M3.1 Earthquake 187 km SSW of Adak, Alaska — October 21, 2022
2022-10-21 23:05:02 UTC (2022-10-21) · approx. 11:05 AM UTC-12 local
On October 21, 2022 at 23:05 UTC, a magnitude 3.1 shallow crustal earthquake struck 187 km SSW of Adak, Alaska, at a depth of 10.0 km and coordinates 50.3317°, -177.7162°.
Physical scale: An earthquake of magnitude 3.1 releases seismic energy equivalent to roughly 674 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 83 m — a useful intuition for the size of the slip patch on the fault.

Earthquake Details
-177.7162°E
Technical Information
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Common Questions
How strong was the magnitude 3.1 earthquake near Adak, Alaska?
The magnitude 3.1 earthquake that struck 187 km SSW of Adak, Alaska on October 21, 2022 at 23:05 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 3.1 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.1 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us7000inpn). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2022, October 21, 2022). M3.1 Earthquake 187 km SSW of Adak, Alaska — October 21, 2022. Retrieved December 31, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000inpn/