QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

25 km S of Ennis, Montana

· 12 km deep · released about 19 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Madison County 28 kmGallatin County 62 kmBeaverhead County 93 kmPark County 100 kmFremont County 102 kmClark County 105 kmSilver Bow County 113 kmJefferson County 115 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
Magnitude
M 1.9 (ml)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Madison County, 28 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 53 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 19 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 810,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 580,000× the energy of this one
  3. Around the size people start to feel M 3.0 51× the energy of this one
  4. This earthquake M 1.9 about 19 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.

Where

Epicentre 45.1213, -111.7133. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Madison County, MT 28 km (17 mi) SE of here earthquakes near Madison County
Gallatin County, MT 62 km (38 mi) SW of here earthquakes near Gallatin County
Beaverhead County, MT 93 km (58 mi) E of here earthquakes near Beaverhead County
Park County, MT 100 km (62 mi) WSW of here earthquakes near Park County
Fremont County, ID 102 km (63 mi) N of here earthquakes near Fremont County
Clark County, ID 105 km (65 mi) NNE of here earthquakes near Clark County

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

Aftershocks so far

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

  1. 0.4 29 km WNW of Hebgen Lake Estates, Montana
  2. 0.1 31 km WNW of Hebgen Lake Estates, Montana
  3. 0.3 24 km WNW of Hebgen Lake Estates, Montana
  4. 0.0 25 km WNW of Hebgen Lake Estates, Montana
  5. 1.6 44 km NNE of Spencer, Idaho
  6. 1.7 12 km W of Hebgen Lake Estates, Montana
  7. 2.2 45 km NNE of Spencer, Idaho
  8. 1.9 45 km NNE of Spencer, Idaho
  9. 2.4 45 km NNE of Spencer, Idaho
  10. 1.8 46 km NNE of Spencer, Idaho
  11. 2.1 12 km NW of Ennis, Montana
  12. 1.5 13 km NNW of Ennis, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.3 on 2016-06-13 — it released about 5,200 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.