Northern California Seismicity Report for the week ending Jul 26, 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

• 18 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 3.4, 6 miles ESE of The Geysers, CA at 09:50 PM UTC Thursday, 07 19, 2001 (02:50 PM PDT Thursday, Jul 19, 2001).

• 10 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 2.4, 7 miles N of Hollister, CA at 07:52 PM UTC Thursday, 07 19, 2001 (12:52 PM PDT Thursday, Jul 19, 2001).

• 7 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 2.1, 8 miles WSW of Toms Place, CA at 12:46 AM UTC Friday, 07 20, 2001 (05:46 PM PDT Thursday, Jul 19, 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 JUL 19 0401 57.34 36  3.65 120  7.65  8.61 40 .12  .3  .2 COA    2.7D  86  2 WW
2001 JUL 19 1952 37.30 36 56.90 121 23.37  8.66 53 .07  .2  .4 HOL    2.4D  63  4 WW
2001 JUL 19 2150 31.12 38 45.09 122 42.58  3.10 35 .07  .1  .4 NAP    3.4L  46  3 WW
2001 JUL 20 0046 13.87 37 32.22 118 48.81  6.54 25 .06  .4  .6 MOR    2.1D 165  4 WW
2001 JUL 20 0234  5.13 38 49.14 122 48.02  3.83 20 .03  .2  .4 GEY    2.1D  40  1 WW
 
2001 JUL 20 1500 25.07 36 43.58 121 22.26  2.95 58 .09  .2  .4 STN    3.3L  42  3 WW
2001 JUL 20 2313 35.08 36 28.24 121  2.40  1.20 44 .08  .2  .7 BIT    2.8D  58  5 WW
2001 JUL 21 1451 48.61 35 38.19 121 24.41  0.63 39 .40 1.9 5.9 SSM  # 2.4D 203 23 WW
2001 JUL 22 2129 10.01 38 51.45 122 45.85  2.07 20 .04  .2  .7 GEY    2.3D  38  5 WW
2001 JUL 22 2241  6.99 38 47.50 122 45.03  1.36 14 .05  .2  .6 GEY    2.1D  69  4 WW
 
2001 JUL 22 2310 49.03 40 25.01 124  5.27 21.71 13 .11  .6  .7 MEN    2.3D 101  3 WW
2001 JUL 23 0826 23.34 36 43.62 121 22.60  2.73 38 .06  .1  .4 STN    2.1D  40  4 WW
2001 JUL 23 2016 54.79 36 41.27 121 18.81  4.15 45 .06  .1  .4 STN    2.4D  38  4 WW
2001 JUL 24 0136 34.95 36 42.26 121 19.98  3.14 57 .07  .1  .3 STN    3.2D  43  1 WW
2001 JUL 24 1154 12.80 36 12.03 120 19.65 10.23 28 .05  .2  .3 COA    2.4D  55 12 WW
 
2001 JUL 24 1204 30.93 36 12.06 120 19.46  9.58 20 .07  .2  .4 COA    2.1D  71 12 WW
2001 JUL 24 1512  3.28 36 12.00 120 19.45 10.20 28 .05  .2  .3 COA    2.6D  66 12 WW
2001 JUL 25 1306 54.94 37 18.62 121 40.80  8.68 65 .05  .1  .5 SFL    2.3D  47  6 WW