QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

3 km NW of Elkhorn, Montana

· 11 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Jefferson County 20 kmBroadwater County 37 kmSilver Bow County 69 kmMeagher County 87 kmDeer Lodge County 92 kmPowell County 95 kmLewis and Clark County 97 kmGallatin County 107 kmMadison County 108 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 2.1 (ml)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Jefferson County, 20 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1446 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 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 46.2950, -111.9791. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Jefferson County, MT 20 km (12 mi) NNE of here earthquakes near Jefferson County
Broadwater County, MT 37 km (23 mi) W of here earthquakes near Broadwater County
Silver Bow County, MT 69 km (43 mi) NE of here earthquakes near Silver Bow County
Meagher County, MT 87 km (54 mi) WSW of here earthquakes near Meagher County
Deer Lodge County, MT 92 km (57 mi) ENE of here earthquakes near Deer Lodge County
Powell County, MT 95 km (59 mi) SE of here earthquakes near Powell County

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

Aftershocks so far

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

  1. 1.7 6 km WSW of Townsend, Montana
  2. 1.8 5 km E of Butte, Montana
  3. 1.9 Western Montana
  4. 1.9 5 km E of Butte, Montana
  5. 1.8 5 km E of Butte, Montana
  6. 1.9 6 km E of Butte, Montana
  7. 2.0 5 km E of Butte, Montana
  8. 1.7 5 km E of Butte, Montana
  9. 1.5 2 km NW of Montana City, Montana
  10. 1.8 5 km E of Butte, Montana
  11. 2.4 12 km E of Elkhorn, Montana
  12. 1.9 6 km ENE of Butte, Montana
  13. 1.8 5 km E of Butte, Montana
  14. 2.1 5 km ENE of Butte, Montana
  15. 1.6 4 km E 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.