Two separate quakes at or near magnitude-4.0 hit Northern and Southern California on Sunday May 3, 2015, with no immediate reports of damage or injuries.
The second quake, measuring 3.6 in magnitude, struck less than 1 mile south of the San Francisco Bay Area suburb of Concord, the U.S. Geological Survey said. The earthquake registered at a preliminary 4.0 magnitude but geologists later revised it to a 3.6 magnitude.
Concord police dispatchers said there appeared to be no damage or injuries. The U.S. Geological Survey’s website recorded more than 4,400 reports from Bay Area residents who felt the shaking.
A 2.7 magnitude tremor, classified as minor, rattled the same area a minute later.
Both Northern California quakes occurred on the Concord-Green Valley fault, one of several in the area that seismologists say are capable of producing major earthquakes. The last large earthquake on the fault happened anywhere from 200 to 500 years ago, the USGS said.
Further south, a magnitude-3.8 earthquake jolted some residents in the greater Los Angeles area awake when it struck at 4:07 a.m.
The tremor was centered a mile northwest of the View Park-Windsor Hills neighborhood, just north of the cities of Inglewood and Culver City, the Geological Survey said.
It was the third earthquake in nearly three weeks along the Newport-Inglewood fault. A magnitude-3.4 quake hit the same area on April 30. A magnitude-3.3 hit the Baldwin Hills area along the fault on April 13.
