QuakeIndex

mining explosion · reviewed by a seismologist

M 1.7ml

Earthquake near Herriman, UT

No earthquake was likely felt in Herriman in the 24 hours to 9:49 am MST (16:49 UTC). The last one was M 1.6, 10 km (6 mi) W, at 3:23 pm MDT on 16 September 2026, estimated intensity II (weak) in town. Every earthquake near Herriman

No: USGS classifies this as a mining explosion, not an earthquake. A magnitude 1.7 mining explosion was recorded 11 km (7 mi) west-southwest of Herriman, UT, at 12:05 pm MDT on 22 March 2023 (18:05 UTC), less than 1 km deep.

USGS: Utah

19 km (12 mi) SW of West Jordan, UT · 11 km (7 mi) WSW of Herriman, UT

12:05 pm MDT, Mar 22, 2023 · · 0.0 km deep · released about 11 lb of TNT

10 km30 km60 km120 km N Salt Lake County 29 kmUtah County 56 kmDavis County 64 kmTooele County 83 kmMorgan County 84 kmWasatch County 84 kmWeber County 92 kmJuab County 100 kmSummit County 109 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
12:05 pm MDT on 22 March 2023 ()
Where
11 km (7 mi) west-southwest of Herriman, UT · earthquakes near Herriman
Magnitude
M 1.7 (ml)
Depth
0.0 km below the surface
Felt
no reports yet
Nearest
Salt Lake County, 29 km NE
Nearest mapped fault
Oquirrh fault, 10 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 1267 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 12 km (7 mi) from the epicentre. In Herriman, 11 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: Herriman 11 km, intensity II. Estimated for each town centre; each link is that town's own record.

USGS catalogues this as mining explosion, not an earthquake.

How big was it?

This earthquake released about 11 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 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× the energy of this one
  4. This earthquake M 1.7 about 11 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 5.7 on 2020-03-18 — about 1,000,000 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.3 Near Salt Lake City, Utah · 39 km NE of this epicentre
  2. 5.0 1 km NE of Magna, Utah · 29 km N 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 40.4654, -112.1445. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Salt Lake County, UT 29 km (18 mi) NE earthquakes near Salt Lake County
Utah County, UT 56 km (35 mi) SE earthquakes near Utah County
Davis County, UT 64 km (40 mi) N earthquakes near Davis County
Tooele County, UT 83 km (51 mi) W earthquakes near Tooele County
Morgan County, UT 84 km (52 mi) NE earthquakes near Morgan County
Wasatch County, UT 84 km (52 mi) E earthquakes near Wasatch County

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

Aftershocks so far

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

  1. 1.1 6 km NE of Magna, Utah
  2. 1.0 6 km SSW of Bingham Canyon, Utah
  3. 2.0 6 km WNW of Lehi, Utah
  4. 1.6 5 km SSW of Bingham Canyon, Utah
  5. 2.3 3 km SW of Bingham Canyon, Utah
  6. 1.6 5 km NNW of Saratoga Springs, Utah
  7. 2.9 6 km NNW of Saratoga Springs, Utah
  8. 1.6 6 km NNW of Saratoga Springs, Utah
  9. 2.2 7 km NNW of Saratoga Springs, Utah
  10. 2.2 5 km ENE of Magna, Utah
  11. 1.7 6 km NW of Saratoga Springs, Utah
  12. 1.8 8 km NW of Saratoga Springs, Utah
  13. 1.7 5 km NE of Magna, Utah
  14. 1.7 5 km ENE of Magna, Utah
  15. 1.9 6 km WNW of Lehi, 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.