Alaska earthquakes

M5.2 earthquake 126 km S of Unalaska, Alaska

A magnitude 5.2 earthquake struck 126 km S of Unalaska, Alaska on Tue, Jan 21, 2025, 2:55 AM AKST (11:55 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M5.6 86 km SSW of Unalaska, Alaska. This one was a foreshock.

Unalaska forecast More in Alaska

Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude: 5.2 (mww), moderate
Local time: Tue, Jan 21, 2025, 2:55 AM AKST
UTC: 2025-01-21 11:55:03 UTC
Depth: 10.0 km (6.2 mi), shallow
Epicenter: 52.743° N, 166.651° W
Region: Alaska
Felt reports: 2
Strongest shaking: III, weak shaking
Tsunami flag: No
Status: Reviewed by a seismologist

Shaking

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

Strongest estimated: III, weak shaking
Peak ground acceleration: 0.5% of gravity
Peak ground velocity: 0.2 cm/s
Map: Automatic

USGS ShakeMap: estimated shaking intensity around the epicenter — Estimated shaking intensity. Map: USGS ShakeMap.

Did you feel it?

2 people reported to the USGS what they felt; the strongest reported shaking was III, weak shaking.

Aftershock forecast

The chance of at least one aftershock this large or larger, from the USGS operational aftershock forecast, issued Wed, Jan 21, 2026, 11:55 AM UTC. The USGS updates it as the sequence unfolds.

Within	M3+	M4+	M5+	M6+	M7+
1 day	Under 1%	Under 1%	Under 1%	Under 1%	Under 1%
1 week	3%	Under 1%	Under 1%	Under 1%	Under 1%
1 month	12%	1%	Under 1%	Under 1%	Under 1%
1 year	63%	11%	1%	Under 1%	Under 1%

In the coming week the USGS expects about 0 aftershocks of magnitude 3 or more, and most likely between 0 and 1.

Fault motion and ground failure

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

Faulting: Reverse (thrust)
Moment magnitude: 5.2 Mww
Nodal plane 1: Strike 245°, dip 31°, rake 83°
Nodal plane 2: Strike 73°, dip 59°, rake 94°

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 3.9 km horizontally, 1.8 km in depth
Magnitude uncertainty: ±0.06
Depth from: Operator assigned
Station coverage gap: 133°
Stations used: 242

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Unalaska, AlaskaPopulation 4,491. Forecast126 kmS

Nearby

Within 100 km, magnitude 2.2 and up: 92 in the 60 days after this one and 23 in the 30 days before it.

After

The first 60 of 92.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000plew (also filed as usauto6000plew, ak025yx5v38). Read Tue, Sep 29, 2026, 12:10 PM UTC.