M3.9 earthquake 67 km N of Atka, Alaska

A magnitude 3.9 earthquake struck 67 km N of Atka, Alaska on Thu, Jun 29, 2023, 11:37 AM HADT (20:37 UTC), 228 km (142 mi) below the surface.

A larger quake followed: M4.1 108 km NE 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
3.9	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.1 · 26 stations
3.4	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: 71 in the 60 days after this one and 15 in the 30 days before it.

The first 60 of 71.

From the USGS Earthquake Hazards Program and its partner networks, event us6000knzc (also filed as ak0238a0v2l9). Read Mon, Oct 5, 2026, 3:27 AM UTC.