QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

7 km WSW of Willow Creek, Montana

· 1.8 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Jefferson County 44 kmGallatin County 54 kmMadison County 54 kmBroadwater County 62 kmSilver Bow County 73 kmPark County 100 kmMeagher County 107 kmDeer Lodge County 114 kmBeaverhead County 117 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
1.8 km below the surface
Felt
no reports yet
Nearest
Jefferson County, 44 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2029 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 45.7980, -111.7305. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Jefferson County, MT 44 km (28 mi) SE of here earthquakes near Jefferson County
Gallatin County, MT 54 km (34 mi) NW of here earthquakes near Gallatin County
Madison County, MT 54 km (34 mi) NNE of here earthquakes near Madison County
Broadwater County, MT 62 km (38 mi) SSW of here earthquakes near Broadwater County
Silver Bow County, MT 73 km (45 mi) E of here earthquakes near Silver Bow County
Park County, MT 100 km (62 mi) WNW of here earthquakes near Park County

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

Aftershocks so far

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

  1. 1.6 11 km NNE of Ennis, Montana
  2. 1.7 3 km NNE of Logan, Montana
  3. 1.5 5 km SW of Manhattan, Montana
  4. 2.1 2 km WSW of Logan, Montana
  5. 1.8 5 km NW of Logan, Montana
  6. 1.7 1 km ENE of Churchill, Montana
  7. 2.0 4 km W of Three Forks, Montana
  8. 2.2 20 km W of Pony, Montana
  9. 1.9 7 km NNE of Manhattan, Montana
  10. 1.5 8 km S of Harrison, Montana
  11. 3.1 6 km NNW of Three Forks, Montana
  12. 2.3 Western Montana
  13. 2.3 3 km NW of Three Forks, Montana
  14. 2.1 3 km NNW of Three Forks, Montana
  15. 2.0 3 km NNW of Three Forks, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.2 on 2019-08-16 — it released about 4,300 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.