M3.5 earthquake 14 km SSW of Willow, Alaska

A magnitude 3.5 earthquake struck 14 km SSW of Willow, Alaska on Thu, Dec 17, 2020, 7:30 PM AKST (04:30 UTC), 50 km (31 mi) below the surface.

A larger quake followed: M3.6 17 km ESE of Susitna North, 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)	Alaska Earthquake Center	Preferred · Preliminary
3.7	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed · ±0.026 · 190 stations

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

This event was felt in Anchorage, Eagle River, Wasilla, and Chugiak.

From the USGS event page for ak020g7v9r9e. U.S. Geological Survey text and figures are in the public domain.

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

29 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 200 in the 60 days after this one and 186 in the 30 days before it.

The first 60 of at least 200.

From the USGS Earthquake Hazards Program and its partner networks, event ak020g7v9r9e (also filed as us7000cs04). Read Sun, Oct 4, 2026, 7:56 AM UTC.