Can climate change and geological past produce enhanced erosion? A case study of the Hel Peninsula, Baltic Sea, Poland

Abstract

The paper explores a possible negative interplay of climate change and sedimentary structure along the Hel Peninsula, located on the Baltic Sea coast of Poland. Greater wave energy fluxes in winter, driven by climate change and the heterogeneous sedimentary structure underneath the peninsula, may lead to direct exposure of weaker sediments to water motion, their depletion, and accelerated erosion. Thus, a possible disequilibrium between harsher hydrodynamics and weaker nearshore sediments (silty sands, silts, and organic soils) can be interpreted as a potential underlying factor in future intensive erosion. This emerging coincidence was not accounted for in previous studies, which focus on sea level rise and storm surges alone as the main drivers of erosion of mostly sand-saturated beaches. In contrast, this study showcases possible climate change-related consequences for a morphologically precarious system, once its built-in vulnerability is activated by more energetic environment. Furthermore, the results demonstrate that many coastal segments built upon weaker earlier geological deposits, relatively stable under current hydrodynamic regimes, can become exposed to enhanced degradation under harsher hydrodynamics.