QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

1 km ESE of Kapowsin, Washington

· -0.3 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Pierce County 9 kmLewis County 46 kmThurston County 48 kmKing County 63 kmKitsap County 81 kmMason County 84 kmCowlitz County 94 kmSkamania County 108 kmKittitas County 117 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
Pierce County, 9 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1265 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 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 46.9785, -122.2035. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Pierce County, WA 9 km (6 mi) SSW of here earthquakes near Pierce County
Lewis County, WA 46 km (29 mi) NNE of here earthquakes near Lewis County
Thurston County, WA 48 km (30 mi) E of here earthquakes near Thurston County
King County, WA 63 km (39 mi) SSW of here earthquakes near King County
Kitsap County, WA 81 km (50 mi) SSE of here earthquakes near Kitsap County
Mason County, WA 84 km (52 mi) ESE of here earthquakes near Mason County

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

Aftershocks so far

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

  1. 2.3 15 km NNE of Ashford, Washington
  2. 2.0 3 km ENE of Eatonville, Washington
  3. 1.9 10 km NE of Ashford, Washington
  4. 1.5 6 km SE of Maplewood, Washington
  5. 1.8 5 km ESE of Maplewood, Washington
  6. 1.6 6 km ENE of Mossyrock, Washington
  7. 1.8 7 km SSE of McKenna, Washington
  8. 2.2 13 km NE of Ashford, Washington
  9. 2.4 10 km NNE of Ashford, Washington
  10. 2.4 14 km SW of Alder, Washington
  11. 1.6 5 km WSW of La Grande, Washington
  12. 1.6 12 km ESE of Enumclaw, Washington
  13. 1.5 1 km ESE of Kapowsin, Washington
  14. 1.8 12 km NE of Ashford, Washington
  15. 2.0 1 km SSE of Dash Point, 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.