QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

11 km NNE of Three Forks, Montana

· 12 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Broadwater County 38 kmJefferson County 45 kmGallatin County 59 kmMeagher County 80 kmMadison County 80 kmSilver Bow County 90 kmPark 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
12 km below the surface
Felt
no reports yet
Nearest
Broadwater County, 38 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2770 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 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× 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 45.9907, -111.5073. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Broadwater County, MT 38 km (23 mi) S of here earthquakes near Broadwater County
Jefferson County, MT 45 km (28 mi) ESE of here earthquakes near Jefferson County
Gallatin County, MT 59 km (37 mi) NNW of here earthquakes near Gallatin County
Meagher County, MT 80 km (50 mi) SW of here earthquakes near Meagher County
Madison County, MT 80 km (50 mi) NNE of here earthquakes near Madison County
Silver Bow County, MT 90 km (56 mi) E of here earthquakes near Silver Bow County

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

Aftershocks so far

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

  1. 1.6 7 km SSW of The Silos, Montana
  2. 1.7 3 km WNW of Manhattan, Montana
  3. 1.6 4 km N of Logan, Montana
  4. 2.0 11 km W of Sedan, Montana
  5. 2.4 2 km WNW of Manhattan, Montana
  6. 1.5 1 km WNW of Manhattan, Montana
  7. 1.7 1 km W of Manhattan, Montana
  8. 1.6 2 km WNW of Manhattan, Montana
  9. 2.3 2 km WNW of Manhattan, Montana
  10. 1.7 2 km WNW of Manhattan, Montana
  11. 1.8 6 km SSW of The Silos, Montana
  12. 2.4 1 km WNW of Manhattan, Montana
  13. 1.6 3 km WNW of Manhattan, Montana
  14. 2.7 2 km WNW of Manhattan, Montana
  15. 1.5 9 km SSW of Elkhorn, 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.