M4.2 earthquake 295 km W of Adak, Alaska

A magnitude 4.2 earthquake struck 295 km W of Adak, Alaska on Sat, Jul 11, 2020, 11:13 AM GMT+12 (23:13 UTC), 175 km (109 mi) below the surface.

A larger quake followed: M4.4 Rat Islands, Aleutian Islands, 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
4.2	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.047 · 127 stations
3.7	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: 88 in the 60 days after this one and 31 in the 30 days before it.

The first 60 of 88.

From the USGS Earthquake Hazards Program and its partner networks, event us7000alqf (also filed as ak0208twyfnf). Read Thu, Oct 1, 2026, 4:15 PM UTC.