Earthquake · reviewed by a seismologist
M 1.6ml
Earthquake near Castaic, CA
No earthquake was likely felt in Castaic in the 24 hours to 5:24 am PST (13:24 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 1.6 earthquake was recorded 13 km (8 mi) north of Castaic, CA, at 7:28 pm PDT on 5 April 2017 (02:28 UTC), 8.9 km deep.
USGS: 14km N of Castaic, CA
69 km (43 mi) NNW of Los Angeles, CA · 25 km (16 mi) NNW of Santa Clarita, CA
- When
- 7:28 pm PDT on 5 April 2017 ()
- Where
- 13 km (8 mi) north of Castaic, CA · earthquakes near Castaic
- Magnitude
- M 1.6 (ml)
- Depth
- 8.9 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 3467 days ago
Earthquake alerts for Castaic, CA
Get a notification in this browser when USGS records an earthquake near Castaic, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 7 km (4 mi) from the epicentre. In Castaic, 13 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 8.1 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
- Around the size people start to feel M 3.0 120× the energy of this one
- This earthquake M 1.6 about 8.1 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 4.1 on 2016-03-12 — about 5,800 times the energy of this one.
Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:
- 6.7 Northridge, California, earthquake · 45 km SSE of this epicentre
- 6.6 1971 San Fernando Earthquake, California · 33 km SE of this epicentre
- 6.0 Tejon Pass, California · 40 km NW of this epicentre
- 5.9 1km ENE of Granada Hills, California · 40 km SSE of this epicentre
- 5.8 10km SSW of Agua Dulce, CA · 33 km SE 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 34.6090, -118.6417. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction 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 | 82 km (51 mi) | N | earthquakes near Kern County |
| Orange County, CA | 131 km (81 mi) | SE | earthquakes near Orange County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
41 earthquakes have been recorded within 50 km since this one.
- 1.6 23km SSW of Frazier Park, CA
- 1.6 15km N of Fillmore, CA
- 1.7 14km N of Fillmore, CA
- 1.9 3km SE of Chatsworth, CA
- 1.8 19km ENE of Grapevine, CA
- 1.6 15km NNE of Ojai, CA
- 1.8 5km ENE of Lebec, CA
- 1.7 3km NW of Castaic, CA
- 3.4 3km NW of Castaic, CA
- 1.6 4km S of Frazier Park, CA
- 1.9 15km N of Santa Paula, CA
- 1.7 1km NNW of Frazier Park, CA
- 1.6 21km N of Fillmore, CA
- 1.8 3km NW of Frazier Park, CA
- 1.9 7km WSW of Santa Clarita, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.