QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

Earthquake near Ponca City, OK

No earthquake was likely felt in Ponca City in the 24 hours to 8:09 am CST (14:09 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 2.8 earthquake was recorded 44 km (27 mi) west-northwest of Ponca City, OK, at 1:32 am CST on 28 February 2017 (07:32 UTC), 8.0 km deep.

USGS: 3 km WNW of Deer Creek, Oklahoma

99 km (61 mi) S of Wichita, KS · 54 km (33 mi) NNE of Enid, OK

1:32 am CST, Feb 28, 2017 · · 8.0 km deep · released about 480 lb of TNT

10 km30 km60 km120 km N Grant County 21 kmKay County 37 kmSumner County 47 kmGarfield County 53 kmNoble County 56 kmHarper County 61 kmAlfalfa County 69 kmCowley County 79 kmPawnee County 95 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
1:32 am CST on 28 February 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 2.8 (ml)
Depth
8.0 km below the surface
Felt
no reports yet
Nearest
Grant County, 21 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3458 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 61 km (38 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 24 km, intensity III · Blackwell 24 km, intensity III · 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 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
  3. Around the size people start to feel M 3.0 2× the energy of this one
  4. This earthquake M 2.8 about 480 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 4.0 on 2016-11-25 — about 63 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 36.8189, -97.5544. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Grant County, OK 21 km (13 mi) W earthquakes near Grant County
Kay County, OK 37 km (23 mi) E earthquakes near Kay County
Sumner County, KS 47 km (29 mi) N earthquakes near Sumner County
Garfield County, OK 53 km (33 mi) SSW earthquakes near Garfield County
Noble County, OK 56 km (35 mi) SSE earthquakes near Noble County
Harper County, KS 61 km (38 mi) NW earthquakes near Harper County

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

Aftershocks so far

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

  1. 1.6 5 km SSE of Freeport, Kansas
  2. 1.5 2 km NE of Caldwell, Kansas
  3. 3.1 10 km W of Lamont, Oklahoma
  4. 3.2 10 km W of Lamont, Oklahoma
  5. 2.0 7 km ESE of Mayfield, Kansas
  6. 2.0 11 km NNW of Caldwell, Kansas
  7. 1.9 11 km NNW of Caldwell, Kansas
  8. 1.8 11 km NNW of Caldwell, Kansas
  9. 1.6 12 km NNW of Caldwell, Kansas
  10. 1.6 11 km NNW of Caldwell, Kansas
  11. 2.1 11 km NNW of Caldwell, Kansas
  12. 2.7 12 km NNW of Caldwell, Kansas
  13. 1.7 9 km W of Bluff City, Kansas
  14. 2.0 9 km W of Bluff City, Kansas
  15. 2.6 9 km ESE of Wakita, 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.