QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3ml

10 km NNW of Swan Lake, Montana

· 11 km deep · released about 88 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Flathead County 33 kmLake County 45 kmGlacier County 100 kmSanders County 102 kmMissoula 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 2.3 (ml)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Flathead County, 33 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 875 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 88 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 170,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 120,000× the energy of this one
  3. Around the size people start to feel M 3.0 11× the energy of this one
  4. This earthquake M 2.3 about 88 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 48.0252, -113.8763. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Flathead County, MT 33 km (20 mi) SSE of here earthquakes near Flathead County
Lake County, MT 45 km (28 mi) NNE of here earthquakes near Lake County
Glacier County, MT 100 km (62 mi) SW of here earthquakes near Glacier County
Sanders County, MT 102 km (63 mi) ENE of here earthquakes near Sanders County
Missoula County, MT 111 km (69 mi) N of here earthquakes near Missoula County
Teton County, MT 121 km (75 mi) WNW of here earthquakes near Teton County

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

Aftershocks so far

20 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. 1.7 20 km E of Finley Point, Montana
  7. 1.6 20 km E of Finley Point, Montana
  8. 1.6 20 km E of Finley Point, Montana
  9. 2.1 20 km E of Finley Point, Montana
  10. 1.7 19 km E of Finley Point, Montana
  11. 1.9 12 km ESE of Evergreen, Montana
  12. 1.6 16 km NNE of Condon, Montana
  13. 1.6 6 km SW of Woods Bay, Montana
  14. 1.7 1 km S of Woods Bay, Montana
  15. 2.1 6 km SW of Woods Bay, 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.