Residual currents in relation to shoreline evolution of the East Anglian coast

Abstract

The importance of residual currents in fashioning the sea-bed configuration off the East Anglian coast can be assessed from a study of hydrographic data, including marine surveys, current observations and drogue runs. The pattern of banks and channels and the changes to which they are subject, the sediment circulation and the character of the sediments, closely reflect the residual current movements. Not only are tidal streams the most effective physiographic agents offshore but their influence also extends to the coast. Here, in combination with wave action, they can create favourable conditions for sedimentation to take place. The origin of the ness features at Winterton, Caister, Benacre and Thorpeness can be explained in these terms as well as their changing form in response to varying conditions offshore. There is also an intimate connection between the offshore zone and coast erosion at places like Pakefield, Kessingland and Covehithe since the residual currents offshore are an important factor in determining the supply of sediment to the shoreline and hence the degree of protection afforded by the beach.