Alaska earthquakes

M3.5 earthquake 155 km SSE of Chignik, Alaska

A magnitude 3.5 earthquake struck 155 km SSE of Chignik, Alaska on Sun, Aug 1, 2021, 12:01 PM AKDT (20:01 UTC), 20 km (12 mi) below the surface.

A larger quake followed: M4.1 146 km SE of Perryville, Alaska. This one was a foreshock.

Sand Point forecastMore in Alaska

Map

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

Open the live map with earthquakes

The earthquake

Magnitude
3.5 (ml), minor
Local time
UTC
2021-08-01 20:01:15 UTC
Depth
19.7 km (12.2 mi), shallow
Epicenter
55.123° N, 157.059° 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
0.0% of gravity
Peak ground velocity
-5.1 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
63

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Nearby

Within 100 km, magnitude 1.5 and up: 200 in the 60 days after this one and 0 in the 30 days before it.

After

The first 60 of 200.

Earthquakes todayAlaska earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event ak0219sldu1b (also filed as us6000f1ay). Read Tue, Sep 22, 2026, 11:00 PM UTC.