The Palos Verdes Peninsula is sliding by much as 4 inches (10 centimeters) per week, putting hundreds of buildings at risk.
A peninsula in L.A. County is slipping at a faster rate than before, according to a NASA analysis of data collected last fall.
The Palos Verdes Peninsula in Southern California has been slipping towards the Pacific Ocean for decades. But according to data from NASA’s Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), that rate swelled to 4 inches (10 centimeters) per week from mid-September 2024 through mid-October 2024. Now, the Advanced Rapid Imaging and Analysis team has produced a visual showing the spread and velocity of the landslide, revealing the breathtaking rate of its movement towards the sea.
“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,” said Alexander Handwerger, a landslide scientist at NASA’s Jet Propulsion Laboratory, in a NASA Earth Observatory release.
The NASA team visualized UAVSAR data in the image above, which shows the direction and velocity of the slipping landmass in the area south of the city of Los Angeles. The UAVSAR instrument was mounted on a Gulfstream III jet to collect the data, taken over four flights in September and October. The darkest areas in the graphic correspond to the highest speeds.
As indicated in the visualization, active landslides in the area have expanded beyond the borders of the geological events set up by the California Geological Survey in 2007. Hundreds of buildings in the area now fall within the active landslide area.
The landslide complex has been active for at least the past 60 years, according to the NASA Earth Observatory. The expansion of the complex’s footprint follows record-breaking rains in the area in 2023 and early 2024. Those same rains counterintuitively contributed to the ongoing devastating Los Angeles wildfires, which fed on the voluminous foliage that flourished in the rains and was parched by subsequent droughts.
Handwerger will head up NASA’s upcoming Landslide Climate Change Experiment, or LACCE, an aerial radar data collection effort that will focus on how extreme precipitation patterns—both wet and dry—influence landslides.
Though landslide-specific, LACCE goes hand-in-hand with the upcoming NISAR satellite, a NASA-ISRO (India’s space agency) effort that will observe and map our planet’s natural processes from low-Earth orbit. Set to launch in 2025, NISAR will visualize Earth’s surface as never before—even 0.4-inch (1 cm) changes will be detectable from space.
Taken together, the experiments are helping scientists understand how climate change changes the planet’s surface, and how humanity needs to prepare for extreme weather events.