The Earth has 657 more barrier islands than previously thought, according to a new global survey by researchers from Duke University and Meredith College in Raleigh, N.C.
Barrier islands often form as chains of long, low, narrow offshore deposits of sand and sediment, running parallel to a coast but separated from it by bays, estuaries or lagoons. Unlike stationary landforms, barrier islands build up, erode, migrate and rebuild over time in response to waves, tides, currents and other physical processes in the open ocean environment.