QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Silver Summit, UT

USGS: 5 km WNW of Silver Summit, Utah

32 km (20 mi) E of Salt Lake City, UT · 25 km (15 mi) ENE of Millcreek, UT

9:22 am MST, Feb 2, 2018 · · 4.4 km deep · released about 15 lb of TNT

10 km30 km60 km120 km N Salt Lake County 33 kmMorgan County 38 kmSummit County 51 kmWasatch County 57 kmDavis County 63 kmWeber County 64 kmUtah County 71 kmRich County 101 kmUinta County 102 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
9:22 am MST on 2 February 2018 ()
Where
5 km (3 mi) WNW of Silver Summit, UT · earthquakes near Silver Summit
Magnitude
M 1.8 (ml)
Depth
4.4 km below the surface
Felt
no reports yet
Nearest
Salt Lake County, 33 km WSW
Nearest mapped fault
Main Canyon fault, 8 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 3164 days ago

A magnitude 1.8 earthquake was recorded 5 km (3 mi) WNW of Silver Summit, UT, at 9:22 am MST on 2 February 2018 (16:22 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Summit Park, Snyderville, Park City, Oakley, Mount Olympus, Coalville.

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. 5.3 Near Salt Lake City, Utah · 22 km WSW of this epicentre
  2. 5.0 1 km NE of Magna, Utah · 46 km W 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 40.7528, -111.5478. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Salt Lake County, UT 33 km (21 mi) WSW earthquakes near Salt Lake County
Morgan County, UT 38 km (23 mi) N earthquakes near Morgan County
Summit County, UT 51 km (31 mi) ENE earthquakes near Summit County
Wasatch County, UT 57 km (35 mi) SE earthquakes near Wasatch County
Davis County, UT 63 km (39 mi) WNW earthquakes near Davis County
Weber County, UT 64 km (40 mi) NNW earthquakes near Weber County

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

Aftershocks so far

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

  1. 1.8 5 km ESE of Morgan, Utah
  2. 1.6 5 km ESE of Morgan, Utah
  3. 1.6 5 km ESE of Morgan, Utah
  4. 1.5 8 km SW of Wallsburg, Utah
  5. 1.6 7 km WSW of Wallsburg, Utah
  6. 2.6 4 km SSW of Daniel, Utah
  7. 1.7 3 km S of Bluffdale, Utah
  8. 1.7 5 km W of Salt Lake City, Utah
  9. 1.9 3 km SSW of Bluffdale, Utah
  10. 2.2 2 km SSW of Bluffdale, Utah
  11. 2.2 3 km SSW of Bluffdale, Utah
  12. 2.3 3 km SSW of Bluffdale, Utah
  13. 1.6 2 km SSE of Bluffdale, Utah
  14. 2.3 2 km S of Bluffdale, Utah
  15. 2.5 2 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.