Alaska earthquakes

M4.6 earthquake 199 km WSW of Adak, Alaska

A magnitude 4.6 earthquake struck 199 km WSW of Adak, Alaska on Thu, Feb 18, 2021, 11:19 PM HAST (09:19 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M5.4 185 km WSW of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 4.6 (mb), light
Local time: Thu, Feb 18, 2021, 11:19 PM HAST
UTC: 2021-02-19 09:19:07 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.091° N, 179.218° W
Region: Alaska
Felt reports: 1
Tsunami flag: No
Status: Reviewed by a seismologist

Did you feel it?

1 person reported to the USGS what they felt; the strongest reported shaking was III, weak shaking.

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 5.8 km horizontally, 1.9 km in depth
Magnitude uncertainty: ±0.04
Depth from: Operator assigned
Station coverage gap: 137°
Stations used: 142

Nearby

Within 100 km, magnitude 1.6 and up: 91 in the 60 days after this one and 42 in the 30 days before it.

After

The first 60 of 91.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us6000divs (also filed as ak0212aucce0). Read Fri, Sep 25, 2026, 9:36 AM UTC.