QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Earthquake near Hoback, WY

No earthquake was likely felt in Hoback in the 24 hours to 7:42 am MST (14:42 UTC). The last one was M 2.7, 5 km (3 mi) E, at 6:18 pm MST on 6 November 2026, estimated intensity III (weak) in town; 1 felt report to USGS. Every earthquake near Hoback

This page: a magnitude 2.1 earthquake was recorded 7 km (5 mi) south-southeast of Hoback, WY, at 4:55 pm MDT on 15 September 2021 (22:55 UTC), 5.6 km deep.

USGS: 7 km SSE of Hoback, Wyoming

4:55 pm MDT, Sep 15, 2021 · · 5.6 km deep · released about 41 lb of TNT

10 km30 km60 km120 km N Teton County 71 kmBonneville County 73 kmCaribou County 80 kmSublette County 85 kmTeton County 96 kmMadison County 96 kmLincoln County 110 kmBear Lake County 114 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
4:55 pm MDT on 15 September 2021 ()
Where
7 km (5 mi) south-southeast of Hoback, WY · earthquakes near Hoback
Magnitude
M 2.1 (ml)
Depth
5.6 km below the surface
Felt
no reports yet
Nearest
Teton County, 71 km NNW
Nearest mapped fault
Grand Valley fault, 19 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 1875 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 16 km (10 mi) from the epicentre. In Hoback, 7 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.

Likely felt in: Hoback 7 km, intensity II. Estimated for each town centre; each link is that town's own record.

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

The largest earthquake within 50 km since 2016 was M 4.8 on 2016-08-27 — about 12,000 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 · 50 km NE 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 43.2185, -110.7593. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Teton County, ID 71 km (44 mi) NNW earthquakes near Teton County
Bonneville County, ID 73 km (45 mi) WNW earthquakes near Bonneville County
Caribou County, ID 80 km (50 mi) SW earthquakes near Caribou County
Sublette County, WY 85 km (53 mi) SE earthquakes near Sublette County
Teton County, WY 96 km (60 mi) NNE earthquakes near Teton County
Madison County, ID 96 km (60 mi) NW earthquakes near Madison County

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

Aftershocks so far

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

  1. 1.7 4 km ENE of Hoback, Wyoming
  2. 1.8 6 km ENE of Hoback, Wyoming
  3. 1.7 14 km E of Irwin, Idaho
  4. 1.5 2 km N of Rafter J Ranch, Wyoming
  5. 1.8 19 km E of Jackson, Wyoming
  6. 1.7 11 km ENE of Swan Valley, Idaho
  7. 1.6 12 km E of Jackson, Wyoming
  8. 1.6 13 km E of Jackson, Wyoming
  9. 1.5 12 km E of Jackson, Wyoming
  10. 1.7 8 km NW of Alpine Northwest, Wyoming
  11. 2.2 Wyoming
  12. 2.8 21 km ESE of Kelly, Wyoming
  13. 2.2 21 km ESE of Kelly, Wyoming
  14. 2.3 7 km E of Alpine Northeast, Wyoming
  15. 2.2 7 km E 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.