M3.5 earthquake 185 km ESE of Atka, Alaska

A magnitude 3.5 earthquake struck 185 km ESE of Atka, Alaska on Sat, Mar 7, 2020, 10:24 PM HAST (08:24 UTC), 35 km (22 mi) below the surface.

A larger quake followed: M4.1 180 km WSW of Nikolski, 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
3.5	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.097 · 14 stations
3.0	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: 18 in the 60 days after this one and 6 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event us60008ecw (also filed as ak02034lgfbl). Read Thu, Oct 1, 2026, 3:34 AM UTC.