M4.1 earthquake 110 km SE of Adak, Alaska

A magnitude 4.1 earthquake struck 110 km SE of Adak, Alaska on Fri, Dec 22, 2023, 8:21 PM HAST (06:21 UTC), 42 km (26 mi) below the surface.

A larger quake followed: M4.9 124 km SSW of Atka, Alaska. This one was a foreshock.

Map

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

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
4.1	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.087 · 36 stations
4.1	mb, body-wave	Alaska Earthquake Center	Preliminary

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

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

Reviewed by a seismologist.

Within 100 km, magnitude 1.5 and up: 102 in the 60 days after this one and 70 in the 30 days before it.

The first 60 of 102.

From the USGS Earthquake Hazards Program and its partner networks, event us7000ll3v (also filed as ak023geik3cl). Read Thu, Oct 1, 2026, 8:03 AM UTC.