QuakeIndex

mining explosion · reviewed by a seismologist

M 2.9ml

10 km SSE of Colstrip, Montana

· 0.0 km deep · released about 680 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Rosebud County 42 kmTreasure County 73 kmBig Horn County 86 kmPowder River County 90 kmCuster County 94 kmSheridan County 116 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
0.0 km below the surface
Felt
no reports yet
Nearest
Rosebud County, 42 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 380 days ago

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

USGS catalogues this as mining explosion, not an earthquake.

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 45.7983, -106.5642. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Rosebud County, MT 42 km (26 mi) S of here earthquakes near Rosebud County
Treasure County, MT 73 km (45 mi) SE of here earthquakes near Treasure County
Big Horn County, MT 86 km (53 mi) ENE of here earthquakes near Big Horn County
Powder River County, MT 90 km (56 mi) WNW of here earthquakes near Powder River County
Custer County, MT 94 km (58 mi) WSW of here earthquakes near Custer County
Sheridan County, WY 116 km (72 mi) NNE of here earthquakes near Sheridan County

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

Aftershocks so far

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

  1. 3.0 18 km WSW of Colstrip, Montana
  2. 3.0 9 km WSW of Colstrip, Montana
  3. 2.8 13 km W of Colstrip, Montana
  4. 3.2 12 km NW of Colstrip, Montana
  5. 3.0 14 km W of Colstrip, Montana
  6. 3.2 19 km N of Colstrip, Montana
  7. 3.0 16 km W of Colstrip, Montana
  8. 3.1 11 km SW of Colstrip, Montana
  9. 3.2 17 km SW of Colstrip, Montana
  10. 3.3 12 km SW of Colstrip, Montana

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.