QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

11 km S of Elkhorn, Montana

· 7.5 km deep · released about 19 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Jefferson County 11 kmBroadwater County 38 kmSilver Bow County 64 kmMeagher County 91 kmDeer Lodge County 93 kmMadison County 94 kmGallatin County 95 kmPowell County 106 kmLewis and Clark County 111 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
7.5 km below the surface
Felt
no reports yet
Nearest
Jefferson County, 11 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 845 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 19 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 810,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 580,000× the energy of this one
  3. Around the size people start to feel M 3.0 51× the energy of this one
  4. This earthquake M 1.9 about 19 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 46.1747, -111.9410. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Jefferson County, MT 11 km (7 mi) ENE of here earthquakes near Jefferson County
Broadwater County, MT 38 km (24 mi) WSW of here earthquakes near Broadwater County
Silver Bow County, MT 64 km (39 mi) ENE of here earthquakes near Silver Bow County
Meagher County, MT 91 km (56 mi) WSW of here earthquakes near Meagher County
Deer Lodge County, MT 93 km (58 mi) E of here earthquakes near Deer Lodge County
Madison County, MT 94 km (59 mi) N of here earthquakes near Madison County

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

Aftershocks so far

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

  1. 1.8 5 km ENE of Butte, Montana
  2. 1.7 5 km ENE of Butte, Montana
  3. 1.5 6 km E of Butte, Montana
  4. 1.6 6 km E of Butte, Montana
  5. 2.2 1 km NW of East Helena, Montana
  6. 1.6 4 km ENE of Butte, Montana
  7. 1.5 10 km NNE of Three Forks, Montana
  8. 1.6 5 km ENE of Butte, Montana
  9. 1.8 4 km WNW of Ponderosa Pines, Montana
  10. 1.6 8 km W of Townsend, Montana
  11. 1.6 5 km ENE of Butte, Montana
  12. 1.8 5 km E of Butte, Montana
  13. 2.2 11 km S of Radersburg, Montana
  14. 1.6 5 km E of Butte, Montana
  15. 1.5 5 km ENE of Butte, 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.