M3.3 earthquake 81 km S of Unalaska, Alaska

A magnitude 3.3 earthquake struck 81 km S of Unalaska, Alaska on Fri, Jan 8, 2021, 6:50 PM AKST (03:50 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.0 68 km SSW of Unalaska, 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
3.3	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.115 · 10 stations
2.9	ML, local (Richter)	Alaska Earthquake Center	Preliminary

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: 75 in the 60 days after this one and 38 in the 30 days before it.

The first 60 of 75.

From the USGS Earthquake Hazards Program and its partner networks, event us7000d1nu (also filed as ak021exx8e3). Read Sun, Oct 4, 2026, 5:20 PM UTC.