M3.1 Earthquake 23 km SE of Unalaska, Alaska — July 27, 2025
2025-07-27 22:52:41 UTC (2025-07-27) · approx. 11:52 AM UTC-11 local
On July 27, 2025 at 22:52 UTC, a magnitude 3.1 intermediate depth earthquake struck 23 km SE of Unalaska, Alaska, at a depth of 87.3 km and coordinates 53.7555°, -166.2418°.
Physical scale: An earthquake of magnitude 3.1 releases seismic energy equivalent to roughly 674 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 83 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-166.2418°E
Technical Information
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Common Questions
How strong was the magnitude 3.1 earthquake near Unalaska, Alaska?
The magnitude 3.1 earthquake that struck 23 km SE of Unalaska, Alaska on July 27, 2025 at 22:52 UTC had a depth of 87.3 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 3.1 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.1 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us7000qvwu). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, July 27, 2025). M3.1 Earthquake 23 km SE of Unalaska, Alaska — July 27, 2025. Retrieved October 11, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000qvwu/