The Ventura-Pitas Point fault courses through downtown Ventura before cutting outward to the coast and along the Santa Barbara Channel. There, it tilts at a steep angle, pushing under the coastline and extending 20 kilometers into the earth’s crust. “It’s about as deep as earthquakes get,” says James Dolan, an earth sciences professor at University of Southern California.
Until just a few years ago, the fault was thought to be relatively shallow, capable only of a moderate earthquake. But a group of scientists intrigued by the area’s complex seismology began to develop a different picture. Their research suggested that the Ventura-Pitas Point fault is capable of producing an earthquake as strong as one caused by the San Andreas fault, potentially setting off temblors from Santa Barbara to Los Angeles.
“For a long time, everyone assumed that the San Andreas fault was the big gorilla,” explained David Oglesby, a seismologist specializing in the physics of earthquakes. But today, he said, scientists believe possible earthquake dangers occur when smaller faults slip together. The Ventura-Pitas Point fault’s depth and length, for example, make it likely that it connects to other faults in the area, such as the Red Mountain and San Cayetano systems.