M2.7 earthquake 227 km W of Adak, Alaska

A magnitude 2.7 earthquake struck 227 km W of Adak, Alaska on Thu, Sep 28, 2023, 6:34 AM HADT (15:34 UTC), 174 km (108 mi) below the surface.

A larger quake followed: M3.9 179 km WNW 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
2.7	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.077 · 22 stations
2.4	ML, local (Richter)	Alaska Earthquake Center	Preliminary

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

Within 100 km, magnitude 1.5 and up: 87 in the 60 days after this one and 52 in the 30 days before it.

The first 60 of 87.

From the USGS Earthquake Hazards Program and its partner networks, event us6000lezk (also filed as ak023cgfrxz2). Read Thu, Oct 1, 2026, 3:35 AM UTC.