QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

Earthquake near Hennessey, OK

No earthquake was likely felt in Hennessey in the 24 hours to 3:54 am CST (09:54 UTC). The last one was M 3.4, 57 km (35 mi) SSW, at 5:53 am CST on 7 November 2026, estimated intensity III (weak) in town; 23 felt reports to USGS. Every earthquake near Hennessey

This page: a magnitude 2.5 earthquake was recorded 5 km (3 mi) east of Hennessey, OK, at 2:25 pm CST on 18 December 2018 (20:25 UTC), 4.6 km deep.

USGS: 5 km E of Hennessey, Oklahoma

78 km (48 mi) NNW of Oklahoma City, OK · 33 km (20 mi) S of Enid, OK

2:25 pm CST, Dec 18, 2018 · · 4.6 km deep · released about 170 lb of TNT

10 km30 km60 km120 km N Kingfisher County 20 kmGarfield County 30 kmLogan County 42 kmBlaine County 59 kmNoble County 62 kmCanadian County 65 kmMajor County 67 kmOklahoma County 73 kmGrant County 75 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
2:25 pm CST on 18 December 2018 ()
Where
5 km (3 mi) east of Hennessey, OK · earthquakes near Hennessey
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 2.5 (ml)
Depth
4.6 km below the surface
Felt
no reports yet
Nearest
Kingfisher County, 20 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2818 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 46 km (29 mi) from the epicentre. In Hennessey, 5 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: Hennessey 5 km, intensity III · Crescent 29 km, intensity II · Kingfisher 29 km, intensity II · Enid 31 km, intensity II · Okeene 43 km, intensity II · Okarche 45 km, intensity II · Guthrie 46 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.6× the energy of this one
  4. This earthquake M 2.5 about 170 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

The largest earthquake within 50 km since 2016 was M 4.6 on 2018-04-09 — about 1,400 times the energy of this one.

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 36.1147, -97.8405. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kingfisher County, OK 20 km (13 mi) SSW earthquakes near Kingfisher County
Garfield County, OK 30 km (18 mi) N earthquakes near Garfield County
Logan County, OK 42 km (26 mi) ESE earthquakes near Logan County
Blaine County, OK 59 km (37 mi) WSW earthquakes near Blaine County
Noble County, OK 62 km (38 mi) ENE earthquakes near Noble County
Canadian County, OK 65 km (40 mi) S earthquakes near Canadian County

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

Aftershocks so far

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

  1. 2.3 Oklahoma
  2. 2.5 11 km NW of Edmond, Oklahoma
  3. 1.9 5 km N of Ames, Oklahoma
  4. 2.2 2 km SSE of Meno, Oklahoma
  5. 2.3 8 km SE of Loyal, Oklahoma
  6. 1.8 13 km ESE of Dover, Oklahoma
  7. 2.2 16 km E of Watonga, Oklahoma
  8. 1.6 16 km E of Watonga, Oklahoma
  9. 2.0 7 km SW of Loyal, Oklahoma
  10. 1.9 16 km E of Watonga, Oklahoma
  11. 2.0 4 km SE of Meno, Oklahoma
  12. 2.3 16 km E of Watonga, Oklahoma
  13. 1.8 11 km SE of Cashion, Oklahoma
  14. 1.8 11 km NW of Edmond, Oklahoma
  15. 3.1 11 km NW of Edmond, 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.