Drone measures erosioin
A drone monitors coastal erosion using laser pulses to measure distances. Photo by Erik Jepsen

Scientists at Scripps Institution of Oceanography will lead new research on cliff erosion in an effort to develop an alert system for deadly collapses.

The three-year, $2.5 million study is funded by Tasha Boerner Horvath‘s Assembly Bill 66, which was signed into law earlier this month.

Scripps researchers will use light detection and ranging, or LiDAR, technology to create three-dimensional maps of the coast and understand how cliff erosion triggers collapses.

AB 66 is a response to the tragic fatalities in August 2019 when a 30-by-25-foot sandstone chunk broke loose and fell onto three women at Grandview Beach in Encinitas.

“With the passage of AB 66, we are one step closer to saving lives along California’s coasts,” said Boerner Horvath. “Bluff collapses are a constant threat to coastal neighborhoods in Northern San Diego County and across the California coast, presenting the risk of fatalities, injuries, and millions of dollars in damage to vital infrastructure.”

Scripps coastal geomorphologist Adam Young, who as been studying cliff erosion for several years, said the goal of the research is to measure and track erosion over time and understand the signals of an impending collapse.

“Each LiDAR survey provides a snapshot in time that we compare to previous surveys, to measure and track erosion over time,” said Young. “We use these surveys combined with other sensors to quantify the  erosion processes, identify erosion patterns, and examine stability conditions.”

Scientists will use LiDAR equipment mounted on both trucks and drones. They’re also planning to install optical-fiber strainmeters at key locations along the cliffs as well as tiltmeters, which can measure microscopic changes in spatial orientation of masses of earth.

“We hope to learn more about what happens before a slope becomes a slide,” said Scripps geophysicist Mark Zumberge.

Chris Jennewein is Editor & Publisher of Times of San Diego.