M4.0 Earthquake 58 km NNW of Atka, Alaska — November 14, 2021
2021-11-14 21:47:18 UTC (2021-11-14) · approx. 9:47 AM UTC-12 local
On November 14, 2021 at 21:47 UTC, a magnitude 4.0 intermediate depth earthquake struck 58 km NNW of Atka, Alaska, at a depth of 210.7 km and coordinates 52.7053°, -174.4139°.
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
-174.4139°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 58 km NNW of Atka, Alaska on November 14, 2021 at 21:47 UTC had a depth of 210.7 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: us7000fu45). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, November 14, 2021). M4.0 Earthquake 58 km NNW of Atka, Alaska — November 14, 2021. Retrieved January 22, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000fu45/