Alaska earthquakes

M4.3 earthquake 127 km SSW of Nikolski, Alaska

A magnitude 4.3 earthquake struck 127 km SSW of Nikolski, Alaska on Mon, Feb 22, 2021, 10:03 AM HAST (20:03 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.8 72 km WSW of Nikolski, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 4.3 (mb), light
Local time: Mon, Feb 22, 2021, 10:03 AM HAST
UTC: 2021-02-22 20:03:21 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.987° N, 169.916° 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 7.1 km horizontally, 2.0 km in depth
Magnitude uncertainty: ±0.06
Depth from: Operator assigned
Station coverage gap: 183°, poorly surrounded by stations
Stations used: 81

Nearby

Within 100 km, magnitude 1.5 and up: 32 in the 60 days after this one and 20 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 us6000dk7g (also filed as ak0212fzerbn). Read Thu, Sep 24, 2026, 3:19 AM UTC.