FELT 10/18 5:42 am 35 44.5 117 37.9 4.2 " FELT 10/18 5:44 am 35 44.4 117 38.2 2.7 " 10/18 5:49 am 35 44.5 117 38.0 3.9 " FELT 10/18 5:51 am 35 43.8 117 38.1 2.2 7 mi. NNE of Ridgecrest 10/18 5:51 am 35 43.8 117 37.8 2.3 " 10/18 5:52 am 35 44.2 117 37.8 3.0 8 mi. NNE of Ridgecrest FELT 10/18 5:54 am 35 44.1 117 37.7 3.4 " FELT 10/18 6:06 am 35 44.4 117 38.1 3.1 " 10/18 6:06 am 35 44.2 117 37.8 2.3 " 10/18 6:30 am 35 43.9 117 37.8 2.8 7 mi. NNE of Ridgecrest 10/18 6:31 am 35 43.8 117 37.8 3.6 " FELT 10/18 8:23 am 35 43.7 117 37.6 2.2 " 10/18 8:58 am 35 43.9 117 37.7 2.2 " 10/18 12:21 pm 34 1.8 117 14.3 2.6 1 mi. SE of Loma Linda 10/18 12:24 pm 34 49.1 119 1.0 2.7 4 mi. W of Frazier Park -------------------------------------------------------------