QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

17 km WNW of Twin Bridges, Montana

· 4.6 km deep · released about 12 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Silver Bow County 34 kmMadison County 58 kmBeaverhead County 60 kmJefferson County 68 kmDeer Lodge County 72 kmGallatin County 107 kmGranite County 111 kmBroadwater County 114 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
4.6 km below the surface
Felt
no reports yet
Nearest
Silver Bow County, 34 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3207 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 12 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 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 870,000× the energy of this one
  3. Around the size people start to feel M 3.0 78× the energy of this one
  4. This earthquake M 1.7 about 12 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 45.6072, -112.5373. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Silver Bow County, MT 34 km (21 mi) SSE of here earthquakes near Silver Bow County
Madison County, MT 58 km (36 mi) WNW of here earthquakes near Madison County
Beaverhead County, MT 60 km (37 mi) NNE of here earthquakes near Beaverhead County
Jefferson County, MT 68 km (42 mi) SSW of here earthquakes near Jefferson County
Deer Lodge County, MT 72 km (45 mi) SE of here earthquakes near Deer Lodge County
Gallatin County, MT 107 km (67 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

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

  1. 1.6 4 km E of Butte, Montana
  2. 1.5 4 km ENE of Butte, Montana
  3. 1.7 5 km E of Butte, Montana
  4. 1.9 5 km E of Butte, Montana
  5. 1.6 5 km ENE of Butte, Montana
  6. 1.9 33 km WNW of Twin Bridges, Montana
  7. 1.7 17 km S of Whitehall, Montana
  8. 1.9 5 km ESE of Walkerville, Montana
  9. 1.6 5 km E of Butte, Montana
  10. 1.5 5 km ESE of Walkerville, Montana
  11. 1.7 5 km W of Butte, MT
  12. 1.6 13 km WNW of Whitehall, Montana
  13. 1.5 5 km ESE of Walkerville, Montana
  14. 1.7 8 km SSW of Dillon, MT
  15. 2.4 4 km E of Walkerville, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.0 on 2016-09-03 — it released about 2,700 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.