mining explosion · reviewed by a seismologist
M 2.8ml
Earthquake near Sheridan, WY
No earthquake was likely felt in Sheridan in the 24 hours to 7:46 am MST (14:46 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 2.8 mining explosion was recorded 34 km (21 mi) north-northwest of Sheridan, WY, at 5:32 pm MST on 9 March 2018 (00:32 UTC), less than 1 km deep.
USGS: 22 km NNE of Ranchester, Wyoming
- When
- 5:32 pm MST on 9 March 2018 ()
- Where
- 34 km (21 mi) north-northwest of Sheridan, WY · earthquakes near Sheridan
- Magnitude
- M 2.8 (ml)
- Depth
- 0.0 km below the surface
- Felt
- no reports yet
- Nearest
- Sheridan County, 38 km SSE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 3078 days ago
Earthquake alerts for Sheridan, WY
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Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 27 km (17 mi) from the epicentre. In Sheridan, 34 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 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
- Magna, Utah 2020 M 5.7 22,000× the energy of this one
- Around the size people start to feel M 3.0 2× the energy of this one
- This earthquake M 2.8 about 480 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 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 45.0938, -107.0633. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Sheridan County, WY | 38 km (23 mi) | SSE | earthquakes near Sheridan County |
| Big Horn County, MT | 50 km (31 mi) | NW | earthquakes near Big Horn County |
| Big Horn County, WY | 97 km (60 mi) | SW | earthquakes near Big Horn County |
| Johnson County, WY | 123 km (76 mi) | SSE | earthquakes near Johnson County |
| Powder River County, MT | 123 km (77 mi) | ENE | earthquakes near Powder River County |
| Yellowstone County, MT | 133 km (83 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.
- 3.3 33 km SW of Birney, Montana
- 3.2 30 km NE of Ranchester, Wyoming
- 3.2 30 km NE of Ranchester, Wyoming
- 2.9 31 km NE of Sheridan, Wyoming
- 2.9 28 km SSW of Birney, Montana
- 3.2 34 km NNE of Ranchester, Wyoming
- 2.8 25 km NNE of Sheridan, Wyoming
- 3.0 29 km NNE of Sheridan, Wyoming
- 2.9 29 km NNE of Sheridan, Wyoming
- 3.4 31 km NE of Ranchester, Wyoming
- 2.8 25 km SW of Birney, Montana
- 3.2 30 km SW of Birney, Montana
- 2.8 33 km SSW of Birney, Montana
- 2.8 32 km NE of Sheridan, Wyoming
- 3.4 30 km SW of Birney, Montana
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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.