QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9ml

45 km W of Biddle, Montana

· 16 km deep · released about 680 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Powder River County 46 kmSheridan County 82 kmCampbell County 104 kmCrook County 120 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
Magnitude
M 2.9 (ml)
Depth
16 km below the surface
Felt
no reports yet
Nearest
Powder River County, 46 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2958 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.4× the energy of this one
  4. This earthquake M 2.9 about 680 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.

Where

Epicentre 45.0801, -105.9220. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Powder River County, MT 46 km (29 mi) SW of here earthquakes near Powder River County
Sheridan County, WY 82 km (51 mi) ENE of here earthquakes near Sheridan County
Campbell County, WY 104 km (65 mi) NNW of here earthquakes near Campbell County
Crook County, WY 120 km (75 mi) WNW of here earthquakes near Crook County
Carter County, MT 120 km (75 mi) WSW of here earthquakes near Carter County
Johnson County, WY 127 km (79 mi) NNE of here earthquakes near Johnson County

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

Aftershocks so far

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

  1. 2.8 9 km SW of Broadus, Montana
  2. 2.8 38 km N of Arvada, Wyoming
  3. 3.1 18 km NNE of Arvada, Wyoming

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.