The authors assessed seasonal changes on 29 beaches along approximately 2,000 kilometers (1,243 miles) of the U.S. West Coast. Surveying the beaches included making 3-D surface maps and cross-shore profiles using aerial lidar (light detection and ranging), GPS topographic surveys, and direct measurements of sand levels, combined with wave and water level data at each beach, collectively spanning 1997-2016. Winter beach erosion or the removal and loss of sand from the beach is a normal seasonal process, but the extent of erosion can be more severe during El Niño events than in other years.
Gallien, who combines field observations and numerical analysis in her research on coastal hazards, was responsible for collecting and analyzing erosion data from Southern California sites. The full report, “Extreme oceanographic forcing and coastal response due to the 2015-16 El Niño,” was published online in Nature Communications.
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Image credit: Christine Hegermiller, U.S. Geological Survey. Public domain.