SAN FRANCISCO—A 4.5 magnitude earthquake struck in Berkeley shortly after 2 a.m. on Thursday, January 4. The U.S. Geological Survey noted that the epicenter of the earthquake was 2 miles from Berkeley, California, which had a depth of 8 miles.
The USGS website notes that the Hayward Fault runs from San Pablo Bay in the north to Fremont in the south, passing through the cities of Berkeley, Oakland, Hayward, and Fremont. South of Fremont the fault branches into a complex set of surface faults that connect the Hayward Fault to the central part of the Calaveras Fault. The Hayward and Calaveras Faults may have a simpler connection at depths more than 5 km (3 miles), joining in the subsurface just south of the Calaveras Reservoir (site of the October 30, 2007 M5.4 Alum Rock earthquake). The Hayward Fault may be segmented into a northern and southern segment in the vicinity of Berkeley or Oakland.
SF resident Claire Lee went to Twitter to reply to her reaction to the earthquake stating, “My heart is beating out of my chest and my whole body is shaking. First time I’ve felt an #earthquake in my time in the Bay Area. Me no likey.”
Acting Mayor for the city of San Francisco, London Breed tweeted “Many of us in #SF felt the 4.5 earthquake in S.E. Berkeley. There is no tsunami expected and departments are working on preliminary damage reports. Given the influx of calls to 911, please only call if you have an emergency. Follow @SF_emergency for more updates.”
The San Francisco Municipal Transportation Authority noted via social media that that all track inspections have been completed and there were no delays to be reported as a result of the earthquake. There were no reports of any major damage or injuries as a result of the quake.