(CBS SF) — The fault that produced a 4.0-magnitude earthquake in Fremont early Tuesday morning is expected to produce a major earthquake “any day now” and Bay Area residents should be prepared, a U.S. Geological Survey scientist said.
The 2:41 a.m. earthquake on the border of Fremont and Union City occurred on the Hayward Fault at a depth of 5 miles. The epicenter was at a spot just north of the intersection of Niles Canyon Road and Mission Boulevard.
The quake caused some BART delays early Tuesday while work crews checked the tracks, but appears to have caused no major damage. At least 13 smaller quakes or aftershocks had been reported near the same location as of 6:42 a.m., the largest of which was a 2.7-magnitude at 2:56 a.m.
While damage from the quake was minimal, scientists warn that a much larger one is expected on the Hayward Fault, which extends from San Pablo Bay in the north to Fremont in the south and passes through heavily populated areas including Berkeley, Oakland, Hayward and Fremont.