4.8

M4.8 Earthquake 118 km SSW of Atka, AlaskaDecember 24, 2025

2025-12-24 10:56:59 UTC (2025-12-24) · approx. 10:56 PM UTC-12 local

MagnitudeM4.8(mb)
Time10:56 UTC10:56 PM UTC-12
Depth10.0 kmshallow crustal
Coordinates51.221°, -174.898°
Felt byNo felt reports
Status✓ Reviewed by USGS

On December 24, 2025 at 10:56 UTC, a magnitude 4.8 shallow crustal earthquake struck 118 km SSW of Atka, Alaska, at a depth of 10.0 km and coordinates 51.2210°, -174.8980°. This earthquake was detected by 136 seismic stations with good location accuracy and was assigned a USGS significance rating of 354, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 4.8 releases seismic energy equivalent to roughly 239 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.2 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 51.22°, -174.90°

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 M4.8 earthquake near 118 km SSW of Atka, Alaska

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

Earthquake Details

Magnitude
4.8 mb
Depth
10.0 km
shallow crustal
Location
51.2210°N
-174.8980°E
Intensity (MMI)
2.9
weak

Technical Information

Event ID
us7000rkjw
Event Type
earthquake
Status
✓ Reviewed
Significance
354
Stations Used
136
Azimuthal Gap
149.0°
Min Station Distance
0.999°
RMS Residual
0.76 sec
Last Updated
2026-04-01 22:48:01 UTC

Common Questions

How strong was the magnitude 4.8 earthquake near Atka, Alaska?

The magnitude 4.8 earthquake that struck 118 km SSW of Atka, Alaska on December 24, 2025 at 10:56 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 51.2210°, -174.8980°, which is 118 km SSW of Atka, Alaska. View all earthquakes in Alaska.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.8 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 4.8 event is significantly smaller than that historical record.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: us7000rkjw). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, December 24, 2025). M4.8 Earthquake 118 km SSW of Atka, AlaskaDecember 24, 2025. Retrieved May 23, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000rkjw/