Past, Present and Future Perspectives of Sediment Compaction as a Driver of Relative Sea Level and Coastal Change

Compaction describes a range of natural syn- and post-depositional processes that reduce the volume of sediments deposited in low-lying coastal areas, causing land-level lowering and a distortion of stratigraphic sequences. Compaction affects our reconstructions and understanding of historic sea levels, influences how relative sea level changes in the future and can act as a catalyst for rapid, widespread changes in coastal geomorphology. Rates of compaction-induced relative sea-level rise vary across space and through time in response to a range of natural and anthropogenically accelerated processes and conditions. This paper provides a summary of our understanding of the causes and effects of compaction, considering findings from key palaeoenvironmental and stratigraphic studies, sea-level reconstructions and recent observational data. It then considers the implications of these findings for our ability to project compaction-induced relative sea-level and associated coastal changes into the future.