by Rancho Palos Verdes, a coastal community in the Los Angeles area, could be described as a geological ticking time bomb.
The wealthy city sits atop steep cliffs overlooking the Pacific Ocean which, over the centuries, have been slowly shifting and yielding.
Now, that movement is accelerating. Although the land slipped down 8 inches per year in the past years, it has lurched 13 inches per week in some places between July and August.
The resulting landslides have torn apart seaside mansions, buckled roads and forced utility provider Southern California Edison to cut power to nearly 250 homes to avoid the possibility of fire.
“Eight inches a year is measurable and they had to repair the road that crosses the area, but now it’s moving so fast that they had to close some roads, turn off the gas supply and cut electricity,” a said Eric Fielding, a geophysicist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “It’s crazy but you can’t keep re-installing electrical wires every week.”
In the Portuguese Bend neighborhood of Rancho Palos Verdes, 140 homes will be without power indefinitely, and about 60 in the city’s Seaview section will be without service for a week or longer.
The Gov announced Gavin Newsom state of emergency in the city on Tuesday.
The situation is the unfortunate culmination of heavy rains in the last two years, experts say. The Palos Verdes Peninsula is made up of loose rocks and clay beds that prevent water from properly draining underground. So during periods of heavy rain or high tectonic activity, the blues can slide, turning steady slow landslides into disasters.
It is not yet clear what, if anything, can be done to stop the ground from moving.
“Basic physics says that when a body is moving, it wants to stay moving,” said Jonathan Godt, coordinator of the landslide hazards program at the US Geological Survey.
The threat to Rancho Palos Verdes is not new. The ground beneath the city has been moving for centuries, scientists say, but was largely stable until a road construction project in the 1950s prompted the landslide to accelerate.
“The landslide was moving even faster in the 1950s than it is today,” Fielding said, “but they managed to stabilize it a lot by drilling wells and pumping water out.”
Now, due to heavy rains earlier this year and last year the speed of the slide has increased again.
Fielding said it is difficult to make a direct link between landslides and climate change, but global warming is causing more rain because a warmer atmosphere can hold more moisture, increasing the chance of severe storms.
Even with the knowledge that heavier rains are likely, predicting when large landslides will strike is challenging, Godt said. It can take months or even years after periods of heavy rainfall for the water to saturate deep rocks and clay and deform the land.
It is also difficult to predict which slow-moving landslides may be a problem. Landslides that move at glacial speeds over hundreds or thousands of years are not uncommon in Southern California — and around the world, Godt said.
“For a lot of those places, it’s not a problem over a human lifetime or even different human generations because that’s just a blink of an eye from a geological point of view,” he said. “However, there are cases where these landslides are moved again by a series of heavy rain events, or an earthquake, or other geological processes that are taking place under our feet.”
Rancho Palos Verdes already has problems with potential efforts to mitigate ground movement. Last month, the city said an even deeper landslide was discovered in the area that is also active. Officials said the movement, at a depth of more than 300 feet, is too fast and too far underground to dig drains and pumps to remove water.
Now that a state of emergency has been declared, Rancho Palos Verdes Mayor John Cruikshank said the money allocated will go toward helping city government and landslide reduction efforts, but not individual homeowners.
Homeowners whose power is out will have to shell out thousands of dollars or more to convert to off-grid alternatives, such as solar and battery technologies, Cruikshank told a local CBS affiliate on Wednesday. He hopes the state will help cover those costs.
Residents are already on the hook for damage to their homes, Cruikshank said, since typical home insurance policies don’t cover landslides, of which hundreds are documented in California each year.
Tim Kelly, a mechanical engineer who moved to the Portuguese Bend neighborhood of Rancho Palos Verdes 30 years ago, said he now relies on his solar panels for power, and it’s still his home. He attended a public meeting Tuesday where residents pleaded with city officials for solutions.
“We’re resilient,” Kelly said of the community. “We’re not going anywhere.”
Kelly said other houses in his area have changed their foundations, with some properties cracking and splitting into sections, but his house remains unmoved. He and his neighbors will not abandon their homes and expect government leaders and scientists to figure out how best to “stop the slide,” he said.
Kelly said the local government has, for years, failed to install long-term solutions to prevent water from saturating the canyon and diverting it into the ocean. Now, the issue is emerging for the city and time is of the essence.
“The patient is sick,” said Kelly, “and something must be done to bring him back to life.”
This article was originally published on NBCNews.com
