M4.0 Earthquake 97 km S of Atka, Alaska — November 2, 2021
2021-11-02 18:14:59 UTC (2021-11-02) · approx. 6:14 AM UTC-12 local
On November 2, 2021 at 18:14 UTC, a magnitude 4.0 shallow crustal earthquake struck 97 km S of Atka, Alaska, at a depth of 11.6 km and coordinates 51.3224°, -174.1248°.
Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-174.1248°E
Technical Information
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Common Questions
How strong was the magnitude 4.0 earthquake near Atka, Alaska?
The magnitude 4.0 earthquake that struck 97 km S of Atka, Alaska on November 2, 2021 at 18:14 UTC had a depth of 11.6 km. For context, this was a light earthquake commonly felt near the epicenter.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.0 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.0 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000frsg). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, November 2, 2021). M4.0 Earthquake 97 km S of Atka, Alaska — November 2, 2021. Retrieved January 14, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000frsg/