QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3ml

14 km SSE of Swan Lake, Montana

· 4.2 km deep · released about 91 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 31 kmFlathead County 58 kmMissoula County 88 kmSanders County 107 kmTeton County 110 kmGlacier County 114 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
4.2 km below the surface
Felt
no reports yet
Nearest
Lake County, 31 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2335 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 91 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 10× the energy of this one
  4. This earthquake M 2.3 about 91 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 47.8147, -113.7535. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lake County, MT 31 km (19 mi) NE of here earthquakes near Lake County
Flathead County, MT 58 km (36 mi) SSE of here earthquakes near Flathead County
Missoula County, MT 88 km (55 mi) N of here earthquakes near Missoula County
Sanders County, MT 107 km (66 mi) E of here earthquakes near Sanders County
Teton County, MT 110 km (68 mi) W of here earthquakes near Teton County
Glacier County, MT 114 km (71 mi) SSW of here earthquakes near Glacier County

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

Aftershocks so far

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

  1. 1.8 12 km NE of Forest Hill Village, Montana
  2. 2.0 15 km ENE of Ronan, Montana
  3. 1.7 20 km E of Finley Point, Montana
  4. 1.6 20 km E of Finley Point, Montana
  5. 1.6 20 km E of Finley Point, Montana
  6. 2.1 20 km E of Finley Point, Montana
  7. 1.8 17 km E of Condon, Montana
  8. 1.7 19 km E of Finley Point, Montana
  9. 1.9 12 km ESE of Evergreen, Montana
  10. 1.6 16 km NNE of Condon, Montana
  11. 1.6 6 km SW of Woods Bay, Montana
  12. 1.7 1 km S of Woods Bay, Montana
  13. 2.1 6 km SW of Woods Bay, Montana
  14. 1.6 6 km SW of Woods Bay, Montana
  15. 1.8 14 km WNW of Condon, 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.