M2.5 earthquake 144 km ESE of Nikolski, Alaska

A magnitude 2.5 earthquake struck 144 km ESE of Nikolski, Alaska on Sun, May 31, 2020, 11:25 AM AKDT (19:25 UTC), 9 km (6 mi) below the surface.

A larger quake followed: M4.8 208 km S 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
2.5	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed
2.5	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: 47 in the 60 days after this one and 13 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event us6000a6av (also filed as ak0206zp5gfj). Read Thu, Oct 1, 2026, 5:58 PM UTC.