QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

4 km SW of Cathlamet, Washington

· -0.5 km deep · released about 7.8 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Wahkiakum County 13 kmClatsop County 27 kmColumbia County 37 kmPacific County 50 kmCowlitz County 58 kmWashington County 74 kmTillamook County 84 kmClark County 85 kmLewis County 92 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
-0.5 km below the surface
Felt
no reports yet
Nearest
Wahkiakum County, 13 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 682 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 7.8 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 120× the energy of this one
  4. This earthquake M 1.6 about 7.8 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 46.1760, -123.4265. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Wahkiakum County, WA 13 km (8 mi) S of here earthquakes near Wahkiakum County
Clatsop County, OR 27 km (17 mi) NE of here earthquakes near Clatsop County
Columbia County, OR 37 km (23 mi) NW of here earthquakes near Columbia County
Pacific County, WA 50 km (31 mi) SSE of here earthquakes near Pacific County
Cowlitz County, WA 58 km (36 mi) W of here earthquakes near Cowlitz County
Washington County, OR 74 km (46 mi) NNW of here earthquakes near Washington County

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

Aftershocks so far

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

  1. 1.6 8 km SW of Vernonia, Oregon
  2. 1.5 3 km WSW of Kalama, Washington
  3. 1.5 11 km ENE of East Cathlamet, Washington
  4. 1.6 6 km NNW of Clatskanie, Oregon
  5. 2.4 10 km ESE of Pe Ell, Washington
  6. 1.6 3 km E of East Cathlamet, Washington
  7. 1.6 14 km ENE of East Cathlamet, Washington
  8. 1.7 8 km SW of Vernonia, Oregon
  9. 1.9 13 km NW of West Longview, Washington
  10. 1.6 13 km NE of Vernonia, Oregon
  11. 2.6 5 km WSW of Pe Ell, Washington
  12. 1.6 3 km W of Winlock, Washington
  13. 1.9 4 km WSW of Winlock, Washington
  14. 1.9 12 km SW of Lebam, Washington
  15. 1.9 5 km NW of Westport, Oregon

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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