Alaska earthquakes

M3.6 earthquake 192 km SSW of Akhiok, Alaska

A magnitude 3.6 earthquake struck 192 km SSW of Akhiok, Alaska on Mon, Aug 9, 2021, 12:30 AM AKDT (08:30 UTC), 37 km (23 mi) below the surface.

A larger quake followed: M5.6 181 km SE of Chignik, 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: 3.6 (ml), minor
Local time: Mon, Aug 9, 2021, 12:30 AM AKDT
UTC: 2021-08-09 08:30:28 UTC
Depth: 37.2 km (23.1 mi), shallow
Epicenter: 55.432° N, 155.677° W
Region: Alaska
Strongest shaking: I, not felt 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: I, not felt shaking
Peak ground acceleration: 0.1% of gravity
Peak ground velocity: -3.9 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.

Stations used: 100

Nearby

Within 100 km, magnitude 1.5 and up: 103 in the 60 days after this one and at least 200 in the 30 days before it.

After

The first 60 of 103.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event ak021a5mpn8x (also filed as us6000f3js). Read Mon, Sep 28, 2026, 2:03 AM UTC.