QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

15 km NNE of Dillon, Montana

· 8.9 km deep · released about 1,400 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Beaverhead County 35 kmMadison County 49 kmSilver Bow County 63 kmJefferson County 95 kmDeer Lodge County 96 kmGallatin County 110 kmLemhi County 115 kmClark County 118 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 3.1 (ml)
Depth
8.9 km below the surface
Felt
8 reports · strongest reported intensity III
Nearest
Beaverhead County, 35 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1962 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 8 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1,400 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 240,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,700× the energy of this one
  4. This earthquake M 3.1 about 1,400 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.5× more

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 45.3385, -112.5460. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Beaverhead County, MT 35 km (22 mi) NE of here earthquakes near Beaverhead County
Madison County, MT 49 km (31 mi) W of here earthquakes near Madison County
Silver Bow County, MT 63 km (39 mi) S of here earthquakes near Silver Bow County
Jefferson County, MT 95 km (59 mi) SSW of here earthquakes near Jefferson County
Deer Lodge County, MT 96 km (60 mi) SSE of here earthquakes near Deer Lodge County
Gallatin County, MT 110 km (68 mi) W of here earthquakes near Gallatin County

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

Aftershocks so far

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

  1. 2.6 15 km N of Dillon, Montana
  2. 2.0 34 km SE of Dillon, Montana
  3. 1.7 29 km WSW of Dillon, Montana
  4. 1.7 28 km WSW of Dillon, Montana
  5. 2.0 28 km WSW of Dillon, Montana
  6. 1.9 33 km WNW of Twin Bridges, Montana
  7. 1.7 8 km SSW of Dillon, MT
  8. 2.8 8 km NE of Alder, Montana
  9. 1.9 23 km NNW of Dillon, Montana
  10. 1.6 16 km ESE of Dillon, Montana
  11. 2.3 16 km NNE of Dillon, Montana
  12. 1.8 14 km NW of Twin Bridges, Montana
  13. 2.0 18 km N of Dillon, Montana
  14. 1.7 17 km WNW of Twin Bridges, Montana
  15. 2.1 13 km N 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.