M3.7 Earthquake 51 km S of False Pass, Alaska — August 1, 2025
2025-08-01 22:12:26 UTC (2025-08-01) · approx. 11:12 AM UTC-11 local
On August 1, 2025 at 22:12 UTC, a magnitude 3.7 shallow crustal earthquake struck 51 km S of False Pass, Alaska, at a depth of 11.2 km and coordinates 54.3988°, -163.2859°.
Physical scale: An earthquake of magnitude 3.7 releases seismic energy equivalent to roughly 5.4 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 215 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 5.4 mainshock that occurred 8 days ago 90 km SSE of False Pass, Alaska. Since the mainshock, the USGS has recorded 18 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Earthquake Details
-163.2859°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 3.7 earthquake near False Pass, Alaska?
The magnitude 3.7 earthquake that struck 51 km S of False Pass, Alaska on August 1, 2025 at 22:12 UTC had a depth of 11.2 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 3.7 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.4 one earlier?
No. This magnitude 3.7 earthquake is an aftershock of the larger magnitude 5.4 mainshock that occurred earlier 90 km SSE of False Pass, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Actions
Understanding This Data
Magnitude 3.7 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000qxj7). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, August 1, 2025). M3.7 Earthquake 51 km S of False Pass, Alaska — August 1, 2025. Retrieved October 17, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000qxj7/