M3.3 Earthquake 75 km WSW of Nikolski, Alaska — March 27, 2021
2021-03-27 13:30:00 UTC (2021-03-27) · approx. 2:30 AM UTC-11 local
On March 27, 2021 at 13:30 UTC, a magnitude 3.3 shallow crustal earthquake struck 75 km WSW of Nikolski, Alaska, at a depth of 10.0 km and coordinates 52.7944°, -169.9552°.
Physical scale: An earthquake of magnitude 3.3 releases seismic energy equivalent to roughly 1.3 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 114 m — a useful intuition for the size of the slip patch on the fault.

Earthquake Details
-169.9552°E
Technical Information
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Common Questions
How strong was the magnitude 3.3 earthquake near Nikolski, Alaska?
The magnitude 3.3 earthquake that struck 75 km WSW of Nikolski, Alaska on March 27, 2021 at 13:30 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 3.3 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.3 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000dx1s). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, March 27, 2021). M3.3 Earthquake 75 km WSW of Nikolski, Alaska — March 27, 2021. Retrieved June 8, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000dx1s/