QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Richfield, UT

No earthquake was likely felt in Richfield in the 24 hours to 2:40 am MST (09:40 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 1.7 earthquake was recorded 42 km (26 mi) west-southwest of Richfield, UT, at 2:33 pm MST on 1 December 2021 (21:33 UTC), less than 1 km deep.

USGS: 19 km SSW of Kanosh, Utah

2:33 pm MST, Dec 1, 2021 · · 0.6 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Piute County 50 kmMillard County 62 kmSevier County 65 kmBeaver County 68 kmIron County 105 kmSanpete 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
2:33 pm MST on 1 December 2021 ()
Where
42 km (26 mi) west-southwest of Richfield, UT · earthquakes near Richfield
Magnitude
M 1.7 (ml)
Depth
0.6 km below the surface
Felt
no reports yet
Nearest
Piute County, 50 km SE
Nearest mapped fault
Beaver Basin faults, 19 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 1029 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 13 km (8 mi) from the epicentre. In Richfield, 42 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.

How big was it?

This earthquake released about 12 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 870,000× the energy of this one
  3. Around the size people start to feel M 3.0 78× the energy of this one
  4. This earthquake M 1.7 about 12 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 4.1 on 2019-04-14 — about 3,000 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 6.6 Near Marysvale, Utah · 20 km SE of this epicentre
  2. 5.2 0 km SSW of Central Valley, Utah · 39 km E of this epicentre
  3. 5.0 10 km NE of Marysvale, Utah · 38 km ESE 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 38.6432, -112.5450. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Piute County, UT 50 km (31 mi) SE earthquakes near Piute County
Millard County, UT 62 km (38 mi) NW earthquakes near Millard County
Sevier County, UT 65 km (40 mi) E earthquakes near Sevier County
Beaver County, UT 68 km (42 mi) WSW earthquakes near Beaver County
Iron County, UT 105 km (65 mi) SW earthquakes near Iron County
Sanpete County, UT 117 km (72 mi) NE earthquakes near Sanpete County

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

Aftershocks so far

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

  1. 1.6 22 km SSW of Kanosh, Utah
  2. 1.6 8 km S of Beaver, Utah
  3. 1.7 21 km SSW of Kanosh, Utah
  4. 1.9 7 km S of Kanosh, Utah
  5. 1.8 5 km WSW of Richfield, Utah
  6. 1.6 7 km WNW of Junction, Utah
  7. 1.8 6 km ESE of Beaver, Utah
  8. 1.8 4 km WNW of Joseph, Utah
  9. 2.0 20 km W of Marysvale, Utah
  10. 1.5 9 km SSE of Joseph, Utah
  11. 2.0 7 km SSE of Joseph, Utah
  12. 1.9 5 km S of Joseph, Utah
  13. 1.9 8 km SE of Beaver, Utah
  14. 1.5 7 km SE of Beaver, Utah
  15. 1.8 27 km NE of Milford, 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.