M3.4 earthquake 51 km SW of Nikolski, Alaska

A magnitude 3.4 earthquake struck 51 km SW of Nikolski, Alaska on Mon, Jul 19, 2021, 8:28 AM AKDT (16:28 UTC), 17 km (10 mi) below the surface.

A larger quake followed: M4.2 74 km WNW of Nikolski, 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
3.4	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.282 · 3 stations
3.1	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: 68 in the 60 days after this one and 19 in the 30 days before it.

The first 60 of 68.

From the USGS Earthquake Hazards Program and its partner networks, event us7000enij (also filed as ak0219716la9). Read Sun, Oct 4, 2026, 1:51 PM UTC.