QuakeIndex

explosion · reviewed by a seismologist

M 1.5ml

1 km NNW of Granite Falls, Washington

· -0.4 km deep · released about 5.4 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Snohomish County 16 kmSkagit County 46 kmIsland County 52 kmKing County 68 kmKitsap County 71 kmWhatcom County 84 kmSan Juan County 95 kmChelan County 104 kmPierce County 117 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 1.5 (ml)
Depth
-0.4 km below the surface
Felt
2 reports · strongest reported intensity III
Nearest
Snohomish County, 16 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 566 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 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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 48.0947, -121.9768. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Snohomish County, WA 16 km (10 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 52 km (32 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 71 km (44 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

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

  1. 1.5 2 km E of Granite Falls, Washington
  2. 1.8 1 km ESE of Union Hill-Novelty Hill, Washington
  3. 1.6 0 km NNE of Lake Marcel-Stillwater, Washington
  4. 1.8 4 km NNW of Bryant, Washington
  5. 1.6 Puget Sound region, Washington
  6. 1.7 4 km E of Granite Falls, Washington
  7. 1.6 0 km N of Lake Marcel-Stillwater, Washington
  8. 1.6 2 km NE of Esperance, Washington
  9. 1.7 Puget Sound region, Washington
  10. 1.9 1 km ENE of Granite Falls, Washington
  11. 1.9 2 km SSW of Esperance, Washington
  12. 1.9 4 km ENE of La Conner, Washington
  13. 1.7 1 km ENE of Granite Falls, Washington
  14. 1.6 7 km SSE of Concrete, Washington
  15. 1.6 2 km NNE of Woods Creek, 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 42,000 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.