QuakeIndex

Fault · California

Santa Ynez fault

148 kmlong (92 mi), as mapped
1–5 mm/yrhow fast it slips
< 15,000 yearssince it last broke the surface
55quakes of M2.5+ within 10 km since 2016

In plain English

The two sides move 1 to 5 mm a year — 10 to 50 cm (4 to 20 inches) every century.

Its most recent surface rupture is younger than 15,000 years.

The largest earthquake recorded near it was M 6.3 in 1821 (Northwest of Santa Barbara, California) — about 89,000 times the energy of an M3.0, the size people start to feel. It released about 43 kilotons of TNT.

USGS maps it as 5 sections: Eastern section, Pacifico section, South Branch section, South section, Western section.

This week vs. its last ten years

0/100

quiet

0 quakes of M1.5+ within 5 km of the trace in the last 7 days — busier than 0% of weeks since 2016. A normal week: 0–0.

Computed from the USGS catalogue · a description of the past, not a forecast · method

San Andreas faultGarlock faultNewport-Inglewood-Rose Canyon faultSan Gabriel faultSierra Madre faultHosgri faultPitas Point faultPalos Verdes faultOak Ridge fault (offshore)Mission Ridge fault systemSan Pedro Basin faultSan Juan faultSanta Cruz Island faultMalibu Coast faultSanta Cruz faultLos Osos faultDume faultOak Ridge faultSimi-Santa Rosa faultWhite Wolf faultPuente Hills blind thrust systemSan Cayetano faultMid-Channel faultRed Mountain faultPleito faultSanta Monica faultNorthridge blind thrustWheeler Ridge faultLos Alamos faultRaymond faultVerdugo faultHollywood faultVentura faultIsla Vista fault M 6.3 · 1821 · Northwest of Santa Barbara, California M 6.0 · 1854 · Near Santa Barbara, California
The Santa Ynez fault as mapped at the surface (glowing), with the other mapped faults nearby, 55 of the M2.5+ earthquakes within 10 km of it since 2016 (dots), and the epicentres of the large historic earthquakes recorded near it (rings). Traces: USGS Quaternary Fault and Fold Database. Historic epicentres are estimates.

Every year since 2016

Earthquakes of M2.5+ with an epicentre within 10 km of the mapped trace. Near is not the same as on: some will have slipped on neighbouring faults.

The big ones recorded near it

  1. M 6.3 Northwest of Santa Barbara, California
    January 1, 1821 · epicentre on the trace
  2. M 6.0 Near Santa Barbara, California
    May 31, 1854 · epicentre 6 km from the trace
  3. M 4.1 17km ENE of Ojai, CA
    March 12, 2016 · epicentre 2 km from the trace

Before 1973 from the USGS ComCat historical catalogue (within 25 km; epicentres of old earthquakes are estimates). Since 2016, M4+ within 10 km.

Most recent near it

  1. M 2.5 11 km N of Fillmore, CA
    2026-09-18 · 8 km from the trace
  2. M 2.5 12 km SSW of Lompoc, CA
    2026-08-17 · 2 km from the trace
  3. M 2.7 12 km S of Lompoc, CA
    2026-08-17 · 2 km from the trace
  4. M 2.5 12 km SSW of Lompoc, CA
    2026-08-14 · 3 km from the trace
  5. M 2.8 12 km SSW of Lompoc, CA
    2026-08-09 · 2 km from the trace
  6. M 2.5 13 km SSW of Lompoc, CA
    2026-08-09 · 2 km from the trace

Neighbouring faults

Fault trace, slip rate and age: USGS Quaternary Fault and Fold Database (public domain), simplified for the web. Earthquakes: USGS ComCat. QuakeIndex does not forecast earthquakes; a fault's history describes the past. For early warning use ShakeAlert.