QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5ml

Earthquake near Alva, OK

No earthquake was likely felt in Alva in the 24 hours to 3:49 pm CST (21:49 UTC). The last one was M 3.4, 144 km (90 mi) SSE, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Alva

This page: a magnitude 2.5 earthquake was recorded 24 km (15 mi) northwest of Alva, OK, at 11:57 pm CDT on 19 May 2017 (04:57 UTC), 6.7 km deep.

USGS: 19 km WSW of Hardtner, Kansas

11:57 pm CDT, May 19, 2017 · · 6.7 km deep · released about 170 lb of TNT

10 km30 km60 km120 km N Woods County 26 kmBarber County 33 kmComanche County 43 kmAlfalfa County 53 kmWoodward County 70 kmHarper County 74 kmHarper County 74 kmMajor County 77 kmKiowa County 77 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
11:57 pm CDT on 19 May 2017 ()
Where
24 km (15 mi) northwest of Alva, OK · earthquakes near Alva
Magnitude
M 2.5 (ml)
Depth
6.7 km below the surface
Felt
no reports yet
Nearest
Woods County, 26 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3386 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 Alva, 24 km away, the estimate is intensity II (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: Alva 24 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 36.9581, -98.8526. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Woods County, OK 26 km (16 mi) S earthquakes near Woods County
Barber County, KS 33 km (20 mi) NNE earthquakes near Barber County
Comanche County, KS 43 km (27 mi) NW earthquakes near Comanche County
Alfalfa County, OK 53 km (33 mi) ESE earthquakes near Alfalfa County
Woodward County, OK 70 km (44 mi) SSW earthquakes near Woodward County
Harper County, OK 74 km (46 mi) WSW earthquakes near Harper County

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

Aftershocks so far

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

  1. 2.6 3 km WNW of Byron, Oklahoma
  2. 2.6 3 km WNW of Byron, Oklahoma
  3. 2.9 4 km W of Amorita, Oklahoma
  4. 2.7 3 km WNW of Byron, Oklahoma
  5. 3.1 3 km WNW of Byron, Oklahoma
  6. 3.4 3 km W of Byron, Oklahoma
  7. 3.7 Oklahoma
  8. 2.9 3 km W of Byron, Oklahoma
  9. 2.3 1 km SW of Cherokee, Oklahoma
  10. 2.5 26 km ENE of Buffalo, Oklahoma
  11. 2.5 5 km NW of Dacoma, Oklahoma
  12. 2.5 27 km ENE of Buffalo, Oklahoma
  13. 2.9 1 km NNW of Lambert, Oklahoma
  14. 2.8 9 km SW of Waynoka, Oklahoma
  15. 3.0 1 km SSW of Cherokee, 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.