UC Santa Barbara Researchers Measure El Niño Coastal Erosion



02/17/2016 (All day)


Edward Keller

With research data on tidal impacts, scientists hope to better predict coastal cliff erosion

By Gina Potthoff
Study area and locations for seven of the nine proposed sites along the Santa Barbara coast for terrestrial LiDAR scans. Approximately 90 percent of the coastline from Santa Barbara harbor to Coal oil point is comprised of sea cliffs. (Contributed photo)
Winter storms and tides may have battered the coastline, but UC Santa Barbararesearchers are using those El Niño conditions to track the rate of cliff erosion in Santa Barbara County.

With any luck, findings might help local officials, planners and homeowners better plan for the future.

So far this winter, high tides and mighty waves have raised sea level 8 to 12 inches at the project’s nine study sites, which range from Coal Oil Point and coastal cliffs in Isla Vista to Goleta Beach Park, Hendry’s Beach and Shoreline Park, according to Paul Alessio, a UCSB Ph.D student working on the project with earth science professor Edward Keller.

Those numbers correspond to projected sea level rise for the next 50 to 100 years, so researchers aim to use the data to map and better understand coastal retreat.

“It’s like we’re looking at 250 years of California sea level rise,” Keller said. “We’re looking into a crystal ball of what the future will be like.”

UCSB’s research was made possible through a NOAA California Sea Grant, which is awarding scientists who track the impacts of El Niño this winter. 

Information from Keller’s study is expected to provide critical data for residents, businesses and resource managers along the coast, said Caitlin Coomber, a NOAA grant spokeswoman.

The UCSB researchers took their first measurements last October and will continue logging them after every large storm or swell and every two months for at least a year, Alessio said.

UCSB researchers are using the machine seen here — a Riegl VZ400 terrestrial LiDAR scanner — to help measure the sea level rise during this El Niño winter storm season.  (UCSB contributed photo)

It may be sunny and warm this week, but Alessio said historically speaking, the biggest El Niño storms come in mid-to-late February or early March before tapering off in April.

He and Keller are using LiDAR (light detecting and ranging), which is a specialized remote sensing technology that produces precise measurements every 1-5 centimeters so researches can create high-resolution 3-D models of the coast.

The machine sits atop a tripod and is powered by two car batteries, reflecting light that’s invisible to the naked eye.

By comparing new and historic LiDAR data, researchers plan to develop a slope change model — information that will be shared with the U.S. Geological Surveyand the public.

“Some people stick around and ask a lot of questions,” Alessio said of folks who see them working on the beaches. “It’s still quite difficult for us to predict.”

What people decide to do with the research remains to be seen, since coastal retreat may not seem like an immediate danger.

Sea level will return to normal position come April, but Alessio said he hopes residents will be aware and careful while walking near cliffs.

“It may seem like it’s safe because it’s sunny out,” he said. “It’s particularly dangerous during this winter after the sea cliffs have been weakened.”