QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

16 km SSE of Swan Lake, Montana

· 16 km deep · released about 1.3 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 27 kmFlathead County 60 kmMissoula County 84 kmSanders County 104 kmTeton County 113 kmGlacier 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 3.3 (ml)
Depth
16 km below the surface
Felt
8 reports · strongest reported intensity IV
Nearest
Lake County, 27 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1411 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 8 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.8× more

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 47.7810, -113.7888. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lake County, MT 27 km (17 mi) NE of here earthquakes near Lake County
Flathead County, MT 60 km (38 mi) SSE of here earthquakes near Flathead County
Missoula County, MT 84 km (52 mi) N of here earthquakes near Missoula County
Sanders County, MT 104 km (65 mi) E of here earthquakes near Sanders County
Teton County, MT 113 km (70 mi) W of here earthquakes near Teton County
Glacier County, MT 119 km (74 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

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

  1. 2.1 20 km E of Finley Point, Montana
  2. 1.8 17 km E of Condon, Montana
  3. 1.7 19 km E of Finley Point, Montana
  4. 1.6 16 km NNE of Condon, Montana
  5. 1.6 6 km SW of Woods Bay, Montana
  6. 1.7 1 km S of Woods Bay, Montana
  7. 2.1 6 km SW of Woods Bay, Montana
  8. 1.6 6 km SW of Woods Bay, Montana
  9. 1.8 14 km WNW of Condon, Montana
  10. 2.1 27 km E of Swan Lake, Montana
  11. 2.5 24 km E of Swan Lake, Montana
  12. 2.4 27 km E of Swan Lake, Montana
  13. 2.3 10 km NNW of Swan Lake, Montana
  14. 1.7 15 km NNE of Bigfork, Montana
  15. 3.0 17 km SSE 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.