Deadly cliff collapse a warning sign for California’s coast
LOS ANGELES — The deadly cliff collapse in Encinitas last week raised questions about the stability of large swaths of the state that are lined by bluffs, many of which support houses or offer enticing patches of shade for families relaxing on the beach.
Friday’s collapse, which killed three people, was a tragic consequence of sea cliffs’ natural erosion process, experts say. Chunks of bluffs regularly fall off to create the beach below, so all beach bluffs should be considered unstable, said Brian Ketterer, coastal division chief for California State Parks.
“Any of our bluffs have the ability to fail, and people just need to be aware of that,” Ketterer said.
Adam Young, project scientist at Scripps Institution of Oceanography at UC San Diego, agreed.
“Most unprotected coastal cliffs are actively eroding and should be considered hazardous,” he said in an email.
In February, two women were walking on a cliff above Fort Funston beach in San Francisco when it collapsed and buried them. In 2017, a woman peering over the edge of a cliff in Santa Cruz County fell to her death when the ground gave way beneath her. Last fall, sections of the cliffs in Del Mar in San Diego County collapsed three times in just a few weeks.
In recent years, officials have been working to ease erosion at popular spots in California, including Palisades Park in Santa Monica, Ventura and areas of Laguna Beach.
Cliffs become increasingly unstable as they get steeper and less supported at the base, Young said. Elevated rainfall and groundwater can then trigger landslides in unstable cliffs, he said.
A U.S. Geological Survey study found that cliffs in Southern California could recede more than 130 feet by 2100 if sea levels keep rising. But Young said that cliff collapse is due to a variety of factors and there isn’t enough data to link it to sea level rise.
However, he added that preventing waves chipping away at the base of cliffs by maintaining a wide beach is one strategy to prevent cliff erosion.