QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

4 km WNW of Saint Helens, Oregon

· -0.6 km deep · released about 13 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Columbia County 19 kmClark County 31 kmCowlitz County 38 kmWashington County 40 kmMultnomah County 50 kmWahkiakum County 64 kmClatsop County 67 kmSkamania County 72 kmYamhill County 78 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
-0.6 km below the surface
Felt
no reports yet
Nearest
Columbia County, 19 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 555 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 13 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 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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 45.8762, -122.8595. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Columbia County, OR 19 km (12 mi) ESE of here earthquakes near Columbia County
Clark County, WA 31 km (19 mi) WNW of here earthquakes near Clark County
Cowlitz County, WA 38 km (24 mi) SSW of here earthquakes near Cowlitz County
Washington County, OR 40 km (25 mi) NNE of here earthquakes near Washington County
Multnomah County, OR 50 km (31 mi) NW of here earthquakes near Multnomah County
Wahkiakum County, WA 64 km (40 mi) SE of here earthquakes near Wahkiakum 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. 1.6 16 km ENE of Kalama, Washington
  2. 1.8 0 km SW of Kalama, Washington
  3. 1.6 1 km SSW of Cherry Grove, Washington
  4. 1.5 4 km NW of North Portland, Oregon
  5. 1.8 24 km N of Amboy, Washington
  6. 1.9 6 km NNW of West Longview, Washington
  7. 1.5 Washington-Oregon border region
  8. 1.8 12 km NNW of Amboy, Washington
  9. 1.7 11 km WNW of Warren, Oregon
  10. 2.0 8 km S of Scappoose, Oregon
  11. 1.6 20 km NE of Kalama, Washington
  12. 1.6 8 km E of Kalama, Washington
  13. 1.5 2 km NNW of Venersborg, Washington
  14. 1.7 23 km NNE of Amboy, Washington
  15. 1.6 1 km NNW of Walnut Grove, 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.