QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Pinckneyville, IL

USGS: 4 km NW of Tamaroa, Illinois

100 km (62 mi) ESE of St. Louis, MO

1:44 am CDT, Sep 20, 2018 · · 13 km deep · released about 82 lb of TNT

10 km30 km60 km120 km N Perry County 13 kmWashington County 24 kmJefferson County 33 kmFranklin County 36 kmJackson County 44 kmRandolph County 50 kmClinton County 50 kmWilliamson County 57 kmMarion County 61 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
1:44 am CDT on 20 September 2018 ()
Where
14 km (9 mi) NE of Pinckneyville, IL · earthquakes near Pinckneyville
Magnitude
M 2.3 (md)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Perry County, 13 km SW
Nearest mapped fault
Wabash Valley liquefaction features, under 1 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 2935 days ago

A magnitude 2.3 earthquake was recorded 14 km (9 mi) NE of Pinckneyville, IL, at 1:44 am CDT on 20 September 2018 (06:44 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Du Quoin, Sesser, Nashville, Christopher.

How big was it?

This earthquake released about 82 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 12× the energy of this one
  4. This earthquake M 2.3 about 82 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 since 1900 lists no earthquake of M5 or more within 50 km.

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 38.1717, -89.2658. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Perry County, IL 13 km (8 mi) SW earthquakes near Perry County
Washington County, IL 24 km (15 mi) NNW earthquakes near Washington County
Jefferson County, IL 33 km (21 mi) ENE earthquakes near Jefferson County
Franklin County, IL 36 km (22 mi) SE earthquakes near Franklin County
Jackson County, IL 44 km (27 mi) SSW earthquakes near Jackson County
Randolph County, IL 50 km (31 mi) WSW earthquakes near Randolph County

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

Aftershocks so far

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

  1. 2.4 4 km NNE of Valier, Illinois
  2. 2.3 7 km NW of Woodlawn, Illinois
  3. 2.5 6 km ENE of Pinckneyville, Illinois
  4. 3.1 5 km WNW of Waltonville, Illinois
  5. 2.2 1 km S of Benton, Illinois
  6. 2.5 6 km NNW of Mount Vernon, Illinois
  7. 2.4 3 km E of Junction City, Illinois
  8. 2.0 4 km NNW of Venedy, Illinois
  9. 2.3 5 km NNW of Thompsonville, Illinois
  10. 2.1 7 km NW of Du Bois, Illinois
  11. 2.5 7 km W of Tamaroa, Illinois
  12. 2.1 6 km NW of Sparta, Illinois

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.