March 23, 1995 Weekly Earthquake Report for Southern California ------------------------------------------------ March 16 - 22, 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, March 16, Pacific Standard Time, to midnight Wednesday night, March 22, 1995, Pacific Standard Time. We recorded 260 earthquakes of M1.0 or larger during the 7-day period covered. It was indeed a quiet week. The largest quake was a M3.3 very early Saturday morning in the Beaumont/Yucaipa area. In that region, the San Andreas fault splits up into several strands. None of the strands are continuous at the Earth's surface, so the "active trace" of the San Andreas is not well-defined. This week's earthquake was located between the Banning strand and the Mission Creek strand. Its focal mechanism shows oblique reverse motion on an east-striking fault, which means that the fault strikes east-west, and the block of rock on the north side moved up and to the east compared to the south side. Although the quake was a few miles removed from both towns and could have been felt, we got no reports. All other quakes were less than M3 in magnitude. 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 ------------------------------------------------------------- 3/16 3:54 am 34 6.4 116 51.9 2.2 2 mi. W of Mt. San Gorgonio 3/16 5:32 pm 34 6.5 116 51.7 2.1 " 3/16 6:57 pm 34 36.0 116 38.8 2.1 20 mi. ENE of Lucerne Valley 3/16 7:07 pm 33 40.7 116 48.3 2.1 7 mi. SW of Idyllwild 3/16 8:08 pm 33 42.0 116 45.7 2.6 4 mi. SW of Idyllwild 3/16 8:19 pm 36 4.7 117 49.9 2.1 6 mi. ENE of Coso Junction 3/16 9:25 pm 33 43.7 118 39.3 2.2 13 mi. WSW of Palos Verdes Point 3/16 9:57 pm 34 34.5 116 35.3 2.3 22 mi. ENE of Lucerne Valley 3/17 3:58 am 33 37.2 116 43.1 2.4 5 mi. NNW of Anza 3/17 5:50 am 34 6.6 116 51.8 2.2 2 mi. WNW of Mt. San Gorgonio 3/17 6:17 am 33 42.2 116 45.6 2.0 3 mi. SW of Idyllwild 3/17 6:40 am 32 46.5 118 18.0 2.3 4 mi. SE of San Clemente Is. 3/17 4:09 pm 35 0.8 116 57.6 2.0 9 mi. NNE of Barstow 3/17 9:17 pm 34 28.6 116 29.5 2.0 24 mi. N of Yucca Valley 3/18 12:30 am 34 1.8 116 57.3 3.3 7 mi. N of Beaumont 3/18 3:09 am 33 11.8 115 34.8 2.0 4 mi. SW of Niland 3/18 3:10 am 34 2.3 116 57.7 2.1 7 mi. N of Beaumont 3/18 3:49 am 34 4.3 116 59.1 2.1 9 mi. N of Beaumont 3/18 6:52 am 34 22.5 116 27.5 2.0 17 mi. N of Yucca Valley 3/18 2:45 pm 34 8.0 117 0.0 2.0 7 mi. SE of Running Springs 3/18 7:44 pm 34 6.5 116 51.9 2.1 2 mi. WNW of Mt. San Gorgonio 3/18 8:38 pm 36 4.8 117 50.2 2.2 6 mi. ENE of Coso Junction 3/19 12:36 am 34 56.9 116 46.5 2.1 14 mi. ENE of Barstow 3/19 3:17 am 34 22.5 116 27.1 2.1 17 mi. N of Yucca Valley 3/19 4:11 am 34 18.8 116 53.1 2.3 3 mi. NNW of Big Bear City 3/19 12:52 pm 33 55.6 116 19.0 2.0 10 mi. ESE of Desert Hot Springs 3/19 4:18 pm 34 24.1 118 37.8 2.1 2 mi. WSW of Magic Mtn. 3/19 5:42 pm 34 20.2 118 44.4 2.1 4 mi. NNW of Simi Valley 3/19 7:54 pm 34 7.3 119 1.4 2.0 6 mi. S of Camarillo 3/19 7:54 pm 34 24.1 118 38.3 2.0 3 mi. WSW of Magic Mtn. 3/19 11:43 pm 34 18.0 116 27.3 2.0 12 mi. N of Yucca Valley 3/20 6:23 am 34 16.6 116 26.3 2.1 10 mi. N of Yucca Valley 3/20 7:53 am 34 2.4 118 6.1 2.0 2 mi. ESE of Monterey Park 3/20 2:01 pm 34 14.1 117 28.8 2.0 Lytle Creek, 3 mi. WNW of the I15/I215 interchange 3/21 1:55 am 34 47.1 116 17.9 2.0 35 mi. SSW of Baker 3/21 8:30 am 32 45.0 115 26.1 2.7 6 mi. NNE of Calexico 3/21 1:13 pm 33 52.3 117 56.6 2.0 Fullerton, 2 mi. ENE of the I5/91 interchange 3/21 4:03 pm 33 58.3 118 26.3 2.1 Under Marina del Rey 3/21 6:30 pm 34 33.2 120 41.2 2.0 2 mi. SW of Pt. Arguello 3/21 6:30 pm 34 33.2 120 41.2 2.0 " 3/22 6:42 am 33 35.1 116 25.5 2.0 9 mi. SSW of Palm Desert 3/22 11:48 am 35 1.9 117 0.3 2.2 9 mi. N of Barstow 3/22 4:34 pm 34 10.4 116 25.8 2.0 3 mi. NNE of Yucca Valley 3/22 6:40 pm 34 15.0 118 27.9 2.4 2 mi. SW of San Fernando 3/22 11:11 pm 34 22.1 118 39.8 2.4 5 mi. SW of Magic Mtn. -------------------------------------------------------------