QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5ml

3 km SSW of Roosevelt, Washington

· 31 km deep · released about 2.3 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Snohomish County 29 kmKing County 44 kmKitsap County 53 kmIsland County 58 kmSkagit County 72 kmPierce County 91 kmMason County 103 kmChelan County 105 kmSan Juan County 107 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 3.5 (ml)
Depth
31 km below the surface
Felt
2925 reports · strongest reported intensity V
Measured shaking
intensity III (ShakeMap)
Nearest
Snohomish County, 29 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1966 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 2925 people have reported feeling it to USGS.

How big was it?

This earthquake released about 2.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 75,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,300× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,400× the energy of this one
  4. This earthquake M 3.5 about 2.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4.7× more

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 47.8645, -122.0290. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Snohomish County, WA 29 km (18 mi) SW of here earthquakes near Snohomish County
King County, WA 44 km (27 mi) NNW of here earthquakes near King County
Kitsap County, WA 53 km (33 mi) ENE of here earthquakes near Kitsap County
Island County, WA 58 km (36 mi) SE of here earthquakes near Island County
Skagit County, WA 72 km (45 mi) SSW of here earthquakes near Skagit County
Pierce County, WA 91 km (56 mi) N of here earthquakes near Pierce 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 6 km NE of Fall City, Washington
  2. 3.0 8 km ENE of Fall City, Washington
  3. 1.7 6 km NE of Fall City, Washington
  4. 3.4 9 km NNE of Snoqualmie, Washington
  5. 1.6 2 km E of Snohomish, Washington
  6. 1.9 3 km ENE of Granite Falls, Washington
  7. 1.8 5 km WSW of Darrington, Washington
  8. 2.7 0 km WSW of Klahanie, Washington
  9. 1.6 8 km S of Baring, Washington
  10. 1.8 1 km E of Snoqualmie, Washington
  11. 1.7 2 km ESE of Lake Marcel-Stillwater, Washington
  12. 1.8 6 km WSW of Clinton, Washington
  13. 2.6 6 km WSW of Clinton, Washington
  14. 2.2 8 km SW of Warm Beach, Washington
  15. 2.6 1 km NE of Lake Marcel-Stillwater, 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 50 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.