M1.5 earthquake 9 km SSW of Prosser, Washington
A magnitude 1.5 earthquake struck 9 km SSW of Prosser, Washington on Mon, Oct 28, 1991, 10:43 AM PST (18:43 UTC), 0 km (0 mi) below the surface.
A larger quake followed: M2.0 8 km SE of Kittitas, Washington. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 1.5 (Md, duration), micro
- Magnitude from
- Pacific Northwest Seismic Network
- Local time
- UTC
- 1991-10-28 18:43:27 UTC
- Depth
- -0.3 km (-0.2 mi), shallow
- Epicenter
- 46.129° N, 119.831° W
- Region
- Washington
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Did you feel it?
No one has reported feeling this quake to the USGS.
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 1.6 km horizontally, 2.3 km in depth
- Magnitude uncertainty
- ±0.05
- Depth from
- From location
- Station coverage gap
- 155°
- Stations used
- 11
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 3 in the 60 days after this one and 1 in the 30 days before it.
After
- 1.819 km SE of Desert Aire, Washington · 12749 days ago · 19 km deep · 47 km away
- 1.511 km SSW of Prosser, Washington · 12749 days ago · -1 km deep · 2 km away
- 2.08 km SE of Kittitas, Washington · 12703 days ago · 3 km deep · 97 km away
Before
Earthquakes todayWashington earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event uw10283338. Read Sun, Oct 4, 2026, 9:51 PM UTC.