Quantifying sediment sources, pathways, and controls on fluvial transport dynamics on James Ross Island, Antarctica

Abstract

Proglacial regions are enlarging across the Antarctic Peninsula as glaciers recede in a warming climate. However, despite the increasing importance of proglacial regions as sediment sources within cold environments, very few studies have considered fluvial sediment dynamics in polar settings and spatio-temporal variability in sediment delivery to the oceans has yet to be unravelled. In this study, we show how air temperature, precipitation, and ground conditions combine to control sediment loads in two catchments on James Ross Island, Antarctica. We estimate that the sediment load for the Bohemian Stream and Algal Stream over the 50 day study period, the average sediment load was 1.18 ± 0.63 t km−2 d−1 and 1.73 ± 1.02 t km−2 d−1, respectively. Both catchments show some sensitivity to changes in precipitation and air temperature, but the Algal catchment also shows some sensitivity to active layer thaw. The downstream changes in sediment provenance are controlled by underlying lithology, while differences in sediment load peaks between the two catchments appear to be primarily due to differing glacier and snowfield coverage. This identification of the controls on sediment load in this sub-polar environment provides insight into how other fluvial systems across the Antarctic Peninsula could respond as glaciers recede in a warming climate.