Very minor earthquakes are usually not felt
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 4.5 kilometers.
| Coordinates | 37.4890°N, 121.5680°W |
| Depth | 4.5 km |
| Magnitude Type | md |
| USGS Status | Reviewed by a seismologist |
| Reports from the Public | No reports |
| Tsunami Risk | No significant tsunami risk flagged |
Epicenter location of the Magnitude 1.1 earthquake, 27 km ENE of Alum Rock, CA
A magnitude 1.1 earthquake occurred near 27 km ENE of Alum Rock, CA on April 20, 2025 at 09:02 AM UTC. This shallow earthquake originated at a depth of 4.5 kilometers below the Earth's surface. The earthquake was recorded by 20 seismic monitoring stations operated by the USGS. The md 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.
No felt reports available for this event.
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.