QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

Earthquake near Yakima, WA

USGS: 8 km NE of Tampico, Washington

18 km (11 mi) W of Yakima, WA · 148 km (92 mi) ESE of Tacoma, WA

5:21 pm PDT, Sep 18, 2018 · · -0.6 km deep · released about 14 lb of TNT

10 km30 km60 km120 km N Yakima County 15 kmKittitas County 61 kmKlickitat County 79 kmBenton County 105 kmSkamania County 110 kmPierce County 117 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
5:21 pm PDT on 18 September 2018 ()
Where
21 km (13 mi) W of Yakima, WA · earthquakes near Yakima
Magnitude
M 1.8 (ml)
Depth
-0.6 km below the surface
Felt
no reports yet
Nearest
Yakima County, 15 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2936 days ago

A magnitude 1.8 earthquake was recorded 21 km (13 mi) W of Yakima, WA, at 5:21 pm PDT on 18 September 2018 (00:21 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Ahtanum, Tieton, West Valley, Gleed, Selah, Union Gap.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 lists one earthquake of M5 or more within 50 km:

  1. 5.0 23 km ESE of Packwood, Washington · 47 km W of this epicentre

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 46.5845, -120.7797. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Yakima County, WA 15 km (9 mi) SSE earthquakes near Yakima County
Kittitas County, WA 61 km (38 mi) N earthquakes near Kittitas County
Klickitat County, WA 79 km (49 mi) S earthquakes near Klickitat County
Benton County, WA 105 km (65 mi) ESE earthquakes near Benton County
Skamania County, WA 110 km (68 mi) SW earthquakes near Skamania County
Pierce County, WA 117 km (73 mi) WNW earthquakes near Pierce County

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

Aftershocks so far

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

  1. 1.7 9 km S of Ellensburg, Washington
  2. 1.6 27 km WSW of White Swan, Washington
  3. 1.6 8 km SSE of Ellensburg, Washington
  4. 1.7 14 km NE of Naches, Washington
  5. 1.9 5 km W of Summitview, Washington
  6. 1.5 13 km SW of Ellensburg, Washington
  7. 1.6 6 km S of Ellensburg, Washington
  8. 2.6 5 km NNW of Naches, Washington
  9. 2.8 17 km SSE of White Swan, Washington
  10. 1.7 5 km S of Ellensburg, Washington
  11. 1.9 7 km S of Ellensburg, Washington
  12. 1.8 8 km S of Ellensburg, Washington
  13. 1.7 32 km ESE of Packwood, Washington
  14. 1.7 2 km S of Selah, Washington
  15. 1.8 10 km NW of Tampico, 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.