A specific impact of waves of fast ferries on sediment transport processes in Tallinn Bay

Abstract

. Tallinn Bay is a semi-enclosed basin in the Gulf of Finland with a mild wave regime and an exceptionally heavy density of high speed ship traffic. Several implications resulting from the difference between the periods of wind waves (typically 3–4 s, maximum 7–8 s in extreme storms) and waves excited by fast ferries (10–15 s) are described. It is shown that ship-generated waves may play a decisive role in certain coastal processes. They cause unusually high near-bottom velocities at depths of 5–25 m. The influence of ship waves may trigger an additional sediment transport mechanism and cause considerable changes in the existing balance of sediment transport processes.