Alaska earthquakes

M4.1 earthquake 194 km WSW of Adak, Alaska

A magnitude 4.1 earthquake struck 194 km WSW of Adak, Alaska on Sun, Oct 17, 2021, 4:08 PM HADT (01:08 UTC), 42 km (26 mi) below the surface.

A larger quake followed: M5.0 128 km WSW of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 4.1 (mb), light
Local time: Sun, Oct 17, 2021, 4:08 PM HADT
UTC: 2021-10-18 01:08:39 UTC
Depth: 42.3 km (26.3 mi), shallow
Epicenter: 51.123° N, 179.170° 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 2.9 km horizontally, 9.5 km in depth
Magnitude uncertainty: ±0.09
Depth from: From location
Station coverage gap: 145°
Stations used: 51

Nearby

Within 100 km, magnitude 1.5 and up: 114 in the 60 days after this one and 72 in the 30 days before it.

After

The first 60 of 114.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000fwq6 (also filed as ak021dda18q6). Read Thu, Sep 24, 2026, 8:32 AM UTC.