Alaska earthquakes

M3.8 earthquake 36 km SSW of Adak, Alaska

A magnitude 3.8 earthquake struck 36 km SSW of Adak, Alaska on Wed, Apr 22, 2020, 4:42 AM HADT (13:42 UTC), 69 km (43 mi) below the surface.

A larger quake followed: M4.0 91 km ESE of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 3.8 (ml), minor
Local time: Wed, Apr 22, 2020, 4:42 AM HADT
UTC: 2020-04-22 13:42:48 UTC
Depth: 68.5 km (42.6 mi), shallow
Epicenter: 51.556° N, 176.771° 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 8.1 km horizontally, 7.7 km in depth
Magnitude uncertainty: ±0.13
Depth from: From location
Station coverage gap: 202°, poorly surrounded by stations
Stations used: 35

Nearby

Within 100 km, magnitude 1.5 and up: at least 200 in the 60 days after this one and 104 in the 30 days before it.

After

The first 60 of at least 200.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us70009cxi (also filed as ak020573pygw). Read Wed, Sep 30, 2026, 10:47 PM UTC.