QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

2 km E of Saint Helens, Oregon

· -0.4 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Clark County 25 kmColumbia County 25 kmCowlitz County 38 kmWashington County 43 kmMultnomah County 45 kmSkamania County 66 kmWahkiakum County 69 kmClatsop County 74 kmYamhill County 80 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
-0.4 km below the surface
Felt
no reports yet
Nearest
Clark County, 25 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 566 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 17 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 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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 45.8637, -122.7740. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Clark County, WA 25 km (15 mi) WNW of here earthquakes near Clark County
Columbia County, OR 25 km (16 mi) ESE of here earthquakes near Columbia County
Cowlitz County, WA 38 km (23 mi) SSW of here earthquakes near Cowlitz County
Washington County, OR 43 km (27 mi) NE of here earthquakes near Washington County
Multnomah County, OR 45 km (28 mi) NW of here earthquakes near Multnomah County
Skamania County, WA 66 km (41 mi) WSW of here earthquakes near Skamania County

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

Aftershocks so far

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

  1. 1.9 3 km NNE of Deer Island, Oregon
  2. 1.9 1 km ESE of La Center, Washington
  3. 1.6 5 km NNE of Kalama, Washington
  4. 3.1 4 km WSW of Deer Island, Oregon
  5. 1.6 10 km SW of Vernonia, Oregon
  6. 1.6 10 km NW of West Longview, Washington
  7. 1.7 2 km WNW of Yacolt, Washington
  8. 1.8 2 km ENE of Brush Prairie, Washington
  9. 1.8 6 km NE of Woodland, Washington
  10. 1.5 13 km SSE of Vernonia, Oregon
  11. 1.7 5 km ENE of Prescott, Oregon
  12. 1.7 3 km W of Columbia City, Oregon
  13. 1.8 4 km NNW of West Longview, Washington
  14. 1.7 Washington-Oregon border region
  15. 1.6 31 km NNE of Amboy, 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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