M4.9 Earthquake 30 km NNE of Attu Station, Alaska — January 31, 2025
2025-01-31 23:19:31 UTC (2025-01-31) · approx. 11:19 AM UTC+12 local
Maximum shaking intensity MMI 4.5 (moderate).
On January 31, 2025 at 23:19 UTC, a magnitude 4.9 shallow crustal earthquake struck 30 km NNE of Attu Station, Alaska, at a depth of 10.0 km and coordinates 53.0906°, 173.3935°. This earthquake was detected by 115 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 369, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 km — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Alaska, a region characterized by Pacific Plate subduction beneath the North American Plate, producing frequent megathrust and crustal earthquakes along the Aleutian arc. The nearest mapped fault system is the Aleutian megathrust. View all earthquakes in Alaska.
Learn more: Magnitude scale · Aftershock sequences
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
173.3935°E
Technical Information
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Common Questions
How strong was the magnitude 4.9 earthquake near Attu Station, Alaska?
The magnitude 4.9 earthquake that struck 30 km NNE of Attu Station, Alaska on January 31, 2025 at 23:19 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 53.0906°, 173.3935°, which is 30 km NNE of Attu Station, Alaska. View all earthquakes in Alaska.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 earthquakes can continue for several days and gradually diminish over time.
Has Alaska had earthquakes this big before?
The largest recorded earthquake in Alaska was the M9.2 Great Alaska earthquake of March 27, 1964. Today's magnitude 4.9 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000pai0). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, January 31, 2025). M4.9 Earthquake 30 km NNE of Attu Station, Alaska — January 31, 2025. Retrieved April 15, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000pai0/