QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

Earthquake near Chickasha, OK

No earthquake was likely felt in Chickasha in the 24 hours to 3:43 pm CST (21:43 UTC). The last one was M 3.4, 63 km (39 mi) N, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Chickasha

This page: a magnitude 2.8 earthquake was recorded 10 km (6 mi) east-southeast of Chickasha, OK, at 7:31 pm CST on 31 December 2020 (01:31 UTC), 9.4 km deep. 15 people have reported feeling it to USGS.

USGS: 9 km ESE of Chickasha, Oklahoma

56 km (35 mi) SSW of Oklahoma City, OK · 46 km (29 mi) SW of Moore, OK

7:31 pm CST, Dec 31, 2020 · · 9.4 km deep · released about 420 lb of TNT

10 km30 km60 km120 km N Grady County 5 kmMcClain County 35 kmCleveland County 50 kmCaddo County 52 kmCanadian County 58 kmGarvin County 60 kmStephens County 62 kmOklahoma County 69 kmComanche County 72 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
7:31 pm CST on 31 December 2020 ()
Where
10 km (6 mi) east-southeast of Chickasha, OK · earthquakes near Chickasha
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 2.8 (ml)
Depth
9.4 km below the surface
Felt
15 reports · strongest reported intensity V
Nearest
Grady County, 5 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1808 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 59 km (37 mi) from the epicentre. In Chickasha, 10 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: Chickasha 10 km, intensity III · Blanchard 20 km, intensity III · Tuttle 29 km, intensity III · Lindsay 31 km, intensity II · Minco 33 km, intensity II · Mustang 40 km, intensity II · Union City 41 km, intensity II · Norman 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 420 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 36,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 26,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.3× the energy of this one
  4. This earthquake M 2.8 about 420 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 35.0347, -97.8325. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Grady County, OK 5 km (3 mi) WSW earthquakes near Grady County
McClain County, OK 35 km (22 mi) E earthquakes near McClain County
Cleveland County, OK 50 km (31 mi) ENE earthquakes near Cleveland County
Caddo County, OK 52 km (32 mi) WNW earthquakes near Caddo County
Canadian County, OK 58 km (36 mi) NNW earthquakes near Canadian County
Garvin County, OK 60 km (37 mi) SE earthquakes near Garvin County

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

Aftershocks so far

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

  1. 1.6 2 km SE of Union City, Oklahoma
  2. 3.2 2 km SE of Union City, Oklahoma
  3. 1.5 7 km SW of Dibble, Oklahoma
  4. 2.7 3 km SSE of Union City, Oklahoma
  5. 2.2 3 km N of Minco, Oklahoma
  6. 1.6 3 km N of Minco, Oklahoma
  7. 1.9 4 km NNE of Minco, Oklahoma
  8. 2.5 4 km N of Minco, Oklahoma
  9. 1.6 4 km NNE of Minco, Oklahoma
  10. 1.6 4 km SSE of Union City, Oklahoma
  11. 1.8 4 km SSE of Union City, Oklahoma
  12. 1.5 4 km SSE of Union City, Oklahoma
  13. 2.5 4 km NNE of Minco, Oklahoma
  14. 2.4 3 km NNE of Minco, Oklahoma
  15. 1.5 4 km SSE of Union City, 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.