4.9

M4.9 Earthquake 51 km S of Adak, AlaskaJanuary 22, 2025

2025-01-22 13:26:06 UTC (2025-01-22) · approx. 1:26 AM UTC-12 local

Maximum shaking intensity MMI 4.8 (moderate).

MagnitudeM4.9(mww)
Time13:26 UTC1:26 AM UTC-12
Depth44.7 kmshallow crustal
Coordinates51.414°, -176.584°
Felt byNo felt reports
Status✓ Reviewed by USGS

On January 22, 2025 at 13:26 UTC, a magnitude 4.9 shallow crustal earthquake struck 51 km S of Adak, Alaska, at a depth of 44.7 km and coordinates 51.4136°, -176.5841°. This earthquake was detected by 215 seismic stations with good 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

Map showing earthquake epicenter at 51.41°, -176.58°

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.

USGS ShakeMap intensity contours for the M4.9 earthquake near 51 km S of Adak, Alaska

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Earthquake Details

Magnitude
4.9 mww
Depth
44.7 km
shallow crustal
Location
51.4136°N
-176.5841°E
Intensity (MMI)
4.8
moderate

Technical Information

Event ID
us6000plkr
Event Type
earthquake
Status
✓ Reviewed
Significance
369
Stations Used
215
Azimuthal Gap
108.0°
Min Station Distance
0.462°
RMS Residual
0.52 sec
Last Updated
2025-04-08 22:00:57 UTC

Common Questions

How strong was the magnitude 4.9 earthquake near Adak, Alaska?

The magnitude 4.9 earthquake that struck 51 km S of Adak, Alaska on January 22, 2025 at 13:26 UTC had a depth of 44.7 km. For context, this was a light earthquake commonly felt near the epicenter.

Where did the earthquake occur?

The earthquake epicenter was located at 51.4136°, -176.5841°, which is 51 km S of Adak, 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: us6000plkr). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, January 22, 2025). M4.9 Earthquake 51 km S of Adak, AlaskaJanuary 22, 2025. Retrieved April 8, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000plkr/