Earthquake · reviewed by a seismologist
M 1.5ml
34 km S of Virginia City, Montana
Yes. A magnitude 1.5 earthquake was recorded 34 km S of Virginia City, Montana, at 2:25 pm MST on 29 December 2019 (21:25 UTC), 2.9 km deep.
- When
- Montana today
- every earthquake in Montana in the last 24 hours
- Magnitude
- M 1.5 (ml)
- Depth
- 2.9 km below the surface
- Felt
- no reports yet
- Nearest
- Madison County, 38 km N
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 2508 days ago
Earthquake alerts for Big Sky, MT
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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, people at rest would likely notice it out to about 10 km (6 mi) from the epicentre. 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 5.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,600,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
- Around the size people start to feel M 3.0 170× the energy of this one
- This earthquake M 1.5 about 5.7 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
The largest earthquake within 50 km since 2016 was M 4.3 on 2016-06-13 — about 17,000 times the energy of this one.
Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:
- 6.1 30 km SSW of Big Sky, Montana · 32 km ENE of this epicentre
- 5.2 32 km WNW of Hebgen Lake Estates, Montana · 33 km ESE of this epicentre
- 5.2 26 km WNW of Hebgen Lake Estates, Montana · 39 km ESE of this epicentre
- 5.0 31 km W of Hebgen Lake Estates, Montana · 34 km ESE of this epicentre
- 5.0 39 km W of Hebgen Lake Estates, Montana · 38 km SE 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 44.9818, -111.9535. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Madison County, MT | 38 km (24 mi) | N | earthquakes near Madison County |
| Beaverhead County, MT | 76 km (47 mi) | WNW | earthquakes near Beaverhead County |
| Clark County, ID | 83 km (52 mi) | SSW | earthquakes near Clark County |
| Gallatin County, MT | 86 km (53 mi) | NE | earthquakes near Gallatin County |
| Fremont County, ID | 93 km (58 mi) | SSE | earthquakes near Fremont County |
| Silver Bow County, MT | 116 km (72 mi) | NNW | earthquakes near Silver Bow 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.
- 1.8 27 km SE of Virginia City, Montana
- 2.0 29 km SSE of Virginia City, Montana
- 1.5 18 km ESE of Dillon, Montana
- 2.4 27 km WNW of Hebgen Lake Estates, Montana
- 1.6 28 km WNW of Hebgen Lake Estates, Montana
- 1.6 27 km WNW of Hebgen Lake Estates, Montana
- 1.6 32 km S of Ennis, Montana
- 1.6 23 km WNW of Hebgen Lake Estates, Montana
- 2.0 22 km WNW of Hebgen Lake Estates, Montana
- 2.7 23 km ESE of Dillon, Montana
- 1.6 23 km ESE of Dillon, Montana
- 2.6 16 km NE of Lima, Montana
- 1.8 46 km NNE of Spencer, Idaho
- 1.7 17 km ESE of Dillon, Montana
- 1.6 24 km SSW of Virginia City, 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.