Researchers find that the fault has a staircase-like structure, which would result in stronger shaking and more damage during an earthquake.
RIVERSIDE, Calif. (www.ucr.edu) — A new study by a team of researchers, including one from the University of California, Riverside, found that the fault under Ventura, Calif., would likely cause stronger shaking during an earthquake and more damage than previously suspected.
The Ventura-Pitas Point fault in southern California has been the focus of a lot of recent attention because it is thought to be capable of magnitude 8 earthquakes. It underlies the city of Ventura and runs offshore, and thus may be capable of generating tsunamis.
Since it was identified as an active and potentially dangerous fault in the late 1980s, there has been a controversy about its location and geometry underground, with two competing models.
Originally, researchers assumed the fault was planar and steeply dipping, like a sheet of plywood positioned against a house, to a depth of about 13 miles. But a more recent study, published in 2014, suggested the fault had a “ramp-flat geometry,” with a flat section between two tilting sections, similar to a portion of a staircase.