M3.7 earthquake 88 km SSE of Unalaska, Alaska

A magnitude 3.7 earthquake struck 88 km SSE of Unalaska, Alaska on Thu, Jul 31, 2025, 6:21 AM AKDT (14:21 UTC), 35 km (22 mi) below the surface.

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
3.7	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.135 · 14 stations
3.6	ML, local (Richter)	Alaska Earthquake Center	Preliminary

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: 74 in the 60 days after this one and 81 in the 30 days before it.

The first 60 of 74.

From the USGS Earthquake Hazards Program and its partner networks, event us6000qwy0 (also filed as ak0259que7u7). Read Sun, Oct 4, 2026, 8:56 AM UTC.