Relative sea level rise, palaeotopography and transgression velocity on the continental shelf

After the Last Glacial Maximum, some 21,000 years BP, the sea level rose from −130 m to its present-day position. This process of marine transgression inundated or eroded palaeolandscapes to varying degrees, resulting in the landward movement of the shoreline. The transgression velocity (TV), i.e., the velocity at which the shoreline migrated landwards, depends on evaluating the balance between the rate of relative sea level rise and the slope of the transgressed palaeotopography. It has a key role in determining the possibilities for reconstructing palaeoenvironments, the potential preservation of archaeological sites and the socio-economic and psychological impact of sea-level rise on past human populations. In this chapter we present a simple conceptual and computational approach to reconstructing the transgression velocity on shelf areas, making use of Digital Terrain Models (DTMs) of seafloor topography coupled with relative sea level curves, and discuss the different outcomes and limitations at different spatial scales, ranging from the continental (European seas) to the ultra-local scale.