M5.3 earthquake 25 km WNW of Atka, Alaska

A magnitude 5.3 earthquake struck 25 km WNW of Atka, Alaska on Wed, May 14, 1986, 11:18 PM HADT (08:18 UTC), 33 km (21 mi) below the surface.

A larger quake followed: M6.5 25 km NW of Atka, 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
5.3	Ms, surface-wave	USGS National Earthquake Information Center	Preferred · Reviewed · 1 stations
5.35	Mw, moment	ISC-GEM global catalog	Final · ±0.4

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

Within 100 km, magnitude 2.3 and up: 36 in the 60 days after this one and 75 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event usp0002u1b (also filed as iscgem495713). Read Sat, Oct 3, 2026, 6:14 AM UTC.