QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7ml

Earthquake near Ronan, MT

No earthquake was likely felt in Ronan in the 24 hours to 4:04 am MST (11:04 UTC). The last one was M 2.6, 20 km (12 mi) SE, at 4:57 am MST on 19 January 2026, estimated intensity II (weak) in town. Every earthquake near Ronan

This page: a magnitude 2.7 earthquake was recorded 14 km (9 mi) east of Ronan, MT, at 8:03 am MST on 29 January 2020 (15:03 UTC), 27 km deep.

USGS: 13 km E of Ronan, Montana

8:03 am MST, Jan 29, 2020 · · 27 km deep · released about 340 lb of TNT

10 km30 km60 km120 km N Lake County 16 kmMissoula County 58 kmFlathead County 83 kmSanders County 97 kmMineral County 100 kmPowell 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
8:03 am MST on 29 January 2020 ()
Where
14 km (9 mi) east of Ronan, MT · earthquakes near Ronan
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 2.7 (ml)
Depth
27 km below the surface
Felt
no reports yet
Nearest
Lake County, 16 km NW
Nearest mapped fault
Mission fault, 7 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 2400 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Ronan, 14 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, Polson.

How big was it?

This earthquake released about 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.8× the energy of this one
  4. This earthquake M 2.7 about 340 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 47.5524, -113.9200. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, MT 16 km (10 mi) NW earthquakes near Lake County
Missoula County, MT 58 km (36 mi) S earthquakes near Missoula County
Flathead County, MT 83 km (52 mi) N earthquakes near Flathead County
Sanders County, MT 97 km (60 mi) WNW earthquakes near Sanders County
Mineral County, MT 100 km (62 mi) WSW earthquakes near Mineral County
Powell County, MT 109 km (67 mi) SE earthquakes near Powell County

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

Aftershocks so far

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

  1. 1.8 14 km WNW of Condon, Montana
  2. 1.6 16 km WSW of Kerr, Montana
  3. 1.5 5 km NE of Saint Ignatius, Montana
  4. 1.8 17 km E of Arlee, Montana
  5. 3.0 17 km SSE of Swan Lake, Montana
  6. 1.6 9 km ENE of Ronan, Montana
  7. 1.5 6 km SW of Condon, Montana
  8. 1.6 15 km ESE of Condon, Montana
  9. 1.6 4 km W of Ravalli, Montana
  10. 1.5 8 km ESE of Woods Bay, Montana
  11. 2.1 18 km SSE of Swan Lake, Montana
  12. 1.8 17 km SSW of Condon, Montana
  13. 1.9 17 km SSW of Condon, Montana
  14. 1.5 11 km ENE of Ronan, Montana
  15. 2.0 8 km S 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.