Short-term development of Arctic beach system: Case study of wave control on beach morphology and sedimentology (Calypsostranda, Bellsund, Svalbard)

Abstract

: The objective of this research is to determine the impact of waves on the segregation of sediment within the area of its supply in the context of meteorological conditions. The research was conducted on a 4 km section of the shore of Calypsostranda (Bellsund, West Spitsbergen), shaped by waves such as swell, wind waves, and tides. Particular attention was paid to the diversity and variability of the surface texture within the intertidal zone. Meteorological measurements, recording of wave climate, as well as analysis of the grain-size distribution of the beach sediments were performed. Nearshore bathymetry, longshore drifts, episodic sediment delivery from land, as well as resistance of the shore to coastal erosion and direction of transport of sediments in the shore zone are important factors controlling shore development. Data show that wind waves contribute to erosion and discharge of material from the nearshore and intertidal zone. The research also shows that oceanic swell, altered by diffraction, reaching the shore of Calypsostranda contributes to better sorting of sediment deposited on the shore through washing it out from among gravels, and longshore transport of its finest fraction. The grain size distribution of shore sediments is significantly changed already during one tidal cycle. The degree of this modification depends not only on wave height and period but on the direction of wave impact. The shore of Calypsostranda can be regarded as transitional between high and low energy coasts.