Alaska earthquakes

M4.1 earthquake 29 km WSW of Adak, Alaska

A magnitude 4.1 earthquake struck 29 km WSW of Adak, Alaska on Sun, Sep 18, 2022, 6:38 PM HADT (03:38 UTC), 91 km (56 mi) below the surface.

A larger quake followed: M5.1 57 km SE 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: 4.1 (mb), light
Local time: Sun, Sep 18, 2022, 6:38 PM HADT
UTC: 2022-09-19 03:38:11 UTC
Depth: 90.9 km (56.5 mi), intermediate-depth
Epicenter: 51.746° N, 177.003° W
Region: Alaska
Strongest shaking: II, weak shaking
Tsunami flag: No
Status: Reviewed by a seismologist

Shaking

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

Strongest estimated: II, weak shaking
Peak ground acceleration: 0.1% of gravity
Peak ground velocity: -4.3 cm/s
Map: Automatic

USGS ShakeMap: estimated shaking intensity around the epicenter — Estimated shaking intensity. Map: USGS ShakeMap.

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 10.7 km horizontally, 10.1 km in depth
Magnitude uncertainty: ±0.06
Depth from: From location
Station coverage gap: 141°
Stations used: 65

Nearby

Within 100 km, magnitude 1.5 and up: at least 199 in the 60 days after this one and 120 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 us7000i970 (also filed as ak022c1ctea2). Read Wed, Sep 30, 2026, 3:34 PM UTC.