QuakeIndex

Earthquake · reviewed by a seismologist

M 4.5mww

Earthquake near Blackwell, OK

No earthquake was likely felt in Blackwell in the 24 hours to 2:25 am CST (08:25 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 4.5 earthquake was recorded 46 km (28 mi) west of Blackwell, OK, at 11:10 am CST on 31 January 2022 (17:10 UTC), 7.8 km deep. 4,769 people have reported feeling it to USGS.

USGS: 7 km NW of Medford, Oklahoma

50 km (31 mi) N of Enid, OK · 101 km (63 mi) SSW of Wichita, KS

11:10 am CST, Jan 31, 2022 · · 7.8 km deep · released about 85 tons of TNT

10 km30 km60 km120 km N Grant County 7 kmHarper County 45 kmAlfalfa County 49 kmSumner County 50 kmGarfield County 53 kmKay County 58 kmNoble County 72 kmKingman County 84 kmBarber County 89 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
11:10 am CST on 31 January 2022 ()
Where
46 km (28 mi) west of Blackwell, OK · earthquakes near Blackwell
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 4.5 (mww)
Depth
7.8 km below the surface
Felt
4,769 reports · strongest reported intensity VI
Measured shaking
intensity VI (ShakeMap)
USGS impact alert
green
Nearest
Grant County, 7 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 821 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 610 km (379 mi) from the epicentre. In Blackwell, 46 km away, the estimate is intensity IV (light). 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 26 km, intensity IV · Anthony 40 km, intensity IV · Blackwell 46 km, intensity IV. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 85 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 2,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 89× the energy of this one
  3. Magna, Utah 2020 M 5.7 63× the energy of this one
  4. This earthquake M 4.5 about 85 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 180× 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 (31 mi) since our catalogue begins in 2016. The previous largest was M 4.4 on 2019-05-17.

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 36.8510, -97.7935. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Grant County, OK 7 km (4 mi) S earthquakes near Grant County
Harper County, KS 45 km (28 mi) NNW earthquakes near Harper County
Alfalfa County, OK 49 km (30 mi) WSW earthquakes near Alfalfa County
Sumner County, KS 50 km (31 mi) NNE earthquakes near Sumner County
Garfield County, OK 53 km (33 mi) S earthquakes near Garfield County
Kay County, OK 58 km (36 mi) E earthquakes near Kay County

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

Aftershocks so far

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

  1. 2.3 7 km NW of Medford, Oklahoma
  2. 1.9 7 km NW of Medford, Oklahoma
  3. 1.6 Oklahoma
  4. 2.2 6 km NW of Jefferson, Oklahoma
  5. 2.3 6 km NW of Jefferson, Oklahoma
  6. 2.2 7 km NW of Jefferson, Oklahoma
  7. 1.9 6 km NW of Jefferson, Oklahoma
  8. 1.6 7 km NW of Jefferson, Oklahoma
  9. 2.9 7 km NW of Jefferson, Oklahoma
  10. 1.8 10 km W of Wakita, Oklahoma
  11. 1.8 0 km ENE of Renfrow, Oklahoma
  12. 2.2 6 km NW of Medford, Oklahoma
  13. 1.9 7 km NW of Jefferson, Oklahoma
  14. 2.2 6 km NW of Medford, Oklahoma
  15. 1.8 6 km NW of Medford, 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.