QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Earthquake near Royal City, WA

USGS: 10 km SW of Royal City, Washington

10:42 pm PST, Feb 9, 2018 · · 2.8 km deep · released about 18 lb of TNT

10 km30 km60 km120 km N Grant County 46 kmBenton County 70 kmFranklin County 72 kmKittitas County 78 kmYakima County 87 kmAdams County 95 kmDouglas County 100 kmWalla Walla 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
10:42 pm PST on 9 February 2018 ()
Where
11 km (7 mi) SW of Royal City, WA · earthquakes near Royal City
Magnitude
M 1.9 (ml)
Depth
2.8 km below the surface
Felt
no reports yet
Nearest
Grant County, 46 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3154 days ago

A magnitude 1.9 earthquake was recorded 11 km (7 mi) SW of Royal City, WA, at 10:42 pm PST on 9 February 2018 (06:42 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Mattawa, Desert Aire.

How big was it?

This earthquake released about 18 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 5.8 840,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 600,000× the energy of this one
  3. Around the size people start to feel M 3.0 53× the energy of this one
  4. This earthquake M 1.9 about 18 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 46.8413, -119.7430. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Grant County, WA 46 km (29 mi) NNE earthquakes near Grant County
Benton County, WA 70 km (44 mi) SSE earthquakes near Benton County
Franklin County, WA 72 km (45 mi) ESE earthquakes near Franklin County
Kittitas County, WA 78 km (48 mi) WNW earthquakes near Kittitas County
Yakima County, WA 87 km (54 mi) WSW earthquakes near Yakima County
Adams County, WA 95 km (59 mi) ENE earthquakes near Adams County

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

Aftershocks so far

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

  1. 1.7 12 km SE of Desert Aire, Washington
  2. 1.6 12 km SE of Desert Aire, Washington
  3. 1.8 12 km SE of Desert Aire, Washington
  4. 1.6 12 km SE of Desert Aire, Washington
  5. 1.6 12 km SE of Desert Aire, Washington
  6. 1.7 12 km SE of Desert Aire, Washington
  7. 2.4 12 km SE of Desert Aire, Washington
  8. 1.7 12 km SE of Desert Aire, Washington
  9. 1.6 12 km SE of Desert Aire, Washington
  10. 2.9 12 km SE of Desert Aire, Washington
  11. 2.2 12 km SE of Desert Aire, Washington
  12. 2.0 12 km SE of Desert Aire, Washington
  13. 2.1 12 km SE of Desert Aire, Washington
  14. 1.8 12 km SE of Desert Aire, Washington
  15. 2.4 8 km SE of Desert Aire, 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.