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 8:57 am MST (15:57 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 8 km (5 mi) west-southwest of Herriman, UT, at 3:16 pm MDT on 12 June 2021 (21:16 UTC), less than 1 km deep.

USGS: Utah

17 km (10 mi) SW of West Jordan, UT · 8 km (5 mi) W of Herriman, UT

3:16 pm MDT, Jun 12, 2021 · · 0.0 km deep · released about 11 lb of TNT

10 km30 km60 km120 km N Salt Lake County 26 kmUtah County 55 kmDavis County 62 kmMorgan County 82 kmWasatch County 82 kmTooele County 85 kmWeber County 90 kmJuab County 103 kmSummit County 106 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
3:16 pm MDT on 12 June 2021 ()
Where
8 km (5 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, 26 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 1905 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, 8 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 8 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 · 36 km NE of this epicentre
  2. 5.0 1 km NE of Magna, Utah · 27 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 40.4797, -112.1147. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Salt Lake County, UT 26 km (16 mi) NE earthquakes near Salt Lake County
Utah County, UT 55 km (34 mi) SE earthquakes near Utah County
Davis County, UT 62 km (39 mi) N earthquakes near Davis County
Morgan County, UT 82 km (51 mi) NNE earthquakes near Morgan County
Wasatch County, UT 82 km (51 mi) E earthquakes near Wasatch County
Tooele County, UT 85 km (53 mi) W earthquakes near Tooele County

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

Aftershocks so far

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

  1. 1.6 6 km WNW of Lehi, Utah
  2. 1.6 7 km WNW of Lehi, Utah
  3. 1.8 3 km WSW of Bluffdale, Utah
  4. 1.8 1 km SE of Bluffdale, Utah
  5. 1.7 3 km ENE of Magna, Utah
  6. 1.8 2 km ENE of Saratoga Springs, Utah
  7. 1.6 2 km SE of North Salt Lake, Utah
  8. 1.5 6 km NE of Magna, Utah
  9. 2.1 5 km SE of Snowbird, Utah
  10. 1.6 7 km SW of Vineyard, Utah
  11. 1.7 5 km ENE of Magna, Utah
  12. 2.5 5 km ENE of Magna, Utah
  13. 2.3 3 km S of Bluffdale, Utah
  14. 1.6 3 km S of Bluffdale, Utah
  15. 1.5 3 km S of Bluffdale, 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.