SOUTHERN CALIFORNIA SEISMOGRAPHIC NETWORK A Cooperative Project of Caltech and the U.S. Geological Survey September 11, 1997 Weekly Earthquake Report for Southern California ------------------------------------------------ September 4 - 10, 1997 Prepared by: Nick Scheckel, 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 626-395-6327. For daily updates, call our Earthquake Information Hotline: 626-395-6977. -------------------------------- ***************************************************************** If you receive this Report by FAX and if you have recently had a change of AREA CODE, please notify us ASAP. We have no other way to know which fax numbers need to be changed!! ***************************************************************** This week's Report covers the time period from midnight Thursday morning, September 4, Universal Time (ie. UTC), to midnight Wednesday night, September 10, Universal Time. In local time, the period of coverage is from 5 p.m., September 3, Pacific Daylight Time, to 5 p.m., September 10, Pacific Daylight Time. We detected 152 earthquakes during the seven-day period covered. These Weekly Reports should not be used for archival purposes. Further data processing often changes the magnitudes slightly and, especially during times of high seismicity, sometimes changes the estimates of total seismicity. For the best earthquake catalog currently available, see: http://scec.gps.caltech.edu/catalog-search.html This was a very quiet week. There were no events reported felt for the entire week. Only one earthquake was over M3.0, a M3.1 on Saturday morning in the Little Lake. It was not an aftershock of any recent earthquake. It is located about 15 km south of the Coso swarm of recent months. Its focal mechanism is strike-slip. 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 ------------------------------------------------------------- 9/ 4 5:03 am 32 12.4 115 49.0 2.5 37 mi. SSE of Ocotillo 9/ 4 9:37 pm 34 22.8 118 37.5 2.4 3 mi. WSW of Valencia 9/ 5 1:20 am 34 52.0 119 14.9 2.3 17 mi. W of Frazier Park 9/ 5 3:48 am 35 6.7 119 5.3 2.1 10 mi. NW of Wheeler Ridge 9/ 5 10:18 pm 32 14.2 115 48.9 2.0 35 mi. SSE of Ocotillo 9/ 6 4:38 am 34 9.0 117 19.9 2.0 3 mi. NW of San Bernardino 9/ 6 9:23 am 35 51.6 117 49.8 3.1 14 mi. SSE of Coso Junction 9/ 6 10:18 am 32 13.7 115 47.5 2.5 34 mi. SSW of Calexico 9/ 6 12:04 pm 32 13.4 115 48.7 2.3 36 mi. SSE of Ocotillo 9/ 7 10:26 am 33 0.5 117 50.7 2.8 32 mi. SSW of Dana Point 9/ 7 11:14 am 33 1.4 117 51.7 2.4 31 mi. SSW of Dana Point 9/ 7 2:18 pm 35 30.5 120 50.0 2.5 9 mi. N of Morro Bay 9/ 8 12:52 am 34 9.6 116 25.6 2.0 3 mi. NNE of Yucca Valley 9/ 8 7:44 pm 32 11.8 115 47.9 2.6 37 mi. SSW of Calexico 9/ 9 11:00 am 33 16.5 116 6.0 2.0 9 mi. N of Ocotillo Wells 9/10 5:57 am 33 57.0 116 44.4 2.0 3 mi. NE of Cabazon 9/10 6:24 am 33 57.0 116 44.3 2.0 " 9/10 10:00 am 32 59.6 117 47.5 2.3 27 mi. WSW of Oceanside -------------------------------------------------------------