M3.1 earthquake 273 km WSW of Adak, Alaska

A magnitude 3.1 earthquake struck 273 km WSW of Adak, Alaska on Fri, Oct 18, 2019, 5:05 PM GMT+12 (05:05 UTC), 64 km (40 mi) below the surface.

A larger quake followed: M4.5 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
3.1	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.148 · 6 stations
2.8	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: 74 in the 60 days after this one and 44 in the 30 days before it.

The first 60 of 74.

From the USGS Earthquake Hazards Program and its partner networks, event us600063ch (also filed as ak019ddceb9e). Read Fri, Oct 2, 2026, 5:05 AM UTC.