QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

3 km NE of Boulder, Montana

· 5.0 km deep · released about 480 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Jefferson County 15 kmBroadwater County 46 kmSilver Bow County 60 kmDeer Lodge County 84 kmPowell County 92 kmMeagher County 96 kmLewis and Clark County 99 kmGranite County 104 kmMadison County 104 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
5.0 km below the surface
Felt
9 reports · strongest reported intensity IV
Nearest
Jefferson County, 15 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2271 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 9 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 46.2575, -112.0823. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Jefferson County, MT 15 km (9 mi) N of here earthquakes near Jefferson County
Broadwater County, MT 46 km (28 mi) W of here earthquakes near Broadwater County
Silver Bow County, MT 60 km (37 mi) NE of here earthquakes near Silver Bow County
Deer Lodge County, MT 84 km (52 mi) ENE of here earthquakes near Deer Lodge County
Powell County, MT 92 km (57 mi) SE of here earthquakes near Powell County
Meagher County, MT 96 km (60 mi) WSW of here earthquakes near Meagher 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. 1.7 4 km ENE of Butte, Montana
  2. 1.9 5 km ENE of Butte, Montana
  3. 1.6 4 km E of Butte, Montana
  4. 1.8 5 km E of Butte, Montana
  5. 1.8 5 km ENE of Butte, Montana
  6. 2.1 5 km ENE of Butte, Montana
  7. 1.7 5 km ENE of Butte, Montana
  8. 1.6 5 km E of Butte, Montana
  9. 1.6 4 km E of Butte, Montana
  10. 1.5 5 km E of Butte, Montana
  11. 2.0 11 km SSW of Radersburg, Montana
  12. 1.6 5 km ENE of Butte, Montana
  13. 1.5 5 km E of Butte, Montana
  14. 2.0 5 km ENE of Butte, Montana
  15. 1.9 5 km ENE 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.

On USGS

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