Alaska earthquakes

M3.8 earthquake 48 km S of Adak, Alaska

A magnitude 3.8 earthquake struck 48 km S of Adak, Alaska on Thu, Jul 23, 2020, 11:15 PM HADT (08:15 UTC), 42 km (26 mi) below the surface.

A larger quake followed: M4.0 51 km SSE of Adak, Alaska. This one was a foreshock.

Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude: 3.8 (ml), minor
Local time: Thu, Jul 23, 2020, 11:15 PM HADT
UTC: 2020-07-24 08:15:41 UTC
Depth: 42.2 km (26.2 mi), shallow
Epicenter: 51.442° N, 176.746° 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 5.7 km horizontally, 13.8 km in depth
Magnitude uncertainty: ±0.12
Depth from: From location
Station coverage gap: 205°, poorly surrounded by stations
Stations used: 35

Nearby

Within 100 km, magnitude 1.5 and up: 173 in the 60 days after this one and 102 in the 30 days before it.

After

The first 60 of 173.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000b909 (also filed as ak0209gtk9ic). Read Tue, Sep 29, 2026, 10:30 AM UTC.