QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2ml

Earthquake near Casper, WY

No earthquake was likely felt in Casper in the 24 hours to 9:09 am MST (16:09 UTC). The last one was M 3.6, 260 km (162 mi) ENE, at 8:14 pm MST on 8 March 2025, estimated intensity II (weak) in town; 7 felt reports to USGS. Every earthquake near Casper

This page: a magnitude 3.2 earthquake was recorded 29 km (18 mi) east-northeast of Casper, WY, at 1:11 pm MDT on 22 July 2020 (19:11 UTC), 34 km deep.

USGS: 16 km NW of Rolling Hills, Wyoming

31 km (19 mi) ENE of Casper, WY

1:11 pm MDT, Jul 22, 2020 · · 34 km deep · released about 1,900 lb of TNT

10 km30 km60 km120 km N Converse County 39 kmNatrona County 62 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
1:11 pm MDT on 22 July 2020 ()
Where
29 km (18 mi) east-northeast of Casper, WY · earthquakes near Casper
Magnitude
M 3.2 (ml)
Depth
34 km below the surface
Felt
no reports yet
Nearest
Converse County, 39 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2230 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 32 km (20 mi) from the epicentre. In Casper, 29 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.

Likely felt in: Casper 29 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,900 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 180,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 7,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 5,600× the energy of this one
  4. This earthquake M 3.2 about 1,900 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 2× 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 42.9892, -106.0040. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Converse County, WY 39 km (24 mi) E earthquakes near Converse County
Natrona County, WY 62 km (39 mi) W earthquakes near Natrona County
Johnson County, WY 126 km (79 mi) NNW earthquakes near Johnson County
Platte County, WY 128 km (80 mi) SE earthquakes near Platte County
Weston County, WY 150 km (93 mi) NE earthquakes near Weston County

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

Aftershocks so far

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

  1. 3.0 12 km SSE of Edgerton, Wyoming
  2. 3.8 12 km NW of Rolling Hills, Wyoming
  3. 2.5 7 km SSE of Edgerton, 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.