QuakeIndex

mining explosion · reviewed by a seismologist

M 3.4ml

Earthquake near Wright, WY

No earthquake was likely felt in Wright in the 24 hours to 4:42 pm MST (23:42 UTC). The last one was M 3.4, 18 km (11 mi) NNE, at 2:13 pm MDT on 6 July 2026, estimated intensity III (weak) in town. Every earthquake near Wright

No: USGS classifies this as a mining explosion, not an earthquake. A magnitude 3.4 mining explosion was recorded 40 km (25 mi) east-southeast of Wright, WY, at 2:04 pm MDT on 29 July 2018 (20:04 UTC), less than 1 km deep.

USGS: 40 km ESE of Wright, Wyoming

2:04 pm MDT, Jul 29, 2018 · · 0.0 km deep · released about 1.9 tons of TNT

10 km30 km60 km120 km N Weston County 46 kmNiobrara County 76 kmCampbell County 76 kmConverse County 79 kmCrook County 116 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
2:04 pm MDT on 29 July 2018 ()
Where
40 km (25 mi) east-southeast of Wright, WY · earthquakes near Wright
Magnitude
M 3.4 (ml)
Depth
0.0 km below the surface
Felt
no reports yet
Nearest
Weston County, 46 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2955 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 58 km (36 mi) from the epicentre. In Wright, 40 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 1.9 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 89,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,800× the energy of this one
  4. This earthquake M 3.4 about 1.9 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4× 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 43.6022, -105.0396. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Weston County, WY 46 km (29 mi) NE earthquakes near Weston County
Niobrara County, WY 76 km (47 mi) SE earthquakes near Niobrara County
Campbell County, WY 76 km (47 mi) NNW earthquakes near Campbell County
Converse County, WY 79 km (49 mi) SSW earthquakes near Converse County
Crook County, WY 116 km (72 mi) NNE earthquakes near Crook County
Lawrence County, SD 129 km (80 mi) NE earthquakes near Lawrence County

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

Aftershocks so far

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

  1. 3.3 17 km ESE of Wright, Wyoming
  2. 3.4 26 km SSE of Wright, Wyoming
  3. 3.4 7 km NNE of Wright, Wyoming
  4. 3.3 31 km ESE of Wright, Wyoming
  5. 3.4 13 km ENE of Wright, Wyoming
  6. 3.2 20 km SSE of Wright, Wyoming
  7. 3.4 15 km N of Wright, Wyoming
  8. 3.3 18 km SE of Wright, Wyoming
  9. 3.2 29 km SSE of Sleepy Hollow, Wyoming
  10. 3.4 12 km E of Wright, Wyoming
  11. 3.2 29 km SSE of Wright, Wyoming
  12. 3.4 11 km E of Wright, Wyoming
  13. 3.3 29 km SSE of Wright, Wyoming
  14. 3.6 23 km ENE of Wright, Wyoming
  15. 3.2 35 km SE of Wright, 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.