QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

24 km E of Swan Lake, Montana

· 10 km deep · released about 170 lb of TNT

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10 km30 km60 km120 km N Lake County 53 kmFlathead County 57 kmTeton County 93 kmGlacier County 95 kmPondera County 102 kmMissoula County 103 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 2.5 (ml)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Lake County, 53 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 758 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.6× the energy of this one
  4. This earthquake M 2.5 about 170 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 47.9219, -113.5167. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lake County, MT 53 km (33 mi) NE of here earthquakes near Lake County
Flathead County, MT 57 km (36 mi) SE of here earthquakes near Flathead County
Teton County, MT 93 km (58 mi) W of here earthquakes near Teton County
Glacier County, MT 95 km (59 mi) SSW of here earthquakes near Glacier County
Pondera County, MT 102 km (63 mi) WSW of here earthquakes near Pondera County
Missoula County, MT 103 km (64 mi) NNE of here earthquakes near Missoula County

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

Aftershocks so far

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

  1. 2.4 9 km SSW of Bear Dance, Montana
  2. 1.8 17 km SSE of Swan Lake, Montana
  3. 1.6 40 km ENE of Condon, Montana
  4. 2.0 15 km ENE of Ronan, Montana
  5. 1.7 20 km E of Finley Point, Montana
  6. 1.6 20 km E of Finley Point, Montana
  7. 1.6 20 km E of Finley Point, Montana
  8. 2.1 20 km E of Finley Point, Montana
  9. 1.8 17 km E of Condon, Montana
  10. 1.7 19 km E of Finley Point, Montana
  11. 1.6 16 km NNE of Condon, Montana
  12. 1.7 1 km S of Woods Bay, Montana
  13. 1.8 14 km WNW of Condon, Montana
  14. 1.7 30 km ESE of Martin City, Montana
  15. 2.1 27 km E 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.