QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

7.0 km ENE of Helena, OK

Yes. A magnitude 1.5 earthquake was recorded 7.0 km ENE of Helena, OK, 44 km (27 mi) WNW of Enid, OK, at 9:56 am CST on 12 November 2020 (15:56 UTC), 6.1 km deep.

44 km (27 mi) WNW of Enid, OK · 139 km (86 mi) NNW of Oklahoma City, OK

· 6.1 km deep · released about 5.6 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Alfalfa County 23 kmMajor County 29 kmWoods County 52 kmGarfield County 52 kmGrant County 58 kmBlaine County 72 kmKingfisher County 73 kmHarper County 78 kmBarber County 84 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
6.1 km below the surface
Felt
no reports yet
Nearest
Alfalfa County, 23 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2186 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. 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: Helena, Cherokee.

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.

For this area

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

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 36.5212, -98.3415. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alfalfa County, OK 23 km (14 mi) N earthquakes near Alfalfa County
Major County, OK 29 km (18 mi) SW earthquakes near Major County
Woods County, OK 52 km (32 mi) WNW earthquakes near Woods County
Garfield County, OK 52 km (32 mi) ESE earthquakes near Garfield County
Grant County, OK 58 km (36 mi) ENE earthquakes near Grant County
Blaine County, OK 72 km (45 mi) S earthquakes near Blaine County

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

Aftershocks so far

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

  1. 1.6 5 km NNE of Cherokee, Oklahoma
  2. 2.6 6 km WSW of Isabella, Oklahoma
  3. 1.8 11 km S of Ames, Oklahoma
  4. 1.9 3 km SE of Meno, Oklahoma
  5. 1.9 17 km SE of Waynoka, Oklahoma
  6. 1.6 7 km NNE of Ames, Oklahoma
  7. 1.5 5 km N of Ames, Oklahoma
  8. 1.6 5 km N of Ames, Oklahoma
  9. 1.9 5 km N of Ames, Oklahoma
  10. 2.3 7 km SSE of Meno, Oklahoma
  11. 1.6 17 km SSE of Waynoka, Oklahoma
  12. 2.0 4 km E of Enid, Oklahoma
  13. 1.6 4 km SE of Meno, Oklahoma
  14. 1.5 3 km SE of Meno, Oklahoma
  15. 1.8 17 km SSE 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.