QuakeIndex

quarry blast · reviewed by a seismologist

M 2.1ml

5 km E of Butte, Montana

· -2.0 km deep · released about 44 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Silver Bow County 19 kmJefferson County 34 kmDeer Lodge County 53 kmBroadwater County 83 kmGranite County 86 kmMadison County 87 kmPowell County 100 kmBeaverhead County 102 kmGallatin County 115 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 2.1 (ml)
Depth
-2.0 km below the surface
Felt
no reports yet
Nearest
Silver Bow County, 19 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1231 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

USGS catalogues this as quarry blast, not an earthquake.

How big was it?

This earthquake released about 44 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 340,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 240,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 44 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 46.0042, -112.4662. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Silver Bow County, MT 19 km (12 mi) NE of here earthquakes near Silver Bow County
Jefferson County, MT 34 km (21 mi) WSW of here earthquakes near Jefferson County
Deer Lodge County, MT 53 km (33 mi) E of here earthquakes near Deer Lodge County
Broadwater County, MT 83 km (52 mi) WSW of here earthquakes near Broadwater County
Granite County, MT 86 km (53 mi) ESE of here earthquakes near Granite County
Madison County, MT 87 km (54 mi) NNW of here earthquakes near Madison County

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

Aftershocks so far

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

  1. 1.7 4 km E of Butte, Montana
  2. 1.6 4 km E of Butte, Montana
  3. 1.9 4 km E of Butte, Montana
  4. 1.6 Western Montana
  5. 2.0 5 km ENE of Butte, Montana
  6. 1.7 4 km E of Butte, Montana
  7. 1.7 4 km E of Butte, Montana
  8. 1.7 Western Montana
  9. 1.7 4 km E of Butte, Montana
  10. 1.9 4 km E of Butte, Montana
  11. 2.0 4 km E of Butte, Montana
  12. 1.7 Western Montana
  13. 2.4 20 km N of Twin Bridges, Montana
  14. 1.8 19 km N of Twin Bridges, Montana
  15. 1.8 Western 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 760 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.