QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

10 km E of Cardwell, Montana

· 11 km deep · released about 13 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Jefferson County 34 kmBroadwater County 57 kmMadison County 60 kmGallatin County 64 kmSilver Bow County 65 kmDeer Lodge County 105 kmMeagher County 106 kmPark County 109 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
11 km below the surface
Felt
no reports yet
Nearest
Jefferson County, 34 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3387 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 45.8640, -111.8182. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Jefferson County, MT 34 km (21 mi) SSE of here earthquakes near Jefferson County
Broadwater County, MT 57 km (36 mi) SSW of here earthquakes near Broadwater County
Madison County, MT 60 km (38 mi) N of here earthquakes near Madison County
Gallatin County, MT 64 km (40 mi) NW of here earthquakes near Gallatin County
Silver Bow County, MT 65 km (41 mi) E of here earthquakes near Silver Bow County
Deer Lodge County, MT 105 km (66 mi) ESE of here earthquakes near Deer Lodge 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. 1.5 1 km WNW of Manhattan, Montana
  2. 1.5 2 km WNW of Manhattan, Montana
  3. 2.8 5 km SSE of Logan, Montana
  4. 1.6 2 km WNW of Manhattan, Montana
  5. 2.5 4 km NW of Manhattan, Montana
  6. 3.3 3 km WSW of Manhattan, Montana
  7. 2.2 0 km E of Manhattan, Montana
  8. 1.5 2 km WNW of Manhattan, Montana
  9. 2.2 2 km WNW of Manhattan, Montana
  10. 1.8 7 km WSW of Townsend, Montana
  11. 1.5 1 km WNW of Manhattan, Montana
  12. 1.9 2 km W of Manhattan, Montana
  13. 2.8 3 km WNW of Manhattan, Montana
  14. 2.0 16 km S of Whitehall, Montana
  15. 2.0 1 km W of Manhattan, 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 4.0 on 2016-09-03 — it released about 2,500 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.