Alaska earthquakes

M3.4 earthquake 44 km SE of Nikolski, Alaska

A magnitude 3.4 earthquake struck 44 km SE of Nikolski, Alaska on Thu, Aug 5, 2021, 5:15 AM AKDT (13:15 UTC), 41 km (25 mi) below the surface.

A larger quake followed: M3.9 42 km WNW of Nikolski, 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 (mb), minor
Local time: Thu, Aug 5, 2021, 5:15 AM AKDT
UTC: 2021-08-05 13:15:19 UTC
Depth: 40.9 km (25.4 mi), shallow
Epicenter: 52.644° N, 168.420° 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 4.8 km horizontally, 15.2 km in depth
Magnitude uncertainty: ±0.24
Depth from: From location
Station coverage gap: 201°, 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. Forecast186 kmSW

Nearby

Within 100 km, magnitude 1.5 and up: 56 in the 60 days after this one and 31 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 us6000f2gr (also filed as ak0219z3g7d8). Read Wed, Sep 23, 2026, 5:30 PM UTC.