QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

9 km NE of Marblemount, Washington

· -1.1 km deep · released about 1,300 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Skagit County 35 kmWhatcom County 44 kmSnohomish County 67 kmChelan County 99 kmIsland County 108 kmOkanogan County 120 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 3.1 (ml)
Depth
-1.1 km below the surface
Felt
24 reports · strongest reported intensity IV
Measured shaking
intensity III (ShakeMap)
Nearest
Skagit County, 35 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3140 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 24 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 260,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 12,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 8,200× the energy of this one
  4. This earthquake M 3.1 about 1,300 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.4× 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 48.5967, -121.3695. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Skagit County, WA 35 km (22 mi) ENE of here earthquakes near Skagit County
Whatcom County, WA 44 km (27 mi) SE of here earthquakes near Whatcom County
Snohomish County, WA 67 km (42 mi) NNE of here earthquakes near Snohomish County
Chelan County, WA 99 km (61 mi) NW of here earthquakes near Chelan County
Island County, WA 108 km (67 mi) ENE of here earthquakes near Island County
Okanogan County, WA 120 km (74 mi) W of here earthquakes near Okanogan County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 3.0 5 km ENE of Oso, Washington
  2. 2.1 54 km NE of Marblemount, Washington
  3. 3.2 55 km NE of Marblemount, Washington
  4. 2.2 7 km ENE of Oso, Washington
  5. 1.8 5 km ENE of Oso, Washington
  6. 3.4 6 km ENE of Oso, Washington
  7. 2.9 7 km NE of Darrington, Washington
  8. 1.9 20 km E of Darrington, Washington
  9. 2.0 4 km SE of Swede Heaven, Washington
  10. 1.6 43 km NE of Marblemount, Washington
  11. 1.9 42 km NE of Marblemount, Washington
  12. 1.6 42 km NE of Marblemount, Washington
  13. 1.8 41 km NE of Marblemount, Washington
  14. 1.6 Washington
  15. 1.9 48 km NNE of Marblemount, 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.