M3.4 Earthquake 126 km W of Nikolski, Alaska — September 10, 2021
2021-09-10 17:49:41 UTC (2021-09-10) · approx. 6:49 AM UTC-11 local
On September 10, 2021 at 17:49 UTC, a magnitude 3.4 intermediate depth earthquake struck 126 km W of Nikolski, Alaska, at a depth of 217.4 km and coordinates 53.0348°, -170.7323°.
Physical scale: An earthquake of magnitude 3.4 releases seismic energy equivalent to roughly 1.9 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 134 m — a useful intuition for the size of the slip patch on the fault.
This earthquake is part of an ongoing aftershock sequence following the magnitude 6.5 mainshock that occurred 3 days ago 169 km W of Nikolski, Alaska. Since the mainshock, the USGS has recorded 3 aftershocks in this area. Aftershock activity is expected to continue for weeks to months as stresses on surrounding faults redistribute.
Earthquake Details
-170.7323°E
Technical Information
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Common Questions
How strong was the magnitude 3.4 earthquake near Nikolski, Alaska?
The magnitude 3.4 earthquake that struck 126 km W of Nikolski, Alaska on September 10, 2021 at 17:49 UTC had a depth of 217.4 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 3.4 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M6.5 one earlier?
No. This magnitude 3.4 earthquake is an aftershock of the larger magnitude 6.5 mainshock that occurred earlier 169 km W of Nikolski, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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Understanding This Data
Magnitude 3.4 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000fsqm). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, September 10, 2021). M3.4 Earthquake 126 km W of Nikolski, Alaska — September 10, 2021. Retrieved November 23, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000fsqm/