Sun Nov 23 09:10:00 UTC 2025: San Ramon Shaken by Earthquake Swarm: Residents on Edge, Experts Say No Major Quake Expected

San Ramon, CA – Residents of San Ramon have been experiencing a series of earthquakes over the past 10 days, with 83 tremors recorded since November 9th. The quakes, ranging from magnitude 0.6 to 3.8, have rattled nerves and prompted questions about the possibility of a larger earthquake.

Six of the quakes have been magnitude 3.0 or higher, strong enough to be felt by most people. “You just don’t know when the next one’s going to come,” said Nita Jain, a local resident.

Geologists have identified the activity as an earthquake swarm, a cluster of small quakes occurring in a concentrated area. While such swarms often happen near volcanoes or geothermal fields, the San Ramon Valley’s complex network of small, unnamed faults, situated between the Calaveras Fault and Mount Diablo, is the likely cause.

David Schwartz, a geologist with the U.S. Geological Survey, explained that the San Ramon Valley is a “fractured-up area with a lot of small faults” that occasionally become active. He emphasized that while the swarm increases the chance of a larger quake, it’s only by a very small amount. He also noted that previous swarms in the area, including those in 1970, 1976, 2002, 2003 and 2015, have not led to major earthquakes.

Experts suggest that underground fluid, possibly water, might be playing a role in triggering the swarm by altering pressure within the fault lines. Despite recent rainfall, experts are skeptical that the rain caused the earthquakes as they are occuring too far below the surface.

Sarah Minson, a research geophysicist with the U.S. Geological Survey, reassured residents, stating, “People probably shouldn’t be concerned. Is this going to cause a ginormous earthquake? This place has had swarms before and nothing larger happened.”

While residents remain somewhat uneasy, many are taking the quakes in stride, a stark reminder of living in earthquake country. “At some point in time, there will be a big, major quake,” said San Ramon resident Dustin Lopes. “I think you just have to realize that that may happen and hope that you’re ready for when it does.”

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