QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Ephraim, UT

No earthquake was likely felt in Ephraim in the 24 hours to 11:02 pm MST (06:02 UTC). The last one was M 1.9, 10 km (7 mi) S, at 2:29 am MDT on 22 June 2026, estimated intensity II (weak) in town. Every earthquake near Ephraim

This page: a magnitude 1.8 earthquake was recorded 41 km (26 mi) south-southeast of Ephraim, UT, at 8:53 pm MST on 12 December 2024 (03:53 UTC), less than 1 km deep.

USGS: 17 km WNW of Emery, Utah

8:53 pm MST, Dec 12, 2024 · · 0.2 km deep · released about 15 lb of TNT

10 km30 km60 km120 km N Sanpete County 42 kmSevier County 45 kmEmery County 61 kmWayne County 92 kmPiute County 97 kmCarbon County 103 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
8:53 pm MST on 12 December 2024 ()
Where
41 km (26 mi) south-southeast of Ephraim, UT · earthquakes near Ephraim
Magnitude
M 1.8 (md)
Depth
0.2 km below the surface
Felt
no reports yet
Nearest
Sanpete County, 42 km NNW
Nearest mapped fault
Snow Lake graben, 12 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 699 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 14 km (9 mi) from the epicentre. In Ephraim, 41 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: Ferron.

How big was it?

This earthquake released about 15 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 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 2 earthquakes of M5 or more within 50 km:

  1. 5.2 13 km ESE of Castle Dale, Utah · 49 km ENE of this epicentre
  2. 5.2 25 km SE of Salina, Utah · 26 km SW 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 39.0118, -111.4225. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sanpete County, UT 42 km (26 mi) NNW earthquakes near Sanpete County
Sevier County, UT 45 km (28 mi) SW earthquakes near Sevier County
Emery County, UT 61 km (38 mi) E earthquakes near Emery County
Wayne County, UT 92 km (57 mi) SSE earthquakes near Wayne County
Piute County, UT 97 km (60 mi) SW earthquakes near Piute County
Carbon County, UT 103 km (64 mi) NE earthquakes near Carbon County

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

Aftershocks so far

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

  1. 1.8 7 km SSE of Salina, Utah
  2. 2.1 13 km SW of Emery, Utah
  3. 1.8 28 km NE of Fremont, Utah
  4. 2.0 27 km NNE of Fremont, Utah
  5. 1.9 3 km E of Manti, Utah
  6. 1.7 31 km N of Fremont, Utah
  7. 1.5 5 km W of Redmond, Utah
  8. 1.6 15 km NW of Emery, Utah
  9. 2.1 19 km WNW of Orangeville, Utah
  10. 1.7 21 km WSW of Emery, Utah
  11. 1.6 15 km WNW of Orangeville, Utah
  12. 1.6 0 km SW of Centerfield, Utah
  13. 1.9 30 km N of Fremont, Utah
  14. 1.6 16 km NW of Emery, Utah
  15. 2.5 27 km W of Emery, 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.