QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

12 km W of Greenwater, Washington

· -0.8 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Pierce County 28 kmKing County 38 kmLewis County 77 kmThurston County 81 kmKitsap County 83 kmKittitas County 86 kmSnohomish County 101 kmMason County 105 kmYakima County 112 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
-0.8 km below the surface
Felt
no reports yet
Nearest
Pierce County, 28 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 567 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 5.8 900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 640,000× the energy of this one
  3. Around the size people start to feel M 3.0 57× 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 47.1508, -121.8133. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Pierce County, WA 28 km (17 mi) ENE of here earthquakes near Pierce County
King County, WA 38 km (23 mi) S of here earthquakes near King County
Lewis County, WA 77 km (48 mi) NE of here earthquakes near Lewis County
Thurston County, WA 81 km (50 mi) ENE of here earthquakes near Thurston County
Kitsap County, WA 83 km (52 mi) SE of here earthquakes near Kitsap County
Kittitas County, WA 86 km (53 mi) W of here earthquakes near Kittitas 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. 1.5 24 km ENE of Ashford, Washington
  2. 1.8 1 km NNE of Kapowsin, Washington
  3. 1.5 25 km ENE of Ashford, Washington
  4. 2.1 24 km ENE of Ashford, Washington
  5. 1.6 6 km W of Wilderness Rim, Washington
  6. 1.5 0 km SSE of Wilderness Rim, Washington
  7. 1.7 15 km SW of Easton, Washington
  8. 2.0 7 km NE of Ashford, Washington
  9. 2.1 7 km NE of Ashford, Washington
  10. 1.6 1 km WNW of Kapowsin, Washington
  11. 2.1 5 km SW of Black Diamond, Washington
  12. 1.9 10 km ENE of Ashford, Washington
  13. 1.7 2 km WNW of Kapowsin, Washington
  14. 1.6 16 km NNE of Ashford, Washington
  15. 2.3 15 km NNE of Ashford, 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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