Alaska earthquakes

M3.3 earthquake 49 km N of Atka, Alaska

A magnitude 3.3 earthquake struck 49 km N of Atka, Alaska on Sat, Aug 21, 2021, 12:45 PM HADT (21:45 UTC), 247 km (154 mi) below the surface.

A larger quake followed: M4.3 116 km NW of Atka, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 3.3 (ml), minor
Local time: Sat, Aug 21, 2021, 12:45 PM HADT
UTC: 2021-08-21 21:45:53 UTC
Depth: 247.2 km (153.6 mi), intermediate-depth
Epicenter: 52.641° N, 174.114° 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 15.0 km horizontally, 9.4 km in depth
Magnitude uncertainty: ±0.09
Depth from: From location
Station coverage gap: 164°
Stations used: 30

Nearby

Within 100 km, magnitude 1.5 and up: 32 in the 60 days after this one and 42 in the 30 days before it.

After

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us7000f6hj (also filed as ak021apozq56). Read Thu, Sep 24, 2026, 9:57 AM UTC.