M2.9 earthquake 109 km SSW of Atka, Alaska

A magnitude 2.9 earthquake struck 109 km SSW of Atka, Alaska on Sun, Sep 17, 2023, 1:05 PM HADT (22:05 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.1 63 km SSE 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
2.9	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.105 · 12 stations
2.5	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: 119 in the 60 days after this one and 88 in the 30 days before it.

The first 60 of 119.

From the USGS Earthquake Hazards Program and its partner networks, event us6000lbun (also filed as ak023bycuykm). Read Thu, Oct 1, 2026, 4:56 AM UTC.