QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

3 km ESE of Twin Bridges, Montana

· 4.7 km deep · released about 5.4 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Madison County 37 kmSilver Bow County 50 kmBeaverhead County 65 kmJefferson County 68 kmGallatin County 87 kmDeer Lodge County 91 kmBroadwater County 107 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 1.5 (ml)
Depth
4.7 km below the surface
Felt
no reports yet
Nearest
Madison County, 37 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1673 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 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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 45.5357, -112.2858. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Madison County, MT 37 km (23 mi) NW of here earthquakes near Madison County
Silver Bow County, MT 50 km (31 mi) SE of here earthquakes near Silver Bow County
Beaverhead County, MT 65 km (40 mi) NE of here earthquakes near Beaverhead County
Jefferson County, MT 68 km (42 mi) SSW of here earthquakes near Jefferson County
Gallatin County, MT 87 km (54 mi) W of here earthquakes near Gallatin County
Deer Lodge County, MT 91 km (56 mi) SE of here earthquakes near Deer Lodge County

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

Aftershocks so far

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

  1. 2.2 30 km NNW of Dillon, Montana
  2. 2.1 3 km SE of Twin Bridges, Montana
  3. 2.3 3 km NNW of Pony, Montana
  4. 2.0 2 km NNW of Pony, Montana
  5. 2.4 13 km N of Dillon, Montana
  6. 1.6 23 km N of Dillon, Montana
  7. 2.4 8 km SSE of Pony, Montana
  8. 1.6 4 km ESE of Twin Bridges, Montana
  9. 2.4 3 km SE of Twin Bridges, Montana
  10. 1.6 13 km E of Dillon, Montana
  11. 1.5 1 km NNE of Twin Bridges, Montana
  12. 1.6 12 km NNE of Dillon, Montana
  13. 1.6 12 km NNE of Dillon, Montana
  14. 2.0 7 km SE of Pony, Montana
  15. 1.5 14 km E 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.0 on 2016-09-03 — it released about 6,200 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.