NASA Study Finds California Coastal City Sliding Into Pacific at 4 Inches per Week

Published: 2/7/2025, 7:22:29 AM EST

NASA Study Finds California Coastal City Sliding Into Pacific at 4 Inches per Week — A partially collapsed cliff at Palos Verdes Estates in Los Angeles on Dec. 9, 2022, in a still from video. (Courtesy of Brett Harris/Screenshot via NTD)

NASA released a study revealing that portions of a coastal city in Los Angeles County are sliding towards the Pacific Ocean as quickly as 4 inches per week, expanding the footprint of an ancient landslide complex that has troubled the area for decades.

The Jet Propulsion Laboratory (JPL) in Southern California measured the movement of the slow-moving landslides on the Palos Verdes Peninsula, utilizing an airborne radar to collect data, they announced in a press release last week. The analysis, conducted over a four-week period in the fall of 2024, showed significant land displacement in residential areas.

"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 JPL landslide scientist who conducted the analysis.

The City of Rancho Palos Verdes acknowledged the JPL's findings in a Feb. 6 statement, saying, "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 Palos Verdes Peninsula, located just south of Los Angeles, has been part of an ancient landslide complex for at least six decades.

To visualize the landslide movement, researchers used data from NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), mounted on a Gulfstream III jet. The resulting image shows the speed and direction of the landslide complex, with the darkest red areas indicating the highest speeds.

However, the city also noted that the landslide has shown signs of deceleration since October 2024, attributing the changes to drier weather and the installation of deep dewatering wells. City officials said these wells have extracted more than 125 million gallons of water from the landslide area to date.

The landslide issues in Rancho Palos Verdes have severely impacted some residents and local infrastructure in the area. In late July 2024, gas service was shut off to 135 homes due to land movement, prompting the city to declare a local emergency on Aug. 6, 2024, to seek federal and state aid, according to The Epoch Times.

The situation has also affected iconic local landmarks. The Wayfarers Chapel, a popular wedding venue known for its glass walls, was permanently closed in 2024 due to land movement and is currently being deconstructed to preserve the structure.

Recent geological investigations have revealed that the landslide complex is more extensive than previously thought. City geologists discovered land movement deeper underground, which prompted a shift in strategies to slow its movement.

"We now realize it is this larger, deeper, slip plane that is moving, which is why our project that we've been working on since 2017 ... has to change," Rancho Palos Verdes City Manager Ara Mihranian said during an Aug. 20 city council meeting, as reported by The Epoch Times.

The deeper landslide, part of the Ancient Altamira Landslide Complex, sits about 245 to 345 feet below ground and has the potential to move upward of 50 feet per year, faster than the shallower landslides in the area.