QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3ml

34 km WSW of Howell, Utah

Yes. A magnitude 2.3 earthquake was recorded 34 km WSW of Howell, Utah, at 7:27 am MST on 8 December 2021 (14:27 UTC), 8.5 km deep.

· 8.5 km deep · released about 88 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Box Elder County 21 kmOneida County 65 kmDavis County 84 kmWeber County 87 kmCache County 89 kmCassia County 99 kmFranklin County 101 kmPower County 117 kmMorgan County 119 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
Magnitude
M 2.3 (ml)
Depth
8.5 km below the surface
Felt
no reports yet
Nearest
Box Elder County, 21 km W
Nearest mapped fault
Hansel Valley fault, 11 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 1799 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. 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 88 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 5.8 170,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 120,000× 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 88 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 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.6 The 1934 Hansel Valley, Utah Earthquake · 2 km NNE of this epicentre
  2. 5.9 35 km SSW of Howell, Utah · 16 km SE of this epicentre
  3. 5.6 Hansel Valley, Utah · 20 km NNE of this epicentre
  4. 5.5 56 km SW of Howell, Utah · 22 km SW of this epicentre
  5. 5.2 27 km SW of Thatcher, Utah · 30 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 41.6383, -112.8043. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Box Elder County, UT 21 km (13 mi) W earthquakes near Box Elder County
Oneida County, ID 65 km (40 mi) NNE earthquakes near Oneida County
Davis County, UT 84 km (52 mi) SE earthquakes near Davis County
Weber County, UT 87 km (54 mi) ESE earthquakes near Weber County
Cache County, UT 89 km (55 mi) E earthquakes near Cache County
Cassia County, ID 99 km (61 mi) NW earthquakes near Cassia County

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

Aftershocks so far

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

  1. 1.6 15 km SW of Thatcher, Utah
  2. 1.8 14 km SW of Thatcher, Utah
  3. 2.2 15 km SW of Thatcher, Utah
  4. 3.1 15 km SW of Thatcher, Utah
  5. 1.8 15 km SW of Thatcher, Utah
  6. 1.7 15 km SW of Thatcher, Utah
  7. 1.9 16 km SW of Thatcher, Utah
  8. 2.0 15 km SW of Thatcher, Utah
  9. 2.0 16 km SW of Thatcher, Utah
  10. 1.8 15 km SW of Thatcher, Utah
  11. 2.0 15 km SW of Thatcher, Utah
  12. 2.0 15 km SW of Thatcher, Utah
  13. 2.6 15 km SW of Thatcher, Utah
  14. 1.5 15 km SW of Thatcher, Utah
  15. 2.1 15 km SW of Thatcher, 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.