3.8-Magnitude Earthquake Shakes San Ramon, California

SAN RAMON, Calif. (AP) — A 3.8-magnitude earthquake struck near San Ramon on Sunday morning, November 9, 2025, at 9:38 a.m. Pacific Time, according to the United States Geological Survey (USGS).

The tremor occurred about two miles southeast of the city and was part of a series of small earthquakes that followed shortly thereafter. U.S.G.S. originally reported the quake’s magnitude as 3.7 but later updated it.

In the minutes following the initial earthquake, a 3.7-magnitude quake was detected at 9:39 a.m., followed by a 3.0-magnitude tremor at 9:41 a.m. and another 2.9-magnitude quake at the same time. By 10:18 a.m., a 2.5 quake registered in the area, followed by subsequent quakes of magnitudes 3.2 and 3.0.

USGS reported that nearly 1,600 people in the East Bay and San Francisco felt the initial quake. Fortunately, no damage or injuries have been reported.

Geological data show an ongoing earthquake swarm along the northern segment of the Calaveras fault, which is situated southeast of San Ramon. Between November 9 and 10, at least 40 earthquakes were recorded, with magnitudes ranging from 0.6 to 3.8.

The largest quake, with a magnitude of 3.8, struck at a depth of 9.2 kilometers (5.7 miles). This clustering of activities suggests a typical fault-segment swarm rather than a standard aftershock sequence.

The Calaveras fault is significant to the region, being capable of generating larger earthquakes over long timeframes. Seismologists continue to monitor the area for any signs of further activity.

Smaller aftershocks below magnitude 2 are expected to continue for some time as the geological situation stabilizes.