Kolander, R., Morche, D., Bimböse, M.
Quantification of moraine cliff coast erosion on Wolin Island (Baltic Sea, northwest Poland)Abstract
There are two long-term causes of continuing transgression in the south Baltic Sea – the glacioisostatic uplift in the Bothnian Bay and the eustatic sea level rise. At a regional scale the cliff sediments and the seasonal climate conditions during the year are significant factors controlling cliff erosion. The erosion of cliffs of glacial sediments has been investigated on Wolin Island, located in the Baltic Sea in northwest Poland. Previous monitoring of morphological processes on Wolin Island provides a baseline for further detailed studies of cliff erosion. In long-term field investigations a mean cliff retreat of 0.14 m a-1 was measured during the last 30 years. In this study a high-resolution terrestrial laser scanner was used for monitoring cliff retreat at two test sites. In a four-month interval and an annual interval both sites were scanned and total cliff erosion of 0.090 m a-1 and 0.043 m a-1 with volume changes of 434.7 m³ and 888.7 m³, respectively, was measured. The cliff erosion is significantly higher in the colder and more humid periods. Cliff stabilization occurs in conditions of low and average rainfall and above-average temperatures.