QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Earthquake near Helena, OK

No earthquake was likely felt in Helena in the 24 hours to 11:21 pm CST (05:21 UTC). The last one was M 3.4, 106 km (66 mi) S, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Helena

This page: a magnitude 2.1 earthquake was recorded 6 km (4 mi) south-southeast of Helena, OK, at 5:33 pm CDT on 26 June 2020 (22:33 UTC), 8.9 km deep.

USGS: 5 km SSE of Helena, Oklahoma

35 km (22 mi) WNW of Enid, OK · 132 km (82 mi) NNW of Oklahoma City, OK

5:33 pm CDT, Jun 26, 2020 · · 8.9 km deep · released about 44 lb of TNT

10 km30 km60 km120 km N Alfalfa County 27 kmMajor County 34 kmGarfield County 43 kmGrant County 52 kmWoods County 61 kmKingfisher County 67 kmBlaine County 71 kmHarper County 78 kmBarber County 90 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
5:33 pm CDT on 26 June 2020 ()
Where
6 km (4 mi) south-southeast of Helena, OK · earthquakes near Helena
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 2.1 (ml)
Depth
8.9 km below the surface
Felt
no reports yet
Nearest
Alfalfa County, 27 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2327 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 28 km (17 mi) from the epicentre. In Helena, 6 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: Helena 6 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 44 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 340,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 240,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 44 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 31,000 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 36.4992, -98.2448. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alfalfa County, OK 27 km (17 mi) NNW earthquakes near Alfalfa County
Major County, OK 34 km (21 mi) SW earthquakes near Major County
Garfield County, OK 43 km (27 mi) ESE earthquakes near Garfield County
Grant County, OK 52 km (32 mi) NE earthquakes near Grant County
Woods County, OK 61 km (38 mi) WNW earthquakes near Woods County
Kingfisher County, OK 67 km (42 mi) SSE earthquakes near Kingfisher County

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

Aftershocks so far

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

  1. 1.5 4 km SE of Meno, Oklahoma
  2. 1.9 3 km SE of Meno, Oklahoma
  3. 1.7 3 km SE of Meno, Oklahoma
  4. 1.8 3 km SE of Meno, Oklahoma
  5. 2.3 5 km NW of Ames, Oklahoma
  6. 2.1 6 km NW of Ames, Oklahoma
  7. 1.7 17 km SSE of Waynoka, Oklahoma
  8. 1.6 0 km N of Lambert, Oklahoma
  9. 2.1 4 km SE of Fairview, Oklahoma
  10. 1.8 5 km SE of Fairview, Oklahoma
  11. 1.5 4 km NNE of Okeene, Oklahoma
  12. 1.6 9 km WSW of Ringwood, Oklahoma
  13. 1.6 9 km ESE of Ames, Oklahoma
  14. 1.6 8 km ENE of Nescatunga, Oklahoma
  15. 1.6 7 km W of Jet, 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.