Four earthquakes, three registering above a magnitude 2.0, hit the area about 6 miles northeast of Milpitas in under an hour Tuesday morning.
The latest and strongest quake struck just after 9 a.m. at a magnitude of 3.3, according to the U.S. Geological Survey. A magnitude 3.0 hit shortly after 8:30 a.m., another 1.3 barely registered at 8:19 a.m. and a 2.7 first rattled the area less than three minutes before.
The epicenter of all four quakes was located on the north end of the Calaveras Reservoir near Calaveras Road and south of the Sunol Regional Wilderness park in Alameda County.
No damage was immediately reported.
Alameda County Calaveras Reservoir Earthquakes fast5 front magnitude Milpitas Santa Clara County U.S. Geological Survey USGS