M2.5 earthquake 228 km WSW of Adak, Alaska

A magnitude 2.5 earthquake struck 228 km WSW of Adak, Alaska on Tue, Dec 16, 2025, 10:49 AM HAST (20:49 UTC), 66 km (41 mi) below the surface.

A larger quake followed: M4.0 294 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
2.5	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.097 · 14 stations
2.7	ML, local (Richter)	Alaska Earthquake Center	Reviewed · ±0.3 · 12 stations

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 32 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event us6000s89n (also filed as ak2025ysfvny). Read Fri, Oct 2, 2026, 5:31 AM UTC.