Migration and welding of an estuarine barrier-spit driven by delta evolution and storms

As sea levels rise globally in response to anthropogenic climate change, coastal depositional systems that persist in dynamic equilibrium with accommodation space, sediment supply and hydrodynamic processes may begin to respond by redistributing sediment, causing erosion or migration of landforms that may have appeared as stable over previous decades to centuries. In contrast, systems that have adjusted to inherited or changing boundary conditions over historical times offer insights on the modes and timescales of potential future change in remobilised coastal systems. We investigate the coupled evolution of an estuarine sand barrier-spit and tidal delta over the past century, focusing on storm-driven erosion and overwash during recent decades that triggered recurrent barrier migration (rollover), ultimately welding it to the bedrock valley framework. Historical aerial photographs and recent high-resolution satellite and aerial imagery are analysed to map morphological change and calculate decadal trends in shoreline and barrier migration. Ocean wave and water level conditions between image dates capturing notable responses are analysed using wave and tide records from nearby measurement stations.