QuakeIndex

mining explosion · reviewed by a seismologist

M 3.3ml

Earthquake near Sheridan, WY

No earthquake was likely felt in Sheridan in the 24 hours to 1:23 pm MST (20:23 UTC). The last one was M 3.5, 40 km (25 mi) N, at 10:02 am MDT on 29 May 2026, estimated intensity II (weak) in town. Every earthquake near Sheridan

No: USGS classifies this as a mining explosion, not an earthquake. A magnitude 3.3 mining explosion was recorded 38 km (24 mi) north-northeast of Sheridan, WY, at 1:10 pm MDT on 2 August 2022 (19:10 UTC), less than 1 km deep.

USGS: 32 km SW of Birney, Montana

1:10 pm MDT, Aug 2, 2022 · · 0.0 km deep · released about 1.3 tons of TNT

10 km30 km60 km120 km N Sheridan County 39 kmBig Horn County 62 kmPowder River County 105 kmBig Horn County 114 kmRosebud County 117 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
1:10 pm MDT on 2 August 2022 ()
Where
38 km (24 mi) north-northeast of Sheridan, WY · earthquakes near Sheridan
Montana today
every earthquake in Montana in the last 24 hours
Magnitude
M 3.3 (ml)
Depth
0.0 km below the surface
Felt
no reports yet
Nearest
Sheridan County, 39 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1491 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 52 km (32 mi) from the epicentre. In Sheridan, 38 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.

USGS catalogues this as mining explosion, not an earthquake.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,000× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.8× more

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 since 1900 lists no earthquake of M5 or more within 50 km.

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 45.1258, -106.8307. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sheridan County, WY 39 km (24 mi) S earthquakes near Sheridan County
Big Horn County, MT 62 km (39 mi) WNW earthquakes near Big Horn County
Powder River County, MT 105 km (65 mi) ENE earthquakes near Powder River County
Big Horn County, WY 114 km (71 mi) SW earthquakes near Big Horn County
Rosebud County, MT 117 km (73 mi) N earthquakes near Rosebud County
Yellowstone County, MT 144 km (90 mi) NW earthquakes near Yellowstone 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. 2.6 17 km NE of Ranchester, Wyoming
  2. 3.5 31 km NE of Ranchester, Wyoming
  3. 2.8 33 km NNE of Sheridan, Wyoming
  4. 3.5 33 km NE of Ranchester, Wyoming
  5. 2.9 28 km ENE of Ranchester, Wyoming
  6. 2.9 29 km NNE of Sheridan, Wyoming
  7. 3.0 31 km NNE of Sheridan, Wyoming
  8. 3.2 28 km NE of Ranchester, Wyoming
  9. 3.3 31 km NE of Ranchester, Wyoming
  10. 2.6 33 km NE of Ranchester, Wyoming
  11. 3.2 29 km NE of Ranchester, Wyoming
  12. 3.5 27 km NE of Ranchester, Wyoming
  13. 3.5 24 km NE of Ranchester, Wyoming
  14. 2.8 28 km NE of Ranchester, Wyoming
  15. 3.1 33 km NNE of Ranchester, 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.