Seabed dynamics in a coastal embayment

Abstract

This study focuses on the morphological history of the seabed adjacent to the St. Ives to Padstow Bay coastlines, southwest England. 1931 and 2008 bathymetric charts covering the North Cornwall coast were examined using bathymetric change maps and transects. The results here showed that the seabed topography in this region is not static, with patterns of net sediment movement varying spatially across the seabed. Rates of erosion and deposition varied because of the seabed exposure to the diverse rates of higher waves and tidal actions. The variation relates to the relative depths at which waves feel the seabed. Waves are more sensitive at nearshore bathymetry depths less than 20m (and 3.5km offshore) than at offshore. However, the amount of energy and increasing wave height reaching the coastlines have a minor impact on sediment transport rates or morphological modification of the adjacent coastlines and estuaries but allow the erosion potentials.