QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

Earthquake near Cut Bank, MT

No earthquake was likely felt in Cut Bank in the 24 hours to 7:13 am MST (14:13 UTC). The last one was M 3.1, 33 km (20 mi) NNW, at 8:12 am MDT on 22 October 2018, estimated intensity II (weak) in town. Every earthquake near Cut Bank

This page: a magnitude 3.1 earthquake was recorded 33 km (20 mi) north-northwest of Cut Bank, MT, at 8:12 am MDT on 22 October 2018 (14:12 UTC), 5.8 km deep.

USGS: 26 km NNW of Santa Rita, Montana

8:12 am MDT, Oct 22, 2018 · · 5.8 km deep · released about 1,300 lb of TNT

10 km30 km60 km120 km N Glacier County 41 kmToole County 64 kmPondera County 78 kmLiberty County 115 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
8:12 am MDT on 22 October 2018 ()
Where
33 km (20 mi) north-northwest of Cut Bank, MT · earthquakes near Cut Bank
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 3.1 (ml)
Depth
5.8 km below the surface
Felt
no reports yet
Nearest
Glacier County, 41 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2862 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 41 km (25 mi) from the epicentre. In Cut Bank, 33 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 250,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 7,900× the energy of this one
  4. This earthquake M 3.1 about 1,300 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.4× 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.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 48.9014, -112.5155. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Glacier County, MT 41 km (25 mi) WSW earthquakes near Glacier County
Toole County, MT 64 km (40 mi) ESE earthquakes near Toole County
Pondera County, MT 78 km (48 mi) SSE earthquakes near Pondera County
Liberty County, MT 115 km (71 mi) ESE earthquakes near Liberty County
Flathead County, MT 132 km (82 mi) WSW earthquakes near Flathead County

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

Aftershocks so far

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

  1. 2.3 40 km SSE of Magrath, Canada
  2. 1.5 12 km WSW of Sunburst, Montana
  3. 1.6 9 km ESE of Cut Bank, Montana
  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. 2.7 17 km NNW of Santa Rita, Montana
  9. 1.8 11 km NNE of Santa Rita, Montana
  10. 2.3 13 km NNE of Santa Rita, Montana
  11. 1.6 16 km NNE of Santa Rita, Montana
  12. 2.3 18 km NNE of Santa Rita, Montana
  13. 2.0 17 km W of Sunburst, Montana
  14. 2.0 Alberta, Canada
  15. 1.9 35 km SE 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.