QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

3 km S of Alberton, Montana

· 14 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Missoula County 45 kmMineral County 49 kmLake County 81 kmClearwater County 95 kmSanders County 102 kmGranite County 103 kmRavalli County 103 kmShoshone County 114 kmPowell County 119 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
14 km below the surface
Felt
no reports yet
Nearest
Missoula County, 45 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 414 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 43 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 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× 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 43 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 46.9708, -114.4817. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Missoula County, MT 45 km (28 mi) W of here earthquakes near Missoula County
Mineral County, MT 49 km (30 mi) ESE of here earthquakes near Mineral County
Lake County, MT 81 km (50 mi) SSW of here earthquakes near Lake County
Clearwater County, ID 95 km (59 mi) ENE of here earthquakes near Clearwater County
Sanders County, MT 102 km (63 mi) SSE of here earthquakes near Sanders County
Granite County, MT 103 km (64 mi) NW of here earthquakes near Granite County

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

Aftershocks so far

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

  1. 1.9 2 km NNE of Alberton, Montana
  2. 1.5 6 km S of Frenchtown, Montana
  3. 1.7 6 km S of Frenchtown, Montana
  4. 1.9 6 km S of Huson, Montana
  5. 1.9 3 km SSW of Alberton, Montana
  6. 1.7 2 km ENE of Alberton, Montana
  7. 2.2 2 km NE of Alberton, Montana
  8. 1.7 4 km WNW of Wye, Montana
  9. 1.7 4 km SSW of Alberton, 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.