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 9:23 am CST (15:23 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 13 km (8 mi) northwest of Harper, KS, at 10:22 am CDT on 28 September 2017 (15:22 UTC), 4.5 km deep. 4 people have reported feeling it to USGS.

USGS: 10 km S of Spivey, Kansas

80 km (50 mi) WSW of Wichita, KS

10:22 am CDT, Sep 28, 2017 · · 4.5 km deep · released about 170 lb of TNT

10 km30 km60 km120 km N Harper County 19 kmKingman County 23 kmBarber County 50 kmSumner County 59 kmPratt County 62 kmReno County 67 kmGrant County 70 kmSedgwick County 70 kmAlfalfa County 71 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
10:22 am CDT on 28 September 2017 ()
Where
13 km (8 mi) northwest of Harper, KS · earthquakes near Harper
Magnitude
M 2.5 (mb_lg)
Depth
4.5 km below the surface
Felt
4 reports · strongest reported intensity III
Nearest
Harper County, 19 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3246 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, 13 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 24 km, intensity II · Conway Springs 44 km, intensity II · Cheney 44 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 37.3504, -98.1427. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Harper County, KS 19 km (12 mi) SSE earthquakes near Harper County
Kingman County, KS 23 km (14 mi) N earthquakes near Kingman County
Barber County, KS 50 km (31 mi) WSW earthquakes near Barber County
Sumner County, KS 59 km (37 mi) ESE earthquakes near Sumner County
Pratt County, KS 62 km (39 mi) WNW earthquakes near Pratt County
Reno County, KS 67 km (41 mi) N earthquakes near Reno County

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

Aftershocks so far

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

  1. 1.9 3 km E of Freeport, Kansas
  2. 1.6 7 km E of Manchester, Oklahoma
  3. 1.6 2 km E of Freeport, Kansas
  4. 1.8 6 km SSW of Freeport, Kansas
  5. 1.7 1 km NNW of Milan, Kansas
  6. 2.5 8 km NE of Hazelton, Kansas
  7. 1.5 6 km ESE of Freeport, Kansas
  8. 1.9 3 km E of Freeport, Kansas
  9. 2.4 7 km ENE of Hazelton, Kansas
  10. 2.5 7 km NE of Hazelton, Kansas
  11. 1.7 4 km NW of Bluff City, Kansas
  12. 1.6 4 km ENE of Milan, Kansas
  13. 2.6 4 km ENE of Milan, Kansas
  14. 1.6 4 km ENE of Milan, Kansas
  15. 1.8 3 km E of Freeport, 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.