QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

9 km SW of Mammoth Spring, Arkansas

· 5.0 km deep · released about 51 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Fulton County 18 kmSharp County 33 kmOregon County 34 kmHowell County 43 kmIzard County 47 kmRandolph County 55 kmBaxter County 65 kmLawrence County 65 kmRipley County 71 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
5.0 km below the surface
Felt
no reports yet
Nearest
Fulton County, 18 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2237 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 51 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 5.8 300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 210,000× the energy of this one
  3. Around the size people start to feel M 3.0 19× the energy of this one
  4. This earthquake M 2.1 about 51 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 36.4453, -91.6305. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Fulton County, AR 18 km (11 mi) ENE of here earthquakes near Fulton County
Sharp County, AR 33 km (21 mi) NNW of here earthquakes near Sharp County
Oregon County, MO 34 km (21 mi) SW of here earthquakes near Oregon County
Howell County, MO 43 km (27 mi) SSE of here earthquakes near Howell County
Izard County, AR 47 km (29 mi) NNE of here earthquakes near Izard County
Randolph County, AR 55 km (34 mi) WNW of here earthquakes near Randolph County

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

Aftershocks so far

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

  1. 2.2 7 km ENE of West Plains, Missouri
  2. 2.3 7 km SSW of Ravenden, Arkansas
  3. 2.1 9 km NNW of Ravenden Springs, Arkansas
  4. 1.8 2 km W of Imboden, Arkansas
  5. 2.2 6 km WNW of West Plains, Missouri
  6. 2.3 4 km SE of Franklin, Arkansas
  7. 2.0 3 km SSW of Imboden, Arkansas
  8. 3.1 4 km SSW of Imboden, Arkansas
  9. 2.1 18 km WNW of Maynard, Arkansas
  10. 2.3 6 km WSW of Ravenden, Arkansas
  11. 1.7 Missouri-Arkansas border region
  12. 1.7 2 km WSW of Imboden, Arkansas
  13. 2.1 2 km SE of Ravenden, Arkansas
  14. 1.9 3 km ESE of Ravenden, Arkansas
  15. 1.8 Missouri-Arkansas border region

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.