QuakeIndex

explosion · reviewed by a seismologist

M 1.8ml

Earthquake near Umatilla, OR

USGS: 3 km E of Umatilla, Oregon

32 km (20 mi) SSW of Kennewick, WA

3:59 pm PST, Dec 9, 2021 · · -0.3 km deep · released about 17 lb of TNT

10 km30 km60 km120 km N Benton County 38 kmUmatilla County 57 kmMorrow County 60 kmWalla Walla County 73 kmFranklin County 75 kmGilliam County 97 kmKlickitat County 115 kmColumbia County 115 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
3:59 pm PST on 9 December 2021 ()
Where
3 km (2 mi) E of Umatilla, OR · earthquakes near Umatilla
Magnitude
M 1.8 (ml)
Depth
-0.3 km below the surface
Felt
1 report · strongest reported intensity IV
Nearest
Benton County, 38 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1757 days ago

A magnitude 1.8 earthquake was recorded 3 km (2 mi) E of Umatilla, OR, at 3:59 pm PST on 9 December 2021 (23:59 UTC). 1 person has reported feeling it to USGS. This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Hermiston, Irrigon, Stanfield, Highland.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 17 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 5.8 900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 640,000× the energy of this one
  3. Around the size people start to feel M 3.0 57× the energy of this one
  4. This earthquake M 1.8 about 17 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 45.9198, -119.3002. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Benton County, WA 38 km (24 mi) NNW earthquakes near Benton County
Umatilla County, OR 57 km (36 mi) SE earthquakes near Umatilla County
Morrow County, OR 60 km (37 mi) SSW earthquakes near Morrow County
Walla Walla County, WA 73 km (46 mi) ENE earthquakes near Walla Walla County
Franklin County, WA 75 km (47 mi) NNE earthquakes near Franklin County
Gilliam County, OR 97 km (60 mi) SW earthquakes near Gilliam County

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

Aftershocks so far

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

  1. 2.0 4 km SE of Umatilla, Oregon
  2. 1.6 10 km ENE of Prosser, Washington
  3. 1.7 6 km E of Wallula, Washington
  4. 2.2 4 km SE of Benton City, Washington
  5. 1.8 3 km N of Highland, Washington
  6. 1.6 6 km W of Highland, Washington
  7. 1.7 9 km ESE of Echo, Oregon
  8. 1.8 4 km SSW of West Richland, Washington
  9. 1.9 11 km WNW of Highland, Washington
  10. 1.7 14 km S of Benton City, Washington
  11. 2.8 4 km S of Richland, Washington
  12. 1.9 3 km WNW of Pendleton, Oregon
  13. 1.7 4 km SSW of West Richland, Washington
  14. 1.7 5 km ENE of Prosser, Washington
  15. 1.6 4 km ENE of Prosser, 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.