M2.5 earthquake 56 km SE of King Salmon, Alaska

A magnitude 2.5 earthquake struck 56 km SE of King Salmon, Alaska on Fri, Aug 20, 2021, 3:13 PM AKDT (23:13 UTC), 155 km (96 mi) below the surface.

A larger quake followed: M3.8 92 km SSE of Igiugig, 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
2.5	ML, local (Richter)	Alaska Earthquake Center	Preferred · Preliminary
2.4	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed · ±0.048 · 58 stations

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

Distance and direction from each place to the epicenter, with its forecast.

Within 100 km, magnitude 1.5 and up: 70 in the 60 days after this one and 29 in the 30 days before it.

The first 60 of 70.

From the USGS Earthquake Hazards Program and its partner networks, event ak021ao2gdwi (also filed as us6000f95s). Read Sat, Oct 3, 2026, 5:24 PM UTC.