QuakeIndex

Earthquake · reviewed by a seismologist

M 4.0mw

26km S of Port Hueneme, CA

· 5.9 km deep · released about 17 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Ventura County 50 kmLos Angeles County 94 kmSanta Barbara County 101 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
5.9 km below the surface
Felt
1967 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Ventura County, 50 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 711 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 1967 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 33.9173, -119.2283. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Ventura County, CA 50 km (31 mi) S of here earthquakes near Ventura County
Los Angeles County, CA 94 km (59 mi) WSW of here earthquakes near Los Angeles County
Santa Barbara County, CA 101 km (63 mi) SE of here earthquakes near Santa Barbara County

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

Aftershocks so far

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

  1. 1.6 17km S of Carpinteria, CA
  2. 1.7 17km SSE of Carpinteria, CA
  3. 1.9 1km S of Malibu, CA
  4. 1.6 10km SE of Port Hueneme, CA
  5. 2.2 3km NNE of Camarillo, CA
  6. 2.1 2km S of Malibu, CA
  7. 1.6 13km SE of Port Hueneme, CA
  8. 2.6 10km WNW of Ventura, CA
  9. 2.0 10km WNW of Ventura, CA
  10. 1.9 8km W of Ventura, CA
  11. 1.5 7km NE of Oxnard, CA
  12. 2.5 22km SE of Santa Cruz Is. (E end), CA
  13. 1.7 15km SSW of Thousand Oaks, CA
  14. 2.4 4km ENE of Port Hueneme, CA
  15. 2.2 30km SE of Santa Cruz Is. (E end), 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 5.3 on 2018-04-05 — it released about 78 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.