QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

23 km NE of Fort Supply, Oklahoma

· 6.5 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Harper County 28 kmWoodward County 33 kmWoods County 45 kmComanche County 54 kmEllis County 64 kmClark County 70 kmBarber County 83 kmMajor County 86 kmDewey County 87 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 1.8 (ml)
Depth
6.5 km below the surface
Felt
no reports yet
Nearest
Harper County, 28 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 818 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 14 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 790,000× the energy of this one
  3. Around the size people start to feel M 3.0 70× the energy of this one
  4. This earthquake M 1.8 about 14 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 36.7087, -99.3695. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Harper County, OK 28 km (17 mi) ESE of here earthquakes near Harper County
Woodward County, OK 33 km (20 mi) NNW of here earthquakes near Woodward County
Woods County, OK 45 km (28 mi) W of here earthquakes near Woods County
Comanche County, KS 54 km (33 mi) SSW of here earthquakes near Comanche County
Ellis County, OK 64 km (40 mi) NNE of here earthquakes near Ellis County
Clark County, KS 70 km (44 mi) SE of here earthquakes near Clark County

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

Aftershocks so far

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

  1. 1.7 14 km SSE of Freedom, Oklahoma
  2. 1.8 15 km S of Freedom, Oklahoma
  3. 2.0 11 km NE of May, Oklahoma
  4. 1.6 10 km NE of May, Oklahoma
  5. 1.6 10 km NNE of Freedom, Oklahoma
  6. 1.6 20 km NNW of Mooreland, Oklahoma
  7. 1.8 7 km NNW of Waynoka, Oklahoma
  8. 1.5 23 km NE of Fort Supply, Oklahoma
  9. 1.9 23 km NE of Fort Supply, Oklahoma
  10. 1.8 22 km WSW of Freedom, Oklahoma

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.