QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

2 km S of Turah, Montana

· 8.5 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Missoula County 24 kmGranite County 56 kmPowell County 68 kmRavalli County 85 kmLake County 94 kmDeer Lodge County 96 kmMineral County 101 kmLewis and Clark County 115 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 1.8 (ml)
Depth
8.5 km below the surface
Felt
no reports yet
Nearest
Missoula County, 24 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1151 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 14 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 46.8167, -113.8302. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Missoula County, MT 24 km (15 mi) SSE of here earthquakes near Missoula County
Granite County, MT 56 km (35 mi) NNW of here earthquakes near Granite County
Powell County, MT 68 km (43 mi) W of here earthquakes near Powell County
Ravalli County, MT 85 km (53 mi) NNE of here earthquakes near Ravalli County
Lake County, MT 94 km (58 mi) SSE of here earthquakes near Lake County
Deer Lodge County, MT 96 km (60 mi) NNW of here earthquakes near Deer Lodge County

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

Aftershocks so far

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

  1. 1.5 6 km S of Frenchtown, Montana
  2. 1.7 6 km S of Frenchtown, Montana
  3. 1.9 6 km S of Huson, Montana
  4. 1.7 4 km WNW of Wye, Montana
  5. 2.9 22 km WSW of Ovando, Montana
  6. 2.7 6 km SSE of Seeley Lake, Montana
  7. 1.9 6 km SSE of Seeley Lake, Montana
  8. 1.5 12 km SW of Seeley Lake, Montana
  9. 1.8 17 km E of Arlee, 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.