Alaska earthquakes

M5.0 earthquake 53 km NE of Adak, Alaska

A magnitude 5.0 earthquake struck 53 km NE of Adak, Alaska on Thu, Feb 27, 2025, 11:48 AM HAST (21:48 UTC), 133 km (83 mi) below the surface.

Map

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

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The earthquake

Magnitude: 5.0 (Mww, W-phase moment), moderate
Magnitude from: USGS National Earthquake Information Center
Local time: Thu, Feb 27, 2025, 11:48 AM HAST
UTC: 2025-02-27 21:48:30 UTC
Depth: 133.3 km (82.8 mi), intermediate-depth
Epicenter: 52.265° N, 176.171° W
Region: Alaska
Felt reports: 2
Strongest shaking: III, weak shaking
Tsunami flag: No
Status: Reviewed by a seismologist

Magnitude estimates

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
5.0	Mww, W-phase moment	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.098 · 10 stations
5.0	Mww, W-phase moment	Alaska Earthquake Center	Preliminary
5.0	Mww, W-phase moment	USGS, automatic first solution	First automatic solution · Preliminary

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: 0.4% of gravity
Peak ground velocity: 0.1 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 Fri, Feb 27, 2026, 9:48 PM 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	Under 1%	Under 1%	Under 1%	Under 1%	Under 1%
1 month	2%	Under 1%	Under 1%	Under 1%	Under 1%
1 year	16%	2%	Under 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 0.

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 7.9 km horizontally, 4.4 km in depth
Magnitude uncertainty: ±0.10
Depth from: From location
Station coverage gap: 53°
Stations used: 154

Nearby

Within 100 km, magnitude 2.0 and up: 96 in the 60 days after this one and 35 in the 30 days before it.

After

The first 60 of 96.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000pvws (also filed as usauto6000pvws, ak0252o9yl4l, ak0252o9z9b7). Read Fri, Oct 2, 2026, 5:52 AM UTC.