M4.5 earthquake 93 km S of Unalaska, Alaska

A magnitude 4.5 earthquake struck 93 km S of Unalaska, Alaska on Sun, Jul 30, 2023, 12:02 AM AKDT (08:02 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
4.5	Mwr, regional moment	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.08 · 15 stations
4.5	Mwr, regional moment	Alaska Earthquake Center	Preliminary

No one has reported feeling this quake to the USGS.

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

Reviewed by a seismologist.

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

Within 100 km, magnitude 1.5 and up: 150 in the 60 days after this one and 89 in the 30 days before it.

The first 60 of 150.

From the USGS Earthquake Hazards Program and its partner networks, event us6000kwn5 (also filed as ak0239p368qj). Read Thu, Oct 1, 2026, 7:23 AM UTC.