M3.8 Earthquake 256 km SE of Chiniak, Alaska — July 27, 2021
2021-07-27 20:01:46 UTC (2021-07-27) · approx. 10:01 AM UTC-10 local
On July 27, 2021 at 20:01 UTC, a magnitude 3.8 shallow crustal earthquake struck 256 km SE of Chiniak, Alaska, at a depth of 20.1 km and coordinates 56.0187°, -149.2536°.
Physical scale: An earthquake of magnitude 3.8 releases seismic energy equivalent to roughly 7.6 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 252 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-149.2536°E
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Common Questions
How strong was the magnitude 3.8 earthquake near Chiniak, Alaska?
The magnitude 3.8 earthquake that struck 256 km SE of Chiniak, Alaska on July 27, 2021 at 20:01 UTC had a depth of 20.1 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 3.8 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.8 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000ezlq). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, July 27, 2021). M3.8 Earthquake 256 km SE of Chiniak, Alaska — July 27, 2021. Retrieved October 3, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000ezlq/