Grain Size Distribution of Bedload Transport in a Glaciated Catchment (Baranowski Glacier, King George Island, Western Antarctica)

Abstract

Abstract:The relationships among grain size distribution (GSD), water discharge, and GSD parameters are investigated to identify regularities in the evolution of two gravel-bed proglacial troughs: Fosa Creek and Siodło Creek. In addition, the potential application of certain parameters obtained from the GSD analysis for the assessment of the formation stage of both creeks is comprehensively discussed. To achieve these goals, River Bedload Traps (RBTs) were used to collect the bedload, and a sieving method for dry material was applied to obtain the GSDs. Statistical comparisons between both streams showed significant differences in flow velocity; however, the lack of significant differences in bedload transport clearly indicated that meteorological conditions are among the most important factors in the erosive process for this catchment. In particular, the instability of flow conditions during high water discharge resulted in an increase in the proportion of medium and coarse gravels. The poorly sorted fine and very fine gravels observed in Siodło Creek suggest that this trough is more susceptible to erosion and less stabilized than Fosa Creek. The results suggest that GSD analyses can be used to define the stage of development of riverbeds relative to that of other riverbeds in polar regions.

Recession and Ice Surface Elevation Changes of Baranowski Glacier and Its Impact on Proglacial Relief (King George Island, West Antarctica)

“…These locations are cut by numerous and periodically active troughs. Sziło and Bialik [39] suggested that the rapid changes in the geomorphology of this part of the Baranowski Glacier forefield were due to the high energetic differentiation of the sediment particles. Furthermore, it has been shown that the differences between two creeks, Fosa and Siodło, are due to their relative stage of formation and position of the glacier terminus.…”

“…Its frontal part is divided into two tongues: the northern tongue and the southern tongue. An ice cliff is present where the northern tongue terminates in close proximity to a coastal lagoon, which is separated from Staszek Cove by a narrow spit during low tides [39,43]. The southern tongue terminates approximately 240 m from the recent shoreline with a varied forefield of proglacial landforms.…”

“…Since the early 1980s, this glacier has terminated on land. The basin is a unique region with a large proportion of ice-free area on which climatic fluctuations and glacial evolution impact the recent proglacial landscape [38,39]. Geomorphological observations were conducted in this area between 1984 and 1986 [40] and from 1990 to 1992 during the Polish expeditions to KGI [38,41,42].…”

Modeling and Practice of Erosion and Sediment Transport under Change

“…A summary of the papers in the Special Issue follows, given in the order in which they appear. The grain size distribution of bedload transported within a given water discharge has been investigated for two polar catchments in Antarctica [45], aimed at determining how the grain size distribution is modified during times of peak discharge, determining the relationship between the grain size distribution and its parameters, and the amount of transported material in gravel-bed rivers, and examining whether the modification of grain size distribution during efficient bedload transport events allow for the identification of the development stage of river throughs during changing meteorological conditions. These questions were answered after a measurement campaign in two creeks with proglacial gravel-bed channels.…”

“…The erosion and sediment transport issues have been investigated in channels and over watersheds. The channels have been either a prototype natural watercourse [45,54] or an artificial flume of a laboratory model [46,54]. As for the watersheds, the scale has changed from 1.25 km 2 subcatchments from the United Kingdom [53] to large, millions of km 2 watersheds in the Maghrib basin that extend over Morocco, Algeria, and Tunisia.…”