M3.3 Earthquake 17 km WSW of Petrolia, CA — September 15, 2026
2026-09-15 07:18:06 UTC (26 min ago) · approx. 11:18 PM UTC-8 local
On September 15, 2026 at 07:18 UTC, a magnitude 3.3 shallow crustal earthquake struck 17 km WSW of Petrolia, CA, at a depth of 9.0 km and coordinates 40.2935°, -124.4850°.
Physical scale: An earthquake of magnitude 3.3 releases seismic energy equivalent to roughly 1.3 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 110 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-124.4850°E
Technical Information
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Common Questions
How strong was the magnitude 3.3 earthquake near Petrolia, CA?
The magnitude 3.3 earthquake that struck 17 km WSW of Petrolia, CA on September 15, 2026 at 07:18 UTC had a depth of 9.0 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 3.3 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.3 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: nc75435962). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, September 15, 2026). M3.3 Earthquake 17 km WSW of Petrolia, CA — September 15, 2026. Retrieved September 15, 2026 from https://www.earthquaketracker.org/earthquakes/event/nc75435962/