Scientists at UC San Diego's Scripps Institution of Oceanography in La Jolla are seeing promising results in their quest to predict bluff collapses before they happen.
Using sophisticated technology, the researchers have successfully anticipated several coastal landslides in north San Diego County — sometimes more than a day in advance.
“In landslides, there are things that are detectable before it happens,” said Mark Zumberge, a research geophysicist at Scripps. “We've had three cases where it was pretty clear something was going to happen.”
The ultimate hope is the research will lead to early warning systems along coastlines that save lives.
The next step for researchers is to install advanced sensors along the bluffs in Del Mar and Encinitas that will unlock more granular data. The scientists caution that a lot more analysis is needed to determine whether it’s possible to reliably predict bluff failures. But they’re optimistic that an early warning system is feasible.
“What we're seeing so far is quite promising, that we will be able to use these signals in the future to develop a system,” said Adam Young, a researcher at Scripps.
Young said he’s not aware of such a system existing anywhere else in the world.
This research is especially meaningful to Dr. Patrick Davis, who lost his wife, daughter and sister-in-law in a 2019 bluff collapse at Grandview Beach in Encinitas.
“I think this could be just a really valuable step in making the bluffs a lot safer,” Davis said. “That could be a real solution.”
His family’s tragic loss motivated state lawmakers to pass legislation that kickstarted the Scripps research.
In 2020, the family filed a lawsuit against the state of California, city of Encinitas and a local homeowners association. The suit is now nearing a settlement that could total more than $30 million.
Measuring bluff movement, down to the atom
Earlier this year, Young stood near a bluff in North County.
“That morning, the signals were showing something unusual,” said the Scripps researcher, referring to the data collected by nearby sensors in the ground. “So I went down to go look at it.”
There were some cracks in the ground but no major movement. He stepped away to make a call, and then a section of the bluff gave way. When he returned, he found large rocks — “the size of like a Volkswagen Bug” — had fallen onto the beach.
Fortunately, no one was hurt. But slides like this routinely happen up and down the coast, and the consequences can be fatal.
The type of sensor used to pick up on this and other landslides is called a “tiltmeter.” Zumberge likens the device to a sophisticated leveling tool.
“So if you could set out a carpenter's level and very precisely keep track of the position of that bubble, you would be able to tell if the land is tilting,” he said.
The sensors have so far returned promising results, but there are still many unknowns. For example, sometimes a signal indicates a collapse may occur, and then nothing happens.
Soon, the researchers will install custom-built sensors that use optical fiber and lasers. The equipment will be able to measure bluff movement down to “the diameter of an atom,” Zumberge said.
“This kind of technology before now has not been applied to landslide studies,” he said.
The researchers are also using LiDAR and traditional land surveying to gather data.
The mandate for the scientists at Scripps, who are a few years into their research, is narrow. The state Legislature passed a bill in 2021 tasking them with collecting and analyzing historical and real-time data on bluff erosion and failures.
In early 2026, they’ll deliver a report to lawmakers with recommendations for the development of an early warning system based on their research.
However, the scientists are not tasked with issuing warnings. If a warning system is rolled out in the future, it likely would be overseen by a different organization. Such a system would likely take years to develop and require additional action from state lawmakers.
Assembly member Tasha Boerner represents the coastal areas of Del Mar and Encinitas. She authored the legislation that kickstarted the Scripps research.
“My hope would be by 2030, the pilot (warning system) would be going across California in these selected locations that are most acutely experiencing bluff collapses,” she said.
By 2035, Boerner believes the system could start being implemented up and down the West Coast. If the warning system is deployed widely, Boerner believes it could be what defines her legacy as a lawmaker.
A special day turned tragic
For 40 years, Patrick Davis and his late wife Julie Davis lived an idyllic coastal San Diego life.
“We raised four children in this beautiful Encinitas community,” he said. “Couldn't have been happier. We had a wonderful life here.”
In August of 2019, friends and family gathered at nearby Grandview Beach for a celebration. Davis’s sister-in-law, Elizabeth Charles, had just completed breast cancer treatment.
The lifeguard on duty suggested the family sit just north of the lifeguard tower, Davis said. The tide was high, which left little room for them to set up beach chairs and lay out towels. They were about 10 feet in front of the cliff.
The kids paddled out on their surfboards. People on the beach ate sandwiches and relaxed in the sun.
“Next thing we knew, the cliff let loose,” said Davis. “And then it was just pure bedlam after that.”
A section of the bluff had collapsed, sending huge rocks and debris onto the beach below.
Several people were pinned under the crushing weight of the fallen boulders. Emergency responders rushed to the scene. But some of the injuries were too severe.
Davis lost Julie, Elizabeth and his daughter, Annie Clave.
“We've never been the same family since,” he said.
Davis gets emotional discussing Julie, the love of his life. But he can’t even talk about Annie. It’s too painful.
“Losing a child is just one of the worst things any parent could ever go through,” he said with tear-filled eyes.
Davis no longer spends time on the beach at Grandview, but he often walks down the long staircase to see where people are sitting.
“And almost every time I've gone down to the beach, I see people sitting right against the bluffs,” he said. “I remind the lifeguards — part of their job is to keep people away from the bluffs. They then respond and run down and tell people how dangerous it is.”
Lawsuit nears settlement
In 2020, the family filed a lawsuit against the state of California, the city of Encinitas and a local homeowners association, alleging they let the bluff to degrade to the point of failure. They also alleged the city’s lifeguards failed in their duty to keep beachgoers a safe distance from unstable bluffs.
Representatives for the defendants did not respond to a request for comment.
The lawsuit has unearthed compelling evidence. For example, attorneys discovered a memo written by a state geologist Syd Willard in 1985 that raised concerns about the Grandview bluff.
After a nearby staircase collapsed, she warned against allowing public access down along that section of the bluff, noting the risk of future injury or death. Nevertheless, the staircase was rebuilt.
“You learned today that three women accessed the beach at Grandview and were killed by a (bluff) fall,” an attorney said during Willard’s deposition. “Is that the type of tragedy that you were hoping to avoid with your recommendation not to rebuild the stairs?”
“Yes,” she said.
The lawsuit is now nearing a settlement that could top $30 million, according to an attorney for the family. A bill on Gov. Gavin Newsom’s desk would release more than $13 million to cover the state’s portion of the settlement.
Beyond the demands for financial damages, the family is also pushing for policy changes to improve safety along California’s coasts.
