QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

Earthquake near Helena, OK

No earthquake was likely felt in Helena in the 24 hours to 4:59 pm CST (22:59 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 2.5 earthquake was recorded 19 km (12 mi) west-southwest of Helena, OK, at 10:42 pm CST on 16 January 2017 (04:42 UTC), 4.1 km deep.

USGS: 2 km W of Aline, Oklahoma

56 km (35 mi) WNW of Enid, OK · 145 km (90 mi) NW of Oklahoma City, OK

10:42 pm CST, Jan 16, 2017 · · 4.1 km deep · released about 170 lb of TNT

10 km30 km60 km120 km N Major County 22 kmAlfalfa County 28 kmWoods County 42 kmGarfield County 63 kmGrant County 69 kmBlaine County 70 kmWoodward County 72 kmDewey County 76 kmKingfisher County 79 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
10:42 pm CST on 16 January 2017 ()
Where
19 km (12 mi) west-southwest of Helena, OK · earthquakes near Helena
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 2.5 (ml)
Depth
4.1 km below the surface
Felt
no reports yet
Nearest
Major County, 22 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3501 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 46 km (29 mi) from the epicentre. In Helena, 19 km away, the estimate is intensity III (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 19 km, intensity III · Fairview 27 km, intensity II · Cherokee 30 km, intensity II · Alva 37 km, intensity II · Okeene 46 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 170 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 89,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 63,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.6× the energy of this one
  4. This earthquake M 2.5 about 170 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 7,900 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 36.5074, -98.4797. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Major County, OK 22 km (14 mi) SSW earthquakes near Major County
Alfalfa County, OK 28 km (18 mi) NNE earthquakes near Alfalfa County
Woods County, OK 42 km (26 mi) NW earthquakes near Woods County
Garfield County, OK 63 km (39 mi) ESE earthquakes near Garfield County
Grant County, OK 69 km (43 mi) ENE earthquakes near Grant County
Blaine County, OK 70 km (44 mi) S earthquakes near Blaine County

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

Aftershocks so far

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

  1. 2.9 7 km S of Dacoma, Oklahoma
  2. 2.9 6 km NW of Jet, Oklahoma
  3. 2.7 17 km SE of Waynoka, Oklahoma
  4. 2.6 8 km SW of Goltry, Oklahoma
  5. 3.8 2 km NNW of Lambert, Oklahoma
  6. 3.1 5 km NW of Lahoma, Oklahoma
  7. 2.5 6 km E of Byron, Oklahoma
  8. 2.9 Oklahoma
  9. 3.8 10 km S of Waynoka, Oklahoma
  10. 2.5 13 km WNW of Canton, Oklahoma
  11. 2.6 13 km WNW of Canton, Oklahoma
  12. 2.8 8 km SSE of Byron, Oklahoma
  13. 2.5 16 km SE of Waynoka, Oklahoma
  14. 2.8 8 km SSE of Byron, Oklahoma
  15. 3.5 10 km NE of Quinlan, 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.