QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Norman, OK

No earthquake was likely felt in Norman in the 24 hours to 2:16 pm CST (20:16 UTC). The last one was M 3.4, 70 km (43 mi) NW, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Norman

This page: a magnitude 1.5 earthquake was recorded 28 km (18 mi) south-southwest of Norman, OK, at 9:27 pm CST on 11 December 2020 (03:27 UTC), 6.8 km deep.

USGS: 5 km SE of Dibble, Oklahoma

53 km (33 mi) S of Oklahoma City, OK · 35 km (22 mi) SW of Norman, OK

9:27 pm CST, Dec 11, 2020 · · 6.8 km deep · released about 5.4 lb of TNT

10 km30 km60 km120 km N McClain County 13 kmGrady County 27 kmCleveland County 34 kmGarvin County 41 kmPottawatomie County 62 kmStephens County 62 kmOklahoma County 64 kmCanadian County 70 kmMurray County 74 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
9:27 pm CST on 11 December 2020 ()
Where
28 km (18 mi) south-southwest of Norman, OK · earthquakes near Norman
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 1.5 (ml)
Depth
6.8 km below the surface
Felt
no reports yet
Nearest
McClain County, 13 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2158 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 Norman, 28 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: Blanchard, Lindsay, Goldsby, Purcell, Lexington, Noble.

How big was it?

This earthquake released about 5.4 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 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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 34.9978, -97.5898. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
McClain County, OK 13 km (8 mi) E earthquakes near McClain County
Grady County, OK 27 km (17 mi) W earthquakes near Grady County
Cleveland County, OK 34 km (21 mi) NE earthquakes near Cleveland County
Garvin County, OK 41 km (25 mi) SE earthquakes near Garvin County
Pottawatomie County, OK 62 km (39 mi) ENE earthquakes near Pottawatomie County
Stephens County, OK 62 km (39 mi) SSW earthquakes near Stephens County

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

Aftershocks so far

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

  1. 1.5 7 km SW of Dibble, Oklahoma
  2. 1.6 4 km NNE of Minco, Oklahoma
  3. 1.8 4 km SSE of Union City, Oklahoma
  4. 1.5 4 km SSE of Union City, Oklahoma
  5. 2.5 4 km NNE of Minco, Oklahoma
  6. 2.4 3 km NNE of Minco, Oklahoma
  7. 1.8 8 km NE of Alex, Oklahoma
  8. 1.6 1 km NE of Minco, Oklahoma
  9. 1.7 2 km ENE of Minco, Oklahoma
  10. 1.5 1 km ENE of Minco, Oklahoma
  11. 1.9 2 km ENE of Minco, Oklahoma
  12. 1.6 9 km E of Chickasha, Oklahoma
  13. 1.9 6 km NNW of Foster, Oklahoma
  14. 2.8 6 km SW of Dibble, Oklahoma
  15. 2.0 9 km E of Chickasha, 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.