QuakeIndex

quarry blast · reviewed by a seismologist

M 1.9ml

5 km NNW of Logan, Montana

· -2.0 km deep · released about 21 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Broadwater County 45 kmGallatin County 51 kmJefferson County 52 kmMadison County 76 kmMeagher County 84 kmPark County 88 kmSilver Bow County 94 kmSweet Grass 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 1.9 (ml)
Depth
-2.0 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Broadwater County, 45 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2767 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 1 person has reported feeling it to USGS.

USGS catalogues this as quarry blast, not an earthquake.

How big was it?

This earthquake released about 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 730,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 520,000× the energy of this one
  3. Around the size people start to feel M 3.0 46× the energy of this one
  4. This earthquake M 1.9 about 21 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 45.9300, -111.4513. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Broadwater County, MT 45 km (28 mi) S of here earthquakes near Broadwater County
Gallatin County, MT 51 km (32 mi) NNW of here earthquakes near Gallatin County
Jefferson County, MT 52 km (32 mi) ESE of here earthquakes near Jefferson County
Madison County, MT 76 km (47 mi) NNE of here earthquakes near Madison County
Meagher County, MT 84 km (52 mi) SSW of here earthquakes near Meagher County
Park County, MT 88 km (55 mi) NW of here earthquakes near Park County

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

Aftershocks so far

57 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.