QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

4 km WNW of Gorst, Washington

· -0.2 km deep · released about 16 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kitsap County 13 kmMason County 38 kmJefferson County 65 kmThurston County 68 kmIsland County 69 kmKing County 69 kmPierce County 71 kmSnohomish County 93 kmGrays Harbor County 94 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
-0.2 km below the surface
Felt
no reports yet
Nearest
Kitsap County, 13 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 278 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 16 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 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. This earthquake M 1.8 about 16 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 47.5423, -122.7530. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Kitsap County, WA 13 km (8 mi) SW of here earthquakes near Kitsap County
Mason County, WA 38 km (24 mi) NE of here earthquakes near Mason County
Jefferson County, WA 65 km (40 mi) ESE of here earthquakes near Jefferson County
Thurston County, WA 68 km (42 mi) N of here earthquakes near Thurston County
Island County, WA 69 km (43 mi) S of here earthquakes near Island County
King County, WA 69 km (43 mi) W of here earthquakes near King County

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

Aftershocks so far

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

  1. 1.6 8 km S of Port Hadlock-Irondale, Washington
  2. 1.7 2 km NNW of Enetai, Washington
  3. 1.6 5 km SSE of Quilcene, Washington
  4. 1.5 5 km WSW of Mercer Island, Washington
  5. 2.2 2 km WSW of Wauna, Washington
  6. 1.5 5 km ENE of Belfair, Washington
  7. 1.6 2 km SSW of Lake Forest Park, Washington
  8. 2.3 5 km SE of Kingston, Washington
  9. 1.7 10 km NE of Hoodsport, Washington
  10. 1.9 10 km NE of Hoodsport, Washington
  11. 1.5 9 km NE of Hoodsport, Washington
  12. 1.5 9 km NE of Hoodsport, Washington
  13. 1.9 5 km WNW of White Center, Washington
  14. 1.6 4 km S of Port Ludlow, Washington
  15. 1.7 1 km ESE of Tacoma, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.1 on 2017-02-23 — it released about 2,500 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.