QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

28 km N of Amboy, Washington

· -1.3 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Cowlitz County 21 kmSkamania County 39 kmClark County 44 kmLewis County 46 kmColumbia County 57 kmMultnomah County 69 kmWahkiakum County 79 kmWashington County 86 kmThurston County 91 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
-1.3 km below the surface
Felt
4 reports · strongest reported intensity II
Nearest
Cowlitz County, 21 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2858 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 4 people have reported feeling it to USGS.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 14 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 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 46.1680, -122.4142. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Cowlitz County, WA 21 km (13 mi) E of here earthquakes near Cowlitz County
Skamania County, WA 39 km (24 mi) WNW of here earthquakes near Skamania County
Clark County, WA 44 km (28 mi) N of here earthquakes near Clark County
Lewis County, WA 46 km (29 mi) S of here earthquakes near Lewis County
Columbia County, OR 57 km (36 mi) ENE of here earthquakes near Columbia County
Multnomah County, OR 69 km (43 mi) N of here earthquakes near Multnomah County

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

Aftershocks so far

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

  1. 1.7 1 km NE of Lewisville, Washington
  2. 1.8 2 km NE of Deer Island, Oregon
  3. 1.6 3 km WSW of Yacolt, Washington
  4. 1.6 14 km SSW of Morton, Washington
  5. 1.6 21 km SSE of Mossyrock, Washington
  6. 1.6 5 km SW of Deer Island, Oregon
  7. 1.5 3 km SW of Yacolt, Washington
  8. 1.8 9 km S of Toledo, Washington
  9. 1.7 6 km ENE of Prescott, Oregon
  10. 1.6 9 km SSE of Toledo, Washington
  11. 1.6 12 km SSE of Toledo, Washington
  12. 1.7 13 km ESE of Yacolt, Washington
  13. 1.8 20 km NNW of Carson, Washington
  14. 2.2 3 km ESE of Woodland, Washington
  15. 1.6 4 km W of Mossyrock, 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.