QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

67 km ESE of West Yellowstone, Montana

Yes. A magnitude 1.7 earthquake was recorded 67 km ESE of West Yellowstone, Montana, at 9:57 am MST on 6 December 2020 (16:57 UTC), 5.2 km deep.

· 5.2 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Teton County 44 kmPark County 58 kmFremont County 96 kmTeton County 103 kmPark County 116 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
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.7 (md)
Depth
5.2 km below the surface
Felt
no reports yet
Nearest
Teton County, 44 km SSW
Nearest mapped fault
Buffalo Fork fault, 3 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2165 days ago

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 12 km (7 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 12 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 900,000× the energy of this one
  3. Around the size people start to feel M 3.0 80× the energy of this one
  4. This earthquake M 1.7 about 12 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 lists 5 earthquakes of M5 or more within 50 km:

  1. 6.0 21 km E of West Yellowstone, Montana · 48 km WNW of this epicentre
  2. 5.9 26 km SSE of Mammoth, Wyoming · 42 km NNW of this epicentre
  3. 5.1 51 km ESE of West Yellowstone, Montana · 16 km WNW of this epicentre
  4. 5.1 23 km S of Mammoth, Wyoming · 49 km NW of this epicentre
  5. 5.0 62 km ESE of West Yellowstone, Montana · 6 km W 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 44.4320, -110.3170. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Teton County, WY 44 km (27 mi) SSW earthquakes near Teton County
Park County, WY 58 km (36 mi) E earthquakes near Park County
Fremont County, ID 96 km (60 mi) WSW earthquakes near Fremont County
Teton County, ID 103 km (64 mi) SW earthquakes near Teton County
Park County, MT 116 km (72 mi) N earthquakes near Park County
Madison County, ID 129 km (80 mi) WSW earthquakes near Madison County

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

Aftershocks so far

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

  1. 1.5 50 km SSE of Mammoth, Wyoming
  2. 1.6 35 km S of Silver Gate, Montana
  3. 2.7 36 km S of Silver Gate, Montana
  4. 1.7 57 km ESE of West Yellowstone, Montana
  5. 2.5 56 km SE of West Yellowstone, Montana
  6. 2.0 55 km SE of West Yellowstone, Montana
  7. 2.3 55 km SE of West Yellowstone, Montana
  8. 1.5 55 km SE of West Yellowstone, Montana
  9. 1.8 56 km SE of West Yellowstone, Montana
  10. 2.0 28 km S of Mammoth, Wyoming
  11. 2.1 28 km S of Mammoth, Wyoming
  12. 2.2 27 km SSE of Mammoth, Wyoming
  13. 1.7 48 km ESE of West Yellowstone, Montana
  14. 1.8 35 km SSW of Silver Gate, Montana
  15. 2.1 65 km NNE of Kelly, Wyoming

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.