Most beaches in California eroded beyond historical extremes this past winter amid one of the most powerful El Niño climate events of the last 145 years, U.S. Geological Survey scientists have found.
In a study released Tuesday, USGS scientists surveyed 29 beaches along the West Coast, from Washington to southern California, and found that winter beach erosion was 76 percent above normal for the 2015-16 winter — the highest ever recorded by far.
Along with the El Niño winters of 1982-83 and 1997-98, the 2015-16 El Niño was one of the strongest ever recorded.
The study also found most California beaches experienced more erosion than they ever had before.
“Wave conditions and coastal response were unprecedented for many locations during the winter of 2015-16,” Patrick Barnard, USGS geologist and lead author of the report, said in a statement. “The winter wave energy equaled or exceeded measured historical maximums along the U.S. West Coast, corresponding to extreme beach erosion across the region.”
To gauge erosion, the authors of the study assessed seasonal changes on 29 beaches along about 1,243 miles of the West Coast by creating 3-D surface maps, and using GPS topographic surveys and measurements of sand levels along with wave and water level data from each beach between 1997 and 2016.
The full report, “Extreme oceanographic forcing and coastal response due to the 2015-16 El Niño,” was published online Tuesday in the journal “Nature Communications.”