M4.8 Earthquake near off the coast of Oregon — December 9, 2021
2021-12-09 15:05:34 UTC (2021-12-09) · approx. 6:05 AM UTC-9 local
On December 9, 2021 at 15:05 UTC, a magnitude 4.8 shallow crustal earthquake struck near off the coast of Oregon, at a depth of 10.0 km and coordinates 44.0898°, -129.1848°.
Physical scale: An earthquake of magnitude 4.8 releases seismic energy equivalent to roughly 239 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.2 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
-129.1848°E
Technical Information
Common Questions
How strong was the magnitude 4.8 earthquake near off the coast of Oregon?
The magnitude 4.8 earthquake that struck near off the coast of Oregon on December 9, 2021 at 15:05 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 44.0898°, -129.1848°, which is near off the coast of Oregon. View all earthquakes in Oregon.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.8 earthquakes can continue for several days 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 4.8 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000gaut). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, December 9, 2021). M4.8 Earthquake near off the coast of Oregon — December 9, 2021. Retrieved February 12, 2022 from https://www.earthquaketracker.org/earthquakes/event/us6000gaut/