M3.1 earthquake 87 km ESE of Atka, Alaska

A magnitude 3.1 earthquake struck 87 km ESE of Atka, Alaska on Fri, Jul 3, 2020, 6:27 PM HADT (03:27 UTC), 170 km (106 mi) below the surface.

A larger quake followed: M3.9 30 km ESE 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
3.1	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.105 · 12 stations
2.6	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: 78 in the 60 days after this one and 33 in the 30 days before it.

The first 60 of 78.

From the USGS Earthquake Hazards Program and its partner networks, event us7000arz5 (also filed as ak0208jnwqn3). Read Thu, Oct 1, 2026, 4:33 PM UTC.