M3.8 Earthquake 11 km ESE of Willits, CA — January 13, 2026
2026-01-13 22:51:55 UTC (2026-01-13) · approx. 2:51 PM UTC-8 local
Felt by 83 people across nearby locations. Aftershock of the M5.6 mainshock.
On January 13, 2026 at 22:51 UTC, a magnitude 3.8 shallow crustal earthquake struck 11 km ESE of Willits, CA, at a depth of 8.7 km and coordinates 39.3723°, -123.2327°. The earthquake was reported felt by 83 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.9 (light). This earthquake was detected by 79 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 252, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 3.8 releases seismic energy equivalent to roughly 6.6 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 237 m — a useful intuition for the size of the slip patch on the fault.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.6 mainshock that occurred 16 days ago 11 km N of Redwood Valley, CA. Since the mainshock, the USGS has recorded 24 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
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
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 83 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
-123.2327°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.8 earthquake near Willits, CA?
The magnitude 3.8 earthquake that struck 11 km ESE of Willits, CA on January 13, 2026 at 22:51 UTC had a depth of 8.7 km. It was felt by 83 people with maximum shaking intensity of MMI 3.9 (light). For context, this was a minor earthquake typically detected only by instruments.
Where did the earthquake occur?
The earthquake epicenter was located at 39.3723°, -123.2327°, which is 11 km ESE of Willits, CA. View all earthquakes in California.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.8 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.6 one earlier?
No. This magnitude 3.8 earthquake is an aftershock of the larger magnitude 5.6 mainshock that occurred earlier 11 km N of Redwood Valley, CA. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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 3.8 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.
Actions
Authoritative source: USGS event page (event ID: nc75295291). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, January 13, 2026). M3.8 Earthquake 11 km ESE of Willits, CA — January 13, 2026. Retrieved June 24, 2026 from https://www.earthquaketracker.org/earthquakes/event/nc75295291/