M3.3 earthquake 49 km S of Adak, Alaska

A magnitude 3.3 earthquake struck 49 km S of Adak, Alaska on Thu, Jul 25, 2019, 11:13 PM HADT (08:13 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.0 59 km SE of Adak, 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
2.5	ML, local (Richter)	Alaska Earthquake Center	Preliminary

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

Within 100 km, magnitude 1.5 and up: 131 in the 60 days after this one and 75 in the 30 days before it.

The first 60 of 131.

From the USGS Earthquake Hazards Program and its partner networks, event us600057a7 (also filed as ak0199ih34xs). Read Fri, Oct 2, 2026, 5:59 AM UTC.