M3.1 Earthquake 140 km W of Adak, Alaska — October 13, 2020
2020-10-13 16:40:38 UTC (2020-10-13) · approx. 4:40 AM UTC-12 local
On October 13, 2020 at 16:40 UTC, a magnitude 3.1 intermediate depth earthquake struck 140 km W of Adak, Alaska, at a depth of 152.7 km and coordinates 51.8833°, -178.6718°.
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
-178.6718°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 140 km W of Adak, Alaska on October 13, 2020 at 16:40 UTC had a depth of 152.7 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: us6000c825). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, October 13, 2020). M3.1 Earthquake 140 km W of Adak, Alaska — October 13, 2020. Retrieved December 19, 2020 from https://www.earthquaketracker.org/earthquakes/event/us6000c825/