New Seismic Research Shows Higher Than Believed Risk From Major Quake For Parts Of South Coast

Feb 16, 2017

An earthquake fault in Ventura and Santa Barbara Counties may be much more dangerous than thought.

A team of researchers has just completed a study about the makeup of what’s called the Ventura-Pitas Point fault. They say it’s closer to the surface than previously believed, which means stronger shaking and more damage during a major quake.

Dr. Gareth Funning is an Associate Professor of Geophysics at UC Riverside, and one of the authors of the new study. Funning says the Ventura-Pitas Point fault is believed to be capable of generating a magnitude seven to eight earthquake.

Funning says the new study tried to solve the controversy about the makeup and location of the fault. There are different types of faults, and some have the potential to be more damaging. Some researchers originally thought the fault was shaped like a piece of plywood leaning against a house, extending deep under the earth’s surface. But, others thought it was like a set of stairs, with more of the fault closer to the surface. Funning says GPS data and computer modeling used for the new study backs the stairs model.

The fault runs through Ventura, and then west along the coastline off of Santa Barbara and Goleta. The danger to Ventura was known, but the new data shows portions of the fault run under Santa Barbara and Goleta, which means a quake would create more intensive shaking and damage for Southern Santa Barbara County than previously thought.

The study is important, because it will allow further modeling on potential quake impacts, including the potential for tsunamis from a quake on the fault.

Funning says it’s possibly been 10,000 years since there’s been a major earthquake on the fault, but the reality is we could have one next year, next month, or in the next five minutes. We simply don’t know when it could happen, but we should be prepared.

The study was published in the latest edition of Geophysical Research Letters.