QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Earthquake near Ellensburg, WA

USGS: 7 km S of Ellensburg, Washington

38 km (24 mi) N of Yakima, WA · 149 km (92 mi) ESE of Tacoma, WA

1:46 am PDT, Sep 27, 2023 · · -0.9 km deep · released about 21 lb of TNT

10 km30 km60 km120 km N Kittitas County 23 kmYakima County 55 kmGrant County 88 kmChelan County 103 kmDouglas County 111 kmBenton County 111 kmKing County 115 kmKlickitat County 119 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
1:46 am PDT on 27 September 2023 ()
Where
7 km (4 mi) S of Ellensburg, WA · earthquakes near Ellensburg
Magnitude
M 1.9 (ml)
Depth
-0.9 km below the surface
Felt
no reports yet
Nearest
Kittitas County, 23 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1100 days ago

A magnitude 1.9 earthquake was recorded 7 km (4 mi) S of Ellensburg, WA, at 1:46 am PDT on 27 September 2023 (08:46 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Kittitas, Tieton.

How big was it?

This earthquake released about 21 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 5.8 730,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 520,000× the energy of this one
  3. Around the size people start to feel M 3.0 46× the energy of this one
  4. This earthquake M 1.9 about 21 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 46.9327, -120.5540. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kittitas County, WA 23 km (14 mi) NNW earthquakes near Kittitas County
Yakima County, WA 55 km (34 mi) SSW earthquakes near Yakima County
Grant County, WA 88 km (55 mi) ENE earthquakes near Grant County
Chelan County, WA 103 km (64 mi) N earthquakes near Chelan County
Douglas County, WA 111 km (69 mi) NE earthquakes near Douglas County
Benton County, WA 111 km (69 mi) SE earthquakes near Benton County

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

Aftershocks so far

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

  1. 1.2 4 km WNW of Tieton, Washington
  2. 0.7 7 km W of Ahtanum, Washington
  3. 1.6 11 km N of Selah, Washington
  4. 1.5 11 km N of Selah, Washington
  5. 1.6 17 km SSW of Nile, Washington
  6. 1.6 12 km NW of Thorp, Washington
  7. 1.8 9 km SSW of Ellensburg, Washington
  8. 1.7 3 km ESE of Kittitas, Washington
  9. 1.6 2 km WNW of Summitview, Washington
  10. 2.1 11 km NNE of Selah, Washington
  11. 1.9 0 km SW of Selah, Washington
  12. 1.8 15 km SW of Thorp, Washington
  13. 1.9 1 km SSW of Selah, Washington
  14. 2.0 9 km S of Ellensburg, Washington
  15. 1.9 9 km S of Ellensburg, 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.