QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Polson, MT

No earthquake was likely felt in Polson in the 24 hours to 9:50 am MST (16:50 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 1.6 earthquake was recorded 20 km (12 mi) south-southwest of Polson, MT, at 2:39 am MDT on 2 June 2023 (08:39 UTC), less than 1 km deep.

USGS: Western Montana

2:39 am MDT, Jun 2, 2023 · · 0.3 km deep · released about 6.6 lb of TNT

10 km30 km60 km120 km N Lake County 20 kmMissoula County 65 kmSanders County 70 kmMineral County 75 kmFlathead 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
2:39 am MDT on 2 June 2023 ()
Where
20 km (12 mi) south-southwest of Polson, MT · earthquakes near Polson
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.6 (ml)
Depth
0.3 km below the surface
Felt
no reports yet
Nearest
Lake County, 20 km NE
Nearest mapped fault
Mission fault, 21 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 1258 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 11 km (7 mi) from the epicentre. In Polson, 20 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.

Earthquakes near other towns within 30 km: Pablo, Ronan.

How big was it?

This earthquake released about 6.6 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 2,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
  3. Around the size people start to feel M 3.0 140× the energy of this one
  4. This earthquake M 1.6 about 6.6 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 47.5443, -114.3013. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, MT 20 km (12 mi) NE earthquakes near Lake County
Missoula County, MT 65 km (41 mi) SSE earthquakes near Missoula County
Sanders County, MT 70 km (43 mi) WNW earthquakes near Sanders County
Mineral County, MT 75 km (47 mi) SW earthquakes near Mineral County
Flathead County, MT 86 km (53 mi) NNE earthquakes near Flathead County
Shoshone County, ID 121 km (75 mi) W earthquakes near Shoshone County

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

Aftershocks so far

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

  1. 1.8 3 km NE of Bear Dance, Montana
  2. 1.1 2 km E of Bear Dance, Montana
  3. 1.4 16 km NW of Old Agency, Montana
  4. -0.0 19 km E of Finley Point, Montana
  5. 0.9 9 km WSW of Condon, Montana
  6. 1.9 18 km E of Saint Ignatius, Montana
  7. 2.4 9 km SSW of Bear Dance, Montana
  8. 1.6 1 km SSW of Dayton, Montana
  9. 1.8 17 km SSE of Swan Lake, Montana
  10. 2.6 13 km ESE of Kicking Horse, Montana
  11. 2.0 15 km ENE of Ronan, Montana
  12. 2.1 5 km WNW of Saint Ignatius, Montana
  13. 1.7 20 km E of Finley Point, Montana
  14. 1.6 20 km E of Finley Point, Montana
  15. 1.6 20 km E of Finley Point, 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.