ALONG-STRIKE VARIABILITY IN BEACH EROSION DURING THE 2015-2016 EL NINO WINTER SEASON

Past strong El Niños such as those that occurred in 1982-1983 and 1997-1998 have brought large changes to the California coastline including large-scale (many meters) beach erosion and cliff retreat. The 2015-2016 El Niño is shaping up to be the strongest El Niño since 1997-1998. In this study, we surveyed seven transects along the beaches of University of California, Santa Barbara and Goleta Beach using a high resolution differential GPS on a weekly basis beginning on September 22, 2015 through April 2016.

As early as November 24, 2015, the early effects of the El Niño winter are observed. However, the changes are not uniform across the beaches. Preliminary results show the western-most transect underwent about two meters of vertical erosion, while the other six locations eroded less than one meter or were the site of deposition. The differences in erosion at each of our transects suggests that erosion is not uniform across the beach and multiple transects must be monitored in order to accurately quantify beach changes. Using only a single measurement of beach erosion may not be representative of the entire beach and could result in misrepresentation of coastal erosion.

Continued monitoring between December 2015 and April 2016 will allow us to quantify beach erosion through the 2015-2016 El Niño winter. These results will be compared to a similar dataset collected in the 2011-2012 winter season.