Alaska earthquakes

M3.3 earthquake 66 km SE of Unalaska, Alaska

A magnitude 3.3 earthquake struck 66 km SE of Unalaska, Alaska on Wed, Mar 31, 2021, 1:15 AM AKDT (09:15 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M3.7 33 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: 3.3 (ml), minor
Local time: Wed, Mar 31, 2021, 1:15 AM AKDT
UTC: 2021-03-31 09:15:49 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 53.496° N, 165.754° 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 2.8 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.10
Depth from: Operator assigned
Station coverage gap: 203°, poorly surrounded by stations
Stations used: 33

Nearest places

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

Unalaska, AlaskaPopulation 4,491. Forecast66 kmSE

Nearby

Within 100 km, magnitude 1.5 and up: 57 in the 60 days after this one and 41 in the 30 days before it.

After

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000e27d (also filed as ak02144ztgkm). Read Wed, Sep 23, 2026, 5:07 PM UTC.