QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3ml

31 km SE of Cardston, Canada

· 5.0 km deep · released about 85 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Glacier County 32 kmToole County 101 kmPondera County 103 kmFlathead County 109 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 2.3 (ml)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Glacier County, 32 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2220 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 85 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 11× the energy of this one
  4. This earthquake M 2.3 about 85 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 48.9918, -113.0033. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Glacier County, MT 32 km (20 mi) N of here earthquakes near Glacier County
Toole County, MT 101 km (63 mi) WNW of here earthquakes near Toole County
Pondera County, MT 103 km (64 mi) NW of here earthquakes near Pondera County
Flathead County, MT 109 km (68 mi) NE of here earthquakes near Flathead County

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

Aftershocks so far

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

  1. 2.3 40 km SSE of Magrath, Canada
  2. 2.3 6 km SSW of Cardston, Canada
  3. 1.7 21 km SSE of Cardston, Canada
  4. 2.0 43 km NNW of Santa Rita, Montana
  5. 2.4 38 km NNW of Santa Rita, Montana
  6. 1.9 40 km SSE of Magrath, Canada
  7. 1.5 20 km NW of Santa Rita, Montana
  8. 2.8 8 km S of Cardston, Canada
  9. 1.7 14 km S of Cardston, Canada
  10. 2.0 Alberta, Canada
  11. 1.9 35 km SE of Cardston, Canada
  12. 1.5 23 km NW of Santa Rita, Montana
  13. 1.9 10 km NNW of Babb, Montana
  14. 2.4 22 km NW of Santa Rita, Montana
  15. 2.1 42 km NW of Santa Rita, 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.