QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Salt Lake City, UT

No earthquake was likely felt in Salt Lake City in the 24 hours to 6:42 pm MST (01:42 UTC). The last one was M 2.2, 13 km (8 mi) WSW, at 8:46 am MDT on 17 June 2026, estimated intensity II (weak) in town; 28 felt reports to USGS. Every earthquake near Salt Lake City

This page: a magnitude 1.8 earthquake was recorded 44 km (28 mi) northeast of Salt Lake City, UT, at 5:11 am MST on 29 December 2021 (12:11 UTC), 12 km deep.

USGS: 4 km NNW of Henefer, Utah

45 km (28 mi) NE of Salt Lake City, UT · 36 km (23 mi) E of Layton, UT

5:11 am MST, Dec 29, 2021 · · 12 km deep · released about 13 lb of TNT

10 km30 km60 km120 km N Morgan County 6 kmWeber County 38 kmSummit County 51 kmSalt Lake County 54 kmDavis County 57 kmRich County 69 kmCache County 78 kmUinta County 85 kmWasatch County 85 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
5:11 am MST on 29 December 2021 ()
Where
44 km (28 mi) northeast of Salt Lake City, UT · earthquakes near Salt Lake City
Magnitude
M 1.8 (ml)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Morgan County, 6 km NW
Nearest mapped fault
Main Canyon fault, 3 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 1777 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 5 km (3 mi) from the epicentre. In Salt Lake City, 44 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: Morgan, Coalville, Mountain Green.

How big was it?

This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 810,000× the energy of this one
  3. Around the size people start to feel M 3.0 72× the energy of this one
  4. This earthquake M 1.8 about 13 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. 5.3 Near Salt Lake City, Utah · 45 km SSW 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 41.0493, -111.5270. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Morgan County, UT 6 km (4 mi) NW earthquakes near Morgan County
Weber County, UT 38 km (24 mi) NW earthquakes near Weber County
Summit County, UT 51 km (32 mi) ESE earthquakes near Summit County
Salt Lake County, UT 54 km (34 mi) SW earthquakes near Salt Lake County
Davis County, UT 57 km (35 mi) W earthquakes near Davis County
Rich County, UT 69 km (43 mi) NNE earthquakes near Rich County

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

Aftershocks so far

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

  1. 1.6 9 km S of Morgan, Utah
  2. 1.6 2 km SE of North Salt Lake, Utah
  3. 1.8 12 km ENE of Wolf Creek, Utah
  4. 2.6 15 km NNW of Summit Park, Utah
  5. 1.7 14 km N of Henefer, Utah
  6. 1.6 13 km SSE of Morgan, Utah
  7. 1.9 25 km SW of Evanston, Wyoming
  8. 1.6 8 km NE of Morgan, Utah
  9. 1.8 7 km NE of Morgan, Utah
  10. 2.3 5 km ENE of Huntsville, Utah
  11. 2.4 11 km ENE of Huntsville, Utah
  12. 1.7 28 km WSW of Bear River, Wyoming
  13. 2.0 12 km WSW of Echo, Utah
  14. 2.0 6 km E of Silver Summit, Utah
  15. 2.3 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.