QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

4 km ENE of Granite Falls, Washington

· -0.4 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Snohomish County 13 kmSkagit County 44 kmIsland County 56 kmKing County 68 kmKitsap County 75 kmWhatcom County 83 kmSan Juan County 98 kmChelan County 101 kmPierce County 118 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
-0.4 km below the surface
Felt
2 reports · strongest reported intensity III
Nearest
Snohomish County, 13 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2794 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 2 people have reported feeling it to USGS.

USGS catalogues this as explosion, not an earthquake.

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 5.7 790,000× the energy of this one
  3. Around the size people start to feel M 3.0 70× 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 48.1022, -121.9217. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Snohomish County, WA 13 km (8 mi) WNW of here earthquakes near Snohomish County
Skagit County, WA 44 km (27 mi) S of here earthquakes near Skagit County
Island County, WA 56 km (35 mi) E of here earthquakes near Island County
King County, WA 68 km (42 mi) N of here earthquakes near King County
Kitsap County, WA 75 km (46 mi) NE of here earthquakes near Kitsap County
Whatcom County, WA 83 km (51 mi) S of here earthquakes near Whatcom 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 2 km ESE of Lake Marcel-Stillwater, Washington
  2. 1.8 6 km WSW of Clinton, Washington
  3. 2.6 6 km WSW of Clinton, Washington
  4. 2.2 8 km SW of Warm Beach, Washington
  5. 2.6 1 km NE of Lake Marcel-Stillwater, Washington
  6. 1.7 2 km WNW of Lake Marcel-Stillwater, Washington
  7. 1.9 1 km NW of Lake Marcel-Stillwater, Washington
  8. 1.8 3 km E of Granite Falls, Washington
  9. 1.7 1 km NE of Granite Falls, Washington
  10. 2.2 2 km ESE of Duvall, Washington
  11. 2.0 3 km E of Granite Falls, Washington
  12. 1.8 4 km N of Duvall, Washington
  13. 1.8 5 km NNE of Duvall, Washington
  14. 1.6 5 km WSW of Darrington, Washington
  15. 1.6 3 km E of Cathcart, 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.