Photo: Corey Buckley//Unsplash
For years, the city of Rancho Palos Verdes, California has monitored the consistent threat of landslides. The coastal community, which is dotted with waves like the infamous Lunada Bay, is under constant threat of land movement. In fact, the problem is so widespread that the city launched a $42-million voluntary property buyout program for local homeowners last October. But we’re not talking about the Earth shifting a smidge here, a smidge there over the course of decades. According to new observations from NASA, the Palos Verdes Peninsula is experiencing a slow-moving landslide in which the peninsula is moving into the ocean as fast as four inches per week.
Researchers discovered this by compiling radar images at four different points in 2024. They measured the rate of movement in three dimensions and calculated that four-inch rate of movement (on average) between September 18, 2024, and October 17, 2024. The area stretches from Abalone Cove to Portuguese Bend, somewhere in the ballpark of about five miles from Lunada Bay. According to a landslide scientist at NASA’s Jet Propulsion Laboratory, little to no infrastructure was built through this area but it still poses a threat to several homes nearby.
NASA’s UAVSAR airborne radar instrument captured data in fall 2024 showing the motion of landslides on the Palos Verdes Peninsula following record-breaking rainfall in Southern California in 2023 and another heavy-precipitation winter in 2024. Darker red indicates faster motion. Image: NASA
“In effect, we’re seeing that the footprint of land experiencing significant impacts has expanded, and the speed is more than enough to put human life and infrastructure at risk,” Alexander Handwerger, the JPL landslide scientist who performed the analysis, said in a statement.
According to NASA, the historic rainfall that came with Hurricane Hillary in 2023 accelerated the large landslide, which now impacts hundreds of buildings in the area. The Wayfarer’s Chapel was closed due to the shifting earth and City Council even voted to prohibit bicyclists and motorcyclists from using a section of road that’s shifted so much locals refer to it as a “ski jump.”
