QuakeIndex

Earthquake · reviewed by a seismologist

M 4.0mw

14km NE of Julian, CA

· 11 km deep · released about 13 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Diego County 31 kmRiverside County 78 kmImperial County 105 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
11 km below the surface
Felt
4037 reports · strongest reported intensity IV
Measured shaking
intensity VI (ShakeMap)
USGS impact alert
green
Nearest
San Diego County, 31 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3072 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 4037 people have reported feeling it to USGS.

How big was it?

This earthquake released about 13 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 13,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 580× the energy of this one
  3. Magna, Utah 2020 M 5.7 410× the energy of this one
  4. This earthquake M 4.0 about 13 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 28× 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 33.1478, -116.4792. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Diego County, CA 31 km (19 mi) ENE of here earthquakes near San Diego County
Riverside County, CA 78 km (49 mi) SW of here earthquakes near Riverside County
Imperial County, CA 105 km (65 mi) W of here earthquakes near Imperial 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. 2.0 16km ESE of Anza, CA
  2. 1.6 9km NE of Aguanga, CA
  3. 1.6 9km S of Ocotillo Wells, CA
  4. 1.6 9km NE of Aguanga, CA
  5. 1.9 22km ESE of Anza, CA
  6. 1.7 26km SSW of Ocotillo Wells, CA
  7. 1.7 10km WSW of Ocotillo Wells, CA
  8. 1.8 17km NW of Ocotillo, CA
  9. 1.6 9km NE of Aguanga, CA
  10. 1.5 25km SW of Ocotillo Wells, CA
  11. 1.6 8km NE of Aguanga, CA
  12. 1.7 8km NE of Aguanga, CA
  13. 1.6 9km NE of Aguanga, CA
  14. 2.1 8km NE of Aguanga, CA
  15. 1.7 8km ENE of Ocotillo Wells, 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 5.2 on 2016-06-10 — it released about 70 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.