Minor earthquakes are often felt but rarely cause damage
Earthquakes are classified by depth: shallow (0-70 km), intermediate (70-300 km), and deep (300-700 km). This event occurred at a shallow depth of 10.0 kilometers.
| Coordinates | 37.7472°N, 121.9455°W |
| Depth | 10.0 km |
| Magnitude Type | mw |
| USGS Status | Reviewed by a seismologist |
| Reports from the Public | 2020 reports |
| Tsunami Risk | No significant tsunami risk flagged |
Epicenter location of the Magnitude 3.9 earthquake, 5 km SE of San Ramon, CA
A magnitude 3.9 earthquake occurred near 5 km SE of San Ramon, CA on December 21, 2025 at 02:31 AM UTC. This shallow earthquake originated at a depth of 10.0 kilometers below the Earth's surface. 2020 people reported feeling this earthquake to the USGS. The earthquake was recorded by 198 seismic monitoring stations operated by the USGS. The mw magnitude measurement indicates this was a magnitude event, which is suitable for earthquakes of this size. Earthquakes of magnitude 3.0 to 3.9 are classified as minor earthquakes by the USGS. This event provides data for ongoing seismic monitoring and research.
2020 people reported feeling this earthquake, with felt intensities reaching moderate shaking (V) and estimated shaking up to weak shaking (IV).
Did you feel the shaking? Your story matters—share it with the USGS to help map this quake's impact!
During an earthquake, remember to Drop, Cover, and Hold On. Stay indoors and take cover under a sturdy table or desk, protecting your head and neck. If you're outside, move to an open area away from buildings, trees, and power lines. After the shaking stops, check for injuries and damage, and be prepared for aftershocks. Residents in the affected area should be aware of potential secondary hazards that are common in your region. Prepare an emergency kit with essential supplies including water, non-perishable food, first aid supplies, flashlight, and batteries. Stay informed by following updates from local authorities and emergency services. Consider submitting a felt report to help seismologists better understand this event's impact.