M2.5 earthquake 63 km SE of Adak, Alaska

A magnitude 2.5 earthquake struck 63 km SE of Adak, Alaska on Fri, Apr 17, 2020, 2:19 PM HADT (23:19 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.5 146 km SSE 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 · ±0.148 · 6 stations
2.0	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: at least 200 in the 60 days after this one and 71 in the 30 days before it.

The first 60 of at least 200.

From the USGS Earthquake Hazards Program and its partner networks, event us60009bgh (also filed as ak0204yzujtb). Read Sat, Oct 3, 2026, 1:12 PM UTC.