M5.1 Earthquake 163 km W of Port Orford, Oregon — September 9, 2025
2025-09-09 05:59:28 UTC (2025-09-09) · approx. 9:59 PM UTC-8 local
On September 9, 2025 at 05:59 UTC, a magnitude 5.1 shallow crustal earthquake struck 163 km W of Port Orford, Oregon, at a depth of 10.0 km and coordinates 42.4867°, -126.4601°. This earthquake was detected by 170 seismic stations with good location accuracy and was assigned a USGS significance rating of 400, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 5.1 releases seismic energy equivalent to roughly 674 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 2.0 km — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Oregon, a region characterized by the southern Cascadia Subduction Zone, with additional seismicity from crustal faults in the Willamette Valley. The nearest mapped fault system is the Cascadia Subduction Zone. View all earthquakes in Oregon.
Learn more: Cascadia Subduction Zone · Magnitude scale · Aftershock sequences
Earthquake Details
-126.4601°E
Technical Information
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Common Questions
How strong was the magnitude 5.1 earthquake near Port Orford, Oregon?
The magnitude 5.1 earthquake that struck 163 km W of Port Orford, Oregon on September 9, 2025 at 05:59 UTC had a depth of 10.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 42.4867°, -126.4601°, which is 163 km W of Port Orford, Oregon. View all earthquakes in Oregon.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.1 earthquakes can continue for days to weeks and gradually diminish over time.
Has Oregon had earthquakes this big before?
The largest recorded earthquake in Oregon was the M7.3 offshore Brookings earthquake of November 23, 1873. Today's magnitude 5.1 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000reas). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, September 9, 2025). M5.1 Earthquake 163 km W of Port Orford, Oregon — September 9, 2025. Retrieved July 21, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000reas/