San Francisco, CA – A cluster of small earthquakes struck parts of the Bay Area Thursday night, with residents from the Peninsula to the East Bay reporting light shaking. The U.S. Geological Survey (USGS) and California Integrated Seismic Network (CISN) recorded at least four tremors within a single hour.
According to USGS data, the first two quakes hit near Lafayette, with magnitudes of 2.5 and 2.8, occurring around 3:36 p.m. PDT. Both were centered roughly 7 to 8 kilometers northwest of the city at depths between 14 and 16 kilometers.
Roughly an hour later, two additional earthquakes were detected near Woodside, located along the Peninsula just west of Palo Alto. Those quakes measured 2.5 and 2.6 in magnitude and struck within minutes of each other at shallow depths of 4 to 5 kilometers.
Residents reported feeling mild shaking in nearby areas including Redwood City, San Jose, and parts of San Francisco, though no damage or injuries have been confirmed. The USGS “Did You Feel It?” map shows intensity levels ranging from II to IV, indicating light to moderate perceived shaking.
Seismologists note that such small clusters, often called earthquake swarms, can occur as stress shifts along local fault lines, such as the San Andreas and Calaveras faults.
