QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3ml

Earthquake near Castaic, CA

No earthquake was likely felt in Castaic in the 24 hours to 7:04 am PST (15:04 UTC). The last one was M 2.2, 11 km (7 mi) S, at 8:32 am PDT on 18 October 2026, estimated intensity II (weak) in town; 16 felt reports to USGS. Every earthquake near Castaic

This page: a magnitude 2.3 earthquake was recorded 14 km (9 mi) north of Castaic, CA, at 11:45 am PDT on 11 September 2020 (18:45 UTC), 9.9 km deep.

USGS: 14km N of Castaic, CA

70 km (43 mi) NNW of Los Angeles, CA · 26 km (16 mi) NNW of Santa Clarita, CA

11:45 am PDT, Sep 11, 2020 · · 9.9 km deep · released about 94 lb of TNT

10 km30 km60 km120 km N Ventura County 53 kmLos Angeles County 58 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
11:45 am PDT on 11 September 2020 ()
Where
14 km (9 mi) north of Castaic, CA · earthquakes near Castaic
Magnitude
M 2.3 (ml)
Depth
9.9 km below the surface
Felt
no reports yet
Nearest
Ventura County, 53 km WSW
Nearest mapped fault
San Gabriel fault, 8 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2250 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 18 km (11 mi) from the epicentre. In Castaic, 14 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Earthquakes near other towns within 30 km: Val Verde, Valencia, Stevenson Ranch, Piru, Santa Clarita.

How big was it?

This earthquake released about 94 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 160,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 110,000× the energy of this one
  3. Around the size people start to feel M 3.0 10× the energy of this one
  4. This earthquake M 2.3 about 94 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.

For this area

The largest earthquake within 50 km since 2016 was M 4.2 on 2020-07-30 — about 580 times the energy of this one.

Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.5 The 1952 Kern County, California Earthquake · 50 km NW of this epicentre
  2. 6.7 Northridge, California, earthquake · 46 km SSE of this epicentre
  3. 6.6 1971 San Fernando Earthquake, California · 34 km SE of this epicentre
  4. 6.0 Tejon Pass, California · 39 km NW of this epicentre
  5. 5.9 1km ENE of Granada Hills, California · 40 km SSE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 34.6178, -118.6418. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Ventura County, CA 53 km (33 mi) WSW earthquakes near Ventura County
Los Angeles County, CA 58 km (36 mi) SE earthquakes near Los Angeles County
Kern County, CA 81 km (51 mi) N earthquakes near Kern County
Orange County, CA 132 km (82 mi) SE earthquakes near Orange County

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

Aftershocks so far

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

  1. 1.9 17km S of Tehachapi, CA
  2. 1.8 4km NNE of Elizabeth Lake, CA
  3. 1.6 19km N of Fillmore, CA
  4. 1.7 19km N of Fillmore, CA
  5. 1.6 19km NNW of Piru, CA
  6. 1.5 3km WNW of Frazier Park, CA
  7. 1.6 19km N of Fillmore, CA
  8. 2.2 6km NE of Chatsworth, CA
  9. 1.7 19km N of Fillmore, CA
  10. 2.0 20km N of Fillmore, CA
  11. 2.1 20km N of Fillmore, CA
  12. 2.0 14km SSW of Frazier Park, CA
  13. 1.7 3km W of Sylmar, CA
  14. 2.8 17km N of Fillmore, CA
  15. 2.8 16km 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.