QuakeIndex

Fault · California

Simi-Santa Rosa fault

47 kmlong (29 mi), as mapped
0.2–1 mm/yrhow fast it slips
< 15,000 yearssince it last broke the surface
16quakes of M2.5+ within 10 km since 2016

In plain English

The two sides move 0.2 to 1 mm a year — 2 to 10 cm every century.

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

USGS maps it as 3 sections: Camarillo-Santa Rosa Valley section, Simi-Santa Rosa section, Springville section.

This week vs. its last ten years

Too quiet to rank: fewer than half a year's worth of weeks with any M1.5+ quake within 5 km, in ten years. A single quake here would read as "unusual", so we do not score it.

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

San Andreas faultGarlock faultNewport-Inglewood-Rose Canyon faultSanta Ynez faultSan Gabriel faultSierra Madre faultPitas Point faultCatalina faultPalos Verdes faultOak Ridge fault (offshore)Mission Ridge fault systemSan Pedro Basin faultSanta Cruz Island faultMalibu Coast faultSanta Cruz faultDume faultOak Ridge faultPuente Hills blind thrust systemSan Cayetano faultMid-Channel faultRed Mountain faultPleito faultSanta Monica faultNorthridge blind thrustSan Joaquin Hills thrustRaymond faultVerdugo faultHollywood faultVentura fault
The Simi-Santa Rosa fault as mapped at the surface (glowing), with the other mapped faults nearby, 16 of the M2.5+ earthquakes within 10 km of it since 2016 (dots), . 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.

Most recent near it

  1. M 2.6 9 km SW of Valencia, CA
    2026-08-12 · 9 km from the trace
  2. M 2.8 10 km SSW of Valencia, CA
    2026-02-08 · 8 km from the trace
  3. M 2.5 10 km SSW of Valencia, CA
    2025-12-27 · 8 km from the trace
  4. M 2.6 10 km SSW of Valencia, CA
    2025-12-27 · 8 km from the trace
  5. M 2.5 10 km SSW of Valencia, CA
    2025-12-25 · 8 km from the trace
  6. M 2.6 8km SE of Piru, CA
    2022-05-25 · 8 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.