QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

9 km NE of Castle Rock, Washington

· -0.3 km deep · released about 6.8 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Cowlitz County 19 kmLewis County 44 kmWahkiakum County 46 kmColumbia County 48 kmThurston County 66 kmClark County 68 kmSkamania County 76 kmClatsop County 76 kmPacific County 77 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 1.6 (ml)
Depth
-0.3 km below the surface
Felt
no reports yet
Nearest
Cowlitz County, 19 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1467 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 6.8 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
  3. Around the size people start to feel M 3.0 140× the energy of this one
  4. This earthquake M 1.6 about 6.8 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 46.3380, -122.8252. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Cowlitz County, WA 19 km (12 mi) NW of here earthquakes near Cowlitz County
Lewis County, WA 44 km (27 mi) SW of here earthquakes near Lewis County
Wahkiakum County, WA 46 km (29 mi) E of here earthquakes near Wahkiakum County
Columbia County, OR 48 km (30 mi) NNE of here earthquakes near Columbia County
Thurston County, WA 66 km (41 mi) S of here earthquakes near Thurston County
Clark County, WA 68 km (42 mi) NNW of here earthquakes near Clark County

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

Aftershocks so far

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

  1. 1.7 33 km NNE of Amboy, Washington
  2. 3.0 33 km NNE of Amboy, Washington
  3. 1.6 5 km NNE of Kalama, Washington
  4. 1.8 8 km SSW of Morton, Washington
  5. 3.1 4 km WSW of Deer Island, Oregon
  6. 1.7 6 km S of Onalaska, Washington
  7. 1.6 10 km NW of West Longview, Washington
  8. 1.8 6 km NE of Woodland, Washington
  9. 1.5 10 km ESE of Centralia, Washington
  10. 1.7 5 km ENE of Prescott, Oregon
  11. 1.7 3 km W of Columbia City, Oregon
  12. 1.6 19 km SSW of Mossyrock, Washington
  13. 1.8 4 km NNW of West Longview, Washington
  14. 1.6 31 km NNE of Amboy, Washington
  15. 1.8 6 km SW of Clatskanie, 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

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