QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

4 km NNW of Port Townsend, Washington

· 24 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Island County 8 kmSan Juan County 46 kmKitsap County 58 kmJefferson County 67 kmSnohomish County 76 kmSkagit County 81 kmClallam County 82 kmMason County 94 kmKing County 102 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
24 km below the surface
Felt
no reports yet
Nearest
Island County, 8 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 709 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

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 48.1512, -122.7822. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Island County, WA 8 km (5 mi) W of here earthquakes near Island County
San Juan County, WA 46 km (29 mi) SSE of here earthquakes near San Juan County
Kitsap County, WA 58 km (36 mi) N of here earthquakes near Kitsap County
Jefferson County, WA 67 km (42 mi) NE of here earthquakes near Jefferson County
Snohomish County, WA 76 km (47 mi) W of here earthquakes near Snohomish County
Skagit County, WA 81 km (50 mi) WSW of here earthquakes near Skagit 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. 1.6 24 km SSW of River Road, Washington
  2. 1.7 6 km SE of Port Ludlow, Washington
  3. 2.8 16 km SSW of River Road, Washington
  4. 1.5 11 km WNW of Ault Field, Washington
  5. 2.3 3 km SW of Oak Harbor, Washington
  6. 1.9 14 km N of Jamestown, Washington
  7. 1.6 5 km SE of Port Ludlow, Washington
  8. 1.5 3 km S of Port Ludlow, Washington
  9. 2.1 8 km E of Port Townsend, Washington
  10. 2.5 6 km SE of Coupeville, Washington
  11. 1.5 8 km WNW of La Conner, Washington
  12. 1.8 5 km SE of Oak Bay, Canada
  13. 1.7 4 km W of Mount Vernon, Washington
  14. 1.9 4 km W of Mount Vernon, Washington
  15. 2.8 4 km W of Mount Vernon, 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 6,200 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.