M3.0 Earthquake 56 km NE of Adak, Alaska — December 22, 2021
2021-12-22 19:26:28 UTC (2021-12-22) · approx. 7:26 AM UTC-12 local
On December 22, 2021 at 19:26 UTC, a magnitude 3.0 intermediate depth earthquake struck 56 km NE of Adak, Alaska, at a depth of 157.8 km and coordinates 52.2315°, -176.0421°.
Physical scale: An earthquake of magnitude 3.0 releases seismic energy equivalent to roughly 477 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 71 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-176.0421°E
Technical Information
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Common Questions
How strong was the magnitude 3.0 earthquake near Adak, Alaska?
The magnitude 3.0 earthquake that struck 56 km NE of Adak, Alaska on December 22, 2021 at 19:26 UTC had a depth of 157.8 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 3.0 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.0 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us7000gcbi). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, December 22, 2021). M3.0 Earthquake 56 km NE of Adak, Alaska — December 22, 2021. Retrieved March 1, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000gcbi/