Alaska earthquakes

M1.8 earthquake 34 km ENE of Adak, Alaska

A magnitude 1.8 earthquake struck 34 km ENE of Adak, Alaska on Thu, Apr 22, 2021, 6:37 PM HADT (03:37 UTC), 11 km (7 mi) below the surface.

A larger quake followed: M4.2 46 km SW of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude: 1.8 (ML, local (Richter)), micro
Magnitude from: Alaska Earthquake Center
Local time: Thu, Apr 22, 2021, 6:37 PM HADT
UTC: 2021-04-23 03:37:05 UTC
Depth: 10.8 km (6.7 mi), shallow
Epicenter: 52.044° N, 176.210° W
Region: Alaska
Tsunami flag: No
Status: Reviewed by a seismologist

Magnitude estimates

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
1.8	ML, local (Richter)	Alaska Earthquake Center	Preferred · Preliminary
1.73	ML, local (Richter)	AV	Final · ±0.35317936156738 · 10 stations

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: 24

Nearby

Within 100 km, magnitude 1.5 and up: 52 in the 60 days after this one and 78 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 ak02156xqgjk (also filed as av91225366). Read Sat, Oct 3, 2026, 10:40 PM UTC.