QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

Earthquake near Ponca City, OK

No earthquake was likely felt in Ponca City in the 24 hours to 10:08 am CST (16:08 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 2.5 earthquake was recorded 44 km (27 mi) west-northwest of Ponca City, OK, at 6:41 am CDT on 8 October 2017 (11:41 UTC), 5.9 km deep.

USGS: 11 km N of Deer Creek, Oklahoma

88 km (55 mi) S of Wichita, KS

6:41 am CDT, Oct 8, 2017 · · 5.9 km deep · released about 170 lb of TNT

10 km30 km60 km120 km N Grant County 28 kmKay County 34 kmSumner County 37 kmHarper County 59 kmNoble County 63 kmGarfield County 64 kmCowley County 70 kmAlfalfa County 75 kmSedgwick County 86 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
6:41 am CDT on 8 October 2017 ()
Where
44 km (27 mi) west-northwest of Ponca City, OK · earthquakes near Ponca City
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 2.5 (ml)
Depth
5.9 km below the surface
Felt
no reports yet
Nearest
Grant County, 28 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3229 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 46 km (29 mi) from the epicentre. In Ponca City, 44 km away, the estimate is intensity II (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 16 km, intensity III · Blackwell 23 km, intensity II · Wellington 41 km, intensity II · Ponca City 44 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.6× the energy of this one
  4. This earthquake M 2.5 about 170 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

The largest earthquake within 50 km since 2016 was M 4.3 on 2017-09-08 — about 500 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 36.9084, -97.5082. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Grant County, OK 28 km (18 mi) WSW earthquakes near Grant County
Kay County, OK 34 km (21 mi) ESE earthquakes near Kay County
Sumner County, KS 37 km (23 mi) N earthquakes near Sumner County
Harper County, KS 59 km (36 mi) WNW earthquakes near Harper County
Noble County, OK 63 km (39 mi) SSE earthquakes near Noble County
Garfield County, OK 64 km (40 mi) SSW earthquakes near Garfield County

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

Aftershocks so far

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

  1. 2.3 2 km SSE of Freeport, Kansas
  2. 1.5 8 km SSE of Mayfield, Kansas
  3. 1.5 6 km NW of Renfrow, Oklahoma
  4. 2.2 2 km S of Caldwell, Kansas
  5. 2.1 9 km W of Bluff City, Kansas
  6. 1.9 1 km NNW of Milan, Kansas
  7. 2.4 10 km WNW of Caldwell, Kansas
  8. 1.6 10 km NNW of Caldwell, Kansas
  9. 1.9 3 km E of Freeport, Kansas
  10. 1.6 7 km E of Manchester, Oklahoma
  11. 1.7 4 km SW of Mayfield, Kansas
  12. 1.6 2 km E of Freeport, Kansas
  13. 1.8 6 km SSW of Freeport, Kansas
  14. 2.5 8 km N of Nardin, Oklahoma
  15. 3.3 7 km N of Nardin, 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.