QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

11 km NNE of Skamokawa Valley, Washington

· -0.2 km deep · released about 13 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Wahkiakum County 14 kmPacific County 35 kmClatsop County 50 kmColumbia County 57 kmCowlitz County 58 kmThurston County 71 kmLewis County 78 kmGrays Harbor County 85 kmWashington County 98 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
Magnitude
M 1.8 (ml)
Depth
-0.2 km below the surface
Felt
no reports yet
Nearest
Wahkiakum County, 14 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2725 days ago

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

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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.

Where

Epicentre 46.4123, -123.3692. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Wahkiakum County, WA 14 km (9 mi) NNE of here earthquakes near Wahkiakum County
Pacific County, WA 35 km (22 mi) ESE of here earthquakes near Pacific County
Clatsop County, OR 50 km (31 mi) NNE of here earthquakes near Clatsop County
Columbia County, OR 57 km (35 mi) NNW of here earthquakes near Columbia County
Cowlitz County, WA 58 km (36 mi) WNW of here earthquakes near Cowlitz County
Thurston County, WA 71 km (44 mi) SW of here earthquakes near Thurston County

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

Aftershocks so far

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

  1. 1.8 6 km SW of Clatskanie, Oregon
  2. 1.7 Washington-Oregon border region
  3. 1.9 Washington-Oregon border region
  4. 1.7 3 km NW of West Longview, Washington
  5. 1.8 4 km NNW of Skamokawa Valley, Washington
  6. 1.5 9 km SSE of Toledo, Washington
  7. 1.5 8 km WSW of Napavine, Washington
  8. 1.8 5 km NNW of Winlock, Washington
  9. 1.6 1 km W of Winlock, Washington
  10. 1.8 6 km NW of Winlock, Washington
  11. 1.6 9 km NE of Castle Rock, Washington
  12. 1.9 3 km WNW of Winlock, Washington
  13. 1.9 4 km SW of Cathlamet, Washington
  14. 1.5 3 km W of Winlock, Washington
  15. 1.7 3 km W of Winlock, 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.