QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9ml

4 km N of Elmo, Montana

· 12 km deep · released about 680 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 32 kmFlathead County 52 kmSanders County 63 kmMineral County 99 kmMissoula County 100 kmLincoln County 112 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 2.9 (ml)
Depth
12 km below the surface
Felt
20 reports · strongest reported intensity III
Nearest
Lake County, 32 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1394 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 20 people have reported feeling it to USGS.

How big was it?

This earthquake released about 680 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 22,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 16,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.4× the energy of this one
  4. This earthquake M 2.9 about 680 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 47.8686, -114.3535. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lake County, MT 32 km (20 mi) NW of here earthquakes near Lake County
Flathead County, MT 52 km (33 mi) SSW of here earthquakes near Flathead County
Sanders County, MT 63 km (39 mi) ENE of here earthquakes near Sanders County
Mineral County, MT 99 km (61 mi) NNE of here earthquakes near Mineral County
Missoula County, MT 100 km (62 mi) NNW of here earthquakes near Missoula County
Lincoln County, MT 112 km (70 mi) SE of here earthquakes near Lincoln County

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

Aftershocks so far

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

  1. 1.7 19 km SW of Marion, Montana
  2. 2.3 18 km SW of Marion, Montana
  3. 2.0 19 km SW of Marion, Montana
  4. 2.4 9 km SSW of Bear Dance, Montana
  5. 1.6 1 km SSW of Dayton, Montana
  6. 1.8 12 km NE of Forest Hill Village, Montana
  7. 2.0 15 km ENE of Ronan, Montana
  8. 1.9 12 km ESE of Evergreen, Montana
  9. 1.6 6 km SW of Woods Bay, Montana
  10. 1.7 1 km S of Woods Bay, Montana
  11. 2.1 6 km SW of Woods Bay, Montana
  12. 1.6 6 km SW of Woods Bay, Montana
  13. 2.2 7 km WNW of Lake Mary Ronan, Montana
  14. 1.7 7 km WNW of Lake Mary Ronan, Montana
  15. 1.8 6 km WNW of Lake Mary Ronan, 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.