QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Absarokee, MT

USGS: 38 km W of Roscoe, Montana

9:42 am MDT, Mar 30, 2017 · · 3.9 km deep · released about 5.6 lb of TNT

10 km30 km60 km120 km N Park County 44 kmSweet Grass County 48 kmStillwater County 56 kmCarbon County 77 kmGallatin County 93 kmPark County 104 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
9:42 am MDT on 30 March 2017 ()
Where
45 km (28 mi) WSW of Absarokee, MT · earthquakes near Absarokee
Magnitude
M 1.5 (ml)
Depth
3.9 km below the surface
Felt
no reports yet
Nearest
Park County, 44 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3473 days ago

A magnitude 1.5 earthquake was recorded 45 km (28 mi) WSW of Absarokee, MT, at 9:42 am MDT on 30 March 2017 (15:42 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 5.6 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.

  1. Mineral, Virginia 2011 M 5.8 2,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.6 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 45.3828, -109.9862. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Park County, MT 44 km (27 mi) WNW earthquakes near Park County
Sweet Grass County, MT 48 km (30 mi) N earthquakes near Sweet Grass County
Stillwater County, MT 56 km (35 mi) ENE earthquakes near Stillwater County
Carbon County, MT 77 km (48 mi) ESE earthquakes near Carbon County
Gallatin County, MT 93 km (58 mi) W earthquakes near Gallatin County
Park County, WY 104 km (64 mi) SSE earthquakes near Park County

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

Aftershocks so far

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

  1. 1.2 21 km ESE of Pray, Montana
  2. 1.7 10 km NNE of Cooke City, Montana
  3. 2.3 15 km E of Livingston, 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.