QuakeIndex

Earthquake · reviewed by a seismologist

M 3.7mwr

Earthquake near Hays, KS

No earthquake was likely felt in Hays in the 24 hours to 2:25 am CST (08:25 UTC). The last one was M 2.7, 55 km (34 mi) ENE, at 12:18 pm CDT on 15 October 2026, estimated intensity II (weak) in town. Every earthquake near Hays

This page: a magnitude 3.7 earthquake was recorded 48 km (30 mi) north-northeast of Hays, KS, at 10:02 am CDT on 22 August 2018 (15:02 UTC), 5.0 km deep. 50 people have reported feeling it to USGS.

USGS: 6 km NNW of Natoma, Kansas

10:02 am CDT, Aug 22, 2018 · · 5.0 km deep · released about 5.4 tons of TNT

10 km30 km60 km120 km N Rooks County 26 kmOsborne County 26 kmEllis County 44 kmRussell County 44 kmSmith County 64 kmPhillips County 65 kmGraham County 73 kmMitchell County 74 kmLincoln County 75 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
10:02 am CDT on 22 August 2018 ()
Where
48 km (30 mi) north-northeast of Hays, KS · earthquakes near Hays
Magnitude
M 3.7 (mwr)
Depth
5.0 km below the surface
Felt
50 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
Nearest
Rooks County, 26 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2699 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 370 km (230 mi) from the epicentre. In Hays, 48 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: Plainville 22 km, intensity IV · Stockton 28 km, intensity III · Russell 42 km, intensity III · Hays 48 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 5.4 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 32,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,400× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,000× the energy of this one
  4. This earthquake M 3.7 about 5.4 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 11× more

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 39.2467, -99.0460. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Rooks County, KS 26 km (16 mi) WNW earthquakes near Rooks County
Osborne County, KS 26 km (16 mi) ENE earthquakes near Osborne County
Ellis County, KS 44 km (27 mi) SSW earthquakes near Ellis County
Russell County, KS 44 km (27 mi) SSE earthquakes near Russell County
Smith County, KS 64 km (40 mi) NNE earthquakes near Smith County
Phillips County, KS 65 km (40 mi) NNW earthquakes near Phillips County

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

Aftershocks so far

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

  1. 2.7 7 km SSW of Luray, Kansas
  2. 2.5 9 km SW of Natoma, Kansas
  3. 2.4 12 km NE of Damar, Kansas
  4. 2.9 7 km N of Hays, Kansas
  5. 2.9 5 km SW of Kirwin, Kansas
  6. 2.8 10 km SSW of Stockton, Kansas
  7. 2.8 8 km NNW of Stockton, Kansas
  8. 3.3 7 km NNW of Stockton, Kansas
  9. 2.5 1 km NE of Zurich, Kansas
  10. 2.5 11 km NNE of Stockton, Kansas
  11. 2.6 14 km WSW of Natoma, Kansas
  12. 3.0 4 km SE of Paradise, Kansas
  13. 3.0 2 km SW of Zurich, Kansas
  14. 2.7 11 km NW of Stockton, Kansas
  15. 3.4 10 km NW of Woodston, 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.