Earthquake · reviewed by a seismologist
M 1.8ml
Earthquake near Big Timber, MT
No earthquake was likely felt in Big Timber in the 24 hours to 2:47 pm MST (21:47 UTC). The last one was M 3.8, 51 km (32 mi) W, at 12:28 pm MST on 30 January 2023, estimated intensity II (weak) in town; 309 felt reports to USGS. Every earthquake near Big Timber
This page: a magnitude 1.8 earthquake was recorded 43 km (26 mi) northwest of Big Timber, MT, at 9:42 am MDT on 9 August 2017 (15:42 UTC), 15 km deep.
USGS: 28 km ENE of Wilsall, Montana
- When
- 9:42 am MDT on 9 August 2017 ()
- Where
- 43 km (26 mi) northwest of Big Timber, MT · earthquakes near Big Timber
- Montana today
- every earthquake in Montana in the last 24 hours
- Magnitude
- M 1.8 (ml)
- Depth
- 15 km below the surface
- Felt
- no reports yet
- Nearest
- Sweet Grass County, 45 km SE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3381 days ago
Earthquake alerts for Big Timber, MT
Get a notification in this browser when USGS records an earthquake near Big Timber, 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 minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth it was probably too small to be felt, even directly above it. In Big Timber, 43 km away, the estimate is intensity I (not felt). 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 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
- Magna, Utah 2020 M 5.7 840,000× the energy of this one
- Around the size people start to feel M 3.0 75× the energy of this one
- This earthquake M 1.8 about 13 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 46.1130, -110.3348. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Sweet Grass County, MT | 45 km (28 mi) | SE | earthquakes near Sweet Grass County |
| Wheatland County, MT | 56 km (35 mi) | NE | earthquakes near Wheatland County |
| Meagher County, MT | 69 km (43 mi) | NW | earthquakes near Meagher County |
| Park County, MT | 74 km (46 mi) | SSW | earthquakes near Park County |
| Stillwater County, MT | 89 km (56 mi) | SE | earthquakes near Stillwater County |
| Gallatin County, MT | 92 km (57 mi) | SW | earthquakes near Gallatin County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
15 earthquakes have been recorded within 50 km since this one.
- 1.7 29 km N of Sedan, Montana
- 1.8 23 km ENE of Wilsall, Montana
- 3.8 9 km NNW of Livingston, Montana
- 2.2 30 km ENE of Wilsall, Montana
- 1.9 23 km SE of White Sulphur Springs, Montana
- 2.7 32 km NE of Wilsall, Montana
- 2.4 32 km ENE of Wilsall, Montana
- 1.7 32 km ENE of Wilsall, Montana
- 2.1 29 km ENE of Wilsall, Montana
- 1.7 28 km ENE of Wilsall, Montana
- 1.5 30 km ENE of Wilsall, Montana
- 1.5 29 km ENE of Wilsall, Montana
- 1.8 29 km ENE of Wilsall, Montana
- 1.6 29 km ENE of Wilsall, Montana
- 2.3 30 km ENE of Wilsall, 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.