M3.9 earthquake 75 km SSW of Adak, Alaska

A magnitude 3.9 earthquake struck 75 km SSW of Adak, Alaska on Wed, Jan 7, 2026, 9:50 AM HAST (19:50 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M5.1 40 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.

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
3.9	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.085 · 18 stations
3.9	ML, local (Richter)	Alaska Earthquake Center	Reviewed · ±0.2 · 30 stations

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

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

Within 100 km, magnitude 1.5 and up: 135 in the 60 days after this one and 100 in the 30 days before it.

The first 60 of 135.

From the USGS Earthquake Hazards Program and its partner networks, event us7000rnb2 (also filed as ak2026amnuwd). Read Fri, Oct 2, 2026, 1:14 AM UTC.