QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

4 km SSW of Port Ludlow, Washington

· -0.1 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kitsap County 28 kmIsland County 31 kmJefferson County 62 kmMason County 69 kmSnohomish County 73 kmSan Juan County 75 kmKing County 79 kmClallam County 91 kmSkagit County 95 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
-0.1 km below the surface
Felt
no reports yet
Nearest
Kitsap County, 28 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1657 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 47.8850, -122.7107. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Kitsap County, WA 28 km (17 mi) N of here earthquakes near Kitsap County
Island County, WA 31 km (19 mi) S of here earthquakes near Island County
Jefferson County, WA 62 km (38 mi) E of here earthquakes near Jefferson County
Mason County, WA 69 km (43 mi) NNE of here earthquakes near Mason County
Snohomish County, WA 73 km (45 mi) WSW of here earthquakes near Snohomish County
San Juan County, WA 75 km (47 mi) SSE of here earthquakes near San Juan 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 5 km SSE of Quilcene, Washington
  2. 1.6 0 km SW of Esperance, Washington
  3. 1.5 6 km WSW of Port Ludlow, Washington
  4. 1.5 Puget Sound region, Washington
  5. 1.7 Puget Sound region, Washington
  6. 2.2 7 km WSW of Seattle, Washington
  7. 1.9 3 km NNE of White Center, Washington
  8. 1.7 4 km SSW of Port Ludlow, Washington
  9. 1.5 2 km SW of Gorst, Washington
  10. 1.9 1 km ENE of Enetai, Washington
  11. 1.6 0 km WSW of Esperance, Washington
  12. 1.6 1 km NNW of Keyport, Washington
  13. 1.9 0 km W of Keyport, Washington
  14. 1.6 5 km SSW of Port Ludlow, Washington
  15. 1.6 3 km N of Kingston, 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.