QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

8 km NNW of Bigfork, Montana

· 7.1 km deep · released about 37 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Flathead County 18 kmLake County 55 kmSanders County 91 kmGlacier County 104 kmLincoln County 111 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
7.1 km below the surface
Felt
no reports yet
Nearest
Flathead County, 18 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1224 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 37 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 5.8 410,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 290,000× the energy of this one
  3. Around the size people start to feel M 3.0 26× the energy of this one
  4. This earthquake M 2.1 about 37 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 48.1385, -114.1030. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Flathead County, MT 18 km (11 mi) SSW of here earthquakes near Flathead County
Lake County, MT 55 km (34 mi) N of here earthquakes near Lake County
Sanders County, MT 91 km (56 mi) ENE of here earthquakes near Sanders County
Glacier County, MT 104 km (64 mi) SW of here earthquakes near Glacier County
Lincoln County, MT 111 km (69 mi) ESE of here earthquakes near Lincoln County
Mineral County, MT 134 km (83 mi) NNE of here earthquakes near Mineral County

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

Aftershocks so far

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

  1. 2.4 9 km SSW of Bear Dance, Montana
  2. 1.6 1 km SSW of Dayton, Montana
  3. 1.8 17 km SSE of Swan Lake, Montana
  4. 2.0 5 km SSW of West Glacier, Montana
  5. 1.8 12 km NE of Forest Hill Village, Montana
  6. 1.9 12 km ESE of Evergreen, Montana
  7. 1.6 6 km SW of Woods Bay, Montana
  8. 1.7 1 km S of Woods Bay, Montana
  9. 2.1 6 km SW of Woods Bay, Montana
  10. 1.6 6 km SW of Woods Bay, Montana
  11. 2.2 7 km WNW of Lake Mary Ronan, Montana
  12. 1.7 7 km WNW of Lake Mary Ronan, Montana
  13. 1.8 6 km WNW of Lake Mary Ronan, Montana
  14. 1.7 30 km ESE of Martin City, Montana
  15. 2.3 10 km NNW of Swan Lake, 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.