Two areas where wave conditions are extremely difficult to forecast are the Gulf of Maine and the Southern California Bight. In these areas, complex underwater topography and irregular shorelines combine with islands and offshore banks to create complicated interactions of shoaling, refraction, and diffraction. These interactions cause nearshore wave conditions to vary greatly even in short distances along the coast. Their findings will aid coastal planners in efforts to limit wave-induced damage to shoreline structures from severe storms and erosion of beaches. Discovering the interactions of shallow water waves with sediments on the bottom is another complex problem for researchers to solve.
Waves generate currents that move the sediment, which in turn modifies the waves passing over it.
MIT Sea Grant has supported a two-pronged approach to solve this dilemma by using both carefully designed laboratory studies and advanced theoretical work. This approach has yielded the most advanced theories on the energy losses of waves propagating over sand beds and on the resulting sand movement and bed modification. At tidal inlets, wave conditions are important because of their influence on movement of sediments along the shore. The U.S. ocean coastline is dominated by sandy barrier islands separated by tidal inlets. Waves, currents, and sediment interact in unusually complex manners at inlets and affect the coastline for great distances.