Earthquake · reviewed by a seismologist
M 2.1ml
Earthquake near Castaic, CA
No earthquake was likely felt in Castaic in the 24 hours to 8:59 pm PST (04:59 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 2.1 earthquake was recorded 15 km (9 mi) north of Castaic, CA, at 1:07 am PDT on 12 May 2021 (08:07 UTC), 11 km deep.
USGS: 15km N of Castaic, CA
70 km (44 mi) NNW of Los Angeles, CA · 26 km (16 mi) NNW of Santa Clarita, CA
- When
- 1:07 am PDT on 12 May 2021 ()
- Where
- 15 km (9 mi) north of Castaic, CA · earthquakes near Castaic
- Magnitude
- M 2.1 (ml)
- Depth
- 11 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 2010 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 14 km (9 mi) from the epicentre. In Castaic, 15 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 47 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 320,000× the energy of this one
- Magna, Utah 2020 M 5.7 230,000× the energy of this one
- Around the size people start to feel M 3.0 20× the energy of this one
- This earthquake M 2.1 about 47 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 1,100 times the energy of this one.
Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:
- 7.5 The 1952 Kern County, California Earthquake · 50 km NW of this epicentre
- 6.7 Northridge, California, earthquake · 46 km SSE of this epicentre
- 6.6 1971 San Fernando Earthquake, California · 34 km SE of this epicentre
- 6.0 Tejon Pass, California · 39 km NW of this epicentre
- 5.9 1km ENE of Granada Hills, California · 41 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 34.6193, -118.6443. 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 | 59 km (36 mi) | SE | earthquakes near Los Angeles County |
| Kern County, CA | 81 km (50 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
27 earthquakes have been recorded within 50 km since this one.
- 1.6 8km W of Frazier Park, CA
- 1.9 9km W of Grapevine, CA
- 1.8 1km SE of Sylmar, CA
- 1.5 1km SE of Sylmar, CA
- 1.5 17km ENE of Lebec, CA
- 1.7 7km N of Piru, CA
- 1.6 9km NNW of Piru, CA
- 2.9 1km NNE of San Fernando, CA
- 3.6 5km NNW of Thousand Oaks, CA
- 1.6 6km S of Frazier Park, CA
- 1.5 3km SSE of Piru, CA
- 2.1 18km N of Fillmore, CA
- 1.7 21km SSW of Frazier Park, CA
- 1.5 17km N of Fillmore, CA
- 1.6 17km NNW of Neenach, 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.