QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

19 km WSW of Alder, Washington

· 18 km deep · released about 16 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lewis County 18 kmThurston County 35 kmPierce County 46 kmCowlitz County 59 kmWahkiakum County 84 kmMason County 87 kmSkamania County 88 kmColumbia County 97 kmPacific County 99 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
18 km below the surface
Felt
no reports yet
Nearest
Lewis County, 18 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 567 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 16 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 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. This earthquake M 1.8 about 16 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 46.7157, -122.5098. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lewis County, WA 18 km (11 mi) NW of here earthquakes near Lewis County
Thurston County, WA 35 km (21 mi) SE of here earthquakes near Thurston County
Pierce County, WA 46 km (29 mi) SW of here earthquakes near Pierce County
Cowlitz County, WA 59 km (37 mi) NNE of here earthquakes near Cowlitz County
Wahkiakum County, WA 84 km (52 mi) NE of here earthquakes near Wahkiakum County
Mason County, WA 87 km (54 mi) SE of here earthquakes near Mason County

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

Aftershocks so far

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

  1. 2.0 6 km NNW of Mossyrock, Washington
  2. 1.5 9 km SSE of Toledo, Washington
  3. 1.8 9 km NE of Castle Rock, Washington
  4. 2.4 Washington
  5. 1.8 11 km SSE of Toledo, Washington
  6. 1.5 26 km S of Morton, Washington
  7. 1.6 2 km E of Kapowsin, Washington
  8. 2.3 12 km NW of Morton, Washington
  9. 2.9 12 km NW of Morton, Washington
  10. 1.6 5 km WNW of Ashford, Washington
  11. 1.6 6 km ENE of Elbe, Washington
  12. 1.8 7 km WSW of Morton, Washington
  13. 2.7 7 km WSW of Morton, Washington
  14. 1.5 8 km WSW of Napavine, Washington
  15. 1.6 10 km SSE of Mossyrock, 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.