M3.9 earthquake 129 km SE of Chignik, Alaska

A magnitude 3.9 earthquake struck 129 km SE of Chignik, Alaska on Sat, Apr 22, 2023, 1:23 PM AKDT (21:23 UTC), 8 km (5 mi) below the surface.

A larger quake followed: M4.8 164 km SSE of Perryville, 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	ML, local (Richter)	Alaska Earthquake Center	Preferred · Preliminary
4.3	mb, body-wave	USGS National Earthquake Information Center	Reviewed · ±0.129 · 17 stations

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

Distance and direction from each place to the epicenter, with its forecast.

Within 100 km, magnitude 1.5 and up: 50 in the 60 days after this one and 29 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event ak02355ku4aj (also filed as us6000k6fv). Read Sun, Oct 4, 2026, 6:21 PM UTC.