QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

2 km ENE of Granite Falls, Washington

· -0.3 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Snohomish County 13 kmSkagit County 46 kmIsland County 55 kmKing County 67 kmKitsap County 73 kmWhatcom County 84 kmSan Juan County 98 kmChelan County 101 kmPierce County 116 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
-0.3 km below the surface
Felt
1 report · strongest reported intensity III
Nearest
Snohomish County, 13 km ESE
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. 1 person has reported feeling it to USGS.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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 48.0885, -121.9367. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Snohomish County, WA 13 km (8 mi) WNW of here earthquakes near Snohomish County
Skagit County, WA 46 km (29 mi) SSW of here earthquakes near Skagit County
Island County, WA 55 km (34 mi) E of here earthquakes near Island County
King County, WA 67 km (42 mi) N of here earthquakes near King County
Kitsap County, WA 73 km (45 mi) NE of here earthquakes near Kitsap County
Whatcom County, WA 84 km (52 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

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

  1. 1.7 2 km NE of Echo Lake, Washington
  2. 1.9 3 km W of Mount Vernon, Washington
  3. 2.9 3 km W of Mount Vernon, Washington
  4. 2.8 4 km N of Echo Lake, Washington
  5. 1.7 4 km W of Mount Vernon, Washington
  6. 2.1 0 km NNW of Esperance, Washington
  7. 1.7 4 km WSW of Mount Vernon, Washington
  8. 1.6 2 km E of Granite Falls, Washington
  9. 1.7 5 km WSW of Mount Vernon, Washington
  10. 2.4 4 km W of Mount Vernon, Washington
  11. 2.1 4 km WSW of Clinton, Washington
  12. 1.6 3 km SSW of Monroe, Washington
  13. 1.6 4 km WSW of Darrington, Washington
  14. 1.7 0 km NNW of Redmond, Washington
  15. 1.7 2 km ENE of Granite Falls, 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 4.6 on 2019-07-12 — it released about 15,000 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.