M2.7 earthquake 186 km SE of Atka, Alaska

A magnitude 2.7 earthquake struck 186 km SE of Atka, Alaska on Mon, Oct 23, 2023, 4:43 PM HADT (01:43 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M3.7 243 km SE 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
2.7	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.128 · 8 stations
2.6	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: 8 in the 60 days after this one and 6 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event us7000la65 (also filed as ak023dn7gsxf). Read Sat, Oct 3, 2026, 2:56 AM UTC.