Alaska earthquakes

M4.2 earthquake 76 km ESE of Atka, Alaska

A magnitude 4.2 earthquake struck 76 km ESE of Atka, Alaska on Tue, Apr 6, 2021, 8:19 PM HADT (05:19 UTC), 189 km (118 mi) below the surface.

A larger quake followed: M5.1 75 km SE of Atka, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 4.2 (mb), light
Local time: Tue, Apr 6, 2021, 8:19 PM HADT
UTC: 2021-04-07 05:19:43 UTC
Depth: 189.2 km (117.5 mi), intermediate-depth
Epicenter: 51.883° N, 173.203° 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 12.8 km horizontally, 7.8 km in depth
Magnitude uncertainty: ±0.10
Depth from: From location
Station coverage gap: 184°, poorly surrounded by stations
Stations used: 53

Nearby

Within 100 km, magnitude 1.5 and up: 55 in the 60 days after this one and 29 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 us6000e1j2 (also filed as ak0214gi84b3). Read Thu, Sep 24, 2026, 7:06 AM UTC.