QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

Earthquake near Vernonia, OR

No earthquake was likely felt in Vernonia in the 24 hours to 3:09 am PST (11:09 UTC). The last one was M 3.0, 26 km (16 mi) E, at 7:25 am PDT on 22 October 2026, estimated intensity II (weak) in town; 113 felt reports to USGS. Every earthquake near Vernonia

No: USGS classifies this as a explosion, not an earthquake. A magnitude 1.6 explosion was recorded 12 km (7 mi) northeast of Vernonia, OR, at 11:59 am PDT on 29 April 2024 (18:59 UTC), less than 1 km deep.

USGS: 11 km NE of Vernonia, Oregon

57 km (35 mi) NW of Portland, OR · 48 km (30 mi) NNW of Hillsboro, OR

11:59 am PDT, Apr 29, 2024 · · -0.3 km deep · released about 6.4 lb of TNT

10 km30 km60 km120 km N Columbia County 1 kmWashington County 43 kmCowlitz County 43 kmWahkiakum County 47 kmClatsop County 48 kmClark County 51 kmMultnomah County 69 kmTillamook County 74 kmYamhill County 79 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
11:59 am PDT on 29 April 2024 ()
Where
12 km (7 mi) northeast of Vernonia, OR · earthquakes near Vernonia
Magnitude
M 1.6 (ml)
Depth
-0.3 km below the surface
Felt
no reports yet
Nearest
Columbia County, 1 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 928 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 11 km (7 mi) from the epicentre. In Vernonia, 12 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Earthquakes near other towns within 30 km: Clatskanie, Rainier, Kalama, Columbia City, Warren, Saint Helens.

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.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 45.9412, -123.0988. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Columbia County, OR 1 km (1 mi) E earthquakes near Columbia County
Washington County, OR 43 km (27 mi) S earthquakes near Washington County
Cowlitz County, WA 43 km (27 mi) NE earthquakes near Cowlitz County
Wahkiakum County, WA 47 km (29 mi) NNW earthquakes near Wahkiakum County
Clatsop County, OR 48 km (30 mi) WNW earthquakes near Clatsop County
Clark County, WA 51 km (32 mi) ESE earthquakes near Clark 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. 1.6 6 km NNW of Clatskanie, Oregon
  2. 1.5 10 km NE of Castle Rock, Washington
  3. 1.6 7 km NE of Castle Rock, Washington
  4. 1.9 2 km WNW of Saint Helens, Oregon
  5. 1.6 3 km E of East Cathlamet, Washington
  6. 1.6 14 km ENE of East Cathlamet, Washington
  7. 2.1 8 km S of Scappoose, Oregon
  8. 1.7 8 km SW of Vernonia, Oregon
  9. 1.9 1 km ESE of North Portland, Oregon
  10. 1.9 13 km NW of West Longview, Washington
  11. 1.6 8 km S of Scappoose, Oregon
  12. 1.6 13 km NE of Vernonia, Oregon
  13. 1.6 2 km NNE of Columbia City, Oregon
  14. 1.7 18 km E of West Side Highway, Washington
  15. 1.6 19 km NE of Kalama, 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.