M3.1 earthquake 64 km SE of Adak, Alaska

A magnitude 3.1 earthquake struck 64 km SE of Adak, Alaska on Tue, Aug 19, 2025, 10:25 AM HADT (19:25 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.4 100 km SW 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
3.1	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.085 · 18 stations
2.8	ML, local (Richter)	Alaska Earthquake Center	Preliminary

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: 68 in the 60 days after this one and 117 in the 30 days before it.

The first 60 of 68.

From the USGS Earthquake Hazards Program and its partner networks, event us6000r26e (also filed as ak025amclrsh). Read Fri, Oct 2, 2026, 8:58 AM UTC.