QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Earthquake near Kalispell, MT

USGS: 11 km S of Hungry Horse, Montana

2:24 am MDT, Aug 28, 2017 · · 6.9 km deep · released about 25 lb of TNT

Every earthquake near Kalispell Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Flathead County 2 kmLake County 71 kmGlacier County 92 kmSanders County 102 kmLincoln County 108 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
2:24 am MDT on 28 August 2017 ()
Where
21 km (13 mi) ENE of Kalispell, MT · earthquakes near Kalispell
Magnitude
M 1.9 (ml)
Depth
6.9 km below the surface
Felt
no reports yet
Nearest
Flathead County, 2 km NNE
Nearest mapped fault
Mission fault, 18 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3322 days ago

A magnitude 1.9 earthquake was recorded 21 km (13 mi) ENE of Kalispell, MT, at 2:24 am MDT on 28 August 2017 (08:24 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Columbia Falls, Evergreen, Bigfork, Whitefish, Somers.

How big was it?

This earthquake released about 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 420,000× the energy of this one
  3. Around the size people start to feel M 3.0 38× the energy of this one
  4. This earthquake M 1.9 about 25 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 · 37 km SSE 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 48.2817, -114.0597. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Flathead County, MT 2 km (1 mi) NNE earthquakes near Flathead County
Lake County, MT 71 km (44 mi) S earthquakes near Lake County
Glacier County, MT 92 km (57 mi) ENE earthquakes near Glacier County
Sanders County, MT 102 km (63 mi) SW earthquakes near Sanders County
Lincoln County, MT 108 km (67 mi) WNW earthquakes near Lincoln County

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

Aftershocks so far

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

  1. 2.2 7 km WNW of Lake Mary Ronan, Montana
  2. 1.7 7 km WNW of Lake Mary Ronan, Montana
  3. 1.8 6 km WNW of Lake Mary Ronan, Montana
  4. 1.7 30 km ESE of Martin City, Montana
  5. 2.3 6 km NNE of Olney, Montana
  6. 2.3 10 km NNW of Swan Lake, Montana
  7. 1.7 15 km NNE of Bigfork, Montana
  8. 1.7 5 km ESE of Lakeside, Montana
  9. 1.5 8 km ESE of Woods Bay, Montana
  10. 1.6 3 km NNE of Somers, Montana
  11. 2.0 1 km ENE of Columbia Falls, Montana
  12. 1.6 Western Montana
  13. 2.1 8 km NNW of Bigfork, Montana
  14. 1.7 11 km NW of Batavia, Montana
  15. 1.6 12 km NNW of Batavia, 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.