M3.2 Earthquake near off the coast of Oregon — September 9, 2021
2021-09-09 21:41:56 UTC (2021-09-09) · approx. 12:41 PM UTC-9 local
On September 9, 2021 at 21:41 UTC, a magnitude 3.2 shallow crustal earthquake struck near off the coast of Oregon, at a depth of 10.0 km and coordinates 44.1400°, -128.5239°.
Physical scale: An earthquake of magnitude 3.2 releases seismic energy equivalent to roughly 951 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 97 m — a useful intuition for the size of the slip patch on the fault.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.3 mainshock that occurred 14 days ago near off the coast of Oregon. Since the mainshock, the USGS has recorded 1 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 1 citizen response 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
-128.5239°E
Technical Information
Common Questions
How strong was the magnitude 3.2 earthquake near off the coast of Oregon?
The magnitude 3.2 earthquake that struck near off the coast of Oregon on September 9, 2021 at 21:41 UTC had a depth of 10.0 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 3.2 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.3 one earlier?
No. This magnitude 3.2 earthquake is an aftershock of the larger magnitude 5.3 mainshock that occurred earlier near off the coast of Oregon. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Understanding This Data
Magnitude 3.2 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us7000f9ug). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, September 9, 2021). M3.2 Earthquake near off the coast of Oregon — September 9, 2021. Retrieved November 17, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000f9ug/