QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7ml

Earthquake near Monroe, UT

No earthquake was likely felt in Monroe in the 24 hours to 11:07 am MST (18:07 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 2.7 earthquake was recorded 9 km (6 mi) south-southwest of Monroe, UT, at 12:48 am MDT on 20 August 2021 (06:48 UTC), 11 km deep.

USGS: 8 km SSE of Joseph, Utah

12:48 am MDT, Aug 20, 2021 · · 11 km deep · released about 350 lb of TNT

10 km30 km60 km120 km N Piute County 25 kmSevier County 38 kmMillard County 94 kmBeaver County 95 kmGarfield County 103 kmSanpete County 104 kmWayne 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
12:48 am MDT on 20 August 2021 ()
Where
9 km (6 mi) south-southwest of Monroe, UT · earthquakes near Monroe
Magnitude
M 2.7 (ml)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Piute County, 25 km S
Nearest mapped fault
Annabella graben faults, 15 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 1836 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 23 km (14 mi) from the epicentre. In Monroe, 9 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: Monroe 9 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 350 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 43,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 31,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.7× the energy of this one
  4. This earthquake M 2.7 about 350 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 4.0 on 2019-02-20 — about 99 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 6.6 Near Marysvale, Utah · 20 km WSW of this epicentre
  2. 5.2 0 km SSW of Central Valley, Utah · 17 km NNE of this epicentre
  3. 5.0 10 km NE of Marysvale, Utah · 6 km SSE 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 38.5597, -112.1787. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Piute County, UT 25 km (16 mi) S earthquakes near Piute County
Sevier County, UT 38 km (24 mi) ENE earthquakes near Sevier County
Millard County, UT 94 km (58 mi) WNW earthquakes near Millard County
Beaver County, UT 95 km (59 mi) WSW earthquakes near Beaver County
Garfield County, UT 103 km (64 mi) SE earthquakes near Garfield County
Sanpete County, UT 104 km (65 mi) NNE earthquakes near Sanpete County

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

Aftershocks so far

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

  1. 2.0 9 km WNW of Circleville, Utah
  2. 1.7 9 km SE of Marysvale, Utah
  3. 2.4 3 km NNW of Joseph, Utah
  4. 1.5 24 km SSW of Kanosh, Utah
  5. 1.6 2 km SW of Junction, Utah
  6. 1.5 6 km S of Joseph, Utah
  7. 1.9 1 km WSW of Junction, Utah
  8. 3.4 4 km S of Joseph, Utah
  9. 1.6 7 km SSE of Joseph, Utah
  10. 2.2 4 km S of Joseph, Utah
  11. 1.9 5 km S of Joseph, Utah
  12. 1.9 5 km S of Joseph, Utah
  13. 2.7 4 km S of Joseph, Utah
  14. 1.9 7 km S of Joseph, Utah
  15. 2.0 8 km S of Joseph, 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.