Alaska earthquakes

M2.5 earthquake 21 km SSW of Atka, Alaska

A magnitude 2.5 earthquake struck 21 km SSW of Atka, Alaska on Mon, Dec 28, 2015, 4:13 AM HAST (14:13 UTC), 91 km (56 mi) below the surface.

A larger quake followed: M5.1 88 km E of Adak, Alaska. This one was a foreshock.

Map

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

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The earthquake

Magnitude: 2.5 (ML, local (Richter)), micro
Magnitude from: USGS National Earthquake Information Center
Local time: Mon, Dec 28, 2015, 4:13 AM HAST
UTC: 2015-12-28 14:13:47 UTC
Depth: 90.9 km (56.5 mi), intermediate-depth
Epicenter: 52.009° N, 174.299° 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
2.5	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed
2.5	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 17.0 km horizontally, 7.5 km in depth
Stations used: 14

Nearby

Within 100 km, magnitude 1.5 and up: 107 in the 60 days after this one and 43 in the 30 days before it.

After

The first 60 of 107.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us10004bcb (also filed as ak12322792, ak015gmwyl78). Read Mon, Oct 5, 2026, 12:57 PM UTC.