M2.7 earthquake 71 km SSE of Adak, Alaska

A magnitude 2.7 earthquake struck 71 km SSE of Adak, Alaska on Mon, Oct 23, 2023, 3:30 PM HADT (00:30 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M6.1 116 km SE 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 · ±0.091 · 16 stations
2.2	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: 184 in the 60 days after this one and 87 in the 30 days before it.

The first 60 of 184.

From the USGS Earthquake Hazards Program and its partner networks, event us7000la5w (also filed as ak023dn6sicy). Read Sat, Oct 3, 2026, 4:50 AM UTC.