QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5mw

2km NNW of Castaic, CA

· 18 km deep · released about 2.9 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Ventura County 49 kmLos Angeles County 49 kmKern County 94 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 3.5 (mw)
Depth
18 km below the surface
Felt
884 reports · strongest reported intensity IV
Measured shaking
intensity V (ShakeMap)
Nearest
Ventura County, 49 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 713 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 884 people have reported feeling it to USGS.

How big was it?

This earthquake released about 2.9 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 59,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 2,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 1,900× the energy of this one
  4. This earthquake M 3.5 about 2.9 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 6× 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 34.5075, -118.6345. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Ventura County, CA 49 km (30 mi) ENE of here earthquakes near Ventura County
Los Angeles County, CA 49 km (30 mi) NW of here earthquakes near Los Angeles County
Kern County, CA 94 km (58 mi) S of here earthquakes near Kern County
Orange County, CA 122 km (76 mi) NW of here earthquakes near Orange County

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

Aftershocks so far

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

  1. 1.9 1km S of Sylmar, CA
  2. 1.8 1km NW of San Fernando, CA
  3. 1.8 1km SSW of Sylmar, CA
  4. 2.5 1km ESE of Sylmar, CA
  5. 1.6 1km WNW of San Fernando, CA
  6. 1.7 0km NNW of San Fernando, CA
  7. 2.6 1km ESE of Sylmar, CA
  8. 1.5 1km SW of Sylmar, CA
  9. 2.7 1km SSE of Sylmar, CA
  10. 3.7 1km NNE of San Fernando, CA
  11. 2.1 1km SE of Sylmar, CA
  12. 1.9 1km NW of San Fernando, CA
  13. 3.1 1km N of San Fernando, CA
  14. 2.1 1km NNW of San Fernando, CA
  15. 2.1 1km ESE of Sylmar, 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 4.1 on 2016-03-12 — it released about 8.2 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.