QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

8 km S of Cardston, Canada

· 20 km deep · released about 480 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Glacier County 51 kmFlathead 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 2.8 (ml)
Depth
20 km below the surface
Felt
no reports yet
Nearest
Glacier County, 51 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 912 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 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
  3. Around the size people start to feel M 3.0 2× the energy of this one
  4. This earthquake M 2.8 about 480 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 49.1193, -113.3075. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Glacier County, MT 51 km (32 mi) NNW of here earthquakes near Glacier County
Flathead County, MT 107 km (66 mi) NNE of here earthquakes near Flathead County
Toole County, MT 127 km (79 mi) WNW of here earthquakes near Toole County
Pondera County, MT 127 km (79 mi) NW of here earthquakes near Pondera County

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

Aftershocks so far

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

  1. 2.3 6 km SSW of Cardston, Canada
  2. 1.7 21 km SSE of Cardston, Canada

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.