M4.7 Earthquake 57 km W of Petrolia, CA — April 20, 2026
2026-04-20 10:41:31 UTC (3 hours ago)
Felt by 3 people across nearby locations.
On April 20, 2026 at 10:41 UTC, a magnitude 4.7 shallow crustal earthquake struck 57 km W of Petrolia, CA, at a depth of 1.7 km and coordinates 40.3482°, -124.9523°. The earthquake was reported felt by 3 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.7 (weak). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 137 seismic stations with moderate location accuracy and was assigned a USGS significance rating of 335, placing it among routine seismic activity. The nearest populated place is Ferndale (population 1,481).
The epicenter is located in California, a region characterized by the San Andreas transform fault system, where the Pacific and North American plates slide past each other at roughly 46 mm per year. The nearest mapped fault system is the San Andreas Fault. View all earthquakes in California.
Learn more: San Andreas Fault · Magnitude scale · Aftershock sequences
Nearest Populated Places
Earthquake Details
-124.9523°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.7 earthquake near Petrolia, CA?
The magnitude 4.7 earthquake that struck 57 km W of Petrolia, CA on April 20, 2026 at 10:41 UTC had a depth of 1.7 km. It was felt by 3 people with maximum shaking intensity of MMI 2.7 (weak). For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 40.3482°, -124.9523°, which is 57 km W of Petrolia, CA. The nearest populated place is Ferndale (population 1,481). View all earthquakes in California.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.7 earthquakes can continue for several days and gradually diminish over time.
Has California had earthquakes this big before?
The largest recorded earthquake in California was the M7.9 Fort Tejon earthquake of January 9, 1857. Today's magnitude 4.7 event is significantly smaller than that historical record.
What should I do after an earthquake?
If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.