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@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
The largest event to occur this week in this region was a minor earthquake of magnitude 3.7 9 miles WSW of Toms Place, CA at 05:17 AM UTC Saturday, Aug 07, 1999 (10:17 PM PDT Friday, Aug 06, 1999).
The largest event to occur this week in this region was a microearthquake of magnitude 1.6 2 miles NNW of Scotts Valley, CA at 01:08 AM UTC Monday, Aug 09, 1999 (06:08 PM PDT Sunday, Aug 08, 1999).
The largest event to occur this week in this region was a minor earthquake of magnitude 3.7 9 miles WSW of Toms Place, CA at 05:17 AM UTC Saturday, Aug 07, 1999 (10:17 PM PDT Friday, Aug 06, 1999).
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 N RMS ERH ERZ LOC PREF YR MON DA HRMN SEC DEG MIN DEG MIN KM RD S SEC KM KM REMKS MAG 99 AUG 5 248 45.86 37 30.18 118 50.01 8.85 23 .05 .4 .9 MOR 2.3D 99 AUG 5 1101 8.68 37 30.47 118 50.15 12.76 30 1 .06 .3 .7 MOR 2.9D 99 AUG 5 2212 31.12 38 49.27 122 47.72 4.24 33 .03 .2 .3 GEY 2.2D 99 AUG 6 919 27.34 37 30.05 118 49.89 8.03 32 1 .05 .3 .7 MOR 2.5D 99 AUG 6 1235 20.37 37 31.10 118 49.67 7.25 34 .04 .3 .6 MOR 3.2L 99 AUG 6 1606 33.49 37 32.50 118 51.98 8.28 36 .06 .2 .6 MOR 3.0D 99 AUG 6 2338 11.31 36 10.31 120 18.41 6.55 14 .06 .3 .6 COA 2.3D 99 AUG 7 517 45.35 37 31.10 118 49.62 7.52 35 .06 .3 .6 MOR 3.7L 99 AUG 7 751 0.68 37 31.01 118 49.63 7.96 33 .04 .3 .5 MOR 2.6D 99 AUG 7 1451 52.33 38 48.41 122 47.97 1.46 37 .05 .1 .3 GEY 2.3D 99 AUG 7 1817 41.19 36 15.87 120 27.94 10.56 36 .14 .2 .3 COA 2.2D 99 AUG 7 2004 52.53 39 35.73 120 51.87 7.90 15 2 .02 .3 2.9 WAK 2.1D 99 AUG 8 205 33.28 37 29.95 118 49.16 0.66 25 .05 .4 .4 MOR 2.1D 99 AUG 8 634 9.63 36 38.48 121 15.72 10.80 63 .06 .1 .2 STN 2.6D 99 AUG 8 913 39.39 36 16.40 120 48.50 7.47 19 .07 .3 .9 BIT 2.2D 99 AUG 8 1018 46.48 37 30.80 118 49.84 2.75 34 1 .06 .3 1.1 MOR 2.5D 99 AUG 8 1242 57.81 38 47.70 122 48.34 4.77 40 .07 .1 .3 GEY 2.1D 99 AUG 8 1412 51.61 39 56.92 120 52.32 0.04 63 1 .49 .5 2.5 WAK # 2.7D 99 AUG 8 1435 32.50 37 36.88 118 27.52 0.42 14 .16 .8 2.8 CHV 2.7D 99 AUG 8 2240 54.84 37 31.26 118 49.60 7.46 35 .06 .2 .5 MOR 2.4D 99 AUG 9 409 21.58 40 58.07 121 35.67 0.05 16 1 .07 .2 2.1 SHA # 2.4D 99 AUG 9 1728 21.04 36 27.99 121 2.70 7.18 48 .05 .1 .3 BIT 2.2D 99 AUG 10 2202 25.46 37 35.91 118 48.83 5.62 18 .05 .3 .4 MOR 2.2D 99 AUG 11 1517 3.95 37 28.57 118 48.44 2.27 22 .06 .3 3.0 MOR 3.0L 99 AUG 11 2036 29.66 35 56.92 120 2.54 9.48 30 .12 .2 .5 COA 2.7D 99 AUG 11 2342 27.80 38 49.63 122 50.24 3.37 27 .06 .2 .7 GEY 2.7D