Alaska earthquakes

M4.2 earthquake 46 km SW of Adak, Alaska

A magnitude 4.2 earthquake struck 46 km SW of Adak, Alaska on Sun, May 30, 2021, 1:56 AM HADT (10:56 UTC), 48 km (30 mi) below the surface.

A larger quake followed: M5.0 49 km ESE of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 4.2 (mb), light
Local time: Sun, May 30, 2021, 1:56 AM HADT
UTC: 2021-05-30 10:56:45 UTC
Depth: 47.7 km (29.6 mi), shallow
Epicenter: 51.587° N, 177.115° 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 4.1 km horizontally, 8.2 km in depth
Magnitude uncertainty: ±0.10
Depth from: From location
Station coverage gap: 178°
Stations used: 81

Nearby

Within 100 km, magnitude 1.5 and up: 164 in the 60 days after this one and 31 in the 30 days before it.

After

The first 60 of 164.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000efzd (also filed as ak0216w8whiw). Read Thu, Sep 24, 2026, 11:11 AM UTC.