M3.8 earthquake 12 km SSE of Prosser, Washington

A magnitude 3.8 earthquake struck 12 km SSE of Prosser, Washington on Sat, Jun 28, 1975, 3:17 PM PDT (22:17 UTC), 10 km (7 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
3.8	Md, duration	Pacific Northwest Seismic Network	Preferred · Final · ±0.05 · 1 stations
3.7	mb, body-wave	USGS National Earthquake Information Center	Reviewed

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: 10 in the 60 days after this one and 20 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event uw10861133 (also filed as usp0000btp). Read Sat, Oct 3, 2026, 9:20 AM UTC.