QuakeIndex

explosion · reviewed by a seismologist

M 1.7ml

Earthquake near Dayton, WA

No earthquake was likely felt in Dayton in the 24 hours to 10:40 am PST (18:40 UTC). The last one was M 1.9, 7 km (4 mi) WSW, at 3:17 pm PDT on 22 July 2026, estimated intensity II (weak) in town. Every earthquake near Dayton

No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.7 explosion was recorded 6 km (4 mi) west-southwest of Dayton, WA, at 11:36 am PDT on 15 May 2025 (18:36 UTC), less than 1 km deep.

USGS: 6 km WSW of Dayton, Washington

11:36 am PDT, May 15, 2025 · · -0.5 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Columbia County 10 kmWalla Walla County 34 kmGarfield County 42 kmAsotin County 64 kmFranklin County 71 kmWhitman County 78 kmAdams County 88 kmUmatilla County 95 kmNez Perce County 99 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
11:36 am PDT on 15 May 2025 ()
Where
6 km (4 mi) west-southwest of Dayton, WA · earthquakes near Dayton
Magnitude
M 1.7 (ml)
Depth
-0.5 km below the surface
Felt
no reports yet
Nearest
Columbia County, 10 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 546 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 13 km (8 mi) from the epicentre. In Dayton, 6 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: Waitsburg.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 12 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 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 900,000× the energy of this one
  3. Around the size people start to feel M 3.0 80× the energy of this one
  4. This earthquake M 1.7 about 12 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 lists one earthquake of M5 or more within 50 km:

  1. 6.0 3 km SW of Garrett, Washington · 42 km SW of this epicentre

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 46.2922, -118.0420. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Columbia County, WA 10 km (6 mi) E earthquakes near Columbia County
Walla Walla County, WA 34 km (21 mi) W earthquakes near Walla Walla County
Garfield County, WA 42 km (26 mi) ENE earthquakes near Garfield County
Asotin County, WA 64 km (40 mi) E earthquakes near Asotin County
Franklin County, WA 71 km (44 mi) WNW earthquakes near Franklin County
Whitman County, WA 78 km (49 mi) NNE earthquakes near Whitman County

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

Aftershocks so far

7 earthquakes have been recorded within 50 km since this one.

  1. 1.9 6 km WSW of Dayton, Washington
  2. 1.7 15 km NW of Pomeroy, Washington
  3. 1.6 5 km SW of Dayton, Washington
  4. 1.7 6 km WSW of Dayton, Washington
  5. 1.6 11 km E of Milton-Freewater, Oregon
  6. 1.7 11 km E of Milton-Freewater, Oregon
  7. 2.0 16 km WNW of Pomeroy, 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.