QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4mb_lg

Earthquake near Harper, KS

No earthquake was likely felt in Harper in the 24 hours to 3:05 pm CST (21:05 UTC). The last one was M 3.4, 186 km (116 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 Harper

This page: a magnitude 2.4 earthquake was recorded 8 km (5 mi) north-northeast of Harper, KS, at 5:17 am CDT on 13 September 2018 (10:17 UTC), 5.0 km deep.

USGS: 8 km NNE of Harper, Kansas

68 km (42 mi) WSW of Wichita, KS

5:17 am CDT, Sep 13, 2018 · · 5.0 km deep · released about 120 lb of TNT

10 km30 km60 km120 km N Harper County 20 kmKingman County 26 kmSumner County 46 kmSedgwick County 59 kmBarber County 63 kmGrant County 66 kmReno County 66 kmPratt County 74 kmAlfalfa County 76 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
5:17 am CDT on 13 September 2018 ()
Where
8 km (5 mi) north-northeast of Harper, KS · earthquakes near Harper
Magnitude
M 2.4 (mb_lg)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Harper County, 20 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2912 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 41 km (25 mi) from the epicentre. In Harper, 8 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: Anthony 23 km, intensity II · Conway Springs 31 km, intensity II · Cheney 35 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 120 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 130,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 89,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.9× the energy of this one
  4. This earthquake M 2.4 about 120 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 37.3575, -97.9905. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Harper County, KS 20 km (12 mi) SSW earthquakes near Harper County
Kingman County, KS 26 km (16 mi) NNW earthquakes near Kingman County
Sumner County, KS 46 km (29 mi) ESE earthquakes near Sumner County
Sedgwick County, KS 59 km (37 mi) NE earthquakes near Sedgwick County
Barber County, KS 63 km (39 mi) WSW earthquakes near Barber County
Grant County, OK 66 km (41 mi) SSE earthquakes near Grant County

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

Aftershocks so far

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

  1. 1.7 3 km WSW of Anthony, Kansas
  2. 3.2 9 km NNE of Harper, Kansas
  3. 1.8 4 km E of Bluff City, Kansas
  4. 1.9 Kansas
  5. 1.7 10 km SE of Freeport, Kansas
  6. 3.1 4 km N of Wakita, Oklahoma
  7. 1.9 7 km NNW of Argonia, Kansas
  8. 2.2 3 km E of Freeport, Kansas
  9. 2.7 9 km NNE of Harper, Kansas
  10. 2.8 8 km NNE of Harper, Kansas
  11. 3.0 11 km NE of Wakita, Oklahoma
  12. 2.5 8 km ESE of Manchester, Oklahoma
  13. 2.3 11 km NE of Wakita, Oklahoma
  14. 1.6 11 km NE of Wakita, Oklahoma
  15. 1.9 11 km NE of Wakita, 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.