QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Rafter J Ranch, WY

No earthquake was likely felt in Rafter J Ranch in the 24 hours to 6:34 am MST (13:34 UTC). The last one was M 2.7, 18 km (11 mi) SSE, at 6:18 pm MST on 6 November 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Rafter J Ranch

This page: a magnitude 1.6 earthquake was recorded 12 km (7 mi) southwest of Rafter J Ranch, WY, at 2:21 am MDT on 28 April 2018 (08:21 UTC), 2.2 km deep.

USGS: 11 km SW of Rafter J Ranch, Wyoming

2:21 am MDT, Apr 28, 2018 · · 2.2 km deep · released about 7.3 lb of TNT

10 km30 km60 km120 km N Teton County 52 kmBonneville County 59 kmMadison County 78 kmCaribou County 82 kmTeton County 86 kmSublette County 103 kmFremont County 107 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
2:21 am MDT on 28 April 2018 ()
Where
12 km (7 mi) southwest of Rafter J Ranch, WY · earthquakes near Rafter J Ranch
Magnitude
M 1.6 (ml)
Depth
2.2 km below the surface
Felt
no reports yet
Nearest
Teton County, 52 km NNW
Nearest mapped fault
Grand Valley fault, 15 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 3117 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 11 km (7 mi) from the epicentre. In Rafter J Ranch, 12 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.

Earthquakes near other towns within 30 km: South Park, Hoback, Wilson, Jackson, Moose Wilson Road.

How big was it?

This earthquake released about 7.3 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 2,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,500,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.3 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 4.8 on 2016-08-27 — about 65,000 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.0 20 km ESE of Kelly, Wyoming · 48 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 43.3502, -110.8977. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Teton County, ID 52 km (32 mi) NNW earthquakes near Teton County
Bonneville County, ID 59 km (37 mi) W earthquakes near Bonneville County
Madison County, ID 78 km (49 mi) NW earthquakes near Madison County
Caribou County, ID 82 km (51 mi) SW earthquakes near Caribou County
Teton County, WY 86 km (54 mi) NNE earthquakes near Teton County
Sublette County, WY 103 km (64 mi) SE earthquakes near Sublette 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. 2.1 7 km WNW of Wilson, Wyoming
  2. 2.0 6 km ESE of Victor, Idaho
  3. 2.3 14 km ESE of Kelly, Wyoming
  4. 1.5 9 km NE of Irwin, Idaho
  5. 2.0 9 km E of Kelly, Wyoming
  6. 2.0 17 km S of Victor, Idaho
  7. 1.6 10 km NNW of Alpine Northeast, Wyoming
  8. 2.2 5 km NE of Alpine Northeast, Wyoming
  9. 3.1 11 km WNW of Hoback, Wyoming
  10. 2.0 14 km SSE of Victor, Idaho
  11. 2.1 15 km SW of Rafter J Ranch, Wyoming
  12. 2.4 15 km WSW of Rafter J Ranch, Wyoming
  13. 1.7 2 km ESE of Alpine Northeast, Wyoming
  14. 1.9 15 km NNW of Alpine Northeast, Wyoming
  15. 1.7 16 km N of Alpine Northeast, 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.