M4.6 Earthquake 200 km SE of Chignik, Alaska — May 23, 2025
2025-05-23 19:36:36 UTC (2025-05-23) · approx. 9:36 AM UTC-10 local
On May 23, 2025 at 19:36 UTC, a magnitude 4.6 shallow crustal earthquake struck 200 km SE of Chignik, Alaska, at a depth of 5.2 km and coordinates 54.9607°, -156.2667°.
Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — 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
-156.2667°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.6 earthquake near Chignik, Alaska?
The magnitude 4.6 earthquake that struck 200 km SE of Chignik, Alaska on May 23, 2025 at 19:36 UTC had a depth of 5.2 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 54.9607°, -156.2667°, which is 200 km SE of Chignik, Alaska. View all earthquakes in Alaska.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 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 4.6 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: ak0256ktdnj4). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, May 23, 2025). M4.6 Earthquake 200 km SE of Chignik, Alaska — May 23, 2025. Retrieved August 13, 2025 from https://www.earthquaketracker.org/earthquakes/event/ak0256ktdnj4/