QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Earthquake near Jackson, WY

No earthquake was likely felt in Jackson in the 24 hours to 4:38 pm MST (23:38 UTC). The last one was M 2.7, 23 km (14 mi) S, at 6:18 pm MST on 6 November 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Jackson

This page: a magnitude 1.9 earthquake was recorded 36 km (23 mi) south-southwest of Jackson, WY, at 1:49 pm MDT on 10 August 2021 (19:49 UTC), 6.0 km deep.

USGS: 1 km E of Alpine Northeast, Wyoming

1:49 pm MDT, Aug 10, 2021 · · 6.0 km deep · released about 25 lb of TNT

10 km30 km60 km120 km N Bonneville County 56 kmCaribou County 64 kmTeton County 65 kmMadison County 85 kmSublette County 99 kmBear Lake County 105 kmTeton County 105 kmLincoln County 110 kmBingham 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
1:49 pm MDT on 10 August 2021 ()
Where
36 km (23 mi) south-southwest of Jackson, WY · earthquakes near Jackson
Magnitude
M 1.9 (ml)
Depth
6.0 km below the surface
Felt
no reports yet
Nearest
Bonneville County, 56 km WNW
Nearest mapped fault
Grand Valley fault, 1 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 1919 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 14 km (9 mi) from the epicentre. In Jackson, 36 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: Hoback, Star Valley Ranch, South Park, Rafter J Ranch.

How big was it?

This earthquake released about 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 620,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 440,000× the energy of this one
  3. Around the size people start to feel M 3.0 39× the energy of this one
  4. This earthquake M 1.9 about 25 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 3 earthquakes of M5 or more within 50 km:

  1. 5.8 4 km SSE of Auburn, Wyoming · 48 km S of this epicentre
  2. 5.3 Southeastern Idaho · 33 km SW of this epicentre
  3. 5.3 29 km WSW of Freedom, Idaho · 45 km SW 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 43.1958, -110.9868. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Bonneville County, ID 56 km (35 mi) WNW earthquakes near Bonneville County
Caribou County, ID 64 km (40 mi) SW earthquakes near Caribou County
Teton County, ID 65 km (41 mi) NNW earthquakes near Teton County
Madison County, ID 85 km (53 mi) NW earthquakes near Madison County
Sublette County, WY 99 km (62 mi) ESE earthquakes near Sublette County
Bear Lake County, ID 105 km (65 mi) SSW earthquakes near Bear Lake 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. 2.2 7 km NNW of Auburn, Wyoming
  2. 1.6 10 km NE of Hoback, Wyoming
  3. 2.0 26 km SSW of Irwin, Idaho
  4. 2.6 12 km NE of Star Valley Ranch, Wyoming
  5. 2.2 11 km NE of Star Valley Ranch, Wyoming
  6. 2.6 13 km NE of Star Valley Ranch, Wyoming
  7. 2.4 Wyoming
  8. 2.3 11 km NE of Star Valley Ranch, Wyoming
  9. 2.1 27 km SSW of Irwin, Idaho
  10. 3.3 10 km W of Hoback, Wyoming
  11. 2.8 7 km WSW of Hoback, Wyoming
  12. 1.9 15 km W of Freedom, Idaho
  13. 3.3 13 km W of Freedom, Idaho
  14. 2.8 13 km W of Freedom, Idaho
  15. 2.4 6 km W of Hoback, 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.