QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

8 km NNW of West Longview, Washington

· -0.3 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Cowlitz County 29 kmWahkiakum County 29 kmColumbia County 33 kmClatsop County 56 kmLewis County 64 kmPacific County 66 kmClark County 68 kmWashington County 76 kmThurston County 79 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
-0.3 km below the surface
Felt
no reports yet
Nearest
Cowlitz County, 29 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2585 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 17 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 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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 46.2398, -123.0500. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Cowlitz County, WA 29 km (18 mi) W of here earthquakes near Cowlitz County
Wahkiakum County, WA 29 km (18 mi) ESE of here earthquakes near Wahkiakum County
Columbia County, OR 33 km (21 mi) N of here earthquakes near Columbia County
Clatsop County, OR 56 km (35 mi) ENE of here earthquakes near Clatsop County
Lewis County, WA 64 km (40 mi) SW of here earthquakes near Lewis County
Pacific County, WA 66 km (41 mi) ESE of here earthquakes near Pacific County

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

Aftershocks so far

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

  1. 1.7 12 km NE of Vernonia, Oregon
  2. 1.5 13 km ENE of Vernonia, Oregon
  3. 1.9 3 km NNW of West Longview, Washington
  4. 1.7 3 km NNE of Deer Island, Oregon
  5. 1.6 4 km NW of West Longview, Washington
  6. 1.8 1 km ENE of Prescott, Oregon
  7. 1.6 1 km W of Winlock, Washington
  8. 2.3 3 km NNW of Winlock, Washington
  9. 1.7 21 km E of Castle Rock, Washington
  10. 1.6 10 km SSE of Toledo, Washington
  11. 1.6 21 km E of Castle Rock, Washington
  12. 1.7 21 km E of Castle Rock, Washington
  13. 2.1 29 km E of Castle Rock, Washington
  14. 1.6 21 km E of Castle Rock, Washington
  15. 1.8 2 km S of Saint Helens, Oregon

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.