A swarm of earthquakes struck San Ramon, California, early Monday morning (2), jolting residents awake and sending tremors across much of the Bay Area. According to the US Geological Survey (USGS), at least 17 moderate and smaller earthquakes were recorded in the area, with the strongest registering a magnitude of 4.2.
The largest quake occurred shortly after 7 a.m. and was felt as far away as San Francisco and Santa Cruz. A second significant tremor, measuring 3.9 in magnitude, followed soon after. The shaking began around 6:30 a.m. with two earlier quakes of magnitude 3.7 and 3.3, signaling the start of a broader seismic sequence.
Several smaller earthquakes, including multiple tremors around magnitude 2.0, continued throughout the morning. Residents across San Ramon, Pleasant Hill, and surrounding communities reported noticeable shaking. At least a dozen people contacted the KTVU newsroom to describe the intensity of the tremors, saying they were strong enough to rattle furniture and wake sleeping households.
The shaking was also felt at KTVU’s studios at Jack London Square in Oakland. San Ramon resident Evan Li shared video footage showing paperclips and loose change vibrating on a table during one of the quakes.
Reports poured in from across the region. Miranda Harmon-Smith wrote on social media that her house creaked in Brentwood and her cat jumped in response to the shaking. Tina Hernandez-Romo said her bed shook in Cherryland near San Leandro. Others reported feeling the earthquakes in Livermore, Orinda, San Francisco, and other Bay Area cities.
Despite the widespread shaking, authorities said there were no immediate reports of injuries or property damage.
Seismologists say the activity is not unexpected. San Ramon sits along the Calaveras Fault, a well-known “creeping” fault that runs through Alameda and Contra Costa counties. Unlike locked faults that build up stress over long periods before releasing it in a major earthquake, creeping faults move slowly and release stress through frequent small-to-moderate quakes.
This type of seismic pattern, known as an earthquake swarm, involves clusters of tremors occurring over a short period without a single dominant mainshock. While most quakes associated with creeping faults are minor, stress can occasionally accumulate enough to produce tremors in the 4.0-magnitude range.
According to the USGS, roughly 300 earthquakes have been recorded in the same area since December 1, 2025. Just last week, at least two quakes were reported on Friday, along with another nearby in Dublin.
Experts continue to monitor the situation but emphasize that such activity is typical for the region and does not necessarily signal a larger earthquake.
