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 light earthquake of magnitude 4.3, 6 miles ESE of Cloverdale, CA at 02:19 PM UTC Tuesday, 01 11, 2000 (06:19 AM PST Tuesday, Jan 11, 2000).
There were two M4.3 events (see list below) that were part of this robust sequence 126 earthquakes as of 1/13/2000 00:00. The sequence occurs on a N-S oriented, strike-slip, near vertical fault located southwest of the main trace of the Maacama fault and apparently intersecting the Maacama fault. The Maacama fault zone in this area is complex and consists of many en echelon and braided strands of minor faults over a zone 2 km wide. The sequence is continuing at the time of this report. The fault has not been seismically active since seismic monitoring in this area commenced in 1975.
The largest event to occur this week in this region was an earthquake of magnitude 2.3, 5 miles ENE of San Martin, CA at 12:07 AM UTC Wednesday, 01 12, 2000 (04:07 PM PST Tuesday, Jan 11, 2000).
The largest event to occur this week in this region was a minor earthquake of magnitude 3.2, 8 miles WSW of Toms Place, CA at 07:34 PM UTC Sunday, 01 09, 2000 (11:34 AM PST Sunday, Jan 09, 2000).
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 2000 JAN 6 2135 12.65 38 50.68 122 49.64 1.24 13 .04 .2 .7 GEY 2.0D 73 4 WW 2000 JAN 6 2138 10.94 38 50.64 122 49.56 2.08 43 .09 .2 .6 GEY 3.5D 31 5 WW 2000 JAN 6 2140 22.03 38 49.65 122 49.85 1.82 15 .04 .2 .6 GEY 2.1D 66 4 WW 2000 JAN 6 2142 29.95 38 49.71 122 49.92 1.02 27 .06 .2 .4 GEY 2.5D 34 4 WW 2000 JAN 6 2156 50.07 38 50.06 122 49.59 1.70 26 .08 .2 .5 GEY 2.3D 37 4 WW 2000 JAN 6 2159 48.99 38 50.14 122 49.90 1.88 25 .05 .2 .5 GEY 2.5D 38 4 WW 2000 JAN 7 0312 32.06 38 49.91 122 49.83 2.58 22 .06 .2 .6 GEY 2.2D 44 4 WW 2000 JAN 7 0725 50.78 36 49.22 121 33.04 6.96 50 .11 .2 .4 SJB 2.2D 35 3 WW 2000 JAN 7 1200 1.52 37 39.31 118 54.10 0.81 9 .04 .3 .5 DOM 2.2D 121 3 WW 2000 JAN 7 1419 22.51 37 39.26 118 54.07 0.24 9 .04 .3 .4 DOM 2.1D 133 0 WW 2000 JAN 7 1616 14.80 37 28.37 118 50.88 5.36 30 .06 .3 .9 MOR 2.3D 131 9 WW 2000 JAN 7 1751 4.01 36 53.14 121 24.01 9.20 54 .06 .2 .4 HOL 2.1D 62 8 WW 2000 JAN 7 2320 55.10 38 13.47 121 48.87 17.92 16 .13 .4 .4 JQN 2.0D 111 8 WW 2000 JAN 8 0017 19.07 39 18.02 122 46.75 8.26 19 .08 .3 1.0 BAR 2.2D 78 15 WW 2000 JAN 8 0646 56.86 40 51.70 123 4.84 36.35 8 .05 .6 1.1 KLA 2.5D 119 22 WW 2000 JAN 8 0918 48.45 38 49.53 122 45.96 1.46 16 .05 .2 .6 GEY 2.1D 53 3 WW 2000 JAN 9 0725 22.16 37 31.99 118 48.94 6.44 31 .04 .3 .5 MOR 2.2D 109 4 WW 2000 JAN 9 1442 31.78 36 33.37 121 5.41 10.21 44 .06 .1 .3 BVL 2.5D 45 5 WW 2000 JAN 9 1622 59.09 36 33.40 121 5.42 10.21 43 .06 .2 .3 BVL 2.5D 45 5 WW 2000 JAN 9 1934 27.76 37 31.74 118 49.17 6.19 28 .05 .3 .8 MOR 3.2D 110 7 WW 2000 JAN 10 0509 46.95 37 32.29 118 49.69 6.77 27 .07 .4 .6 MOR 2.0D 110 5 WW 2000 JAN 10 0937 4.39 37 32.08 118 48.91 6.11 29 .05 .3 .5 MOR 2.7D 129 4 WW 2000 JAN 10 1149 25.25 37 28.67 118 21.27 5.22 16 .05 .3 .8 CHV 2.2D 155 9 WW 2000 JAN 10 1301 0.72 40 20.17 124 12.71 26.41 8 .06 .8 1.6 MEN 2.4D 157 12 WW 2000 JAN 10 1431 26.66 37 28.61 118 20.98 5.51 18 .04 .5 .7 CHV 2.3D 182 9 WW 2000 JAN 10 2141 27.13 38 45.41 122 54.79 6.20 41 .14 .2 .7 ROG 4.3L 54 9 WW 2000 JAN 10 2257 5.21 38 45.35 122 55.12 4.86 32 .11 .2 .7 ROG 2.5D 53 6 WW 2000 JAN 10 2305 38.40 39 1.95 123 4.52 2.93 19 .09 .2 1.1 MAA 2.3D 45 5 WW 2000 JAN 10 2326 39.66 40 31.11 124 0.61 21.95 12 .07 .4 .6 EUR 2.9D 110 15 WW 2000 JAN 10 2354 23.50 37 9.96 119 51.01 20.07 11 .05 .6 .4 KAI 2.6D 157 7 WW 2000 JAN 11 1419 52.08 38 46.06 122 54.81 6.63 43 .12 .2 .4 GEY 4.3L 44 6 WW 2000 JAN 11 1423 22.00 38 47.23 122 54.50 4.56 10 .07 .4 1.1 GEY 2.1D 117 6 WW 2000 JAN 11 1423 46.59 38 45.70 122 55.00 5.92 25 .07 .2 .6 ROG 2.6D 75 6 WW 2000 JAN 11 1425 30.79 38 47.17 122 54.94 4.80 24 .09 .2 .9 GEY 2.6D 44 7 WW 2000 JAN 11 1427 27.41 38 46.90 122 54.87 5.69 20 .08 .3 .6 GEY 2.3D 46 6 WW 2000 JAN 11 1432 12.56 38 47.08 122 55.04 5.28 28 .08 .2 .6 GEY 2.6D 45 7 WW 2000 JAN 11 1433 20.14 38 47.11 122 54.97 4.32 20 .08 .3 1.0 GEY 2.3D 44 7 WW 2000 JAN 11 1524 54.12 38 46.49 122 54.86 6.62 26 .09 .2 .6 GEY 2.3D 49 6 WW 2000 JAN 11 1800 53.29 38 46.86 122 54.95 5.16 23 .08 .2 .8 GEY 2.6D 46 6 WW 2000 JAN 11 1839 55.53 38 46.78 122 55.20 4.00 29 .08 .2 .8 GEY 2.3D 46 7 WW 2000 JAN 11 1926 3.75 38 45.29 122 55.02 5.81 24 .09 .2 .6 ROG 2.2D 61 6 WW 2000 JAN 12 0007 59.74 37 7.62 121 31.51 8.05 66 .07 .2 .3 CYN 2.3D 73 2 WW 2000 JAN 12 0255 29.65 41 3.52 121 58.13 3.55 9 .11 .512.0 SHA - 2.2D 106 26 WW 2000 JAN 12 0533 2.89 37 33.38 118 48.06 6.91 19 .07 .4 .8 MOR 2.5D 159 4 WW 2000 JAN 12 1007 31.89 37 29.42 118 50.31 3.34 25 .05 .5 1.0 MOR 2.1D 181 7 WW ---ORIGIN TIME (UT)--- -LAT N-- --LON W-- DEPTH N RMS ERH ERZ LOC PREF AZ MIN S. PAGE 2 YEAR MON DA HRMN SEC DEG MIN DEG MIN KM RD SEC KM KM REMKS MAG GAP DS PF
