An earthquake swarm struck the San Francisco Bay Area on Sunday morning, with up to eight tremors ranging from magnitude 2.5 to 3.8. The quakes occurred between 9:38 and 9:41 a.m., centered southeast of San Ramon.
The quakes struck near San Ramon, with the final tremor recorded at 10:42 a.m., less than a mile west of the city. Residents in Emeryville, Dublin, and San Ramon reported feeling the shaking.
“Felt a lot stronger than 3.7! I was guessing at least a 5 — strong jolt and rumble,” wrote one user on X, who said they were in San Ramon.
Earthquake swarm rattles Bay Area with back-to-back tremors
An earthquake swarm struck the San Francisco Bay Area on Sunday morning, with up to eight tremors ranging from magnitude 2.5 to 3.8. The quakes occurred between 9:38 and 9:41 a.m., centered southeast of San Ramon.
The swarm was followed by another quake at 10:42 a.m., less than a mile west of San Ramon. Residents in Emeryville, Dublin, and San Ramon reported feeling the shaking.
“Felt a lot stronger than 3.7! I was guessing at least a 5 — strong jolt and rumble,” wrote one user on X, who said they were in San Ramon.
According to Michigan Tech University’s earthquake magnitude scale, quakes above 2.5 are typically felt but generally cause only minor damage. No damage has been reported from Sunday’s swarm.
The cluster of quakes struck about 25 to 30 miles east of San Francisco. One smaller tremor had an epicenter south of Patterson, roughly 50 miles away from the main cluster.
California’s seismic activity is largely driven by the San Andreas Fault — the boundary between two shifting tectonic plates that frequently generates earthquakes.
In August, a swarm of more than 100 small quakes was recorded about 90 miles north of San Francisco, the strongest reaching a magnitude of 4.0. No damage was reported in that event either.
Modeling by the U.S. Geological Survey (USGS) predicts that a major earthquake is likely to strike California before 2032.
