QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Woodward, OK

No earthquake was likely felt in Woodward in the 24 hours to 7:22 am CST (13:22 UTC). The last one was M 3.4, 152 km (94 mi) SE, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Woodward

This page: a magnitude 1.8 earthquake was recorded 32 km (20 mi) east-northeast of Woodward, OK, at 11:19 pm CDT on 25 September 2021 (04:19 UTC), 7.9 km deep.

USGS: 5 km N of Quinlan, Oklahoma

11:19 pm CDT, Sep 25, 2021 · · 7.9 km deep · released about 13 lb of TNT

10 km30 km60 km120 km N Woodward County 23 kmWoods County 29 kmMajor County 49 kmDewey County 59 kmHarper County 64 kmAlfalfa County 69 kmEllis County 71 kmComanche County 77 kmBarber County 86 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
11:19 pm CDT on 25 September 2021 ()
Where
32 km (20 mi) east-northeast of Woodward, OK · earthquakes near Woodward
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 1.8 (ml)
Depth
7.9 km below the surface
Felt
no reports yet
Nearest
Woodward County, 23 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1873 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 12 km (7 mi) from the epicentre. In Woodward, 32 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: Mooreland.

How big was it?

This earthquake released about 13 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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 5.1 on 2016-02-13 — about 110,000 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 36.5060, -99.0400. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Woodward County, OK 23 km (14 mi) WSW earthquakes near Woodward County
Woods County, OK 29 km (18 mi) NNE earthquakes near Woods County
Major County, OK 49 km (31 mi) ESE earthquakes near Major County
Dewey County, OK 59 km (37 mi) S earthquakes near Dewey County
Harper County, OK 64 km (40 mi) WNW earthquakes near Harper County
Alfalfa County, OK 69 km (43 mi) ENE earthquakes near Alfalfa County

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

Aftershocks so far

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

  1. 1.8 9 km WSW of Waynoka, Oklahoma
  2. 1.9 11 km E of Chester, Oklahoma
  3. 1.8 17 km SE of Waynoka, Oklahoma
  4. 2.0 6 km WSW of Aline, Oklahoma
  5. 1.6 5 km NNE of Fort Supply, Oklahoma
  6. 2.3 17 km SE of Waynoka, Oklahoma
  7. 1.8 17 km SE of Waynoka, Oklahoma
  8. 1.6 16 km SE of Waynoka, Oklahoma
  9. 1.7 9 km WSW of Waynoka, Oklahoma
  10. 1.6 8 km NW of Waynoka, Oklahoma
  11. 1.5 16 km ESE of Quinlan, Oklahoma
  12. 1.5 17 km SSE of Waynoka, Oklahoma
  13. 1.5 16 km SE of Waynoka, Oklahoma
  14. 1.6 10 km ESE of Chester, Oklahoma
  15. 2.4 17 km SE of Waynoka, 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.