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 3.3 10 miles NW of Parkfield, CA at 07:35 PM UTC Wednesday, Oct 13, 1999 (12:35 PM PDT Wednesday, Oct 13, 1999).
The largest event to occur this week in this region was a microearthquake of magnitude 2.7 2 miles E of Berkeley, CA at 01:04 AM UTC Wednesday, Oct 13, 1999 (06:04 PM PDT Tuesday, Oct 12, 1999).
The largest event to occur this week in this region was a minor earthquake of magnitude 3.2 10 miles WSW of Toms Place, CA at 02:46 PM UTC Tuesday, Oct 12, 1999 (07:46 AM PDT Tuesday, Oct 12, 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 OCT 8 1401 51.49 37 31.74 118 49.09 6.84 33 .04 .2 .4 MOR 2.1D 99 OCT 8 1408 13.13 37 31.84 118 49.09 6.56 35 1 .05 .2 .4 MOR 2.2D 99 OCT 9 822 48.44 40 27.00 124 39.69 23.88 29 1 .06 1.0 .6 MEN 2.1D 99 OCT 9 2029 26.15 37 31.61 118 49.17 6.38 35 .05 .2 .4 MOR 2.2D 99 OCT 10 252 36.20 40 33.61 124 4.03 25.13 13 1 .04 .3 .6 EUR 2.2D 99 OCT 10 1644 4.04 38 31.71 122 17.14 5.80 53 .17 .2 .6 GVL 3.0D 99 OCT 10 1751 22.37 38 47.38 122 44.86 0.98 30 .05 .1 .3 GEY 2.3D 99 OCT 11 712 31.74 40 52.22 124 25.25 21.00 20 1 .04 .6 .7 EUR 2.2D 99 OCT 11 1447 16.16 39 49.92 122 36.73 17.99 44 1 .32 .5 .4 SAC 2.7D 99 OCT 11 1824 51.30 37 28.61 118 46.69 6.58 33 .05 .3 .5 MOR 2.6D 99 OCT 12 43 7.22 38 46.09 122 44.39 1.99 33 .05 .1 .3 GEY 2.5D 99 OCT 12 1318 47.43 38 31.66 122 17.77 3.39 47 .20 .2 .8 GVL 2.4D 99 OCT 12 1446 33.20 37 29.20 118 50.37 4.14 34 1 .06 .3 .9 MOR 3.2D 99 OCT 12 1558 5.31 36 50.31 120 4.45 0.09 22 .28 1.4 5.1 JQN # 2.1D 99 OCT 12 1726 32.15 38 48.99 122 47.08 0.11 12 .03 .3 .4 GEY 2.1D 99 OCT 13 104 22.91 37 52.51 122 14.29 10.15 52 .06 .1 .3 HAY 2.7D 99 OCT 13 248 45.71 37 5.25 122 2.35 9.28 45 .12 .2 .4 MON 2.1D 99 OCT 13 1935 56.39 35 59.83 120 33.33 4.39 52 .06 .2 .2 MID 3.3L