QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

28 km WNW of Dillon, Montana

· 3.0 km deep · released about 10 lb of TNT

10 km30 km60 km120 km N Beaverhead County 23 kmSilver Bow County 66 kmMadison County 81 kmDeer Lodge County 85 kmLemhi County 86 kmJefferson County 112 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 1.7 (ml)
Depth
3.0 km below the surface
Felt
no reports yet
Nearest
Beaverhead County, 23 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1090 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 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 92× the energy of this one
  4. This earthquake M 1.7 about 10 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 45.3382, -112.9517. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Beaverhead County, MT 23 km (14 mi) NNW of here earthquakes near Beaverhead County
Silver Bow County, MT 66 km (41 mi) SSW of here earthquakes near Silver Bow County
Madison County, MT 81 km (50 mi) W of here earthquakes near Madison County
Deer Lodge County, MT 85 km (53 mi) S of here earthquakes near Deer Lodge County
Lemhi County, ID 86 km (54 mi) ENE of here earthquakes near Lemhi County
Jefferson County, MT 112 km (69 mi) SW of here earthquakes near Jefferson County

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

Aftershocks so far

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

  1. 2.0 13 km N of Dillon, Montana
  2. 1.6 11 km NNE of Dillon, Montana
  3. 2.5 9 km NNE of Dillon, Montana
  4. 1.5 14 km NNE of Dillon, Montana
  5. 2.5 10 km NNE of Dillon, Montana
  6. 1.8 27 km SW of Dillon, Montana
  7. 1.6 16 km SSW of Dillon, Montana
  8. 1.5 12 km N of Dillon, Montana
  9. 1.7 17 km NNE of Dillon, Montana
  10. 2.2 30 km NNW of Dillon, Montana
  11. 1.9 37 km SW of Dillon, Montana
  12. 2.4 13 km N of Dillon, Montana
  13. 1.6 23 km N of Dillon, Montana
  14. 1.6 13 km E of Dillon, Montana
  15. 1.6 12 km NNE of Dillon, 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.