QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

21 km SE of Toledo, Washington

· -0.6 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Cowlitz County 15 kmLewis County 34 kmColumbia County 55 kmSkamania County 61 kmWahkiakum County 62 kmClark County 62 kmThurston County 70 kmMultnomah County 88 kmPierce County 88 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
-0.6 km below the surface
Felt
no reports yet
Nearest
Cowlitz County, 15 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 655 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 46.3230, -122.6180. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Cowlitz County, WA 15 km (9 mi) NNE of here earthquakes near Cowlitz County
Lewis County, WA 34 km (21 mi) SSW of here earthquakes near Lewis County
Columbia County, OR 55 km (34 mi) NE of here earthquakes near Columbia County
Skamania County, WA 61 km (38 mi) WNW of here earthquakes near Skamania County
Wahkiakum County, WA 62 km (39 mi) E of here earthquakes near Wahkiakum County
Clark County, WA 62 km (39 mi) N of here earthquakes near Clark County

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

Aftershocks so far

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

  1. 1.6 6 km NNW of Winlock, Washington
  2. 1.5 10 km SSE of Toledo, Washington
  3. 1.9 13 km NW of West Longview, Washington
  4. 2.1 8 km W of Napavine, Washington
  5. 1.5 4 km ESE of Mossyrock, Washington
  6. 1.8 7 km ESE of Mossyrock, Washington
  7. 1.9 5 km ESE of Mossyrock, Washington
  8. 1.8 5 km ESE of Mossyrock, Washington
  9. 1.7 12 km SSW of Alder, Washington
  10. 1.9 3 km NW of Winlock, Washington
  11. 1.6 6 km ESE of Mossyrock, Washington
  12. 1.6 2 km NNE of Columbia City, Oregon
  13. 1.7 13 km N of Onalaska, Washington
  14. 2.3 38 km SSE of Morton, Washington
  15. 1.7 18 km E of West Side Highway, 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

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