M3.0 earthquake 22 km N of Halfway, Oregon

A magnitude 3.0 earthquake struck 22 km N of Halfway, Oregon on Sun, Aug 20, 2017, 11:01 AM PDT (18:01 UTC), 2 km (1 mi) below the surface.

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
2.95	ML, local (Richter)	Pacific Northwest Seismic Network	Preferred · Reviewed · ±0.237 · 8 stations
3.0	ML, local (Richter)	USGS National Earthquake Information Center	Reviewed · ±0.237 · 8 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.

Reviewed by a seismologist.

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

Within 100 km, magnitude 1.5 and up: 3 in the 60 days after this one and 5 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event uw61296227 (also filed as us2000a9ym). Read Fri, Oct 2, 2026, 10:28 PM UTC.