A series of earthquakes rattled the San Ramon area Friday night, with the largest being a preliminary magnitude 4.0, according to the U.S. Geological Survey.
At about 7:41 p.m., the USGS recorded the first earthquake, with a preliminary magnitude of 2.5. About eight minutes later, a preliminary magnitude 3.8 earthquake struck, which was initially recorded as a magnitude 4.0.
In the following minutes, the USGS recorded four more earthquakes, including a preliminary magnitude of 4.0…