QuakeIndex

Earthquake · reviewed by a seismologist

M 4.0mw

16km SW of Westmorland, CA

· 3.2 km deep · released about 17 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Imperial County 39 kmRiverside County 89 kmSan Diego County 95 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 4.0 (mw)
Depth
3.2 km below the surface
Felt
42 reports · strongest reported intensity IV
Measured shaking
intensity VI (ShakeMap)
USGS impact alert
green
Nearest
Imperial County, 39 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3630 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 42 people have reported feeling it to USGS.

How big was it?

This earthquake released about 17 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 10,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 450× the energy of this one
  3. Magna, Utah 2020 M 5.7 320× the energy of this one
  4. This earthquake M 4.0 about 17 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 35× 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 32.9583, -115.7605. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Imperial County, CA 39 km (24 mi) WSW of here earthquakes near Imperial County
Riverside County, CA 89 km (55 mi) SSE of here earthquakes near Riverside County
San Diego County, CA 95 km (59 mi) E of here earthquakes near San Diego County

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

Aftershocks so far

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

  1. 1.8 14km WNW of Calipatria, CA
  2. 2.2 9km ENE of Ocotillo Wells, CA
  3. 1.7 13km WNW of Calipatria, CA
  4. 1.6 13km WNW of Calipatria, CA
  5. 1.5 12km SSE of Bombay Beach, CA
  6. 2.1 7km NE of Imperial, CA
  7. 2.4 20km SW of Ocotillo Wells, CA
  8. 2.4 14km N of Ocotillo Wells, CA
  9. 1.7 12km WNW of Progreso, B.C., MX
  10. 3.1 14km N of Ocotillo Wells, CA
  11. 1.8 14km N of Ocotillo Wells, CA
  12. 1.8 14km N of Ocotillo Wells, CA
  13. 2.0 9km NE of Ocotillo Wells, CA
  14. 1.7 16km W of Progreso, B.C., MX
  15. 1.6 6km SSE of Bombay Beach, CA

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.