QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

4km ENE of Westmorland, CA

· 13 km deep · released about 1.5 tons of TNT

10 km30 km60 km120 km N Imperial County 21 kmRiverside County 85 kmSan Diego County 111 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 3.3 (ml)
Depth
13 km below the surface
Felt
17 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
Nearest
Imperial County, 21 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2053 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 17 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1.5 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 110,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,100× the energy of this one
  3. Magna, Utah 2020 M 5.7 3,600× the energy of this one
  4. This earthquake M 3.3 about 1.5 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 3.1× 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 33.0455, -115.5842. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Imperial County, CA 21 km (13 mi) W of here earthquakes near Imperial County
Riverside County, CA 85 km (53 mi) SSE of here earthquakes near Riverside County
San Diego County, CA 111 km (69 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

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

  1. 1.7 15km E of Ocotillo, CA
  2. 1.8 16km E of Ocotillo, CA
  3. 1.6 9km SW of Niland, CA
  4. 2.3 16km E of Ocotillo, CA
  5. 1.5 9km SW of Niland, CA
  6. 1.6 9km SW of Niland, CA
  7. 2.0 10km SW of Niland, CA
  8. 1.8 9km SW of Niland, CA
  9. 1.5 8km SW of Niland, CA
  10. 2.4 10km SW of Niland, CA
  11. 1.6 10km SW of Niland, CA
  12. 3.4 10km SW of Niland, CA
  13. 1.8 9km SW of Niland, CA
  14. 1.6 10km SW of Niland, CA
  15. 1.6 9km SW of Niland, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.9 on 2020-10-01 — it released about 250 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.