Has earthquake activity returned to San Ramon?

Yes, seismic activity has returned to San Ramon after weeks of unusual calm, with two tremors detected on Friday.

What was the magnitude of the recent earthquakes in San Ramon?

The largest of the two recent earthquakes measured 3.4 magnitude, with a second tremor registering 2.9 magnitude.

What is the long-term earthquake risk in the Bay Area?

There is a 72 percent chance of a magnitude 6.7 or larger earthquake occurring anywhere in the Bay Area between now and 2043.

Home / Disasters and Accidents / San Ramon Shakes: First Tremors in Weeks Erupt

San Ramon Shakes: First Tremors in Weeks Erupt

31 Jan

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Summary

San Ramon experienced its first tremors in weeks after a period of unusual calm.
Over 300 earthquakes were detected in the region from November through December.
A 3.4 magnitude quake was the largest of two tremors felt by over 600 people.

San Ramon Shakes: First Tremors in Weeks Erupt

Seismic activity has resurfaced in San Ramon, California, following weeks of unusual quiet. Two tremors were detected near the city on Friday, marking the first notable shakes since activity appeared to subside earlier this year. The largest of these earthquakes registered a 3.4 magnitude, followed by a 2.9 magnitude tremor just 19 seconds later. These events were felt by over 600 people, reviving concerns from months prior.

From November through December, the region experienced over 300 earthquakes, prompting worries that the swarm could indicate mounting stress along nearby faults. Despite the renewed tremors, a research geophysicist from the USGS assured that these small events do not signal an impending major earthquake. However, she emphasized the region's long-term earthquake risk remains high, noting a 72 percent chance of a magnitude 6.7 or larger earthquake in the Bay Area by 2043. San Ramon is situated on the Calaveras Fault, an active branch of the San Andreas Fault system.