Postglacial sea-level change and shoreline development in SE Africa: implications for past and present human populations
The relationship between sea-level change and shoreline response is complex and is governed, amongst other things, by the rate of sea-level change, sediment supply/volume and antecedent topography. The nature of the shoreline and its response to changing sea level have important implications for human societies in the past and in the present.
In SE Africa, sea level has changed over a vertical range of >130 m since the last interglacial. The course of sea level change is reflected in the development and preservation of shoreline deposits that are preserved on the narrow continental shelf and along the modern shoreline. Shoreline morphology shows marked differences at different sea-level stages and these mainly reflect variations in geological setting. The preservation of shorelines is linked to alternating periods of slow and fast sea-level rise and they occur at predictable elevations and time periods. These observations have the potential to inform prediction of future shoreline position.
The changing nature and position of the shoreline has influenced its exploitation by humans and various forms of evidence of human utilisation are preserved. In the Anthropocene, threats to human interests from changes in shoreline position are reciprocated by threats to shoreline integrity via human interventions.