QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

7 km E of Alton, Missouri

· 12 km deep · released about 41 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Oregon County 7 kmRipley County 40 kmCarter County 43 kmRandolph County 48 kmShannon County 50 kmHowell County 51 kmFulton County 57 kmSharp County 61 kmLawrence County 76 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
Magnitude
M 2.1 (md)
Depth
12 km below the surface
Felt
no reports yet
Nearest
Oregon County, 7 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1009 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 41 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 370,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 260,000× the energy of this one
  3. Around the size people start to feel M 3.0 23× the energy of this one
  4. This earthquake M 2.1 about 41 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.

Where

Epicentre 36.7055, -91.3222. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Oregon County, MO 7 km (5 mi) ENE of here earthquakes near Oregon County
Ripley County, MO 40 km (25 mi) W of here earthquakes near Ripley County
Carter County, MO 43 km (27 mi) SW of here earthquakes near Carter County
Randolph County, AR 48 km (30 mi) NNW of here earthquakes near Randolph County
Shannon County, MO 50 km (31 mi) S of here earthquakes near Shannon County
Howell County, MO 51 km (32 mi) E of here earthquakes near Howell County

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

Aftershocks so far

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

  1. 2.2 10 km SSW of Birch Tree, Missouri
  2. 1.8 9 km W of Maynard, Arkansas
  3. 1.9 9 km SW of Koshkonong, Missouri
  4. 1.9 10 km NNE of Salem, Arkansas
  5. 2.3 11 km NNE of Salem, Arkansas
  6. 2.9 12 km WSW of Grandin, Missouri
  7. 2.2 13 km W of Maynard, Arkansas

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.