Joseph T. Kelley, a professor of Marine Geology at the University of Maine, is co-author with three other scientists of “The World’s Beaches: A Global Guide to the Science of the Shoreline,” which the NY Times calls “a comprehensive, readable guide to the physical features of many kinds of beaches and some of the threats they face.” The lead author, Duke’s Orin Pilkey, has been arguing for years that beachfront development – be it sea walls or condos – actually destroys beaches. The problem is most acute on barrier islands like Plum Island, which that naturally shift over time.
A beach, simply, is the end product of sediment (sand or gravel or even pebbles or cobbles), wave energy to move it around and a place where it can accumulate. But beaches, as one might expect, are far from simple. In a section called “How to Read a Beach,” we learn why sand, for example, accumulates in particular ways, how ripple action turns some flat stretches of sand into corrugations, the way swash and backwash shape the beach slope, how even a few strands of sea oats can trap enough sand to start building a dune and why foam piles up at the high water line.