QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2ml

Earthquake near Ponca City, OK

No earthquake was likely felt in Ponca City in the 24 hours to 7:34 am CST (13:34 UTC). The last one was M 3.4, 149 km (93 mi) SW, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Ponca City

This page: a magnitude 3.2 earthquake was recorded 48 km (30 mi) northwest of Ponca City, OK, at 8:30 am CDT on 24 March 2018 (13:30 UTC), 6.7 km deep.

USGS: 7 km W of Hunnewell, Kansas

79 km (49 mi) S of Wichita, KS

8:30 am CDT, Mar 24, 2018 · · 6.7 km deep · released about 1,900 lb of TNT

10 km30 km60 km120 km N Sumner County 27 kmGrant County 35 kmKay County 37 kmHarper County 55 kmCowley County 64 kmNoble County 71 kmGarfield County 73 kmSedgwick County 76 kmAlfalfa County 80 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
8:30 am CDT on 24 March 2018 ()
Where
48 km (30 mi) northwest of Ponca City, OK · earthquakes near Ponca City
Magnitude
M 3.2 (ml)
Depth
6.7 km below the surface
Felt
no reports yet
Nearest
Sumner County, 27 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3068 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 190 km (118 mi) from the epicentre. In Ponca City, 48 km away, the estimate is intensity III (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: Caldwell 11 km, intensity III · Blackwell 28 km, intensity III · Wellington 32 km, intensity III · Conway Springs 46 km, intensity III · Ponca City 48 km, intensity III · Belle Plaine 48 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,900 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 180,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 7,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 5,600× the energy of this one
  4. This earthquake M 3.2 about 1,900 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 2× more

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 4.3 on 2017-09-08 — about 45 times the energy of this one.

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 36.9938, -97.4917. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sumner County, KS 27 km (17 mi) N earthquakes near Sumner County
Grant County, OK 35 km (22 mi) SW earthquakes near Grant County
Kay County, OK 37 km (23 mi) ESE earthquakes near Kay County
Harper County, KS 55 km (34 mi) WNW earthquakes near Harper County
Cowley County, KS 64 km (40 mi) ENE earthquakes near Cowley County
Noble County, OK 71 km (44 mi) SSE earthquakes near Noble County

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

Aftershocks so far

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

  1. 1.6 4 km ESE of Freeport, Kansas
  2. 1.5 4 km ESE of Freeport, Kansas
  3. 2.6 11 km SSW of Mayfield, Kansas
  4. 2.6 0 km SW of Wakita, Oklahoma
  5. 1.7 1 km S of Bluff City, Kansas
  6. 2.8 4 km NNW of Medford, Oklahoma
  7. 1.6 7 km ESE of Freeport, Kansas
  8. 1.5 7 km E of Freeport, Kansas
  9. 2.0 4 km SW of Bluff City, Kansas
  10. 1.5 4 km SW of Bluff City, Kansas
  11. 1.6 7 km N of Argonia, Kansas
  12. 1.7 7 km N of Argonia, Kansas
  13. 1.7 9 km ESE of Caldwell, Kansas
  14. 1.8 5 km SSE of Anthony, Kansas
  15. 2.8 3 km E of Freeport, Kansas

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.