LONG-TERM GOALS

To explain the genesis, dynamics, morphology, and evolution of bedforms found in sandy inner-shelf environments, with emphasis on those bedforms that affect the penetration of sound into the seabed. OBJECTIVES We seek to improve our understanding of the relationships between hydrodynamics and sediment motion near the seabed, as well as develop models for nearshore sediment transport derived from our understanding of the relevant physical processes. This requires coupling between hydrodynamic forcing, bedform response and feedback, bedload sediment transport response, and the suspended sediment response. APPROACH We use a combination of field observations, laboratory experiments, and numerical modeling to determine the relationships between ripple morphology, wave and current conditions, and sediment characteristics. WORK COMPLETED Laboratory experiments studying ripples formed under combined waves and currents were conducted in the large flume in Tsukuba, Japan, in January 2005. We developed an oscillating plate system an