QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

15km N of Castaic, CA

· 9.1 km deep · released about 10 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Ventura County 53 kmLos Angeles County 59 kmKern County 81 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 1.7 (ml)
Depth
9.1 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Ventura County, 53 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1511 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 2 people have reported feeling it to USGS.

How big was it?

This earthquake released about 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 95× the energy of this one
  4. This earthquake M 1.7 about 10 lb of TNT

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 34.6187, -118.6440. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Ventura County, CA 53 km (33 mi) ENE of here earthquakes near Ventura County
Los Angeles County, CA 59 km (36 mi) NW of here earthquakes near Los Angeles County
Kern County, CA 81 km (51 mi) S of here earthquakes near Kern County
Orange County, CA 132 km (82 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

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

  1. 1.8 2km SSW of Sylmar, CA
  2. 1.9 5km NNW of Chatsworth, CA
  3. 1.8 13km N of Fillmore, CA
  4. 1.7 13km N of Fillmore, CA
  5. 1.6 13km N of Fillmore, CA
  6. 1.9 17km S of Tehachapi, CA
  7. 1.8 4km NNE of Elizabeth Lake, CA
  8. 1.6 19km N of Fillmore, CA
  9. 1.7 19km N of Fillmore, CA
  10. 1.6 19km NNW of Piru, CA
  11. 1.5 3km WNW of Frazier Park, CA
  12. 1.6 19km N of Fillmore, CA
  13. 2.2 6km NE of Chatsworth, CA
  14. 1.7 19km N of Fillmore, CA
  15. 2.0 20km N of Fillmore, 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 4.2 on 2020-07-30 — it released about 5,400 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.