QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9ml

18 km SE of Ackerly, Texas

· 6.9 km deep · released about 11 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Howard County 18 kmMartin County 37 kmBorden County 39 kmDawson County 51 kmGlasscock County 60 kmMitchell County 63 kmScurry County 73 kmMidland County 77 kmSterling County 81 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
Magnitude
M 3.9 (ml)
Depth
6.9 km below the surface
Felt
10 reports · strongest reported intensity III
Measured shaking
intensity V (ShakeMap)
USGS impact alert
green
Nearest
Howard County, 18 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1506 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 10 people have reported feeling it to USGS.

How big was it?

This earthquake released about 11 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 16,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 710× the energy of this one
  3. Magna, Utah 2020 M 5.7 500× the energy of this one
  4. This earthquake M 3.9 about 11 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 22× more

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.

Where

Epicentre 32.4069, -101.5833. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Howard County, TX 18 km (11 mi) NW of here earthquakes near Howard County
Martin County, TX 37 km (23 mi) ENE of here earthquakes near Martin County
Borden County, TX 39 km (24 mi) SSW of here earthquakes near Borden County
Dawson County, TX 51 km (31 mi) SE of here earthquakes near Dawson County
Glasscock County, TX 60 km (37 mi) N of here earthquakes near Glasscock County
Mitchell County, TX 63 km (39 mi) W of here earthquakes near Mitchell County

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

Aftershocks so far

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

  1. 1.5 5 km SE of Ackerly, Texas
  2. 3.4 5 km SE of Ackerly, Texas
  3. 2.0 16 km NW of Stanton, Texas
  4. 2.4 10 km W of Forsan, Texas
  5. 1.9 22 km NW of Stanton, Texas
  6. 1.5 19 km N of Stanton, Texas
  7. 2.9 19 km NW of Stanton, Texas
  8. 2.2 33 km SSW of Los Ybanez, Texas
  9. 2.0 32 km SSW of Los Ybanez, Texas
  10. 2.1 32 km SSW of Los Ybanez, Texas
  11. 1.5 2 km SSE of Coahoma, Texas
  12. 2.4 31 km SSW of Los Ybanez, Texas
  13. 3.3 30 km SSW of Los Ybanez, Texas
  14. 2.4 31 km SSW of Los Ybanez, Texas
  15. 2.2 31 km SSW of Los Ybanez, Texas

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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.6 on 2021-12-28 — it released about 11 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.