Alaska earthquakes

M3.4 earthquake 70 km SSW of Unalaska, Alaska

A magnitude 3.4 earthquake struck 70 km SSW of Unalaska, Alaska on Thu, Oct 28, 2021, 11:39 PM AKDT (07:39 UTC), 30 km (19 mi) below the surface.

A larger quake followed: M3.6 76 km S 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: 3.4 (ml), minor
Local time: Thu, Oct 28, 2021, 11:39 PM AKDT
UTC: 2021-10-29 07:39:28 UTC
Depth: 29.8 km (18.5 mi), shallow
Epicenter: 53.258° N, 166.784° W
Region: Alaska
Tsunami flag: No
Status: Reviewed by a seismologist

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 3.6 km horizontally, 11.1 km in depth
Magnitude uncertainty: ±0.10
Depth from: From location
Station coverage gap: 201°, poorly surrounded by stations
Stations used: 66

Nearest places

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

Unalaska, AlaskaPopulation 4,491. Forecast70 kmSSW

Nearby

Within 100 km, magnitude 1.5 and up: 91 in the 60 days after this one and 45 in the 30 days before it.

After

The first 60 of 91.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000ga5q (also filed as ak021dvkp9jg). Read Wed, Sep 23, 2026, 8:12 AM UTC.