QuakeIndex

Earthquake · reviewed by a seismologist

M 3.7ml

5 km NW of Clancy, Montana

· 6.9 km deep · released about 4.8 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Jefferson County 42 kmBroadwater County 45 kmLewis and Clark County 74 kmPowell County 78 kmSilver Bow County 83 kmMeagher County 86 kmDeer Lodge County 96 kmCascade County 104 kmGranite County 107 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 3.7 (ml)
Depth
6.9 km below the surface
Felt
no reports yet
Measured shaking
intensity IV (ShakeMap)
Nearest
Jefferson County, 42 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1512 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 4.8 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 35,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,100× the energy of this one
  4. This earthquake M 3.7 about 4.8 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 10× more

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 46.5037, -112.0352. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Jefferson County, MT 42 km (26 mi) N of here earthquakes near Jefferson County
Broadwater County, MT 45 km (28 mi) WNW of here earthquakes near Broadwater County
Lewis and Clark County, MT 74 km (46 mi) SSE of here earthquakes near Lewis and Clark County
Powell County, MT 78 km (49 mi) ESE of here earthquakes near Powell County
Silver Bow County, MT 83 km (52 mi) NE of here earthquakes near Silver Bow County
Meagher County, MT 86 km (53 mi) W of here earthquakes near Meagher County

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

Aftershocks so far

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

  1. 3.8 4 km ESE of Avon, Montana
  2. 3.4 9 km ENE of Marysville, Montana
  3. 2.0 2 km NE of The Silos, Montana
  4. 2.2 2 km NE of The Silos, Montana
  5. 1.8 21 km SW of Craig, Montana
  6. 1.6 22 km NE of Helena Valley Northeast, Montana
  7. 1.6 3 km NNW of Helena Valley Northwest, Montana
  8. 1.5 2 km NE of South Hills, Montana
  9. 1.5 3 km NW of Helena Valley Northwest, Montana
  10. 1.6 7 km WSW of Elliston, Montana
  11. 1.7 2 km ENE of South Hills, Montana
  12. 1.7 9 km NW of Radersburg, Montana
  13. 2.7 8 km WSW of Elliston, MT
  14. 1.8 7 km WSW of Elliston, Montana
  15. 1.8 12 km N of Helena Valley Northeast, 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

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