QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

Earthquake near Monroe, UT

No earthquake was likely felt in Monroe in the 24 hours to 12:34 am MST (07:34 UTC). The last one was M 3.3, 41 km (25 mi) SSW, at 10:44 pm MDT on 30 October 2026, estimated intensity II (weak) in town; 5 felt reports to USGS. Every earthquake near Monroe

This page: a magnitude 3.3 earthquake was recorded 6 km (4 mi) east-southeast of Monroe, UT, at 10:38 pm MDT on 23 September 2017 (04:38 UTC), 7.1 km deep. 53 people have reported feeling it to USGS.

USGS: 5 km ESE of Monroe, Utah

10:38 pm MDT, Sep 23, 2017 · · 7.1 km deep · released about 1.5 tons of TNT

Every earthquake near Monroe Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sevier County 26 kmPiute County 32 kmSanpete County 94 kmMillard County 101 kmWayne County 101 kmGarfield County 102 kmBeaver County 107 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
10:38 pm MDT on 23 September 2017 ()
Where
6 km (4 mi) east-southeast of Monroe, UT · earthquakes near Monroe
Magnitude
M 3.3 (ml)
Depth
7.1 km below the surface
Felt
53 reports · strongest reported intensity III
Measured shaking
intensity IV (ShakeMap)
Nearest
Sevier County, 26 km NE
Nearest mapped fault
Annabella graben faults, 5 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 3246 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 54 km (34 mi) from the epicentre. In Monroe, 6 km away, the estimate is intensity III (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: Monroe 6 km, intensity III · Richfield 18 km, intensity III · Salina 42 km, intensity II · Fillmore 46 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.5 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 110,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 3,500× the energy of this one
  4. This earthquake M 3.3 about 1.5 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 3.2× more

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 4 earthquakes of M5 or more within 50 km:

  1. 6.6 Near Marysvale, Utah · 33 km WSW of this epicentre
  2. 5.2 0 km SSW of Central Valley, Utah · 10 km NNW of this epicentre
  3. 5.2 25 km SE of Salina, Utah · 45 km ENE of this epicentre
  4. 5.0 10 km NE of Marysvale, Utah · 13 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 38.6150, -112.0560. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sevier County, UT 26 km (16 mi) NE earthquakes near Sevier County
Piute County, UT 32 km (20 mi) SSW earthquakes near Piute County
Sanpete County, UT 94 km (58 mi) NNE earthquakes near Sanpete County
Millard County, UT 101 km (63 mi) WNW earthquakes near Millard County
Wayne County, UT 101 km (63 mi) ESE earthquakes near Wayne County
Garfield County, UT 102 km (63 mi) SSE earthquakes near Garfield County

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

Aftershocks so far

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

  1. 1.8 21 km W of Marysvale, Utah
  2. 1.7 1 km WNW of Loa, Utah
  3. 2.6 1 km NW of Loa, Utah
  4. 1.5 9 km NNW of Marysvale, Utah
  5. 1.8 1 km WNW of Loa, Utah
  6. 1.8 3 km NW of Loa, Utah
  7. 1.7 1 km NNW of Loa, Utah
  8. 1.7 1 km WNW of Loa, Utah
  9. 2.6 1 km NW of Loa, Utah
  10. 1.6 1 km NW of Loa, Utah
  11. 1.8 1 km WNW of Loa, Utah
  12. 1.7 2 km W of Loa, Utah
  13. 3.1 2 km NNW of Loa, Utah
  14. 2.0 1 km WNW of Loa, Utah
  15. 2.6 1 km NNW of Loa, 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.