QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

4 km NNE of Helena, Oklahoma

· 7.2 km deep · released about 5.6 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Alfalfa County 17 kmMajor County 40 kmGrant County 47 kmGarfield County 47 kmWoods County 57 kmHarper County 69 kmKingfisher County 76 kmBlaine County 80 kmBarber County 81 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
Magnitude
M 1.5 (ml)
Depth
7.2 km below the surface
Felt
no reports yet
Nearest
Alfalfa County, 17 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1271 days ago

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

How big was it?

This earthquake released about 5.6 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 2,700,000× 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 5.6 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.

Where

Epicentre 36.5857, -98.2527. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Alfalfa County, OK 17 km (11 mi) SSE of here earthquakes near Alfalfa County
Major County, OK 40 km (25 mi) NE of here earthquakes near Major County
Grant County, OK 47 km (29 mi) WSW of here earthquakes near Grant County
Garfield County, OK 47 km (29 mi) WNW of here earthquakes near Garfield County
Woods County, OK 57 km (35 mi) ESE of here earthquakes near Woods County
Harper County, KS 69 km (43 mi) SSW of here earthquakes near Harper County

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

Aftershocks so far

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

  1. 1.7 7 km SSE of Manchester, Oklahoma
  2. 1.9 7 km SSE of Manchester, Oklahoma
  3. 2.3 8 km N of Nash, Oklahoma
  4. 1.5 6 km ENE of Avard, Oklahoma
  5. 1.7 10 km WNW of Dacoma, Oklahoma
  6. 1.8 17 km SE of Waynoka, Oklahoma
  7. 1.9 7 km E of Nescatunga, Oklahoma
  8. 1.6 9 km W of Jefferson, Oklahoma
  9. 1.6 2 km SE of Meno, Oklahoma
  10. 1.5 2 km SSE of Meno, Oklahoma
  11. 1.7 5 km SE of Meno, Oklahoma
  12. 1.6 4 km SE of Fairview, Oklahoma
  13. 1.8 0 km SSW of Cleo Springs, Oklahoma
  14. 1.6 16 km SE of Waynoka, Oklahoma
  15. 2.1 8 km E of Nescatunga, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 5.1 on 2016-02-13 — it released about 240,000 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.