4.9

M4.9 Earthquake 257 km W of Ferndale, CaliforniaDecember 10, 2022

2022-12-10 03:17:30 UTC (2022-12-10) · approx. 7:17 PM UTC-8 local

Felt by 10 people across nearby locations.

MagnitudeM4.9(mww)
Time03:17 UTC7:17 PM UTC-8
Depth11.1 kmshallow crustal
Coordinates40.622°, -127.306°
Felt by10DYFI responses
Status✓ Reviewed by USGS· Tsunami evaluation
Tsunami Warning Issued

On December 10, 2022 at 03:17 UTC, a magnitude 4.9 shallow crustal earthquake struck 257 km W of Ferndale, California, at a depth of 11.1 km and coordinates 40.6221°, -127.3059°. This earthquake was detected by 67 seismic stations with good location accuracy and was assigned a USGS significance rating of 372, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 km — a useful intuition for the size of the slip patch on the fault.

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

Map showing earthquake epicenter at 40.62°, -127.31°

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 10 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M4.9 earthquake near 257 km W of Ferndale, California

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
4.9 mww
Depth
11.1 km
shallow crustal
Location
40.6221°N
-127.3059°E
Felt Reports
10
DYFI responses
Community Intensity
3.1
CDI from reports

Technical Information

Event ID
us6000j8c6
Event Type
earthquake
Status
✓ Reviewed
Significance
372
Stations Used
67
Azimuthal Gap
121.0°
Min Station Distance
2.267°
RMS Residual
0.67 sec
Last Updated
2023-02-18 22:04:00 UTC

Common Questions

How strong was the magnitude 4.9 earthquake near Ferndale, California?

The magnitude 4.9 earthquake that struck 257 km W of Ferndale, California on December 10, 2022 at 03:17 UTC had a depth of 11.1 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 40.6221°, -127.3059°, which is 257 km W of Ferndale, California. View all earthquakes in California.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 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 4.9 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000j8c6). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2022, December 10, 2022). M4.9 Earthquake 257 km W of Ferndale, CaliforniaDecember 10, 2022. Retrieved February 18, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000j8c6/