QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

33 km WNW of Twin Bridges, Montana

· 0.6 km deep · released about 25 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Silver Bow County 32 kmBeaverhead County 54 kmDeer Lodge County 62 kmMadison County 72 kmJefferson County 78 kmGranite County 102 kmLemhi County 117 kmRavalli County 117 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 1.9 (ml)
Depth
0.6 km below the surface
Felt
no reports yet
Nearest
Silver Bow County, 32 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2941 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 420,000× the energy of this one
  3. Around the size people start to feel M 3.0 38× the energy of this one
  4. This earthquake M 1.9 about 25 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 45.6115, -112.7450. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Silver Bow County, MT 32 km (20 mi) SSW of here earthquakes near Silver Bow County
Beaverhead County, MT 54 km (34 mi) NNE of here earthquakes near Beaverhead County
Deer Lodge County, MT 62 km (38 mi) SSE of here earthquakes near Deer Lodge County
Madison County, MT 72 km (45 mi) WNW of here earthquakes near Madison County
Jefferson County, MT 78 km (48 mi) SW of here earthquakes near Jefferson County
Granite County, MT 102 km (63 mi) SSE of here earthquakes near Granite County

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

Aftershocks so far

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

  1. 1.7 5 km E of Butte, Montana
  2. 1.7 3 km ESE of Butte, Montana
  3. 1.9 5 km ENE of Butte, Montana
  4. 1.6 5 km ENE of Butte, Montana
  5. 2.0 17 km NNE of Dillon, Montana
  6. 1.8 4 km ENE of Butte, Montana
  7. 2.2 6 km E of Butte, Montana
  8. 1.9 5 km E of Butte, Montana
  9. 1.7 3 km E of Butte, Montana
  10. 1.9 3 km E of Butte, Montana
  11. 1.7 6 km E of Butte, Montana
  12. 1.6 4 km E of Butte, Montana
  13. 1.9 5 km E of Butte, Montana
  14. 1.8 5 km E of Butte, Montana
  15. 1.8 Western 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.