QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

Earthquake near Apache, OK

No earthquake was likely felt in Apache in the 24 hours to 11:28 am CST (17:28 UTC). The last one was M 3.4, 85 km (53 mi) NNE, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Apache

This page: a magnitude 2.8 earthquake was recorded 7 km (4 mi) west-southwest of Apache, OK, at 10:39 pm CDT on 20 August 2020 (03:39 UTC), 18 km deep. 53 people have reported feeling it to USGS.

USGS: 6 km WSW of Apache, Oklahoma

27 km (17 mi) N of Lawton, OK · 107 km (66 mi) SW of Oklahoma City, OK

10:39 pm CDT, Aug 20, 2020 · · 18 km deep · released about 530 lb of TNT

10 km30 km60 km120 km N Comanche County 23 kmCaddo County 34 kmKiowa County 51 kmGrady County 52 kmCotton County 64 kmStephens County 67 kmWashita County 70 kmTillman County 72 kmCanadian County 86 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
10:39 pm CDT on 20 August 2020 ()
Where
7 km (4 mi) west-southwest of Apache, OK · earthquakes near Apache
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 2.8 (ml)
Depth
18 km below the surface
Felt
53 reports · strongest reported intensity IV
Nearest
Comanche County, 23 km SSW
Nearest mapped fault
Meers fault, 10 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2203 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 61 km (38 mi) from the epicentre. In Apache, 7 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: Chickasha 49 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 530 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 29,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 20,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.8× the energy of this one
  4. This earthquake M 2.8 about 530 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 34.8642, -98.4278. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Comanche County, OK 23 km (14 mi) SSW earthquakes near Comanche County
Caddo County, OK 34 km (21 mi) N earthquakes near Caddo County
Kiowa County, OK 51 km (32 mi) W earthquakes near Kiowa County
Grady County, OK 52 km (32 mi) ENE earthquakes near Grady County
Cotton County, OK 64 km (40 mi) S earthquakes near Cotton County
Stephens County, OK 67 km (42 mi) SE earthquakes near Stephens County

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

Aftershocks so far

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

  1. 2.8 1 km ESE of Medicine Park, Oklahoma
  2. 1.7 6 km NW of Cooperton, Oklahoma
  3. 1.6 8 km NE of Cooperton, Oklahoma
  4. 1.6 4 km ENE of Medicine Park, Oklahoma
  5. 1.8 9 km NNE of Cooperton, Oklahoma
  6. 1.6 4 km E of Medicine Park, Oklahoma
  7. 1.6 4 km E of Medicine Park, Oklahoma
  8. 1.6 8 km E of Medicine Park, Oklahoma
  9. 1.6 3 km E of Medicine Park, Oklahoma
  10. 2.1 1 km SSW of Verden, Oklahoma
  11. 1.6 7 km NW of Cooperton, Oklahoma
  12. 1.7 6 km NNW of Cooperton, Oklahoma
  13. 2.2 6 km ESE of Cache, Oklahoma
  14. 1.6 4 km NNE of Cooperton, Oklahoma
  15. 1.5 4 km E of Medicine Park, 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.