M3.9 earthquake 12 km N of Georgetown, Idaho

A magnitude 3.9 earthquake struck 12 km N of Georgetown, Idaho on Mon, Sep 4, 2017, 9:12 PM MDT (03:12 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M5.0 9 km NNW of Georgetown, Idaho. 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
3.9	Mwr, regional moment	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.05 · 38 stations
3.42	ML, local (Richter)	University of Utah Seismograph Stations	Final · ±0.133 · 5 stations

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

No one has reported feeling this quake to the USGS.

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

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 202 in the 60 days after this one and at least 200 in the 30 days before it.

The first 60 of at least 202.

From the USGS Earthquake Hazards Program and its partner networks, event us2000afuy (also filed as uu60013524). Read Fri, Oct 2, 2026, 12:05 PM UTC.