mining explosion · reviewed by a seismologist
M 2.7ml
Earthquake near Torrington, WY
No earthquake was likely felt in Torrington in the 24 hours to 1:26 pm MST (20:26 UTC). The last one was M 5.0, 739 km (459 mi) SSE, at 4:21 am MDT on 23 July 2026, estimated intensity II (weak) in town; 499 felt reports to USGS. Every earthquake near Torrington
No: USGS classifies this as a mining explosion, not an earthquake. A magnitude 2.7 mining explosion was recorded 47 km (29 mi) northwest of Torrington, WY, at 3:57 pm MDT on 12 September 2021 (21:57 UTC), less than 1 km deep.
USGS: 19 km ENE of Hartville, Wyoming
- When
- 3:57 pm MDT on 12 September 2021 ()
- Where
- 47 km (29 mi) northwest of Torrington, WY · earthquakes near Torrington
- Magnitude
- M 2.7 (ml)
- Depth
- 0.0 km below the surface
- Felt
- no reports yet
- Nearest
- Goshen County, 38 km SSE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1814 days ago
Earthquake alerts for Torrington, WY
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Alerts are on for .
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 56 km (35 mi) from the epicentre. In Torrington, 47 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: Guernsey.
USGS catalogues this as mining explosion, not an earthquake.
How big was it?
This earthquake released about 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
- Magna, Utah 2020 M 5.7 32,000× the energy of this one
- Around the size people start to feel M 3.0 2.8× the energy of this one
- This earthquake M 2.7 about 340 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 42.4077, -104.5095. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Goshen County, WY | 38 km (23 mi) | SSE | earthquakes near Goshen County |
| Platte County, WY | 48 km (30 mi) | SW | earthquakes near Platte County |
| Sioux County, NE | 64 km (40 mi) | E | earthquakes near Sioux County |
| Niobrara County, WY | 73 km (45 mi) | N | earthquakes near Niobrara County |
| Scotts Bluff County, NE | 91 km (56 mi) | SE | earthquakes near Scotts Bluff County |
| Converse County, WY | 105 km (65 mi) | NW | earthquakes near Converse County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
1 earthquake has been recorded within 50 km since this one.
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.