East Bay Struck by Monday Morning Earthquake
The U.S. Geological Survey recorded a magnitude 2.8 quake in San Ramon at 3:34 a.m. Monday. The epicenter was north of Bollinger Canyon Road and east of Alcosta Boulevard, near Bridges Golf Club. The tremor occurred at a depth of 8.9 kilometers.
Seismic details
| Magnitude | Time | Depth | Nearest landmarks |
|---|---|---|---|
| 2.8 | 3:34 a.m. Monday (USGS) | 8.9 km | North of Bollinger Canyon Rd; east of Alcosta Blvd; near Bridges Golf Club |
Residents reported weak to light shaking on the USGS “Did You Feel It?” map. The East Bay experienced a brief Monday morning quake felt by many locals.
Pattern of activity
This event is the latest in hundreds of small quakes to affect San Ramon since November. Officials recorded another magnitude 2.8 tremor on the morning of March 13. San Ramon sits along the Calaveras Fault, which produces frequent microseismic activity.
What drives swarm events
Seismologists say networks of tiny faults can produce rapid quake swarms. Movement of fluids, such as water or gas, through cracks may trigger many small quakes in quick succession.
Local response and outreach
On Feb. 27 the city hosted a public Q&A on seismic risk and preparedness. Participants included local mayors, Contra Costa Supervisor Candace Andersen, SRVFPD Chief Jonas Aguiar and UC Berkeley seismologist Dr. Angie Lux. Filmogaz.com will continue to follow updates and official guidance for residents.
