QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

4 km SW of Port Ludlow, Washington

· -0.0 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kitsap County 29 kmIsland County 30 kmJefferson County 61 kmMason County 69 kmSnohomish County 74 kmSan Juan County 74 kmKing County 80 kmClallam County 90 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
-0.0 km below the surface
Felt
no reports yet
Nearest
Kitsap County, 29 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 914 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 47.8928, -122.7262. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Kitsap County, WA 29 km (18 mi) NNW of here earthquakes near Kitsap County
Island County, WA 30 km (19 mi) S of here earthquakes near Island County
Jefferson County, WA 61 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 74 km (46 mi) WSW of here earthquakes near Snohomish County
San Juan County, WA 74 km (46 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

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

  1. 1.9 6 km SSW of River Road, Washington
  2. 1.7 2 km N of Enetai, Washington
  3. 1.7 2 km E of Tracyton, Washington
  4. 1.5 16 km SW of Brinnon, Washington
  5. 1.6 1 km NE of Mill Creek, Washington
  6. 2.3 7 km ESE of Quilcene, Washington
  7. 2.2 7 km E of Quilcene, Washington
  8. 1.5 6 km WNW of Lofall, Washington
  9. 1.7 5 km WSW of Clinton, Washington
  10. 1.6 5 km N of Port Townsend, Washington
  11. 1.8 6 km WSW of Port Hadlock-Irondale, Washington
  12. 1.7 7 km WSW of Quilcene, Washington
  13. 1.8 4 km SSW of Port Ludlow, Washington
  14. 2.3 3 km WNW of Navy Yard City, Washington
  15. 1.7 2 km N of White Center, 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 4.3 on 2023-10-09 — it released about 5,100 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.