California town hit by landslides has been at risk for decades, and the slide may not be stopped | The Times Of Update

Rancho Palos Verdes, a coastal community in the Los Angeles area, could be described as a geological time bomb.

This thriving city is perched atop sheer cliffs overlooking the Pacific Ocean that have been slowly shifting and giving way for hundreds of years.

NOW, This movement is acceleratingWhile the ground has been sliding down 8 inches per year in recent years, it has been hovering at 13 inches per week in some places between July and August.

The resulting landslides destroyed beachfront mansions, buckled roads and forced utility Southern California Edison to cut power to nearly 250 homes to prevent fires.

“You can measure 8 inches a year and they had to fix the road that goes through the area, but now it’s moving so fast that they’ve had to close a number of roads, turn off the gas and turn off the power,” said Eric Fielding, a geophysicist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “It’s crazy, but you can’t keep reinstalling power lines every week.”

In the Portuguese Bend neighborhood of Rancho Palos Verdes, 140 homes will be without power indefinitely, while about 60 homes in the city’s Seaview neighborhood will be without service for a week or more.

Governor Gavin Newsom on Tuesday declared a state of emergency in the city.

According to experts, this situation is the unfortunate result of the intense rains of the last two years. The Palos Verdes Peninsula is composed of fragile rocks and layers of clay that prevent water from flowing properly underground. Thus, during periods of heavy rain or strong tectonic activity, the cliffs can slide, turning constant and slow landslides into disasters.

It is not yet clear what, if anything, can be done to prevent the land from moving.

“Basic principles of physics say that once a body is in motion, it wants to stay in motion,” said Jonathan Godt, landslide hazards program coordinator at the U.S. Geological Survey.

The threat to Rancho Palos Verdes is not new. Scientists say the ground beneath the town has been shifting for hundreds of years, but it was largely stable until a road construction project in the 1950s triggered the landslide’s acceleration.

“In the 1950s, the landslide was moving even faster than it is today,” Fielding said, “but they were able to stabilize it to a large extent by drilling wells and pumping out the water.”

However, heavy rains earlier this year and last year have again accelerated the pace of landslides.

Fielding said it is difficult to establish a direct link between landslides and climate change, but precipitation is increasing due to global warming because a warmer atmosphere can hold more moisture, increasing the risk of severe storms.

Even though it is known that heavier rains are more likely, it is difficult to predict when major landslides will occur, Godt said. It can take months or even years after periods of heavy rainfall for landslides to occur.