QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Altus, OK

No earthquake was likely felt in Altus in the 24 hours to 12:35 am CST (06:35 UTC). The last one was M 3.4, 160 km (99 mi) NE, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Altus

This page: a magnitude 1.8 earthquake was recorded 20 km (12 mi) northeast of Altus, OK, at 10:26 pm CDT on 18 September 2026 (03:26 UTC), 5.0 km deep.

USGS: 9 km NNE of Friendship, Oklahoma

10:26 pm CDT, Sep 18, 2026 · · 5.0 km deep · released about 15 lb of TNT

10 km30 km60 km120 km N Kiowa County 26 kmJackson County 28 kmGreer County 36 kmTillman County 52 kmHarmon County 58 kmWashita County 60 kmComanche County 68 kmBeckham County 70 kmHardeman County 74 km
Distance rings around the epicentre, with the nearest towns at their true direction. Not a shaking map — see the USGS ShakeMap for that.
When
10:26 pm CDT on 18 September 2026 ()
Where
20 km (12 mi) northeast of Altus, OK · earthquakes near Altus
Oklahoma today
every earthquake in Oklahoma in the last 24 hours
Magnitude
M 1.8 (ml)
Depth
5.0 km below the surface
Felt
no reports yet
Nearest
Kiowa County, 26 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 53 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 16 km (10 mi) from the epicentre. In Altus, 20 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: Granite, Snyder, Mangum, Hobart.

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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 34.7837, -99.2077. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kiowa County, OK 26 km (16 mi) NE earthquakes near Kiowa County
Jackson County, OK 28 km (18 mi) SW earthquakes near Jackson County
Greer County, OK 36 km (22 mi) WNW earthquakes near Greer County
Tillman County, OK 52 km (33 mi) SSE earthquakes near Tillman County
Harmon County, OK 58 km (36 mi) W earthquakes near Harmon County
Washita County, OK 60 km (37 mi) NNE earthquakes near Washita County

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

Aftershocks so far

No further earthquakes have been recorded within 50 km since this one.

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.