Alaska earthquakes

M3.5 earthquake 69 km ESE of Adak, Alaska

A magnitude 3.5 earthquake struck 69 km ESE of Adak, Alaska on Wed, Oct 28, 2020, 1:58 AM HADT (10:58 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.6 47 km WSW of Atka, 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: 3.5 (mb), minor
Local time: Wed, Oct 28, 2020, 1:58 AM HADT
UTC: 2020-10-28 10:58:07 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.602° N, 175.723° 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 4.0 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.35
Depth from: Operator assigned
Station coverage gap: 203°, poorly surrounded by stations
Stations used: 41

Nearby

Within 100 km, magnitude 1.5 and up: 117 in the 60 days after this one and 66 in the 30 days before it.

After

The first 60 of 117.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000cdp9 (also filed as ak020dvmll41). Read Mon, Sep 28, 2026, 3:38 PM UTC.