SOUTHERN CALIFORNIA SEISMOGRAPHIC NETWORK A Cooperative Project of Caltech and the U.S. Geological Survey April 4, 1996 Weekly Earthquake Report for Southern California ------------------------------------------------ March 28 - April 3, 1996 Prepared by: Debbie Wells, 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, March 28, Universal Time (ie. GMT), to midnight Wednesday night, April 3, Universal Time. In local time, the period of coverage is from 4 p.m., March 27 to 4 p.m., April 3, Pacific Standard Time. We detected and processed 393 earthquakes during the 7-day period covered. The largest quake of the week was a M3.3 near Mecca on Monday evening. We did not get any inquiries about this quake in the lab, but it was probably felt in the epicentral area. This was part of a cluster of small earthquakes in the same location, that began on Saturday and has produced 8 quakes of M2.0 or greater. The only local quake to generate any public interest this week was a M2.8 aftershock of Northridge (Jan. 17, 1994, Mw6.7) early Tuesday morning. The elevated activity level in Mammoth has attracted some attention, though, and readers who are interested in that area should consult the Weekly Earth- quake Report for Northern California. 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 ------------------------------------------------------------- 3/27 4:04 pm 34 22.0 116 27.4 2.2 17 mi. N of Yucca Valley 3/27 8:58 pm 34 17.3 117 4.6 2.0 5 mi. NNE of Running Springs 3/27 10:05 pm 35 45.0 117 37.5 2.0 9 mi. NNE of Ridgecrest 3/28 2:13 am 34 21.5 116 28.1 2.1 16 mi. N of Yucca Valley 3/28 2:30 am 32 0.8 116 22.3 3.0 54 mi. SSW of Ocotillo 3/28 3:07 am 34 20.3 116 28.2 2.1 15 mi. N of Yucca Valley 3/28 11:39 pm 33 41.3 117 59.3 2.4 2 mi. SW of Fountain Valley 3/29 3:31 am 33 54.6 116 42.1 2.0 4 mi. E of Cabazon 3/29 7:18 am 32 55.8 117 41.8 2.0 25 mi. SW of Oceanside 3/29 12:12 pm 35 45.2 117 37.8 2.2 9 mi. NNE of Ridgecrest 3/29 3:59 pm 33 29.0 116 28.3 2.1 12 mi. ESE of Anza 3/29 4:00 pm 34 15.3 118 28.0 2.1 2 mi. NNW of Panorama City 3/29 8:38 pm 34 42.0 116 25.6 2.0 39 mi. N of Joshua Tree 3/29 9:31 pm 34 58.7 116 56.7 2.4 7 mi. NE of Barstow 3/29 10:14 pm 33 39.2 116 46.9 2.3 7 mi. SSW of Idyllwild 3/30 2:13 am 33 44.5 115 55.0 2.0 14 mi. N of North Shore 3/30 2:37 am 32 13.6 116 27.3 2.3 41 mi. ESE of San Ysidro 3/30 4:13 am 33 44.4 115 55.3 2.4 14 mi. N of North Shore 3/30 5:10 am 33 44.2 115 55.1 2.0 " 3/30 8:25 am 33 44.3 115 55.2 2.6 " 3/30 10:36 am 32 58.9 116 26.8 2.1 11 mi. SE of Julian 3/30 12:28 pm 34 34.2 116 35.1 2.4 22 mi. ENE of Lucerne Valley 3/30 2:27 pm 34 12.0 115 49.5 2.0 13 mi. ENE of Twentynine Palms 3/30 4:22 pm 33 44.3 115 55.3 2.7 14 mi. N of North Shore 3/30 5:22 pm 34 14.8 116 26.0 2.4 8 mi. N of Yucca Valley 3/31 2:30 am 35 44.9 117 37.8 2.0 9 mi. NNE of Ridgecrest 3/31 9:41 am 34 33.4 116 32.0 2.0 24 mi. ENE of Lucerne Valley 3/31 11:23 am 34 37.8 116 39.3 2.3 20 mi. NE of Lucerne Valley 4/1 12:48 am 34 12.9 116 26.3 2.9 6 mi. N of Yucca Valley 4/1 10:28 am 32 14.8 115 19.7 2.5 30 mi. SSE of Calexico 4/1 7:47 pm 33 44.3 115 55.3 3.3 14 mi. N of North Shore 4/1 7:56 pm 33 44.1 115 55.3 2.1 " 4/1 8:54 pm 32 7.2 116 25.3 2.1 49 mi. SSW of Ocotillo 4/1 9:12 pm 32 4.1 116 27.4 2.1 47 mi. SE of San Ysidro 4/2 12:25 am 34 21.5 118 39.5 2.8 6 mi. NNE of Simi Valley 4/2 11:30 am 33 56.3 116 18.7 2.3 11 mi. E of Desert Hot Springs 4/2 1:20 pm 34 22.8 116 27.4 2.1 18 mi. N of Yucca Valley 4/2 1:36 pm 34 16.2 118 27.8 2.0 1 mi. WSW of Pacoima 4/2 2:01 pm 34 3.0 116 23.9 2.2 5 mi. SSE of Yucca Valley 4/2 4:38 pm 34 58.8 116 56.8 2.0 7 mi. NE of Barstow 4/2 5:39 pm 33 44.3 115 55.3 2.9 14 mi. N of North Shore 4/3 1:16 am 35 45.0 118 2.8 2.2 21 mi. SSW of Coso Junction 4/3 4:17 am 34 3.6 117 15.4 2.1 Under Loma Linda 4/3 5:10 am 35 44.8 117 38.0 2.1 8 mi. NNE of Ridgecrest 4/3 5:56 am 35 44.9 117 38.1 2.3 " 4/3 10:13 am 32 44.7 117 54.3 2.4 26 mi. ESE of San Clemente Is. (SE tip) -------------------------------------------------------------