QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Longtown, OK

No earthquake was likely felt in Longtown in the 24 hours to 4:53 pm CST (22:53 UTC). The last one was M 3.4, 233 km (145 mi) W, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Longtown

This page: a magnitude 1.5 earthquake was recorded 13 km (8 mi) east of Longtown, OK, at 12:55 pm CDT on 24 September 2021 (17:55 UTC), 3.2 km deep.

USGS: 11 km W of Whitefield, Oklahoma

12:55 pm CDT, Sep 24, 2021 · · 3.2 km deep · released about 5.7 lb of TNT

10 km30 km60 km120 km N Haskell County 23 kmMcIntosh County 31 kmMuskogee County 41 kmLatimer County 43 kmPittsburg County 50 kmSequoyah County 62 kmOkmulgee County 70 kmLe Flore County 73 kmCherokee County 80 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
12:55 pm CDT on 24 September 2021 ()
Where
13 km (8 mi) east of Longtown, OK · earthquakes near Longtown
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 1.5 (ml)
Depth
3.2 km below the surface
Felt
no reports yet
Nearest
Haskell County, 23 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1871 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 Longtown, 13 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: Texanna, Quinton, Eufaula, Stigler, Warner, Checotah.

How big was it?

This earthquake released about 5.7 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 2,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.7 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 35.2518, -95.3645. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Haskell County, OK 23 km (14 mi) E earthquakes near Haskell County
McIntosh County, OK 31 km (19 mi) WNW earthquakes near McIntosh County
Muskogee County, OK 41 km (25 mi) N earthquakes near Muskogee County
Latimer County, OK 43 km (27 mi) SSE earthquakes near Latimer County
Pittsburg County, OK 50 km (31 mi) SW earthquakes near Pittsburg County
Sequoyah County, OK 62 km (39 mi) ENE earthquakes near Sequoyah 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. 2.5 13 km E of Crowder, Oklahoma
  2. 1.8 13 km E of Crowder, Oklahoma
  3. 1.6 9 km NW of Canadian, Oklahoma
  4. 1.6 10 km ESE of Canadian, Oklahoma
  5. 1.5 7 km ESE of Canadian, Oklahoma
  6. 1.5 12 km E of Crowder, Oklahoma
  7. 1.9 12 km ESE of Crowder, Oklahoma
  8. 2.2 11 km E of Crowder, Oklahoma
  9. 1.8 12 km E of Crowder, Oklahoma
  10. 2.0 12 km E of Crowder, Oklahoma
  11. 1.8 9 km SE of Texanna, Oklahoma
  12. 2.1 3 km ENE of Quinton, Oklahoma
  13. 2.3 13 km W of Quinton, Oklahoma
  14. 1.5 11 km ESE of Canadian, Oklahoma
  15. 2.0 12 km E of Crowder, 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.