Wave force causes portion of cliff to collapse
Rocks and debris fall in the path of a favorite surf spot
SANTA CRUZ >> A collapse of a portion of the cliff on the Steamer Lane side of Lighthouse Point has left a hazard for surfers and boogie boarders, and a foreboding crack along the edge of the mudstone point.
“The Public Works team was out conducting assessments and will continue to monitor the area,” said Nathan Nguyen, Santa Cruz public works director. “Please follow all posted signage and use caution near our coastal cliffs as portions of the cliffs are naturally unstable.”
The collapse happened Friday around 11 a.m. and was witnessed by numerous people both in and near the ocean, including Santa Cruz resident and boogie boarder Ed Thorpe.
“I was in the water when it happened, and our buddy was actually on the wave when it detonated on the wall,” Thorpe said. “He said that it sounded like a landslide. He had that deer-inthe-headlights kind of look after.”
Thorpe said that the pile of rocks is right in the path of those who like to surf close to the point and that the rocks are jagged and should be avoided.
“The rock is right in the pathway of where we used to travel,” Thorpe said. “You have to adjust there if you want to ride close to the wall or turn off before the wave hits the rock, if you're coming in from the point, and then make a good judgment call. What you don't want to do is get caught and pushed into the wall where the rocks are.”
UC Santa Cruz professor Gary Griggs points out that the cliffside at Lighthouse
Point is made from Purisma Formation mudstone, which cracks and fissures over time like the broken windshield of a car.
“It's weaker and softer and younger and pervasively jointed and fractured,” Griggs said. “This whole area has been under
a lot of tectonic stress, so the rocks are fractured in a lot of different directions.”
The fallen chunk of mudstone, which Murphy said was about the size of a large van, was the result of the fracturing phenomenon. Griggs points out that the continual erosive pounding of the waves, especially during the recent storms, could have primed the mudstone cliffs to fail.
“Weak rock like mudstone will stand up as a cliff for a while,” he said. “Then with wear and tear, a big wave or a big winter storm, it'll come apart and collapse.”
Both the surfers and Griggs warn people to stay away from cliff edges and watch out for overhanging rock while tide pooling or exploring the coastline because more collapses similar to the one Friday will continue to occur. It's just a matter of time.
“Mother Nature always bats last,” Griggs said. “And in the long run, there is nothing we can do to hold back the Pacific Ocean. Everything that we do is just a Band-Aid.”