mine collapse · reviewed by a seismologist
M 2.6ml
Earthquake near Libby, MT
No earthquake was likely felt in Libby in the 24 hours to 2:53 pm MST (21:53 UTC). The last one was M 3.1, 31 km (19 mi) WSW, at 2:24 pm MST on 21 November 2025, estimated intensity II (weak) in town. Every earthquake near Libby
No: USGS classifies this as a mine collapse, not an earthquake. A magnitude 2.6 mine collapse was recorded 23 km (14 mi) west of Libby, MT, at 5:49 pm MDT on 15 April 2019 (23:49 UTC), 1.0 km deep.
USGS: 9 km S of Troy, Montana
- When
- 5:49 pm MDT on 15 April 2019 ()
- Where
- 23 km (14 mi) west of Libby, MT · earthquakes near Libby
- Montana today
- every earthquake in Montana in the last 24 hours
- Magnitude
- M 2.6 (ml)
- Depth
- 1.0 km below the surface
- Felt
- no reports yet
- Nearest
- Lincoln County, 35 km ENE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2701 days ago
Earthquake alerts for Libby, MT
Get a notification in this browser when USGS records an earthquake near Libby, MT. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 23 km (14 mi) from the epicentre. In Libby, 23 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.
USGS catalogues this as mine collapse, not an earthquake.
How big was it?
This earthquake released about 240 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 63,000× the energy of this one
- Magna, Utah 2020 M 5.7 45,000× the energy of this one
- Around the size people start to feel M 3.0 4× the energy of this one
- This earthquake M 2.6 about 240 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 48.3831, -115.8705. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Lincoln County, MT | 35 km (22 mi) | ENE | earthquakes near Lincoln County |
| Bonner County, ID | 56 km (35 mi) | W | earthquakes near Bonner County |
| Boundary County, ID | 65 km (40 mi) | NW | earthquakes near Boundary County |
| Sanders County, MT | 87 km (54 mi) | SE | earthquakes near Sanders County |
| Kootenai County, ID | 100 km (62 mi) | SW | earthquakes near Kootenai County |
| Pend Oreille County, WA | 102 km (63 mi) | W | earthquakes near Pend Oreille County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
14 earthquakes have been recorded within 50 km since this one.
- 3.1 20 km N of Heron, Montana
- 2.1 7 km WSW of Clark Fork, Idaho
- 1.8 13 km SSW of East Hope, Idaho
- 1.5 11 km SSW of East Hope, Idaho
- 2.5 10 km SSW of East Hope, Idaho
- 2.6 7 km W of Clark Fork, Idaho
- 1.9 19 km NE of Troy, Montana
- 1.8 15 km SE of Sylvanite, Montana
- 1.6 13 km SSW of East Hope, Idaho
- 2.4 23 km ENE of Noxon, Montana
- 2.0 13 km WSW of Libby, Montana
- 1.6 7 km S of Moyie Springs, Idaho
- 1.6 10 km SSW of East Hope, Idaho
- 1.6 6 km NW of Libby, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.