QuakeIndex

explosion · reviewed by a seismologist

M 1.9ml

Earthquake near Vernonia, OR

USGS: 14 km NE of Vernonia, Oregon

55 km (34 mi) NW of Portland, OR · 47 km (29 mi) N of Hillsboro, OR

1:34 pm PDT, Jun 15, 2018 · · -0.4 km deep · released about 23 lb of TNT

10 km30 km60 km120 km N Columbia County 3 kmCowlitz County 40 kmWashington County 44 kmClark County 48 kmWahkiakum County 49 kmClatsop County 52 kmMultnomah County 66 kmTillamook County 77 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
1:34 pm PDT on 15 June 2018 ()
Where
15 km (9 mi) NE of Vernonia, OR · earthquakes near Vernonia
Magnitude
M 1.9 (ml)
Depth
-0.4 km below the surface
Felt
no reports yet
Nearest
Columbia County, 3 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3028 days ago

A magnitude 1.9 earthquake was recorded 15 km (9 mi) NE of Vernonia, OR, at 1:34 pm PDT on 15 June 2018 (20:34 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

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

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 23 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 660,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 470,000× the energy of this one
  3. Around the size people start to feel M 3.0 42× the energy of this one
  4. This earthquake M 1.9 about 23 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 45.9445, -123.0485. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Columbia County, OR 3 km (2 mi) W earthquakes near Columbia County
Cowlitz County, WA 40 km (25 mi) NE earthquakes near Cowlitz County
Washington County, OR 44 km (27 mi) S earthquakes near Washington County
Clark County, WA 48 km (30 mi) ESE earthquakes near Clark County
Wahkiakum County, WA 49 km (30 mi) NW earthquakes near Wahkiakum County
Clatsop County, OR 52 km (32 mi) W earthquakes near Clatsop 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 12 km SSE of Toledo, Washington
  2. 1.9 8 km NW of West Longview, Washington
  3. 2.2 3 km ESE of Woodland, Washington
  4. 1.7 3 km NW of West Longview, Washington
  5. 1.6 16 km ENE of Kalama, Washington
  6. 1.8 0 km SW of Kalama, Washington
  7. 1.6 1 km SSW of Cherry Grove, Washington
  8. 1.5 4 km NW of North Portland, Oregon
  9. 1.9 6 km NNW of West Longview, Washington
  10. 1.5 Washington-Oregon border region
  11. 1.8 12 km NNW of Amboy, Washington
  12. 1.7 11 km WNW of Warren, Oregon
  13. 2.0 8 km S of Scappoose, Oregon
  14. 1.6 20 km NE of Kalama, Washington
  15. 1.8 2 km SSW of Cathlamet, 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.