QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Kalispell, MT

No earthquake was likely felt in Kalispell in the 24 hours to 1:26 pm MST (20:26 UTC). The last one was M 2.6, 22 km (13 mi) NNW, at 1:53 am MST on 1 March 2021, estimated intensity II (weak) in town. Every earthquake near Kalispell

This page: a magnitude 1.6 earthquake was recorded 41 km (25 mi) northeast of Kalispell, MT, at 11:26 am MDT on 1 November 2021 (17:26 UTC), 9.9 km deep.

USGS: 13 km E of Martin City, Montana

11:26 am MDT, Nov 1, 2021 · · 9.9 km deep · released about 8.1 lb of TNT

10 km30 km60 km120 km N Flathead County 19 kmGlacier County 72 kmLake County 86 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
11:26 am MDT on 1 November 2021 ()
Where
41 km (25 mi) northeast of Kalispell, MT · earthquakes near Kalispell
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.6 (ml)
Depth
9.9 km below the surface
Felt
no reports yet
Nearest
Flathead County, 19 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1836 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 6 km (4 mi) from the epicentre. In Kalispell, 41 km away, the estimate is intensity I (not felt). 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.

Earthquakes near other towns within 30 km: Columbia Falls.

How big was it?

This earthquake released about 8.1 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
  3. Around the size people start to feel M 3.0 120× the energy of this one
  4. This earthquake M 1.6 about 8.1 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.

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 lists one earthquake of M5 or more within 50 km:

  1. 5.5 Western Montana · 45 km S of this epicentre

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 48.4000, -113.8510. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Flathead County, MT 19 km (12 mi) SW earthquakes near Flathead County
Glacier County, MT 72 km (45 mi) ENE earthquakes near Glacier County
Lake County, MT 86 km (53 mi) SSW earthquakes near Lake County
Lincoln County, MT 120 km (75 mi) W earthquakes near Lincoln County
Sanders County, MT 122 km (76 mi) SW earthquakes near Sanders County
Teton County, MT 133 km (83 mi) ESE earthquakes near Teton County

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

Aftershocks so far

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

  1. 1.2 3 km E of Somers, Montana
  2. 2.0 5 km SSW of West Glacier, Montana
  3. 1.8 12 km NE of Forest Hill Village, Montana
  4. 1.9 12 km ESE of Evergreen, Montana
  5. 1.7 1 km S of Woods Bay, Montana
  6. 1.7 30 km ESE of Martin City, Montana
  7. 2.3 10 km NNW of Swan Lake, Montana
  8. 1.7 15 km NNE of Bigfork, Montana
  9. 1.7 5 km ESE of Lakeside, Montana
  10. 1.5 8 km ESE of Woods Bay, Montana
  11. 1.6 3 km NNE of Somers, Montana
  12. 2.0 1 km ENE of Columbia Falls, Montana
  13. 1.6 Western Montana
  14. 2.1 8 km NNW of Bigfork, Montana
  15. 2.1 16 km NNE of Swan Lake, 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.