QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6ml

Earthquake near Norman, OK

No earthquake was likely felt in Norman in the 24 hours to 5:45 pm CST (23:45 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 2.6 earthquake was recorded 28 km (17 mi) south-southwest of Norman, OK, at 1:02 am CDT on 2 August 2018 (06:02 UTC), 5.5 km deep. 2 people have reported feeling it to USGS.

USGS: 9 km ESE of Dibble, Oklahoma

53 km (33 mi) S of Oklahoma City, OK · 33 km (21 mi) SSW of Norman, OK

1:02 am CDT, Aug 2, 2018 · · 5.5 km deep · released about 240 lb of TNT

10 km30 km60 km120 km N McClain County 9 kmGrady County 32 kmCleveland County 32 kmGarvin County 37 kmPottawatomie County 59 kmStephens County 63 kmOklahoma County 64 kmMurray County 70 kmCanadian County 73 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
1:02 am CDT on 2 August 2018 ()
Where
28 km (17 mi) south-southwest of Norman, OK · earthquakes near Norman
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 2.6 (ml)
Depth
5.5 km below the surface
Felt
2 reports · strongest reported intensity IV
Nearest
McClain County, 9 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2948 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 51 km (32 mi) from the epicentre. 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.

Likely felt in: Lindsay 18 km, intensity III · Blanchard 20 km, intensity III · Norman 28 km, intensity II · Chickasha 37 km, intensity II · Moore 40 km, intensity II · Tuttle 42 km, intensity II · Mustang 47 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 240 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 63,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 45,000× the energy of this one
  3. Around the size people start to feel M 3.0 4× the energy of this one
  4. This earthquake M 2.6 about 240 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 34.9869, -97.5431. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
McClain County, OK 9 km (6 mi) ENE earthquakes near McClain County
Grady County, OK 32 km (20 mi) W earthquakes near Grady County
Cleveland County, OK 32 km (20 mi) NE earthquakes near Cleveland County
Garvin County, OK 37 km (23 mi) SE earthquakes near Garvin County
Pottawatomie County, OK 59 km (37 mi) ENE earthquakes near Pottawatomie County
Stephens County, OK 63 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

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

  1. 2.3 3 km E of Blanchard, Oklahoma
  2. 1.9 2 km N of Cole, Oklahoma
  3. 2.6 4 km NNW of Cole, Oklahoma
  4. 1.8 4 km ENE of Blanchard, Oklahoma
  5. 2.7 3 km S of Amber, Oklahoma
  6. 2.6 6 km SSE of Amber, Oklahoma
  7. 3.0 6 km SSE of Amber, Oklahoma
  8. 2.2 7 km S of Amber, Oklahoma
  9. 2.3 4 km S of Amber, Oklahoma
  10. 2.1 6 km S of Amber, Oklahoma
  11. 2.2 4 km SW of Tuttle, Oklahoma
  12. 2.5 5 km S of Amber, Oklahoma
  13. 2.4 5 km S of Amber, Oklahoma
  14. 2.7 5 km S of Amber, Oklahoma
  15. 2.1 3 km WNW of Alex, 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.