QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5ml

Earthquake near Alva, OK

No earthquake was likely felt in Alva in the 24 hours to 10:12 am CST (16:12 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 1.5 earthquake was recorded 23 km (15 mi) northeast of Alva, OK, at 2:41 pm CST on 23 November 2020 (20:41 UTC), 6.4 km deep.

USGS: 3 km NW of Burlington, Oklahoma

2:41 pm CST, Nov 23, 2020 · · 6.4 km deep · released about 5.9 lb of TNT

10 km30 km60 km120 km N Alfalfa County 25 kmBarber County 39 kmWoods County 43 kmHarper County 45 kmGrant County 61 kmMajor County 69 kmKingman County 75 kmComanche County 76 kmPratt County 84 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
2:41 pm CST on 23 November 2020 ()
Where
23 km (15 mi) northeast of Alva, OK · earthquakes near Alva
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 1.5 (ml)
Depth
6.4 km below the surface
Felt
no reports yet
Nearest
Alfalfa County, 25 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2178 days ago

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

At this magnitude and depth it was probably too small to be felt, even directly above it. In Alva, 23 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.

Earthquakes near other towns within 30 km: Kiowa, Cherokee.

How big was it?

This earthquake released about 5.9 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,800,000× the energy of this one
  3. Around the size people start to feel M 3.0 160× the energy of this one
  4. This earthquake M 1.5 about 5.9 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

The largest earthquake within 50 km since 2016 was M 4.4 on 2018-06-09 — about 20,000 times the energy of this one.

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 36.9257, -98.4523. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alfalfa County, OK 25 km (15 mi) SSE earthquakes near Alfalfa County
Barber County, KS 39 km (24 mi) NNW earthquakes near Barber County
Woods County, OK 43 km (27 mi) WSW earthquakes near Woods County
Harper County, KS 45 km (28 mi) NE earthquakes near Harper County
Grant County, OK 61 km (38 mi) ESE earthquakes near Grant County
Major County, OK 69 km (43 mi) S earthquakes near Major County

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

Aftershocks so far

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

  1. 2.0 7 km E of Nescatunga, Oklahoma
  2. 2.0 7 km E of Nescatunga, Oklahoma
  3. 1.5 3 km NW of Burlington, Oklahoma
  4. 2.0 14 km WNW of Alva, Oklahoma
  5. 2.1 1 km SE of Wakita, Oklahoma
  6. 1.6 3 km NW of Burlington, Oklahoma
  7. 2.4 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.