QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4ml

Earthquake near Blackwell, OK

No earthquake was likely felt in Blackwell in the 24 hours to 10:56 am CST (16:56 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 2.4 earthquake was recorded 19 km (12 mi) north-northwest of Blackwell, OK, at 1:31 am CDT on 14 March 2018 (06:31 UTC), 8.1 km deep.

USGS: 5 km NW of Braman, Oklahoma

81 km (51 mi) S of Wichita, KS

1:31 am CDT, Mar 14, 2018 · · 8.1 km deep · released about 120 lb of TNT

10 km30 km60 km120 km N Kay County 26 kmSumner County 32 kmGrant County 41 kmCowley County 57 kmNoble County 65 kmHarper County 66 kmGarfield County 74 kmSedgwick County 81 kmAlfalfa County 88 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
1:31 am CDT on 14 March 2018 ()
Where
19 km (12 mi) north-northwest of Blackwell, OK · earthquakes near Blackwell
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 2.4 (ml)
Depth
8.1 km below the surface
Felt
no reports yet
Nearest
Kay County, 26 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3075 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 41 km (25 mi) from the epicentre. In Blackwell, 19 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: Blackwell 19 km, intensity II · Caldwell 22 km, intensity II · Wellington 34 km, intensity II · Ponca City 38 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 120 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 89,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.9× the energy of this one
  4. This earthquake M 2.4 about 120 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 710 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 36.9598, -97.3764. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kay County, OK 26 km (16 mi) SE earthquakes near Kay County
Sumner County, KS 32 km (20 mi) NNW earthquakes near Sumner County
Grant County, OK 41 km (26 mi) WSW earthquakes near Grant County
Cowley County, KS 57 km (35 mi) ENE earthquakes near Cowley County
Noble County, OK 65 km (40 mi) S earthquakes near Noble County
Harper County, KS 66 km (41 mi) WNW 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. 2.8 4 km NNW of Medford, Oklahoma
  2. 1.6 7 km ESE of Freeport, Kansas
  3. 1.5 7 km E of Freeport, Kansas
  4. 2.0 4 km SW of Bluff City, Kansas
  5. 1.5 4 km SW of Bluff City, Kansas
  6. 1.7 9 km ESE of Caldwell, Kansas
  7. 2.8 3 km E of Freeport, Kansas
  8. 1.7 9 km WSW of Hunnewell, Kansas
  9. 1.9 4 km WSW of Bluff City, Kansas
  10. 2.8 7 km SSW of Conway Springs, Kansas
  11. 3.0 3 km NE of Renfrow, Oklahoma
  12. 2.9 2 km NE of Renfrow, Oklahoma
  13. 2.6 2 km NE of Renfrow, Oklahoma
  14. 2.3 2 km NE of Renfrow, Oklahoma
  15. 3.0 2 km NE of Renfrow, 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.