QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

22 km ENE of Seeley Lake, Montana

· 10 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Powell County 54 kmMissoula County 57 kmLewis and Clark County 67 kmLake County 75 kmTeton County 93 kmGranite County 100 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
10 km below the surface
Felt
no reports yet
Nearest
Powell County, 54 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2186 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 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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 47.2865, -113.2348. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Powell County, MT 54 km (34 mi) NNW of here earthquakes near Powell County
Missoula County, MT 57 km (36 mi) ENE of here earthquakes near Missoula County
Lewis and Clark County, MT 67 km (42 mi) WNW of here earthquakes near Lewis and Clark County
Lake County, MT 75 km (47 mi) ESE of here earthquakes near Lake County
Teton County, MT 93 km (58 mi) SW of here earthquakes near Teton County
Granite County, MT 100 km (62 mi) N of here earthquakes near Granite County

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

Aftershocks so far

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

  1. 1.8 19 km ENE of Ovando, Montana
  2. 1.5 6 km SW of Condon, Montana
  3. 1.7 10 km ESE of Ovando, Montana
  4. 1.6 15 km ESE of Condon, Montana
  5. 1.5 20 km ENE of Seeley Lake, Montana
  6. 1.9 26 km W of Augusta, Montana
  7. 1.5 39 km NNE of Ovando, Montana
  8. 1.9 17 km SSW of Condon, Montana
  9. 2.5 25 km ENE of Seeley Lake, Montana
  10. 2.0 8 km S of Condon, Montana
  11. 2.4 21 km ENE of Seeley Lake, Montana
  12. 2.2 8 km NW of Lincoln, Montana
  13. 2.2 7 km NW of Lincoln, Montana
  14. 1.6 36 km NE of Seeley Lake, Montana
  15. 2.0 40 km WSW of Augusta, 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.