QuakeIndex

Earthquake · automatic estimate, may change

M 2.1ml

Earthquake near Alva, OK

No earthquake was likely felt in Alva in the 24 hours to 1:40 pm CST (19:40 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 2.1 earthquake was recorded 46 km (29 mi) west-northwest of Alva, OK, at 1:14 am CDT on 16 August 2020 (06:14 UTC), 6.9 km deep. The magnitude and location are an automatic first estimate and may change.

USGS: 22 km N of Freedom, Oklahoma

1:14 am CDT, Aug 16, 2020 · · 6.9 km deep · released about 38 lb of TNT

10 km30 km60 km120 km N Comanche County 26 kmWoods County 37 kmBarber County 49 kmHarper County 50 kmWoodward County 61 kmClark County 67 kmKiowa County 67 kmAlfalfa County 77 kmPratt County 83 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
1:14 am CDT on 16 August 2020 ()
Where
46 km (29 mi) west-northwest of Alva, OK · earthquakes near Alva
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 2.1 (ml)
Depth
6.9 km below the surface
Felt
no reports yet
Nearest
Comanche County, 26 km NNW
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 2279 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 26 km (16 mi) from the epicentre. In Alva, 46 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.

How big was it?

This earthquake released about 38 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 390,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 280,000× the energy of this one
  3. Around the size people start to feel M 3.0 25× the energy of this one
  4. This earthquake M 2.1 about 38 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 36.9683, -99.1417. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Comanche County, KS 26 km (16 mi) NNW earthquakes near Comanche County
Woods County, OK 37 km (23 mi) SE earthquakes near Woods County
Barber County, KS 49 km (31 mi) NE earthquakes near Barber County
Harper County, OK 50 km (31 mi) WSW earthquakes near Harper County
Woodward County, OK 61 km (38 mi) S earthquakes near Woodward County
Clark County, KS 67 km (41 mi) WNW earthquakes near Clark County

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

Aftershocks so far

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

  1. 1.9 4 km S of Avard, Oklahoma
  2. 2.0 4 km S of Avard, Oklahoma
  3. 1.6 25 km NE of Buffalo, Oklahoma
  4. 1.6 17 km NW of Alva, Oklahoma
  5. 1.5 Oklahoma
  6. 1.8 16 km NW of Alva, Oklahoma
  7. 2.2 6 km WNW of Hardtner, Kansas
  8. 1.8 4 km S of Avard, Oklahoma
  9. 1.9 12 km WNW of Avard, Oklahoma
  10. 1.7 15 km ENE of Fort Supply, Oklahoma
  11. 1.7 3 km S of Avard, Oklahoma
  12. 1.7 8 km NW of Waynoka, 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.