SOUTHERN CALIFORNIA SEISMOGRAPHIC NETWORK A Cooperative Project of Caltech and the U.S. Geological Survey May 9, 1996 Weekly Earthquake Report for Southern California ------------------------------------------------ April May 2 - 8, 1996 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 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, May 1, Universal Time (ie. GMT), to midnight Wednesday night, May 8, Universal Time. In local time, the period of coverage is from 5 p.m., May 1, Pacific Daylight Time, to 5 p.m., May 8, Pacific Daylight Time. We detected and processed 326 earthquakes during the 7-day period covered. The largest event this week, a M2.9 Landers aftershock, (M7.3, 28 June, 1992) went unfelt Tuesday evening, but a M2.8 aftershock to the M6.7 Northridge mainshock (17 Jan., 1994) was felt Thursday morning. This event was located in a dense cluster of aftershocks at the eastern side of the aftershock zone. This zone includes the largest aftershock of the sequence--a M5.9 that occurred less than one minute after the Northridge mainshock. Also the people of the Imperial Valley were shaken on the afternoon of Tuesday by a M2.8. 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 ------------------------------------------------------------- 5/ 1 6:17 pm 35 44.6 117 40.2 2.4 8 mi. N of Ridgecrest 5/ 1 8:49 pm 34 37.0 116 27.9 2.4 34 mi. N of Yucca Valley 5/ 1 10:37 pm 34 20.8 118 42.6 2.4 4 mi. N of Simi Valley 5/ 2 10:38 am 34 15.5 118 27.7 2.8 2 mi. SSW of San Fernando FELT 5/ 2 7:51 pm 34 22.9 116 27.0 2.3 18 mi. N of Yucca Valley 5/ 2 10:19 pm 35 44.2 117 37.4 2.0 8 mi. NNE of Ridgecrest 5/ 2 11:51 pm 32 43.3 115 55.8 2.1 3 mi. ESE of Ocotillo 5/ 3 10:49 am 34 25.3 116 29.9 2.0 21 mi. N of Yucca Valley 5/ 3 11:42 am 34 21.1 118 39.2 2.4 5 mi. NNE of Simi Valley 5/ 4 8:18 am 34 55.0 119 0.5 2.4 4 mi. WSW of Grapevine 5/ 4 8:34 am 35 44.0 117 38.3 2.6 7 mi. NNE of Ridgecrest 5/ 5 5:48 am 32 23.5 117 58.6 2.3 36 mi. SE of San Clemente Is. 5/ 5 6:10 am 34 17.3 117 28.8 2.0 6 mi. NW of Devore 5/ 5 10:17 am 35 48.2 117 37.4 2.1 12 mi. N of Ridgecrest 5/ 5 11:46 am 33 34.5 118 11.3 2.0 10 mi. SE of Pt. Fermin, San Pedro 5/ 5 6:36 pm 32 1.8 116 13.2 2.2 50 mi. SSW of Ocotillo 5/ 5 6:38 pm 36 5.1 117 52.6 2.5 4 mi. NE of Coso Junction 5/ 5 7:28 pm 36 5.5 117 53.0 2.3 4 mi. SE of Haiwee Reservoir 5/ 5 9:01 pm 34 31.9 119 1.6 2.2 11 mi. NNW of Fillmore 5/ 5 11:40 pm 33 49.5 118 8.8 2.1 2 mi. NNE of Signal Hill 5/ 6 2:26 pm 34 20.3 116 27.9 2.3 15 mi. N of Yucca Valley 5/ 6 10:29 pm 36 5.2 117 52.5 2.0 4 mi. NE of Coso Junction 5/ 6 10:29 pm 36 5.2 117 52.5 2.6 " 5/ 6 11:53 pm 33 54.2 116 17.6 2.5 13 mi. NNW of Indio 5/ 7 11:09 am 35 45.3 117 39.2 2.0 9 mi. N of Ridgecrest 5/ 7 11:57 am 35 45.0 117 38.2 2.2 " 5/ 7 2:20 pm 34 3.6 117 16.4 2.3 1 mi. NW of Loma Linda 5/ 7 2:35 pm 32 44.0 115 56.3 2.2 3 mi. E of Ocotillo 5/ 7 4:46 pm 32 42.7 115 24.7 2.8 5 mi. ENE of Calexico FELT 5/ 7 10:36 pm 34 2.8 116 23.8 2.0 5 mi. SSE of Yucca Valley 5/ 7 11:27 pm 34 23.8 116 27.9 2.7 19 mi. N of Yucca Valley 5/ 7 11:27 pm 34 23.7 116 28.0 2.9 " 5/ 8 12:17 pm 33 16.3 115 59.2 2.4 1 mi. WSW of Salton City 5/ 8 4:43 pm 33 49.6 118 7.6 2.1 2 mi. S of Lakewood -------------------------------------------------------------