Northern California Seismicity Report for the week ending Sep 20, 2001

This report provides a brief summary of earthquake activity recorded by the U.S. Geological Survey Northern California Seismic Network in Menlo Park and the University of California Berkeley Seismological Laboratory. It is automatically generated each Wednesday shortly after midnight, Universal time (UT). UT (ie., Greenwich Mean Time) is 8 hours ahead of PST or 7 hours ahead of PDT.

Because it is not possible to review all of the earthquakes before this report is generated, it may contain errors. Please report errors or provide suggestions and comments to ncsn@andreas.wr.usgs.gov

The report no longer includes maps showing earthquakes for the entire US or world. Those maps are now available from the U.S.G.S. National Earthquake Information Center. In addition, all earthquake data can be retrieved from the Northern California Earthquake Data Center.

Please note that some of the earthquake data in this report have been reviewed by seismic analysts. Consequently, the parameters that describe the hypocenter, magnitude, origin time, and solution statistics may differ slightly from the information contained on the real-time earthquake web page. The differences reflect revised arrival times at seismic stations and the analysts' decisions to include or exclude information from seismic stations.

The minimum magnitude ( M) values in the following bullets reflect the smallest earthquake which the network can routinely record within the region. During the previous seven-day period ending at midnight (UT) Wednesday, our seismic networks recorded

• 21 M >2.0 earthquakes in Northern and Central California (map) (within dashed polygon of figure).

The largest event to occur this week in this region was a minor earthquake of magnitude 3.2, 12 miles SW of Toms Place, CA at 12:33 AM UTC Thursday, 09 13, 2001 (05:33 PM PDT Wednesday, Sep 12, 2001).

• 16 M >1.2 earthquakes in the San Francisco Bay area (map).

The largest event to occur this week in this region was a microearthquake of magnitude 2.5, 2 miles W of San Juan Bautista, CA at 11:40 AM UTC Tuesday, 09 18, 2001 (04:40 AM PDT Tuesday, Sep 18, 2001).

• 9 M >1.2 earthquakes in the Long Valley region (map).

The largest event to occur this week in this region was a minor earthquake of magnitude 3.2, 12 miles SW of Toms Place, CA at 12:33 AM UTC Thursday, 09 13, 2001 (05:33 PM PDT Wednesday, Sep 12, 2001).

The following table provides a listing of all M >2 earthquakes that occurred this week. An explanation of the entries in the table is available.

---ORIGIN TIME (UT)--- -LAT N-- --LON W-- DEPTH  N RMS ERH ERZ LOC    PREF AZ MIN S. PAGE   1
YEAR MON DA HRMN  SEC  DEG MIN  DEG  MIN    KM  RD SEC  KM  KM REMKS  MAG  GAP DS PF

2001 SEP 13 0033  2.01 37 26.75 118 51.19  6.63 36 .06  .3 1.2 MOR    3.2D  91 12 NN
2001 SEP 13 1630 15.93 39 25.72 123  5.88  6.85 31 .07  .2  .8 BAR    2.6D  44 16 WW
2001 SEP 13 1839 56.91 38 49.69 122 49.56  2.55 33 .04  .1  .4 GEY    2.5D  33  4 NN
2001 SEP 13 2244 55.12 37 35.01 118 47.81  7.50 33 .06  .2  .4 MOR    2.1D  77  3 NN
2001 SEP 14 0811  5.02 40 37.10 122 26.43 23.07 13 .17  .6  .5 SHA    2.7D 106  8 NN
 
2001 SEP 14 1549 53.69 37  8.88 118 25.55 14.44 20 .06  .4 1.2 KAI    2.2D 166 44 NN
2001 SEP 14 1848 48.29 36 47.88 121 31.08  7.88 53 .09  .2  .3 SJB    2.1D  35  3 NN
2001 SEP 15 1253  2.59 38 47.94 122 43.96  2.92 35 .05  .1  .3 GEY    2.6D  50  3 NN
2001 SEP 15 2050 39.96 39 43.96 121  2.88 12.95 12 .03 1.0 2.7 WAK    2.0D 226 28 NN
2001 SEP 16 2142  9.06 35 57.88 120 31.13 11.19 42 .05  .2  .2 MID    2.4D  47  4 NN
 
2001 SEP 17 0101 59.35 39 20.95 122 33.81  0.30 28 .21  .3 1.4 SAC    2.4D  69  5 NN
2001 SEP 17 0245  0.50 36 33.73 121  9.08  2.90 44 .06  .1  .4 PIN    2.4D  33  4 WW
2001 SEP 17 0425 44.59 36 34.56 121 10.15  5.83 31 .05  .2  .4 PIN    2.0D  37  2 WW
2001 SEP 18 1140  9.32 36 50.56 121 34.10  4.99 54 .13  .2  .3 SJB    2.5D  33  2 WW
2001 SEP 18 1508 52.63 37 54.73 122 17.38  4.64  8 .07  .4  .8 HAY    2.2D  95  7 WW
 
2001 SEP 18 1649 38.74 36 50.63 121 34.17  5.16 48 .13  .2  .4 SJB    2.4D  33  2 WW
2001 SEP 18 2048  1.95 38 47.40 122 46.54  2.26 33 .06  .2  .5 GEY    3.0D  37  3 WW
2001 SEP 19 1218 39.12 36 33.93 121  9.62  6.16 42 .05  .2  .4 PIN    2.2D  42  3 WW
2001 SEP 19 1800 52.14 35 48.44 121 16.47  5.42 16 .03  .6 1.1 SSM    2.0D 179 13 WW
2001 SEP 19 2146 26.44 38 45.03 122 43.64  2.30 27 .05  .2  .4 GEY    2.4D  73  3 WW
 
2001 SEP 19 2254 51.07 37 33.36 118 51.81 10.50 30 .06  .3  .6 MOR    2.4D 105  5 WW