QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7ml

Earthquake near Santa Clarita, CA

No earthquake was likely felt in Santa Clarita in the 24 hours to 4:29 am PST (12:29 UTC). The last one was M 2.3, 16 km (10 mi) SSW, at 9:45 am PST on 7 November 2026, estimated intensity II (weak) in town; 26 felt reports to USGS. Every earthquake near Santa Clarita

This page: a magnitude 1.7 earthquake was recorded 14 km (9 mi) east-northeast of Santa Clarita, CA, at 2:39 pm PDT on 4 August 2023 (21:39 UTC), 11 km deep.

USGS: 10 km E of Santa Clarita, CA

10 km (6 mi) E of Santa Clarita, CA · 45 km (28 mi) N of Los Angeles, CA

2:39 pm PDT, Aug 4, 2023 · · 11 km deep · released about 9.6 lb of TNT

10 km30 km60 km120 km N Los Angeles County 28 kmVentura County 68 kmOrange County 101 kmKern County 107 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
2:39 pm PDT on 4 August 2023 ()
Where
14 km (9 mi) east-northeast of Santa Clarita, CA · earthquakes near Santa Clarita
Magnitude
M 1.7 (ml)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Los Angeles County, 28 km SSE
Nearest mapped fault
San Gabriel fault, 7 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 1193 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 4 km (2 mi) from the epicentre. In Santa Clarita, 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: Agua Dulce, Stevenson Ranch, Acton, Valencia, Castaic, Val Verde.

How big was it?

This earthquake released about 9.6 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 1,600,000× 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 99× the energy of this one
  4. This earthquake M 1.7 about 9.6 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 5,600 times the energy of this one.

Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 Northridge, California, earthquake · 26 km SSW of this epicentre
  2. 6.6 1971 San Fernando Earthquake, California · 2 km ESE of this epicentre
  3. 5.9 The 1987 Whittier Narrows, California Earthquake · 50 km SE of this epicentre
  4. 5.9 1km ENE of Granada Hills, California · 18 km SSW of this epicentre
  5. 5.8 10km SSW of Agua Dulce, CA · 2 km ESE 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 34.4208, -118.3965. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Los Angeles County, CA 28 km (17 mi) SSE earthquakes near Los Angeles County
Ventura County, CA 68 km (42 mi) W earthquakes near Ventura County
Orange County, CA 101 km (63 mi) SE earthquakes near Orange County
Kern County, CA 107 km (67 mi) NNW earthquakes near Kern County

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

Aftershocks so far

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

  1. 1.6 2 km NW of Tarzana, CA
  2. 2.3 4 km SW of Sherman Oaks, CA
  3. 1.5 3 km NNE of Granada Hills, CA
  4. 2.0 1 km SSE of Century City, CA
  5. 1.6 16 km NNE of Bradbury, CA
  6. 1.7 16 km NNE of Bradbury, CA
  7. 1.9 11 km NNE of Valencia, CA
  8. 1.6 17 km NNE of Bradbury, CA
  9. 1.6 17 km NNE of Bradbury, CA
  10. 1.8 6 km W of Simi Valley, CA
  11. 1.6 1 km N of Universal City, CA
  12. 2.6 0 km NNW of View Park-Windsor Hills, CA
  13. 1.8 0 km N of View Park-Windsor Hills, CA
  14. 1.6 0 km W of View Park-Windsor Hills, CA
  15. 1.6 13 km SW of Valencia, 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.