QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Earthquake near Star Valley Ranch, WY

No earthquake was likely felt in Star Valley Ranch in the 24 hours to 4:33 pm MST (23:33 UTC). The last one was M 3.8, 75 km (47 mi) SSW, at 5:05 am MDT on 15 May 2026, estimated intensity II (weak) in town; 29 felt reports to USGS. Every earthquake near Star Valley Ranch

This page: a magnitude 2.1 earthquake was recorded 43 km (27 mi) west-northwest of Star Valley Ranch, WY, at 5:12 pm MDT on 15 May 2023 (23:12 UTC), less than 1 km deep.

USGS: 27 km SSW of Irwin, Idaho

5:12 pm MDT, May 15, 2023 · · 0.4 km deep · released about 41 lb of TNT

10 km30 km60 km120 km N Bonneville County 30 kmCaribou County 45 kmTeton County 67 kmMadison County 71 kmBingham County 80 kmBannock County 86 kmBear Lake County 99 kmJefferson County 101 kmFremont 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
5:12 pm MDT on 15 May 2023 ()
Where
43 km (27 mi) west-northwest of Star Valley Ranch, WY · earthquakes near Star Valley Ranch
Idaho today
every earthquake in Idaho in the last 24 hours
Magnitude
M 2.1 (ml)
Depth
0.4 km below the surface
Felt
no reports yet
Nearest
Bonneville County, 30 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1275 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 17 km (11 mi) from the epicentre. In Star Valley Ranch, 43 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 41 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 5.8 370,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 260,000× the energy of this one
  3. Around the size people start to feel M 3.0 23× the energy of this one
  4. This earthquake M 2.1 about 41 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 2 earthquakes of M5 or more within 50 km:

  1. 5.3 Southeastern Idaho · 22 km SSE of this epicentre
  2. 5.3 29 km WSW of Freedom, Idaho · 28 km S 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 43.1775, -111.4102. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Bonneville County, ID 30 km (18 mi) NW earthquakes near Bonneville County
Caribou County, ID 45 km (28 mi) SSW earthquakes near Caribou County
Teton County, ID 67 km (42 mi) NNE earthquakes near Teton County
Madison County, ID 71 km (44 mi) NNW earthquakes near Madison County
Bingham County, ID 80 km (50 mi) W earthquakes near Bingham County
Bannock County, ID 86 km (53 mi) SW earthquakes near Bannock County

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

Aftershocks so far

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

  1. 2.6 5 km NNE of Star Valley Ranch, Wyoming
  2. 2.9 15 km WSW of Freedom, Idaho
  3. 2.0 13 km E of Irwin, Idaho
  4. 1.6 22 km ENE of Soda Springs, Idaho
  5. 2.5 17 km E of Irwin, Idaho
  6. 2.0 9 km ESE of Alpine Northeast, Wyoming
  7. 2.3 3 km NNE of Star Valley Ranch, Wyoming
  8. 2.8 5 km NE of Star Valley Ranch, Wyoming
  9. 1.7 5 km N of Alpine Northeast, Wyoming
  10. 2.2 12 km NNW of Alpine Northeast, Wyoming
  11. 1.9 19 km SSW of Irwin, Idaho
  12. 1.6 32 km W of Freedom, Idaho
  13. 3.0 7 km W of Thayne, Wyoming
  14. 2.3 4 km WSW of Thayne, Wyoming
  15. 2.7 7 km SW of Freedom, Idaho

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.