QuakeIndex

explosion · reviewed by a seismologist

M 2.3ml

Earthquake near Spokane, WA

USGS: 11 km NE of Sprague, Washington

47 km (29 mi) SW of Spokane, WA

3:01 pm PDT, Aug 11, 2020 · · -0.4 km deep · released about 98 lb of TNT

10 km30 km60 km120 km N Spokane County 45 kmLincoln County 48 kmWhitman County 57 kmAdams County 63 kmBenewah County 94 kmKootenai County 94 kmLatah County 105 kmGarfield County 107 kmStevens County 114 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
3:01 pm PDT on 11 August 2020 ()
Where
46 km (29 mi) SW of Spokane, WA · earthquakes near Spokane
Magnitude
M 2.3 (ml)
Depth
-0.4 km below the surface
Felt
no reports yet
Nearest
Spokane County, 45 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2243 days ago

A magnitude 2.3 earthquake was recorded 46 km (29 mi) SW of Spokane, WA, at 3:01 pm PDT on 11 August 2020 (22:01 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Cheney, Medical Lake.

USGS catalogues this as explosion, not an earthquake.

How big was it?

This earthquake released about 98 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 150,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 110,000× the energy of this one
  3. Around the size people start to feel M 3.0 9.8× the energy of this one
  4. This earthquake M 2.3 about 98 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 47.3650, -117.8635. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Spokane County, WA 45 km (28 mi) NE earthquakes near Spokane County
Lincoln County, WA 48 km (30 mi) WNW earthquakes near Lincoln County
Whitman County, WA 57 km (35 mi) SSE earthquakes near Whitman County
Adams County, WA 63 km (39 mi) SW earthquakes near Adams County
Benewah County, ID 94 km (59 mi) E earthquakes near Benewah County
Kootenai County, ID 94 km (59 mi) ENE earthquakes near Kootenai County

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

Aftershocks so far

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

  1. 2.5 9 km NE of Sprague, Washington
  2. 1.6 10 km NNW of Airway Heights, Washington
  3. 2.1 5 km ENE of Sprague, Washington
  4. 1.8 9 km NNW of Airway Heights, Washington
  5. 2.2 9 km NNW of Airway Heights, Washington
  6. 1.5 9 km NNW of Airway Heights, Washington
  7. 2.1 6 km NE of Sprague, Washington
  8. 2.3 8 km NE of Sprague, Washington
  9. 2.2 8 km NE of Sprague, Washington
  10. 2.3 8 km NE of Sprague, Washington
  11. 1.5 8 km ENE of Four Lakes, Washington
  12. 1.9 6 km ENE of Sprague, Washington
  13. 2.2 6 km E of Sprague, Washington
  14. 2.1 4 km E of Four Lakes, Washington
  15. 2.3 8 km ENE of Sprague, 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.