QuakeIndex

explosion · reviewed by a seismologist

M 1.7ml

Earthquake near Coulee Dam, WA

No earthquake was likely felt in Coulee Dam in the 24 hours to 6:58 am PST (14:58 UTC). The last one was M 3.5, 27 km (17 mi) SW, at 8:48 am PST on 18 November 2019, estimated intensity II (weak) in town; 15 felt reports to USGS. Every earthquake near Coulee Dam

No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.7 explosion was recorded 28 km (17 mi) southeast of Coulee Dam, WA, at 4:41 pm PDT on 6 October 2025 (23:41 UTC), less than 1 km deep.

USGS: 2 km NW of Wilbur, Washington

98 km (61 mi) W of Spokane, WA

4:41 pm PDT, Oct 6, 2025 · · -0.7 km deep · released about 9 lb of TNT

10 km30 km60 km120 km N Lincoln County 32 kmDouglas County 72 kmFerry County 79 kmGrant County 84 kmAdams County 87 kmStevens County 94 kmSpokane County 101 kmOkanogan County 114 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
4:41 pm PDT on 6 October 2025 ()
Where
28 km (17 mi) southeast of Coulee Dam, WA · earthquakes near Coulee Dam
Magnitude
M 1.7 (ml)
Depth
-0.7 km below the surface
Felt
no reports yet
Nearest
Lincoln County, 32 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 387 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 12 km (7 mi) from the epicentre. In Coulee Dam, 28 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Earthquakes near other towns within 30 km: Grand Coulee, Electric City.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 9 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,200,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.7 about 9 lb of TNT

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 47.7780, -118.7315. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lincoln County, WA 32 km (20 mi) SE earthquakes near Lincoln County
Douglas County, WA 72 km (45 mi) W earthquakes near Douglas County
Ferry County, WA 79 km (49 mi) N earthquakes near Ferry County
Grant County, WA 84 km (52 mi) SW earthquakes near Grant County
Adams County, WA 87 km (54 mi) S earthquakes near Adams County
Stevens County, WA 94 km (58 mi) NE earthquakes near Stevens County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

1 earthquake has been recorded within 50 km since this one.

  1. 1.6 19 km NNW of Davenport, Washington

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.