QuakeIndex

explosion · reviewed by a seismologist

M 2.1ml

Earthquake near Benton City, WA

USGS: 0 km SSE of Benton City, Washington

15 km (9 mi) WSW of Richland, WA

11:17 am PDT, Jul 30, 2021 · · -0.3 km deep · released about 37 lb of TNT

10 km30 km60 km120 km N Benton County 4 kmFranklin County 54 kmWalla Walla County 77 kmMorrow County 93 kmUmatilla County 94 kmYakima County 99 kmGrant County 106 kmKlickitat County 109 kmAdams County 112 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
11:17 am PDT on 30 July 2021 ()
Where
in Benton City, WA · earthquakes near Benton City
Magnitude
M 2.1 (ml)
Depth
-0.3 km below the surface
Felt
no reports yet
Nearest
Benton County, 4 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 572 days ago

A magnitude 2.1 earthquake was recorded in Benton City, WA, at 11:17 am PDT on 30 July 2021 (18:17 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: West Richland, Richland, Tri-Cities, Prosser, West Pasco, Kennewick.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 37 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 410,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 290,000× the energy of this one
  3. Around the size people start to feel M 3.0 26× the energy of this one
  4. This earthquake M 2.1 about 37 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 46.2592, -119.4843. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Benton County, WA 4 km (3 mi) SW earthquakes near Benton County
Franklin County, WA 54 km (34 mi) NE earthquakes near Franklin County
Walla Walla County, WA 77 km (48 mi) E earthquakes near Walla Walla County
Morrow County, OR 93 km (58 mi) S earthquakes near Morrow County
Umatilla County, OR 94 km (59 mi) SE earthquakes near Umatilla County
Yakima County, WA 99 km (61 mi) WNW earthquakes near Yakima 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. 2.8 4 km S of Richland, Washington
  2. 1.7 4 km SSW of West Richland, Washington
  3. 1.7 5 km ENE of Prosser, Washington
  4. 1.6 4 km ENE of Prosser, Washington
  5. 1.6 8 km SSW of Prosser, Washington
  6. 1.7 15 km S of Mesa, Washington
  7. 1.5 8 km NE of Sunnyside, Washington
  8. 1.6 3 km ESE of Umatilla, Oregon
  9. 1.6 10 km ENE of Prosser, Washington
  10. 1.9 2 km NNW of Highland, Washington
  11. 2.1 4 km SE of Benton City, Washington
  12. 1.6 Washington
  13. 1.7 6 km SW of Highland, Washington
  14. 2.1 2 km SE of Umatilla, Oregon
  15. 1.9 4 km E of Umatilla, Oregon

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.