M3.2 Earthquake 28 km S of Willow Creek, CA — September 26, 2023
2023-09-26 18:40:03 UTC (2023-09-26) · approx. 10:40 AM UTC-8 local
On September 26, 2023 at 18:40 UTC, a magnitude 3.2 shallow crustal earthquake struck 28 km S of Willow Creek, CA, at a depth of 30.7 km and coordinates 40.6940°, -123.5810°.
Physical scale: An earthquake of magnitude 3.2 releases seismic energy equivalent to roughly 858 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 93 m — a useful intuition for the size of the slip patch on the fault.
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 6 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
-123.5810°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.2 earthquake near Willow Creek, CA?
The magnitude 3.2 earthquake that struck 28 km S of Willow Creek, CA on September 26, 2023 at 18:40 UTC had a depth of 30.7 km. For context, this was a minor earthquake typically detected only by instruments.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.2 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.2 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: nc73942216). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, September 26, 2023). M3.2 Earthquake 28 km S of Willow Creek, CA — September 26, 2023. Retrieved December 9, 2023 from https://www.earthquaketracker.org/earthquakes/event/nc73942216/