Northern California Seismicity Report for the week ending Dec 13, 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

• 30 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 light earthquake of magnitude 4.1, 9 miles SSE of Ukiah, CA at 02:29 PM UTC Friday, 12 07, 2001 (06:29 AM PST Friday, Dec 07, 2001).

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

The largest event to occur this week in this region was a minor earthquake of magnitude 3.2, 9 miles N of Morgan Hill, CA at 10:41 AM UTC Thursday, 12 06, 2001 (02:41 AM PST Thursday, Dec 06, 2001).

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

The largest event to occur this week in this region was a microearthquake of magnitude 2.7, 8 miles WSW of Toms Place, CA at 04:08 PM UTC Thursday, 12 06, 2001 (08:08 AM PST Thursday, Dec 06, 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 DEC  6 1041 49.82 37 15.44 121 38.56  4.60 77 .07  .1  .3 SFL    3.2L  55  3 NN
2001 DEC  6 1608  0.98 37 29.74 118 48.51  8.21 30 .07  .3  .7 MOR    2.7D 122  8 NN
2001 DEC  6 1638 44.33 36 31.61 120 46.81  8.24 44 .08  .1  .3 CRV    2.8D  54 15 NN
2001 DEC  7 0102 22.05 38 16.00 122 19.64 11.42 60 .12  .1  .4 NAP    2.9D  49 10 NN
2001 DEC  7 0130 36.52 38 49.45 122 47.44  0.73 13 .04  .2  .5 GEY    2.2D  49  2 WW
 
2001 DEC  7 0208 58.01 36 51.35 121 35.16  6.41 56 .09  .2  .3 SJB    2.2D  47  3 NN
2001 DEC  7 0419 50.31 38 54.85 122 30.93  6.25 35 .09  .2  .6 BAR    2.8D 103 13 NN
2001 DEC  7 0420 47.37 38 53.74 122 31.27  5.55 26 .16  .5 1.4 BAR    2.6D  82 12 NN
2001 DEC  7 1429  8.48 39  2.57 123  6.98  6.59 34 .09  .2  .6 MAA    4.1L  80  8 WW
2001 DEC  7 1447 38.83 39  2.81 123  7.37  5.52 18 .08  .3  .8 MAA    2.5D  81  9 WW
 
2001 DEC  7 1522  5.20 39  2.40 123  7.21  5.73 13 .05  .3  .8 MAA    2.0D 110  9 WW
2001 DEC  7 2211 14.73 36 47.80 121 22.84  4.08 64 .07  .1  .2 HOL    2.7D  25  4 NN
2001 DEC  7 2237 23.22 40 46.83 123 39.74 26.34 14 .04  .3  .6 EUR    2.5D 106 12 NN
2001 DEC  8 1348 58.17 36 47.79 121 22.74  4.12 63 .07  .1  .3 HOL    2.9D  40  3 NN
2001 DEC  8 1357 48.03 36 47.59 121 22.68  3.11 37 .08  .2  .5 HOL    2.1D  38  3 WW
 
2001 DEC  8 1528  7.82 36 47.82 121 22.71  4.05 59 .07  .1  .3 HOL    2.6D  40  3 NN
2001 DEC  8 1622 43.60 38 46.38 122 44.06  0.05 14 .11  .3 1.1 GEY  # 2.1D  59  6 WW
2001 DEC 10 0532 29.02 38 47.92 122 47.85  5.34 43 .04  .1  .4 GEY    3.1L  35  1 NN
2001 DEC 10 0559  4.87 38 48.13 122 47.49  0.93 18 .03  .2  .3 GEY    2.0D  42  1 NN
2001 DEC 10 1042 44.99 37 51.11 122 14.01  7.10 65 .09  .1  .2 HAY    2.3D  34  4 AN
 
2001 DEC 10 1054 25.52 37 51.10 122 13.96  7.19 72 .09  .1  .2 HAY    2.6D  30  4 AN
2001 DEC 10 1246  0.15 38 49.82 122 48.07  0.18 42 .14  .2  .6 GEY    3.6L  31  3 WW
2001 DEC 10 1250 20.14 38 49.87 122 48.99  2.66  9 .01  .4  .6 GEY    2.5D 108  3 WW
2001 DEC 10 1250 40.69 38 50.23 122 49.02  0.02 12 .36 1.1 8.8 GEY  # 2.0D  64 11 WW
2001 DEC 10 1254 20.24 38 49.72 122 48.98  2.75 21 .04  .2  .4 GEY    2.0D  38  3 NN
 
2001 DEC 10 1355 53.13 38 50.03 122 49.05  3.22 27 .06  .2  .6 GEY    2.9D  46  3 WW
2001 DEC 11 1230  0.02 37 12.56 122  3.31 12.83 59 .09  .2  .4 BLM    2.4D  90  6 WW
2001 DEC 11 1405  1.52 36 21.37 120 55.03  1.66 10 .06  .4  .9 BIT    2.0D 119  5 WW
2001 DEC 12 1540 55.09 37 36.65 119 23.08 23.50 21 .10  .5 1.5 KAI    2.2D  75 27 WW
2001 DEC 12 2320 22.25 37 21.33 121 43.11  6.37 48 .08  .1  .5 ALU    2.0D  48 11 WW