Breaking: 4.8-Magnitude San Ramon Earthquake Rattles the Bay Area

SAN RAMON, Calif. — A mild but noticeable 2.5-magnitude earthquake jolted residents two miles east-southeast of San Ramon at 2:56 p.m. Saturday, the U.S. Geological Survey (USGS) confirmed. The tremor, centered about five miles underground, is the latest in a flurry of quakes to rattle the East Bay city this month. Latest quake at a glance • Magnitude: 2.5 • Time: 2:56 p.m. PT, Saturday, Nov. 15 • Epicenter: 2 mi ESE of downtown San Ramon • Depth: ~5 mi (8 km) • Felt reports: 6 submitted to USGS within the first hour A week-long swarm continues The Saturday shake came on the heels of a stronger 3.8-magnitude event that struck at 9:38 a.m. on Nov. 9, followed by several aftershocks measuring between 2.5 and 3.2 on the same morning. In total, the San Ramon area has recorded at least ten quakes of 2.5 or greater in the past seven days, underscoring an active period along the northern Calaveras Fault. Why San Ramon keeps shaking San Ramon sits atop a complex network of faults, including the Calaveras and neighboring Greenville strands. These right-lateral strike-slip faults routinely release small amounts of energy rather than building toward a single large rupture. Seismologists note that earthquake “swarms” like the current sequence are common in the region and, while unnerving, rarely produce serious damage. What residents felt Most people described a quick jolt followed by a gentle roll, likening it to “a heavy truck passing.” No injuries or structural damage have been reported, though items rattled off shelves in several homes. The quake was felt as far north as Walnut Creek and as far south as Pleasanton, according to USGS “Did You Feel It?” reports. Safety refresher: Drop, Cover, Hold On 1. Drop to hands and knees to avoid being knocked over. 2. Cover head and neck under a sturdy table or desk. If no shelter is nearby, use your arms to protect vital areas. 3. Hold on until the shaking stops. Be ready for aftershocks. Preparedness tips • Secure tall furniture and water heaters with straps. • Keep a flashlight, sturdy shoes, and a whistle near your bed. • Store a three-day supply of food, water, and medications. • Sign up for the MyShake or ShakeAlertLA apps for real-time warnings. Stay informed Live seismic data for California is updated within minutes on the USGS event page and the Berkeley Seismology Lab websites, allowing residents to track aftershocks and longer-term patterns. Local officials also encourage signing up for Contra Costa County Community Warning System alerts to receive emergency notifications directly to phones and email. Bottom line While a 2.5-magnitude earthquake is unlikely to cause damage, the ongoing San Ramon earthquake swarm is an important reminder that the Bay Area remains one of the most seismically active regions in the United States. Residents are urged to review emergency plans, update disaster kits, and remain vigilant as minor tremors continue to ripple beneath the East Bay.