Earlier estimates said the fault zone could generate up to a magnitude 7.4 earthquake, but a new report shows it could produce a quake as strong as 7.8.
that struck in 2019, said John H. Shaw, a professor of structural and economic geology at Harvard University and one of three authors of the new study.
“Rather than one line in the map, we could see a rupture [series] that could occur in a wide area,” Shaw said of a major quake along the Palos Verdes fault zone. Aftershocks would be like falling dominoes, he said. Oil studies can be helpful to earthquake scientists because they offer insights into how the Earth looks below the surface, where earthquake faults lie.
The study, published by the Bulletin of the Seismological Society of America, also found the Palos Verdes fault slips at a much faster rate than most active fracture zones in Los Angeles County, moving 1 to 6 millimeters a year. More than 50 active faults run under L.A. County, and the majority move 1 millimeter or less annually, Shaw said.