QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near West Yellowstone, MT

No earthquake was likely felt in West Yellowstone in the 24 hours to 6:56 pm MST (01:56 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 1.7 earthquake was recorded 14 km (9 mi) south of West Yellowstone, MT, at 1:51 pm MDT on 16 September 2018 (19:51 UTC), 13 km deep.

USGS: 14 km S of West Yellowstone, Montana

1:51 pm MDT, Sep 16, 2018 · · 13 km deep · released about 12 lb of TNT

Every earthquake near West Yellowstone Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Fremont County 47 kmTeton County 76 kmTeton County 86 kmMadison County 94 kmClark County 103 kmMadison County 109 kmGallatin County 110 kmPark County 112 kmPark County 120 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
1:51 pm MDT on 16 September 2018 ()
Where
14 km (9 mi) south of West Yellowstone, MT · earthquakes near West Yellowstone
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 1.7 (ml)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Fremont County, 47 km SW
Nearest mapped fault
Madison fault, 16 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 2978 days ago

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

At this magnitude and depth it was probably too small to be felt, even directly above it. In West Yellowstone, 14 km away, the estimate is intensity II (weak). 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 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 870,000× the energy of this one
  3. Around the size people start to feel M 3.0 78× 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

The largest earthquake within 50 km since 2016 was M 4.4 on 2017-06-16 — about 8,500 times the energy of this one.

Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.2 The 1959 Hebgen Lake, Montana Earthquake · 30 km NNW of this epicentre
  2. 6.5 14 km N of Madison Junction, Wyoming · 31 km NNE of this epicentre
  3. 6.3 22 km SW of Mammoth, Wyoming · 36 km NNE of this epicentre
  4. 6.0 21 km E of West Yellowstone, Montana · 24 km ENE of this epicentre
  5. 5.9 26 km SSE of Mammoth, Wyoming · 46 km ENE 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 44.5338, -111.1000. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Fremont County, ID 47 km (29 mi) SW earthquakes near Fremont County
Teton County, WY 76 km (47 mi) SE earthquakes near Teton County
Teton County, ID 86 km (54 mi) S earthquakes near Teton County
Madison County, ID 94 km (58 mi) SSW earthquakes near Madison County
Clark County, ID 103 km (64 mi) WSW earthquakes near Clark County
Madison County, MT 109 km (68 mi) NW earthquakes near Madison County

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

Aftershocks so far

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

  1. 1.6 42 km ESE of West Yellowstone, Montana
  2. 1.7 6 km ESE of Hebgen Lake Estates, Montana
  3. 1.6 12 km NE of West Yellowstone, Montana
  4. 1.5 16 km SE of West Yellowstone, Montana
  5. 1.5 23 km SSE of West Yellowstone, Montana
  6. 3.1 23 km SSE of West Yellowstone, Montana
  7. 1.9 33 km E of West Yellowstone, Montana
  8. 1.9 27 km W of Hebgen Lake Estates, Montana
  9. 1.6 3 km ENE of Hebgen Lake Estates, Montana
  10. 2.1 3 km ENE of Hebgen Lake Estates, Montana
  11. 1.5 16 km SE of West Yellowstone, Montana
  12. 1.6 11 km ESE of West Yellowstone, Montana
  13. 1.6 25 km WNW of Hebgen Lake Estates, Montana
  14. 3.0 52 km SE of West Yellowstone, Montana
  15. 1.6 51 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.