M4.3 Earthquake 107 km SSW of Atka, Alaska — December 2, 2021
2021-12-02 21:42:57 UTC (2021-12-02) · approx. 9:42 AM UTC-12 local
On December 2, 2021 at 21:42 UTC, a magnitude 4.3 shallow crustal earthquake struck 107 km SSW of Atka, Alaska, at a depth of 32.0 km and coordinates 51.3011°, -174.7942°.
Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 m — a useful intuition for the size of the slip patch on the fault.
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Earthquake Details
-174.7942°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.3 earthquake near Atka, Alaska?
The magnitude 4.3 earthquake that struck 107 km SSW of Atka, Alaska on December 2, 2021 at 21:42 UTC had a depth of 32.0 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 4.3 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.3 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us6000g8kb). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, December 2, 2021). M4.3 Earthquake 107 km SSW of Atka, Alaska — December 2, 2021. Retrieved February 5, 2022 from https://www.earthquaketracker.org/earthquakes/event/us6000g8kb/