QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

3 km NE of Mirrormont, Washington

· 23 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N King County 9 kmPierce County 50 kmKitsap County 55 kmSnohomish County 65 kmThurston County 90 kmIsland County 92 kmMason County 92 kmKittitas County 105 kmLewis County 105 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
23 km below the surface
Felt
no reports yet
Nearest
King County, 9 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 564 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 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 790,000× the energy of this one
  3. Around the size people start to feel M 3.0 70× the energy of this one
  4. This earthquake M 1.8 about 14 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 47.4830, -121.9595. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
King County, WA 9 km (6 mi) W of here earthquakes near King County
Pierce County, WA 50 km (31 mi) NNE of here earthquakes near Pierce County
Kitsap County, WA 55 km (34 mi) ESE of here earthquakes near Kitsap County
Snohomish County, WA 65 km (41 mi) SSW of here earthquakes near Snohomish County
Thurston County, WA 90 km (56 mi) NE of here earthquakes near Thurston County
Island County, WA 92 km (57 mi) SE of here earthquakes near Island 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. 1.8 3 km N of Cathcart, Washington
  2. 1.7 1 km SSE of Riverton, Washington
  3. 1.6 2 km E of Snoqualmie, Washington
  4. 2.4 2 km NE of Mirrormont, Washington
  5. 1.9 2 km SW of Sultan, Washington
  6. 1.9 7 km ENE of Fall City, Washington
  7. 1.8 2 km NE of Mirrormont, Washington
  8. 1.6 3 km NW of Snoqualmie Pass, Washington
  9. 1.5 2 km SSW of Carnation, Washington
  10. 2.0 3 km SE of Southworth, Washington
  11. 1.8 1 km S of Snoqualmie, Washington
  12. 1.8 2 km S of Monroe, Washington
  13. 2.0 2 km SE of Duvall, Washington
  14. 1.8 2 km ENE of Maple Valley, Washington
  15. 1.6 4 km E of Cathcart, 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 16,000 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.