New NASA Data Reveals Details About Palos Verdes Landslides

RANCHO PALOS VERDES, CA — New radar imagery and data from NASA's Jet Propulsion Laboratory revealed additional information about the landslides on the Palos Verdes Peninsula.

According to the data, during a period of four weeks in the fall of 2024, land in the residential area slid toward the ocean by as much as 4 inches per week.

"Portions of the peninsula, which juts into the Pacific Ocean just south of the city of Los Angeles, is part of an ancient complex of landslides and has been moving for at least the past six decades, affecting hundreds of buildings in local communities," NASA officials said in a statement. "The motion accelerated and the active area expanded following record-breaking rainfall in Southern California in 2023 and another heavy-precipitation winter in 2024."

To create the visualization of the land movement, the Advanced Rapid Imaging and Analysis team used data from four flights that took place between Sept. 18 and Oct. 17 in 2024. Researchers mounted a radar tool to a Gulfstream III jet that took the four flights to estimate the speed and direction of the landlines in three dimensions.

In the image, colors indicate how fast parts of the landslide moved during the time period, with the darkest reds indicating the highest speed. The arrows represent the direction of the land movement.

"JPL’s study confirms and validates what the City has been observing in its robust GPS survey monitoring of the landslide. The landslide has significantly accelerated and expanded since spring 2023 due to the unprecedented rainfall of the winters of 2023 and 2024," the city said in a statement.

Since October, land movement in Rancho Palos Verdes has started decelerating due to drier weather conditions and the installation of productive deep dewatering wells.

The insights from the flights were part of a package of analyses NASA provided to California officials to support the state's response to the landsides and made available to the public at NASA's Disaster Mapping Portal.