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 3.8 11 miles SW of Toms Place, CA at 10:14 AM UTC Friday, Jul 16, 1999 (03:14 AM PDT Friday, Jul 16, 1999).
The largest event to occur this week in this region was a microearthquake of magnitude 1.8 5 miles SE of San Juan Bautista, CA at 10:54 PM UTC Thursday, Jul 15, 1999 (03:54 PM PDT Thursday, Jul 15, 1999).
The largest event to occur this week in this region was a minor earthquake of magnitude 3.8 11 miles SW of Toms Place, CA at 10:14 AM UTC Friday, Jul 16, 1999 (03:14 AM PDT Friday, Jul 16, 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 JUL 15 857 12.57 37 32.30 118 51.62 10.70 35 1 .06 .3 .5 MOR 3.2L 99 JUL 15 1313 44.51 40 18.54 124 34.47 19.02 22 1 .06 .9 .3 MEN 3.0L 99 JUL 15 1327 17.04 37 24.03 118 24.88 10.61 26 .06 .4 .8 CHV 2.1D 99 JUL 15 1731 34.19 39 36.91 123 25.39 8.18 21 .03 .2 .6 MAA 2.7D 99 JUL 15 2117 54.11 37 28.31 118 50.64 5.33 30 .06 .4 .6 MOR 2.9D 99 JUL 15 2119 16.61 37 28.17 118 50.81 4.70 33 .06 .3 1.0 MOR 2.9D 99 JUL 15 2236 3.12 37 27.60 118 50.65 0.14 35 .08 .3 2.1 MOR 3.1D 99 JUL 16 647 51.96 37 28.32 118 50.18 4.61 26 .04 .3 1.0 MOR 2.1D 99 JUL 16 812 56.01 37 27.63 118 50.18 0.03 31 .06 .4 .6 MOR # 2.4D 99 JUL 16 844 13.08 37 28.13 118 51.04 0.73 34 1 .08 .3 .7 MOR 2.3D 99 JUL 16 844 38.02 37 27.76 118 51.06 0.26 31 .05 .3 6.8 MOR - 3.7L 99 JUL 16 910 50.54 37 27.83 118 50.86 0.85 32 .07 .3 .8 MOR 3.1D 99 JUL 16 932 35.82 37 27.85 118 50.70 0.03 32 .08 .4 3.8 MOR # 3.0D 99 JUL 16 954 34.98 37 27.45 118 50.16 0.07 33 1 .08 .3 .6 MOR 2.6D 99 JUL 16 1014 50.89 37 27.74 118 50.58 0.10 33 .07 .3 3.4 MOR # 3.8L 99 JUL 16 1933 39.08 37 28.52 118 50.28 0.01 24 .07 .4 1.2 MOR # 2.1D 99 JUL 16 2026 8.94 40 9.18 121 14.40 1.32 12 .05 .6 8.1 ALM - 2.2D 99 JUL 16 2057 22.40 37 28.70 118 50.16 0.01 24 .08 .6 .6 MOR # 2.3D 99 JUL 17 639 7.12 35 53.90 120 26.36 6.31 48 .06 .2 .2 GOL 3.1L 99 JUL 18 244 38.98 41 56.32 121 56.87 11.69 9 .04 .6 3.2 MOD 3.0D 99 JUL 18 1826 10.29 37 33.18 118 48.17 3.37 27 .05 .2 .6 MOR 2.1D 99 JUL 19 150 54.05 36 26.31 120 27.20 8.39 86 1 .18 .2 .4 CRV 3.1D 99 JUL 19 1215 51.83 37 25.97 118 41.94 2.50 20 .19 1.112.9 WCS - 2.9D 99 JUL 19 2329 49.61 37 32.06 118 48.89 6.16 37 1 .05 .3 .5 MOR 3.5L 99 JUL 20 1243 58.91 37 29.59 118 50.12 7.40 34 2 .05 .3 .7 MOR 2.4D 99 JUL 20 1542 30.07 38 48.16 122 48.49 1.77 16 .03 .2 .3 GEY 2.1D 99 JUL 20 1753 57.34 37 28.89 118 51.25 1.32 34 .06 .3 1.9 MOR 2.7D 99 JUL 20 2149 48.40 38 50.17 122 46.23 1.60 19 .06 .2 .5 GEY 2.1D 99 JUL 20 2200 30.96 38 50.24 122 46.36 2.05 24 .04 .2 .5 GEY 2.2D 99 JUL 21 626 26.93 37 31.52 118 49.19 7.11 28 .06 .3 .8 MOR 2.5D 99 JUL 21 1538 11.41 36 7.51 120 10.23 7.37 13 .04 .2 .5 COA 2.1D 99 JUL 21 2054 3.88 36 2.54 120 39.49 3.27 18 .20 .5 1.4 SLA 2.2D
