QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Blanchard, OK

No earthquake was likely felt in Blanchard in the 24 hours to 10:10 am CST (16:10 UTC). The last one was M 3.4, 63 km (39 mi) NNW, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Blanchard

This page: a magnitude 1.5 earthquake was recorded 7 km (5 mi) west-southwest of Blanchard, OK, at 5:33 pm CDT on 20 August 2020 (22:33 UTC), 7.2 km deep.

USGS: 7 km WSW of Blanchard, Oklahoma

45 km (28 mi) SSW of Oklahoma City, OK · 34 km (21 mi) SW of Moore, OK

5:33 pm CDT, Aug 20, 2020 · · 7.2 km deep · released about 6.2 lb of TNT

10 km30 km60 km120 km N Grady County 17 kmMcClain County 27 kmCleveland County 39 kmCanadian County 54 kmGarvin County 58 kmOklahoma County 58 kmCaddo County 60 kmStephens County 70 kmPottawatomie County 71 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
5:33 pm CDT on 20 August 2020 ()
Where
7 km (5 mi) west-southwest of Blanchard, OK · earthquakes near Blanchard
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 1.5 (ml)
Depth
7.2 km below the surface
Felt
no reports yet
Nearest
Grady County, 17 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2273 days ago

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

At this magnitude and depth it was probably too small to be felt, even directly above it. In Blanchard, 7 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.

Earthquakes near other towns within 30 km: Chickasha, Newcastle, Tuttle, Goldsby, Ninnekah, Norman.

How big was it?

This earthquake released about 6.2 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.5 about 6.2 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 35.1015, -97.7272. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Grady County, OK 17 km (11 mi) WSW earthquakes near Grady County
McClain County, OK 27 km (17 mi) ESE earthquakes near McClain County
Cleveland County, OK 39 km (24 mi) ENE earthquakes near Cleveland County
Canadian County, OK 54 km (34 mi) NNW earthquakes near Canadian County
Garvin County, OK 58 km (36 mi) SE earthquakes near Garvin County
Oklahoma County, OK 58 km (36 mi) NNE earthquakes near Oklahoma County

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

Aftershocks so far

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

  1. 1.6 3 km SSE of Union City, Oklahoma
  2. 2.6 3 km SSE of Union City, Oklahoma
  3. 1.9 3 km SSE of Union City, Oklahoma
  4. 1.7 3 km SE of Union City, Oklahoma
  5. 2.2 3 km SSE of Union City, Oklahoma
  6. 1.6 9 km E of Chickasha, Oklahoma
  7. 2.8 6 km SW of Dibble, Oklahoma
  8. 2.0 9 km E of Chickasha, Oklahoma
  9. 1.6 9 km E of Chickasha, Oklahoma
  10. 1.7 6 km SSW of Dibble, Oklahoma
  11. 2.0 6 km SSW of Dibble, Oklahoma
  12. 1.9 6 km SW of Dibble, Oklahoma
  13. 2.0 5 km SSW of Dibble, Oklahoma
  14. 2.7 5 km SW of Dibble, Oklahoma
  15. 2.2 6 km WSW of Dibble, 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.