M3.5 earthquake 228 km WSW of Adak, Alaska

A magnitude 3.5 earthquake struck 228 km WSW of Adak, Alaska on Sun, Mar 23, 2025, 2:30 AM HADT (11:30 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M5.2 148 km WSW 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
3.5	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.127 · 15 stations
3.0	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: 166 in the 60 days after this one and 64 in the 30 days before it.

The first 60 of 166.

From the USGS Earthquake Hazards Program and its partner networks, event us6000q7if (also filed as ak0253rssp74). Read Fri, Oct 2, 2026, 7:58 PM UTC.