QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

Western Montana

· 17 km deep · released about 480 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Silver Bow County 37 kmMadison County 53 kmBeaverhead County 59 kmJefferson County 69 kmDeer Lodge County 76 kmGallatin County 104 kmBroadwater County 113 kmGranite County 116 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 2.8 (ml)
Depth
17 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Silver Bow County, 37 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2037 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 2 people have reported feeling it to USGS.

How big was it?

This earthquake released about 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
  3. Around the size people start to feel M 3.0 2× the energy of this one
  4. This earthquake M 2.8 about 480 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 45.5857, -112.4902. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Silver Bow County, MT 37 km (23 mi) SSE of here earthquakes near Silver Bow County
Madison County, MT 53 km (33 mi) WNW of here earthquakes near Madison County
Beaverhead County, MT 59 km (37 mi) NNE of here earthquakes near Beaverhead County
Jefferson County, MT 69 km (43 mi) SSW of here earthquakes near Jefferson County
Deer Lodge County, MT 76 km (47 mi) SE of here earthquakes near Deer Lodge County
Gallatin County, MT 104 km (64 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. 1.8 6 km SE of Butte, Montana
  2. 1.8 5 km E of Butte, Montana
  3. 1.6 17 km ESE of Dillon, Montana
  4. 1.7 10 km SW of Twin Bridges, Montana
  5. 1.7 17 km ESE of Dillon, Montana
  6. 1.9 5 km ENE of Butte, Montana
  7. 1.6 17 km ESE of Dillon, Montana
  8. 2.0 5 km ENE of Butte, Montana
  9. 1.9 4 km E of Butte, Montana
  10. 1.5 2 km NW of Alder, Montana
  11. 1.7 3 km NW of Alder, Montana
  12. 2.1 4 km NNW of Alder, Montana
  13. 2.2 3 km NW of Alder, Montana
  14. 1.6 5 km ENE of Butte, Montana
  15. 1.8 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.0 on 2016-09-03 — it released about 70 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.