QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2ml

Earthquake near Polson, MT

No earthquake was likely felt in Polson in the 24 hours to 3:01 pm MST (22:01 UTC). The last one was M 3.0, 32 km (20 mi) ENE, at 9:19 pm MDT on 14 March 2024, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Polson

This page: a magnitude 2.2 earthquake was recorded 44 km (27 mi) west-northwest of Polson, MT, at 11:03 pm MDT on 22 June 2022 (05:03 UTC), 7.2 km deep.

USGS: 8 km WNW of Niarada, Montana

11:03 pm MDT, Jun 22, 2022 · · 7.2 km deep · released about 58 lb of TNT

10 km30 km60 km120 km N Sanders County 36 kmLake County 52 kmFlathead County 71 kmMineral County 83 kmLincoln County 97 kmShoshone County 103 kmMissoula 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
11:03 pm MDT on 22 June 2022 ()
Where
44 km (27 mi) west-northwest of Polson, MT · earthquakes near Polson
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 2.2 (ml)
Depth
7.2 km below the surface
Felt
no reports yet
Nearest
Sanders County, 36 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1602 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 17 km (11 mi) from the epicentre. In Polson, 44 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 58 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 260,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 180,000× the energy of this one
  3. Around the size people start to feel M 3.0 16× the energy of this one
  4. This earthquake M 2.2 about 58 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 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 47.8307, -114.7163. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sanders County, MT 36 km (22 mi) WSW earthquakes near Sanders County
Lake County, MT 52 km (32 mi) ESE earthquakes near Lake County
Flathead County, MT 71 km (44 mi) NE earthquakes near Flathead County
Mineral County, MT 83 km (51 mi) SSW earthquakes near Mineral County
Lincoln County, MT 97 km (61 mi) NW earthquakes near Lincoln County
Shoshone County, ID 103 km (64 mi) WSW earthquakes near Shoshone County

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

Aftershocks so far

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

  1. 1.2 3 km E of Somers, Montana
  2. 1.4 16 km NW of Old Agency, Montana
  3. 1.7 19 km SW of Marion, Montana
  4. 2.3 18 km SW of Marion, Montana
  5. 2.0 19 km SW of Marion, Montana
  6. 1.6 1 km SSW of Dayton, Montana
  7. 2.2 7 km WNW of Lake Mary Ronan, Montana
  8. 1.7 7 km WNW of Lake Mary Ronan, Montana
  9. 1.8 6 km WNW of Lake Mary Ronan, Montana
  10. 1.7 21 km SSE of Happys Inn, Montana
  11. 1.6 16 km WSW of Kerr, Montana
  12. 2.0 17 km W of Niarada, Montana
  13. 1.8 3 km NW of Happys Inn, Montana
  14. 1.6 4 km NW of Niarada, Montana
  15. 2.6 4 km NW of Happys Inn, 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.