Longitudinal development of clast shape characteristics from different material sources in Hrbye River, Central Svalbard

Abstract

The sediment transport in polar regions is highly changeable and it is getting faster in connection with a climate change. This study describes the Hrbye River catchment located in the northern Billefjorden, Central Svalbard. The Czech Arctic Station and AMUPS - Adam Mickiewicz University Polish Polar Station are located in near this locality Petunia Bay. The material for this study was sampled in August 2016, during the summer research campaign of Czech Arctic Station together with a cooperation between Masaryk University in Brno and the University of Oslo via Norway Grants. The catchment area is 60 km 2 . The area of interest lies around the 10 km long Hrbye River in its braidplain, which is 2.3 km wide and 4.5 km long. In the Hrbye Glacier forefield, 27 sediment sampling localities were selected and defined into seven groups: (i) esker complex; (ii) debris stripes; (iii) till plain; (iv) hummocky moraine; (v) post-LIA braidplain; (vi) LIA moraine; (vii) LIA braidplain. Three main petrological types of rocks were studied (SVP – sandstone, VAP – limestone, ORT – orthogneiss). Lithology and roundness of the clasts were evaluated in order to study clast shape properties from various glacial sediments. The results show the dominant role of lithology on the clast shape modification in the Hrbye Glacier forefield.