QuakeIndex

explosion · reviewed by a seismologist

M 1.6ml

Earthquake near West Longview, WA

USGS: 10 km NW of West Longview, Washington

86 km (53 mi) NNW of Portland, OR

2:36 pm PST, Nov 29, 2018 · · -0.7 km deep · released about 6.4 lb of TNT

10 km30 km60 km120 km N Wahkiakum County 27 kmCowlitz County 32 kmColumbia County 34 kmClatsop County 54 kmPacific County 64 kmLewis County 66 kmClark County 70 kmWashington County 77 kmThurston 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
2:36 pm PST on 29 November 2018 ()
Where
11 km (7 mi) NW of West Longview, WA · earthquakes near West Longview
Magnitude
M 1.6 (ml)
Depth
-0.7 km below the surface
Felt
no reports yet
Nearest
Wahkiakum County, 27 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2863 days ago

A magnitude 1.6 earthquake was recorded 11 km (7 mi) NW of West Longview, WA, at 2:36 pm PST on 29 November 2018 (22:36 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Longview Heights, Castle Rock, West Side Highway, Longview, Kelso, Clatskanie.

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 46.2462, -123.0838. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Wahkiakum County, WA 27 km (17 mi) WNW earthquakes near Wahkiakum County
Cowlitz County, WA 32 km (20 mi) E earthquakes near Cowlitz County
Columbia County, OR 34 km (21 mi) S earthquakes near Columbia County
Clatsop County, OR 54 km (33 mi) WSW earthquakes near Clatsop County
Pacific County, WA 64 km (40 mi) WNW earthquakes near Pacific County
Lewis County, WA 66 km (41 mi) NE earthquakes near Lewis County

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

Aftershocks so far

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

  1. 1.7 1 km SSE of Prescott, Oregon
  2. 1.6 7 km ENE of Prescott, Oregon
  3. 1.6 12 km NW of West Longview, Washington
  4. 1.6 11 km SSW of Pe Ell, Washington
  5. 1.7 3 km NW of West Longview, Washington
  6. 1.6 10 km SW of Prescott, Oregon
  7. 1.6 4 km W of West Longview, Washington
  8. 1.8 3 km SW of Cathlamet, Washington
  9. 1.8 9 km NW of West Longview, Washington
  10. 2.2 23 km SW of Westport, Oregon
  11. 1.8 4 km NW of West Longview, Washington
  12. 2.0 21 km WSW of Westport, Oregon
  13. 2.9 1 km WSW of Onalaska, Washington
  14. 2.1 10 km WSW of Chehalis, Washington
  15. 1.7 4 km SE 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.