Torfowiska Mierzei i Niziny Karwieńskiej potencjalnym archiwum ekstremalnych zalewów sztormowych
The peatlands of the Karwia Barrier and Karwia Lowland as a potential archive of extreme storm floods

Summary/Abstract: Storm surges influences local communities and landscape most severely. If the storm surge levelreaches the height of a dune, sea water may flow towards the backbarrier and leave a sedimentological mark in peatlands. The Karwia Barrier peatlands are a potential archive of extreme storm floods due totheir low absolute heights and relatively flat morphology. During the field work, the subsurface sedimentsof the investigated area were recognized to verify the hypothesis of the presence of storm surgedeposits within the barrier and accompanying peatlands. Numerous shallow drillings were performedand the most essential of them are presented in this paper. Profiles described in the peatlands which are most exposed to the sea showed the presence of alayer which was composed mostly of medium to coarse, moderately to well sorted sand. The base ofthe layer revealed a sharp erosive boundary. The thickness of the sands decreased from 30 cm in landward direction at the distance of approximately 20 meters. Textural characteristics of sandy grainsrevealed a beach and dune source of this sediment. Profiles described in the peatland at the back ofbarrier were composed mostly of peats and muds. Different types of mineral sediments were dispersedand irregular. It was the lack of sediments features that could be linked to storm processes. This leadsto a conclusion that none of the historical storm floods left an easily distinguishable sandy layer here. The paper shows that more studies of storm surge geological and geomorphological effects areneeded for a better recognition of extreme past events and a better understanding of the nature of stormdeposits. It also showed that under suitable conditions coastal peatlands may be a good archive forextreme storm processes.

• Details
• Contents