QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Polson, MT

USGS: 14 km WNW of Condon, Montana

2:46 am MST, Feb 13, 2019 · · 6.6 km deep · released about 6.6 lb of TNT

10 km30 km60 km120 km N Lake County 16 kmMissoula County 63 kmFlathead County 79 kmSanders County 99 kmMineral County 105 kmPowell County 110 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
2:46 am MST on 13 February 2019 ()
Where
24 km (15 mi) ESE of Polson, MT · earthquakes near Polson
Magnitude
M 1.6 (ml)
Depth
6.6 km below the surface
Felt
no reports yet
Nearest
Lake County, 16 km WNW
Nearest mapped fault
Mission fault, 10 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 2789 days ago

A magnitude 1.6 earthquake was recorded 24 km (15 mi) ESE of Polson, MT, at 2:46 am MST on 13 February 2019 (09:46 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

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 lists one earthquake of M5 or more within 50 km:

  1. 5.5 Western Montana · 45 km N 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 47.5967, -113.8763. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, MT 16 km (10 mi) WNW earthquakes near Lake County
Missoula County, MT 63 km (39 mi) S earthquakes near Missoula County
Flathead County, MT 79 km (49 mi) N earthquakes near Flathead County
Sanders County, MT 99 km (62 mi) W earthquakes near Sanders County
Mineral County, MT 105 km (65 mi) WSW earthquakes near Mineral County
Powell County, MT 110 km (68 mi) SE earthquakes near Powell County

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

Aftershocks so far

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

  1. 2.0 8 km S of Condon, Montana
  2. 1.6 Western Montana
  3. 1.9 21 km NNW of Condon, Montana
  4. 3.7 3 km NE of Ravalli, Montana
  5. 1.5 Western Montana
  6. 3.2 2 km ESE of Ravalli, Montana
  7. 2.9 4 km N of Elmo, Montana
  8. 2.3 26 km ESE of Condon, Montana
  9. 2.1 14 km N of Seeley Lake, Montana
  10. 1.7 Western Montana
  11. 2.5 6 km WNW of Bear Dance, Montana
  12. 1.9 1 km W of Charlo, Montana
  13. 1.6 4 km ESE of Rollins, Montana
  14. 2.3 19 km SSE of Swan Lake, Montana
  15. 1.5 11 km WNW of Condon, 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.