M3.8 earthquake 41 km WNW of Nanwalek, Alaska

A magnitude 3.8 earthquake struck 41 km WNW of Nanwalek, Alaska on Fri, Mar 12, 2021, 9:57 PM AKST (06:57 UTC), 83 km (52 mi) below the surface.

A larger quake followed: M4.2 41 km E of Pedro Bay, 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
3.8	ML, local (Richter)	Alaska Earthquake Center	Preferred · Preliminary
3.9	mb, body-wave	USGS National Earthquake Information Center	Reviewed · ±0.181 · 8 stations

The USGS’s account of the effects of this earthquake.

Also felt at Kasilof.

From the USGS event page for ak0213b6lwgp. U.S. Geological Survey text and figures are in the public domain.

14 people reported to the USGS what they felt; the strongest reported shaking was III, weak shaking.

Reviewed by a seismologist.

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

Within 100 km, magnitude 1.5 and up: at least 199 in the 60 days after this one and at least 200 in the 30 days before it.

The first 60 of at least 199.

From the USGS Earthquake Hazards Program and its partner networks, event ak0213b6lwgp (also filed as us7000dj1n). Read Thu, Oct 1, 2026, 5:31 PM UTC.