M1.6 earthquake 6 km N of Outlook, Washington
A magnitude 1.6 earthquake struck 6 km N of Outlook, Washington on Mon, Sep 20, 1999, 5:46 AM PDT (12:46 UTC), 7 km (4 mi) below the surface.
A larger quake followed: M2.2 5 km SW of West Richland, Washington. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 1.6 (md), micro
- Local time
- UTC
- 1999-09-20 12:46:21 UTC
- Depth
- 7.2 km (4.5 mi), shallow
- Epicenter
- 46.390° N, 120.102° 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 0.6 km horizontally, 0.5 km in depth
- Magnitude uncertainty
- ±0.30
- Depth from
- From location
- Station coverage gap
- 141°
- Stations used
- 14
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 5 in the 60 days after this one and 4 in the 30 days before it.
After
- 1.57 km N of Outlook, Washington · 9870 days ago · 11 km deep · 1 km away
- 1.610 km N of Thorp, Washington · 9852 days ago · 3 km deep · 96 km away
- 1.613 km NNE of Prosser, Washington · 9845 days ago · -1 km deep · 32 km away
- 2.25 km SW of West Richland, Washington · 9844 days ago · 1 km deep · 54 km away
- 1.63 km N of Tieton, Washington · 9818 days ago · 9 km deep · 63 km away
Before
- 1.523 km NNW of Benton City, Washington · 9873 days ago · 16 km deep · 36 km away
- 2.77 km N of Outlook, Washington · 9873 days ago · 11 km deep · 1 km away
- 3.122 km NNW of Benton City, Washington · 9874 days ago · 19 km deep · 37 km away
- 1.54 km NE of Cliffdell, Washington · 9898 days ago · -1 km deep · 95 km away
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event uw10485133. Read Wed, Sep 30, 2026, 7:56 PM UTC.