September 22, 1994 Weekly Earthquake Report for Southern California ------------------------------------------------ September 15 - 21, 1994 Prepared by: Kate Hutton, Seismological Laboratory (kate@bombay.gps.caltech.edu) Lucy Jones, U.S. Geological Survey California Institute of Technology This document is a commentary on current seismic activity. The earthquakes discussed have been detected and processed automatically. All epicenters and magnitudes have been reviewed to exclude obvious blunders; however, they must still be considered preliminary. 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, September 15, Pacific Daylight Time, to midnight Wednesday night, September 21, Pacific Daylight Time. We recorded 327 earthquakes of M1.0 or larger this week. Although the total number of earthquakes this week was about the same as it has been of late, the only one above M3 occurred in the Mojave Desert, SSW of Baker, early Friday morning (M3.1). It may have woken up a few coyotes. In fact, no-one reported feeling an earthquake in our area this week, although several people felt the sonic boom caused by the Space Shuttle landing about 2:08 pm on Tuesday. None of the Northridge or Landers/Big Bear aftershocks were larger than M3. The table lists the quakes 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 Daylight Time listed. Table 1 ------- Date Time N Lat. W Long. Mag ------------------------------------------------------------- 9/15 3:19 am 33 57.8 116 19.7 2.1 9 mi. E of Desert Hot Springs 9/15 6:32 am 34 18.5 118 25.6 2.0 1 mi. NNE of San Fernando 9/15 7:27 am 34 7.3 116 51.1 2.0 2 mi. NW of Mt. San Gorgonio 9/15 7:35 am 33 32.5 117 39.3 2.1 7 mi. E of Laguna Beach 9/15 10:48 am 34 46.8 116 17.7 2.3 35 mi. SSW of Baker 9/15 11:27 am 34 59.3 116 56.6 2.4 8 mi. NNE of Barstow 9/15 1:55 pm 34 11.4 116 26.0 2.6 4 mi. N of Yucca Valley 9/15 2:07 pm 33 42.5 116 46.2 2.2 4 mi. SW of Idyllwild 9/15 2:46 pm 33 57.3 117 4.7 2.1 6 mi. WNW of Beaumont 9/15 3:13 pm 33 48.7 116 11.7 2.3 6 mi. N of Indio 9/15 5:43 pm 35 41.2 119 51.9 2.0 24 mi. NNE of Simmler 9/15 5:53 pm 36 1.7 119 49.9 2.2 30 mi. ESE of Coalinga 9/16 2:56 am 34 29.0 116 30.5 2.0 25 mi. N of Yucca Valley 9/16 3:07 am 34 14.3 116 25.5 2.5 8 mi. N of Yucca Valley 9/16 3:29 am 35 39.9 117 37.8 2.5 3 mi. NE of Ridgecrest 9/16 4:39 am 34 47.9 116 17.9 3.1 34 mi. SSW of Baker 9/16 6:56 am 34 46.7 116 17.8 2.0 " 9/16 5:21 pm 33 40.3 116 45.0 2.1 5 mi. SSW of Idyllwild 9/16 5:37 pm 34 18.1 118 26.5 2.4 1 mi. N of San Fernando 9/16 6:03 pm 34 47.1 116 18.0 2.3 35 mi. SSW of Baker 9/16 11:30 pm 35 58.6 118 20.6 2.6 24 mi. NNE of the town of Lake Isabella 9/17 12:52 am 34 6.4 116 24.3 2.5 2 mi. ESE of Yucca Valley 9/17 6:21 am 34 37.1 116 36.7 2.1 22 mi. ENE of Lucerne Valley 9/17 7:02 am 34 8.2 117 42.9 2.3 2 mi. NNE of Claremont Colleges 9/17 7:10 am 34 45.5 121 35.2 2.8 61 mi. SSW of Cambria 9/17 11:23 am 34 9.9 118 9.3 2.2 2 mi. NW of Caltech, Pasadena 9/17 5:35 pm 34 28.9 116 30.7 2.0 25 mi. N of Yucca Valley 9/17 6:43 pm 34 8.0 116 46.5 2.6 3 mi. NE of Mt. San Gorgonio 9/17 8:13 pm 34 18.9 118 26.5 2.9 2 mi. N of San Fernando 9/18 12:36 am 34 6.7 116 24.0 2.0 2 mi. E of Yucca Valley 9/18 3:41 pm 34 19.1 118 26.0 2.3 2 mi. N of San Fernando 9/18 5:21 pm 34 2.5 117 31.0 2.1 Fontana, 2 mi. SE of the I10/I15 interchange 9/18 9:43 pm 34 47.2 116 18.1 2.6 35 mi. SSW of Baker 9/18 11:50 pm 34 23.9 116 27.5 2.0 19 mi. N of Yucca Valley 9/19 7:06 pm 33 12.0 115 34.1 2.0 3 mi. SW of Niland 9/19 9:32 pm 34 20.3 116 28.1 2.8 15 mi. N of Yucca Valley 9/20 4:23 am 34 9.4 116 25.8 2.3 2 mi. NNE of Yucca Valley 9/20 10:52 am 33 20.3 116 22.6 2.3 5 mi. N of Borrego Springs 9/20 12:21 pm 34 37.5 116 38.4 2.2 21 mi. NE of Lucerne Valley 9/20 9:16 pm 34 14.1 117 27.8 2.2 Lytle Creek, 3 mi. WNW of the I15/I215 interchange 9/20 10:08 pm 34 23.2 116 27.9 2.1 18 mi. N of Yucca Valley 9/20 11:02 pm 34 47.3 116 17.9 2.2 35 mi. SSW of Baker 9/21 8:13 am 34 37.3 116 35.9 2.1 23 mi. ENE of Lucerne Valley 9/21 3:15 pm 33 31.6 116 31.2 2.9 8 mi. ESE of Anza 9/21 3:31 pm 34 17.5 118 40.8 2.1 1 mi. ENE of Simi Valley 9/21 7:23 pm 34 17.3 118 40.5 2.0 " 9/21 7:51 pm 36 2.4 117 42.4 2.2 13 mi. E of Coso Junction 9/21 10:20 pm 34 47.0 116 17.8 2.1 35 mi. SSW of Baker 9/21 10:21 pm 34 47.6 116 17.8 2.8 " 9/21 10:31 pm 34 47.5 116 17.8 2.6 " ------------------------------------------------------------- Figure 1. A map of southern California showing the earthquakes recorded during the past week by the Caltech/USGS Seismic Network. Major faults are marked, as well as the metropolitan areas of Los Angeles (L.A.), Palm Springs (P.S.), San Diego (S.D.), and Santa Barbara (S.B.). The circles denote the earthquakes, the size of the circle indicating the magnitude.