QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

4 km WSW of Concrete, Washington

· 4.8 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Skagit County 4 kmWhatcom County 35 kmSnohomish County 53 kmIsland County 76 kmSan Juan County 96 kmChelan County 115 kmKing County 115 kmKitsap 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 1.8 (ml)
Depth
4.8 km below the surface
Felt
no reports yet
Nearest
Skagit County, 4 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 158 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 17 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 5.8 900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 640,000× the energy of this one
  3. Around the size people start to feel M 3.0 57× the energy of this one
  4. This earthquake M 1.8 about 17 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 48.5283, -121.8037. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Skagit County, WA 4 km (2 mi) NNE of here earthquakes near Skagit County
Whatcom County, WA 35 km (22 mi) S of here earthquakes near Whatcom County
Snohomish County, WA 53 km (33 mi) N of here earthquakes near Snohomish County
Island County, WA 76 km (47 mi) ENE of here earthquakes near Island County
San Juan County, WA 96 km (60 mi) E of here earthquakes near San Juan County
Chelan County, WA 115 km (71 mi) NW of here earthquakes near Chelan County

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

Aftershocks so far

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

  1. 1.1 6 km NE of Oso, Washington
  2. 0.7 6 km SSE of Concrete, Washington
  3. 1.6 3 km WSW of Lake Cavanaugh, Washington
  4. 2.6 2 km ENE of Mount Vernon, Washington
  5. 1.8 15 km ESE of Acme, Washington
  6. 1.9 7 km SSE of Concrete, Washington
  7. 1.9 2 km NNE of Lyman, Washington
  8. 1.7 3 km N of Lyman, Washington
  9. 2.2 2 km N of Lyman, Washington
  10. 1.5 2 km ENE of Granite Falls, Washington
  11. 1.6 3 km E of Granite Falls, Washington
  12. 1.8 5 km E of Acme, Washington
  13. 1.7 2 km ENE of Granite Falls, Washington
  14. 1.7 1 km WNW of Marblemount, Washington
  15. 2.5 4 km WSW of Concrete, 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.