QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

19 km SE of Sula, Montana

· 1.4 km deep · released about 13 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Ravalli County 46 kmDeer Lodge County 64 kmGranite County 79 kmSilver Bow County 89 kmLemhi County 89 kmBeaverhead County 96 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
1.4 km below the surface
Felt
no reports yet
Nearest
Ravalli County, 46 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3474 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 13 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 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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 45.7295, -113.7883. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Ravalli County, MT 46 km (28 mi) SSE of here earthquakes near Ravalli County
Deer Lodge County, MT 64 km (40 mi) SW of here earthquakes near Deer Lodge County
Granite County, MT 79 km (49 mi) SSW of here earthquakes near Granite County
Silver Bow County, MT 89 km (56 mi) WSW of here earthquakes near Silver Bow County
Lemhi County, ID 89 km (56 mi) N of here earthquakes near Lemhi County
Beaverhead County, MT 96 km (60 mi) NW of here earthquakes near Beaverhead County

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

Aftershocks so far

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

  1. 2.7 10 km WNW of Wisdom, Montana
  2. 2.4 7 km W of Wisdom, Montana
  3. 1.9 6 km NW of Wisdom, Montana
  4. 1.6 4 km WSW of Wisdom, Montana
  5. 1.9 8 km WNW of Wisdom, Montana
  6. 3.4 12 km WNW of Wisdom, Montana
  7. 2.0 10 km WNW of Wisdom, Montana
  8. 1.8 21 km NNW of Wisdom, Montana
  9. 1.9 21 km NNW of Wisdom, Montana
  10. 1.7 22 km NNW of Wisdom, Montana
  11. 1.7 22 km NNW of Wisdom, Montana
  12. 1.6 22 km NNW of Wisdom, Montana
  13. 1.8 21 km NNW of Wisdom, Montana
  14. 1.6 12 km WNW of Wisdom, Montana
  15. 1.8 12 km WNW of Wisdom, 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.