QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3ml

Earthquake near Saint George, UT

No earthquake was likely felt in Saint George in the 24 hours to 2:41 pm MST (21:41 UTC). The last one was M 4.0, 95 km (59 mi) W, at 1:16 am MDT on 6 June 2025, estimated intensity II (weak) in town; 37 felt reports to USGS. Every earthquake near Saint George

This page: a magnitude 2.3 earthquake was recorded 33 km (20 mi) south of Saint George, UT, at 6:36 am MDT on 24 August 2021 (12:36 UTC), 8.6 km deep.

USGS: 32 km S of Saint George, Utah

30 km (18 mi) S of St. George, UT

6:36 am MDT, Aug 24, 2021 · · 8.6 km deep · released about 85 lb of TNT

Every earthquake near Saint George Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Washington County 50 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
6:36 am MDT on 24 August 2021 ()
Where
33 km (20 mi) south of Saint George, UT · earthquakes near Saint George
Magnitude
M 2.3 (ml)
Depth
8.6 km below the surface
Felt
no reports yet
Nearest
Washington County, 50 km N
Nearest mapped fault
Washington fault, 5 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1906 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 18 km (11 mi) from the epicentre. In Saint George, 33 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.

How big was it?

This earthquake released about 85 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 11× the energy of this one
  4. This earthquake M 2.3 about 85 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 lists one earthquake of M5 or more within 50 km:

  1. 5.9 3 km SSE of Washington, Utah · 32 km N of this epicentre

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 36.8140, -113.5187. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Washington County, UT 50 km (31 mi) N earthquakes near Washington County
Lincoln County, NV 150 km (93 mi) NW earthquakes near Lincoln County

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

Aftershocks so far

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

  1. 1.6 41 km SSE of Saint George, Utah
  2. 2.7 56 km SE of Scenic, Arizona
  3. 1.6 11 km NNE of Beaver Dam, Arizona
  4. 2.0 37 km SSE of Saint George, Utah
  5. 1.8 3 km SW of Saint George, Utah
  6. 1.8 13 km SSW of Saint George, Utah
  7. 2.9 10 km SSE of Washington, Utah
  8. 1.7 14 km NE of Beaver Dam, Arizona
  9. 1.7 13 km NE of Beaver Dam, Arizona
  10. 2.3 10 km N of Beaver Dam, Arizona
  11. 1.6 10 km W of Ivins, Utah
  12. 1.6 16 km SW of Apple Valley, Utah
  13. 2.1 14 km NNE of Beaver Dam, Arizona
  14. 1.8 14 km NNE of Beaver Dam, Arizona
  15. 1.6 18 km WSW of Santa Clara, Utah

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.