Sea-level rises that are unrelated to major storm events could be eroding coastlines as much as hurricanes do.
Weather and oceanographic processes that are not linked to storms cause sea levels to rise over weeks to months, but their effects have been overlooked in models of beach erosion. So Ethan Theuerkauf and his colleagues at the University of North Carolina's Institute of Marine Sciences in Morehead City studied sediment cores from six sites along Onslow Beach on the US east coast after a year of frequent sea-level changes but no major storms. They compared these cores with those obtained after a storm year and found similar levels of erosion.
The authors suggest that sea-level changes could become more frequent in this region because climate change is predicted to weaken the Gulf Stream, which can lead to these sea-level anomalies.
Geophys. Res. Lett. http://doi.org/ttn (2014)