QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

59 km ESE of West Yellowstone, Montana

Yes. A magnitude 2.1 earthquake was recorded 59 km ESE of West Yellowstone, Montana, at 10:42 am MDT on 11 April 2018 (16:42 UTC), 12 km deep.

· 12 km deep · released about 51 lb of TNT

10 km30 km60 km120 km N Teton County 42 kmPark County 67 kmFremont County 87 kmTeton County 97 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 2.1 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Teton County, 42 km S
Nearest mapped fault
Eagle Bay fault, 2 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 3136 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 13 km (8 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 51 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 210,000× the energy of this one
  3. Around the size people start to feel M 3.0 19× the energy of this one
  4. This earthquake M 2.1 about 51 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 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.0 21 km E of West Yellowstone, Montana · 41 km NW of this epicentre
  2. 5.9 26 km SSE of Mammoth, Wyoming · 38 km NNW of this epicentre
  3. 5.5 25 km SSW of Mammoth, Wyoming · 47 km NW of this epicentre
  4. 5.3 24 km ENE of West Yellowstone, Montana · 46 km NW of this epicentre
  5. 5.3 20 km S of Mammoth, Wyoming · 46 km NNW 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 44.4263, -110.4283. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Teton County, WY 42 km (26 mi) S earthquakes near Teton County
Park County, WY 67 km (41 mi) E earthquakes near Park County
Fremont County, ID 87 km (54 mi) WSW earthquakes near Fremont County
Teton County, ID 97 km (60 mi) SW earthquakes near Teton County
Park County, MT 116 km (72 mi) N earthquakes near Park County
Madison County, ID 121 km (75 mi) SW earthquakes near Madison County

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

Aftershocks so far

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

  1. 1.6 47 km SE of Mammoth, Wyoming
  2. 2.1 59 km NNE of Kelly, Wyoming
  3. 1.7 29 km ESE of West Yellowstone, Montana
  4. 1.5 29 km ESE of West Yellowstone, Montana
  5. 1.9 29 km ESE of West Yellowstone, Montana
  6. 1.6 21 km SSE of Mammoth, Wyoming
  7. 2.0 21 km SSE of Mammoth, Wyoming
  8. 1.9 38 km S of Silver Gate, Montana
  9. 1.7 22 km SSE of Mammoth, Wyoming
  10. 1.6 Wyoming
  11. 1.8 21 km SSE of Mammoth, Wyoming
  12. 2.1 20 km SSE of Mammoth, Wyoming
  13. 1.5 21 km SSE of Mammoth, Wyoming
  14. 1.8 22 km SSE of Mammoth, Wyoming
  15. 2.1 20 km SSE of Mammoth, 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.