Fluvial suspended sediment transport from cold and warm-based glaciers in Svalbard

An analysis of temporal variability in proglacial suspended sediment concen tration is undertaken using time series data collected from three Svalbard basins which include one largely cold-based glacier (Austre Broggerbreen), one largely warm-based glacier (Finsterwalderbreen) and one intermediate po lythermal glacier (Erdmannbreen). The temporal variability in proglacial su spended sediment concentration is analysed using multiple regression techni ques in which discharge is supplemented by other predictors acting as surro gates for variability in sediment supply at diurnal, medium-term and-season al timescales. These multiple regression models improve upon the statistica l explanation of suspended sediment concentration produced by simple sedime nt rating curves but need to account for additional stochastic elements wit hin the time series before they may be considered successful. An interpreta tion of the physical processes which are responsible for the regression mod el characteristics-is offered as a basis for comparing the different arctic glaciofluvial suspended sediment transport systems with that of their bett er known temperate glaciofluvial counterparts. It is inferred that the larg ely warm-based glacier is dominated by sediment supply from subglacial rese rvoirs which evolve in a similar manner to temperate glaciers and which cau se a pronounced seasonal exhaustion of suspended sediment supply. The large ly cold-based glacier, however, is dominated by sediment supply from margin al sources which generate a responsive system at short time scales but no s ignificant seasonal pattern. The intermediate polythermal glacier basin, wh ich was anticipated to be similar to the warm-based glacier, instead shows a highly significant seasonal increase in suspended sediment supply from an unusual subglacial reservoir emerging under pressure in the glacier forela nd; The temperate model of glaciofluvial suspended sediment transport is th erefore found to be of limited use in an arctic context. Copyright (C) 1999 John Wiley & Sons, Ltd.