QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2ml

Earthquake near Richfield, UT

No earthquake was likely felt in Richfield in the 24 hours to 4:20 am MST (11:20 UTC). The last one was M 3.2, 34 km (21 mi) W, at 8:35 am MDT on 22 April 2026, estimated intensity II (weak) in town; 6 felt reports to USGS. Every earthquake near Richfield

This page: a magnitude 2.2 earthquake was recorded 4 km (3 mi) north of Richfield, UT, at 10:43 am MDT on 31 October 2021 (16:43 UTC), 9.4 km deep.

USGS: 4 km N of Richfield, Utah

10:43 am MDT, Oct 31, 2021 · · 9.4 km deep · released about 60 lb of TNT

10 km30 km60 km120 km N Sevier County 25 kmPiute County 53 kmSanpete County 77 kmMillard County 92 kmBeaver County 112 kmWayne County 113 kmJuab County 117 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
10:43 am MDT on 31 October 2021 ()
Where
4 km (3 mi) north of Richfield, UT · earthquakes near Richfield
Magnitude
M 2.2 (ml)
Depth
9.4 km below the surface
Felt
no reports yet
Nearest
Sevier County, 25 km ESE
Nearest mapped fault
Annabella graben faults, 15 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 1764 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 16 km (10 mi) from the epicentre. In Richfield, 4 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: Richfield 4 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 60 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 250,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 180,000× the energy of this one
  3. Around the size people start to feel M 3.0 16× the energy of this one
  4. This earthquake M 2.2 about 60 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 4.0 on 2019-02-20 — about 580 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 6.6 Near Marysvale, Utah · 44 km SW of this epicentre
  2. 5.2 0 km SSW of Central Valley, Utah · 12 km S of this epicentre
  3. 5.2 25 km SE of Salina, Utah · 41 km E of this epicentre
  4. 5.0 10 km NE of Marysvale, Utah · 33 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 38.8095, -112.0900. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sevier County, UT 25 km (16 mi) ESE earthquakes near Sevier County
Piute County, UT 53 km (33 mi) S earthquakes near Piute County
Sanpete County, UT 77 km (48 mi) NE earthquakes near Sanpete County
Millard County, UT 92 km (57 mi) W earthquakes near Millard County
Beaver County, UT 112 km (69 mi) WSW earthquakes near Beaver County
Wayne County, UT 113 km (71 mi) ESE earthquakes near Wayne 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. 1.6 27 km WSW of Emery, Utah
  2. 2.0 9 km ESE of Scipio, Utah
  3. 1.6 8 km SE of Mayfield, Utah
  4. 1.9 6 km S of Joseph, Utah
  5. 2.0 16 km W of Marysvale, Utah
  6. 1.5 17 km W of Marysvale, Utah
  7. 1.8 10 km W of Fayette, Utah
  8. 1.8 24 km SSW of Kanosh, Utah
  9. 2.0 7 km SW of Fayette, Utah
  10. 2.1 20 km SSW of Kanosh, Utah
  11. 1.6 21 km SSW of Kanosh, Utah
  12. 1.6 22 km SSW of Kanosh, Utah
  13. 1.7 21 km SSW of Kanosh, Utah
  14. 1.9 7 km S of Kanosh, Utah
  15. 1.8 5 km WSW of Richfield, 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.