Alaska earthquakes

M2.8 earthquake 92 km ESE of Atka, Alaska

A magnitude 2.8 earthquake struck 92 km ESE of Atka, Alaska on Fri, Apr 20, 2018, 2:09 PM HADT (23:09 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.4 172 km ESE of Atka, Alaska. This one was a foreshock.

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

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The earthquake

Magnitude: 2.8 (ML, local (Richter)), micro
Magnitude from: USGS National Earthquake Information Center
Local time: Fri, Apr 20, 2018, 2:09 PM HADT
UTC: 2018-04-20 23:09:56 UTC
Depth: 35.0 km (21.7 mi), shallow
Epicenter: 51.752° N, 173.070° 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
2.8	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed
2.8	ML, local (Richter)	Alaska Earthquake Center	Preliminary

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 4.4 km horizontally, 2.0 km in depth
Depth from: Operator assigned
Station coverage gap: 240°, poorly surrounded by stations
Stations used: 14

Nearby

Within 100 km, magnitude 1.5 and up: 33 in the 60 days after this one and 14 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 us1000dral (also filed as ak19263896, ak01852av748). Read Thu, Oct 1, 2026, 8:10 PM UTC.