QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5mb_lg

Earthquake near Harper, KS

No earthquake was likely felt in Harper in the 24 hours to 6:29 am CST (12:29 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 2.5 earthquake was recorded 17 km (11 mi) east-northeast of Harper, KS, at 1:52 am CDT on 26 August 2018 (06:52 UTC), 5.0 km deep.

USGS: 7 km NE of Danville, Kansas

59 km (37 mi) SW of Wichita, KS

1:52 am CDT, Aug 26, 2018 · · 5.0 km deep · released about 170 lb of TNT

10 km30 km60 km120 km N Harper County 26 kmSumner County 32 kmKingman County 36 kmSedgwick County 51 kmGrant County 61 kmReno County 72 kmBarber County 76 kmAlfalfa County 80 kmKay 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
1:52 am CDT on 26 August 2018 ()
Where
17 km (11 mi) east-northeast of Harper, KS · earthquakes near Harper
Magnitude
M 2.5 (mb_lg)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Harper County, 26 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2932 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 Harper, 17 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: Conway Springs 18 km, intensity III · Anthony 26 km, intensity II · Cheney 33 km, intensity II · Caldwell 39 km, intensity II · Wellington 42 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

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 37.3336, -97.8390. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Harper County, KS 26 km (16 mi) SW earthquakes near Harper County
Sumner County, KS 32 km (20 mi) ESE earthquakes near Sumner County
Kingman County, KS 36 km (23 mi) NW earthquakes near Kingman County
Sedgwick County, KS 51 km (32 mi) NE earthquakes near Sedgwick County
Grant County, OK 61 km (38 mi) S earthquakes near Grant County
Reno County, KS 72 km (44 mi) NNW earthquakes near Reno County

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

Aftershocks so far

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

  1. 1.6 6 km NNW of Argonia, Kansas
  2. 2.1 2 km SSE of Bluff City, Kansas
  3. 2.6 8 km WSW of Hunnewell, Kansas
  4. 2.7 8 km WSW of Hunnewell, Kansas
  5. 2.4 8 km NNE of Harper, Kansas
  6. 3.1 7 km NE of Harper, Kansas
  7. 1.8 9 km WSW of Hunnewell, Kansas
  8. 1.6 11 km N of Caldwell, Kansas
  9. 1.5 7 km S of Argonia, Kansas
  10. 1.9 7 km E of Freeport, Kansas
  11. 1.8 7 km S of Argonia, Kansas
  12. 1.7 7 km S of Argonia, Kansas
  13. 2.8 7 km S of Argonia, Kansas
  14. 3.7 7 km E of Freeport, Kansas
  15. 2.4 8 km NNE of Danville, Kansas

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.