M2.5 earthquake 91 km NNE of Adak, Alaska

A magnitude 2.5 earthquake struck 91 km NNE of Adak, Alaska on Fri, Sep 20, 2024, 11:35 PM HADT (08:35 UTC), 155 km (96 mi) below the surface.

A larger quake followed: M4.0 45 km NNE 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
2.5	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.105 · 12 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: 41 in the 60 days after this one and 30 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event us7000nncc (also filed as ak024c6ee0cb). Read Thu, Oct 1, 2026, 4:18 PM UTC.