Alaska earthquakes

M4.0 earthquake 70 km SSW of Adak, Alaska

A magnitude 4.0 earthquake struck 70 km SSW of Adak, Alaska on Thu, Oct 20, 2022, 2:40 PM HADT (23:40 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M5.1 57 km SE of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 4.0 (ml), light
Local time: Thu, Oct 20, 2022, 2:40 PM HADT
UTC: 2022-10-20 23:40:10 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.324° N, 177.128° 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 3.1 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.10
Depth from: Operator assigned
Station coverage gap: 209°, poorly surrounded by stations
Stations used: 22

Nearby

Within 100 km, magnitude 1.5 and up: at least 199 in the 60 days after this one and 103 in the 30 days before it.

After

The first 60 of at least 199.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000indq (also filed as ak022dgye93x). Read Wed, Sep 30, 2026, 6:25 AM UTC.