M3.4 Earthquake 204 km SSW of Adak, Alaska — September 15, 2021
2021-09-15 16:41:23 UTC (2021-09-15) · approx. 4:41 AM UTC-12 local
On September 15, 2021 at 16:41 UTC, a magnitude 3.4 shallow crustal earthquake struck 204 km SSW of Adak, Alaska, at a depth of 10.0 km and coordinates 50.2492°, -177.9979°.
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.
Earthquake Details
-177.9979°E
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Common Questions
How strong was the magnitude 3.4 earthquake near Adak, Alaska?
The magnitude 3.4 earthquake that struck 204 km SSW of Adak, Alaska on September 15, 2021 at 16:41 UTC had a depth of 10.0 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.
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Understanding This Data
Magnitude 3.4 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000fudv). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, September 15, 2021). M3.4 Earthquake 204 km SSW of Adak, Alaska — September 15, 2021. Retrieved November 23, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000fudv/