© USGS
The U.S. Geological Survey reported another pair of magnitude 3.0 and larger earthquakes struck Wednesday evening near Monterey County, less than a day after a 4.5-magnitude tremor and numerous aftershocks rattled the region.
The largest earthquakes this evening - one with a magnitude of 3.7 and the other with a magnitude of 3.9 - shook an area seven miles west of Prunedale at 7:54 p.m. and 8 p.m., respectively.
Since Wednesday morning, that area of the hills bordering Monterey and San Benito counties has experienced 27 earthquakes following the magnitude 4.5 quake that punctuated the day's seismic activity.
That tremor struck near Fremont Peak State Park at 12:51 a.m., according to the USGS, and had a depth of 1.8 miles. The epicenter was located 10 miles east-southeast of Prunedale and 45 miles south-southeast of San Jose.
Most of the aftershocks had a magnitude between 1.1 and 2.9, but four of the 27 measured 3.0 or larger.
Comment: These are relatively shallow earthquakes. Perhaps they have to do with the Army Depot in Hawthorne that drills frequently in the area for geothermal energy. See page 2 of this link for the map of the rather impressive US Military Geothermal Resource locations across the US.