QuakeIndex

Fault · California

Oak Ridge fault (offshore)

93 kmlong (58 mi), as mapped
0.2–1 mm/yrhow fast it slips
< 15,000 yearssince it last broke the surface
37quakes 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.

The largest earthquake recorded near it was M 7.1 in 1812 (Santa Barbara Channel, California) — about 1,400,000 times the energy of an M3.0, the size people start to feel. It released about 670 kilotons of TNT.

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 faultSanta Ynez faultSan Gabriel faultHosgri faultPitas Point faultCatalina faultMission Ridge fault systemSanta Cruz Island faultMalibu Coast faultSanta Cruz faultDume faultOak Ridge faultSimi-Santa Rosa faultSan Cayetano faultMid-Channel faultRed Mountain faultPleito faultLos Alamos faultVentura faultIsla Vista fault M 7.1 · 1812 · Santa Barbara Channel, California M 6.8 · 1925 · The 1925 Santa Barbara, California Earthquake M 6.0 · 1854 · Near Santa Barbara, California
The Oak Ridge fault (offshore) as mapped at the surface (glowing), with the other mapped faults nearby, 37 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 7.1 Santa Barbara Channel, California
    December 21, 1812 · epicentre 13 km from the trace
  2. M 6.8 The 1925 Santa Barbara, California Earthquake
    June 29, 1925 · epicentre 1 km from the trace
  3. M 6.0 Near Santa Barbara, California
    May 31, 1854 · epicentre 20 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 2.9 9 km S of Carpinteria, CA
    2025-12-26 · 7 km from the trace
  2. M 2.7 11 km SSE of Isla Vista, CA
    2025-07-03 · 2 km from the trace
  3. M 2.9 16 km SSE of Isla Vista, CA
    2025-01-09 · 0 km from the trace
  4. M 2.9 14 km SSE of Isla Vista, CA
    2025-01-06 · 0 km from the trace
  5. M 3.1 21km S of Santa Barbara, CA
    2023-06-04 · 2 km from the trace
  6. M 2.7 21km SW of Isla Vista, CA
    2022-07-09 · 3 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.