QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6ml

Earthquake near Blackwell, OK

No earthquake was likely felt in Blackwell in the 24 hours to 3:28 pm CST (21:28 UTC). The last one was M 3.4, 149 km (93 mi) SSW, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Blackwell

This page: a magnitude 2.6 earthquake was recorded 20 km (13 mi) west-northwest of Blackwell, OK, at 8:55 pm CST on 11 November 2016 (02:55 UTC), 4.5 km deep. 2 people have reported feeling it to USGS.

USGS: 11 km NNW of Nardin, Oklahoma

88 km (55 mi) S of Wichita, KS

8:55 pm CST, Nov 11, 2016 · · 4.5 km deep · released about 240 lb of TNT

10 km30 km60 km120 km N Grant County 31 kmKay County 31 kmSumner County 37 kmHarper County 61 kmNoble County 61 kmGarfield County 65 kmCowley County 68 kmAlfalfa County 78 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
8:55 pm CST on 11 November 2016 ()
Where
20 km (13 mi) west-northwest of Blackwell, OK · earthquakes near Blackwell
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 2.6 (ml)
Depth
4.5 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Grant County, 31 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3563 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 51 km (32 mi) from the epicentre. In Blackwell, 20 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 18 km, intensity III · Blackwell 20 km, intensity III · Ponca City 41 km, intensity II · Wellington 41 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 240 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 63,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 45,000× the energy of this one
  3. Around the size people start to feel M 3.0 4× the energy of this one
  4. This earthquake M 2.6 about 240 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

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 36.9033, -97.4759. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Grant County, OK 31 km (19 mi) WSW earthquakes near Grant County
Kay County, OK 31 km (19 mi) ESE earthquakes near Kay County
Sumner County, KS 37 km (23 mi) N earthquakes near Sumner County
Harper County, KS 61 km (38 mi) WNW earthquakes near Harper County
Noble County, OK 61 km (38 mi) SSE earthquakes near Noble County
Garfield County, OK 65 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

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

  1. 2.5 10 km W of Lamont, Oklahoma
  2. 1.5 11 km W of Caldwell, Kansas
  3. 3.0 6 km E of Renfrow, Oklahoma
  4. 2.5 6 km WSW of Bluff City, Kansas
  5. 2.2 8 km ENE of Bluff City, Kansas
  6. 1.6 Kansas
  7. 1.8 9 km W of Bluff City, Kansas
  8. 1.8 5 km ESE of Freeport, Kansas
  9. 2.1 4 km NE of Bluff City, Kansas
  10. 2.8 3 km NNW of Medford, Oklahoma
  11. 2.7 3 km N of Renfrow, Oklahoma
  12. 2.7 3 km NW of Medford, Oklahoma
  13. 1.5 5 km NE of Caldwell, Kansas
  14. 1.6 1 km SE of Mayfield, Kansas
  15. 1.8 4 km ESE of Caldwell, 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.