QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

15 km SW of Ryderwood, Washington

· -0.2 km deep · released about 6.4 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Wahkiakum County 19 kmColumbia County 38 kmCowlitz County 40 kmClatsop County 49 kmPacific County 55 kmLewis County 70 kmThurston County 78 kmClark County 78 kmWashington County 81 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 1.6 (ml)
Depth
-0.2 km below the surface
Felt
no reports yet
Nearest
Wahkiakum County, 19 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2490 days ago

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

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 6.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.6 about 6.4 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 46.2800, -123.1828. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Wahkiakum County, WA 19 km (12 mi) E of here earthquakes near Wahkiakum County
Columbia County, OR 38 km (24 mi) NNW of here earthquakes near Columbia County
Cowlitz County, WA 40 km (25 mi) WNW of here earthquakes near Cowlitz County
Clatsop County, OR 49 km (31 mi) NE of here earthquakes near Clatsop County
Pacific County, WA 55 km (34 mi) ESE of here earthquakes near Pacific County
Lewis County, WA 70 km (44 mi) WSW of here earthquakes near Lewis County

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

Aftershocks so far

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

  1. 1.7 3 km W of Winlock, Washington
  2. 1.5 4 km ESE of Chehalis, Washington
  3. 2.8 21 km E of Castle Rock, Washington
  4. 2.5 21 km E of Castle Rock, Washington
  5. 1.6 6 km WSW of Napavine, Washington
  6. 1.6 4 km NW of Winlock, Washington
  7. 1.8 2 km N of West Longview, Washington
  8. 1.7 12 km NE of Vernonia, Oregon
  9. 1.5 13 km ENE of Vernonia, Oregon
  10. 1.9 3 km NNW of West Longview, Washington
  11. 1.7 3 km NNE of Deer Island, Oregon
  12. 1.6 4 km NW of West Longview, Washington
  13. 1.8 1 km ENE of Prescott, Oregon
  14. 1.6 1 km W of Winlock, Washington
  15. 2.3 3 km NNW of Winlock, 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

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