QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near West Yellowstone, MT

No earthquake was likely felt in West Yellowstone in the 24 hours to 11:43 pm MST (06:43 UTC). The last one was M 2.8, 11 km (7 mi) NNW, at 1:21 am MDT on 8 September 2026, estimated intensity II (weak) in town. Every earthquake near West Yellowstone

This page: a magnitude 1.6 earthquake was recorded 47 km (29 mi) east-northeast of West Yellowstone, MT, at 9:29 am MDT on 6 May 2018 (15:29 UTC), 5.4 km deep.

USGS: 25 km SSE of Mammoth, Wyoming

9:29 am MDT, May 6, 2018 · · 5.4 km deep · released about 6.6 lb of TNT

Every earthquake near West Yellowstone Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Park County 76 kmPark County 81 kmTeton County 81 kmGallatin County 96 kmFremont County 98 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
9:29 am MDT on 6 May 2018 ()
Where
47 km (29 mi) east-northeast of West Yellowstone, MT · earthquakes near West Yellowstone
Magnitude
M 1.6 (ml)
Depth
5.4 km below the surface
Felt
no reports yet
Nearest
Park County, 76 km N
Nearest mapped fault
Mirror Plateau faults, 20 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 3110 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 9 km (6 mi) from the epicentre. In West Yellowstone, 47 km away, the estimate is intensity I (not felt). 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 6.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
  3. Around the size people start to feel M 3.0 140× the energy of this one
  4. This earthquake M 1.6 about 6.6 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

The largest earthquake within 50 km since 2016 was M 4.4 on 2017-06-16 — about 16,000 times the energy of this one.

Before 2016, the USGS record lists 12 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 14 km N of Madison Junction, Wyoming · 28 km W of this epicentre
  2. 6.3 22 km SW of Mammoth, Wyoming · 26 km W of this epicentre
  3. 6.0 21 km E of West Yellowstone, Montana · 28 km WSW of this epicentre
  4. 5.9 26 km SSE of Mammoth, Wyoming · 7 km WSW of this epicentre
  5. 5.7 13 km SSW of Mammoth, Wyoming · 20 km WNW 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 44.7775, -110.5332. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Park County, MT 76 km (47 mi) N earthquakes near Park County
Park County, WY 81 km (50 mi) ESE earthquakes near Park County
Teton County, WY 81 km (51 mi) S earthquakes near Teton County
Gallatin County, MT 96 km (60 mi) NNW earthquakes near Gallatin County
Fremont County, ID 98 km (61 mi) SW earthquakes near Fremont County
Sweet Grass County, MT 124 km (77 mi) NNE earthquakes near Sweet Grass County

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

Aftershocks so far

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

  1. 1.7 23 km SSW of Mammoth, Wyoming
  2. 2.1 23 km SSW of Mammoth, Wyoming
  3. 1.5 23 km SSW of Mammoth, Wyoming
  4. 2.3 24 km SSW of Mammoth, Wyoming
  5. 1.8 23 km SSW of Mammoth, Wyoming
  6. 2.0 22 km SSW of Mammoth, Wyoming
  7. 2.1 23 km SSW of Mammoth, Wyoming
  8. 1.6 22 km SSW of Mammoth, Wyoming
  9. 1.5 23 km SSW of Mammoth, Wyoming
  10. 1.5 15 km NE of West Yellowstone, Montana
  11. 1.5 12 km SSE of West Yellowstone, Montana
  12. 1.5 23 km SSW of Mammoth, Wyoming
  13. 1.6 23 km SSW of Mammoth, Wyoming
  14. 1.8 48 km SSW of Silver Gate, Montana
  15. 1.9 43 km SE of West Yellowstone, 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.