QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Saint George, UT

No earthquake was likely felt in Saint George in the 24 hours to 2:37 am MST (09:37 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 1.5 earthquake was recorded 46 km (28 mi) north-northeast of Saint George, UT, at 2:41 am MDT on 21 August 2020 (08:41 UTC), 7.9 km deep.

USGS: 13 km NNE of Pine Valley, Utah

48 km (30 mi) NNE of St. George, UT

2:41 am MDT, Aug 21, 2020 · · 7.9 km deep · released about 6.2 lb of TNT

Every earthquake near Saint George Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Washington County 27 kmIron County 47 kmBeaver County 97 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
2:41 am MDT on 21 August 2020 ()
Where
46 km (28 mi) north-northeast of Saint George, UT · earthquakes near Saint George
Magnitude
M 1.5 (ml)
Depth
7.9 km below the surface
Felt
no reports yet
Nearest
Washington County, 27 km S
Nearest mapped fault
Hurricane fault, 22 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 2274 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 7 km (4 mi) from the epicentre. In Saint George, 46 km away, the estimate is intensity I (not felt). 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: Enterprise.

How big was it?

This earthquake released about 6.2 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.5 about 6.2 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

The largest earthquake within 50 km since 2016 was M 4.2 on 2016-01-15 — about 11,000 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 6.3 Near Pine Valley, Utah · 12 km SSW of this epicentre
  2. 5.9 3 km SSE of Washington, Utah · 45 km S 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 37.5028, -113.4625. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Washington County, UT 27 km (17 mi) S earthquakes near Washington County
Iron County, UT 47 km (29 mi) NNE earthquakes near Iron County
Beaver County, UT 97 km (60 mi) NNE earthquakes near Beaver County
Piute County, UT 149 km (93 mi) NE earthquakes near Piute County

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

Aftershocks so far

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

  1. 3.1 20 km ESE of Kanarraville, Utah
  2. 2.1 21 km ESE of Kanarraville, Utah
  3. 1.5 12 km S of Cedar City, Utah
  4. 1.6 27 km NNE of Beryl Junction, Utah
  5. 2.0 27 km NNE of Beryl Junction, Utah
  6. 1.6 4 km NNE of Saint George, Utah
  7. 2.0 10 km SE of New Harmony, Utah
  8. 1.6 23 km WNW of Veyo, Utah
  9. 2.2 4 km E of New Harmony, Utah
  10. 1.7 13 km SSE of Kanarraville, Utah
  11. 1.5 7 km ESE of Kanarraville, Utah
  12. 1.8 8 km ENE of Kanarraville, Utah
  13. 2.2 6 km E of Washington, Utah
  14. 1.9 9 km S of Cedar City, Utah
  15. 2.1 18 km NW of Beryl Junction, 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.