Mechanisms and Processes of Suspended Sediment Transport and Deposition in High Arctic Proglacial Lake Linnévatnet,
Svalbard, Norway

Benjamin B. Schupack

Whitman College, Walla Walla, WA 99362

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High Arctic sedimentary processes in a distal, proglacial lake (Linnévatnet, Spitsbergen, Svalbard) were studied in July and August of 2006 to understand links between climatic controls and suspended sediment entering the lake. Linnévatnet, one of the largest lakes in Svalbard (4.7 km long, 35 m deep), contains sediments dating to the late Pleistocene. Previous studies have attempted to quantify annual sedimentation rates and calibrate the lake’s lamination, however much remains unknown about the suspended sediment entering the lake from the south, and the unique seasonal mechanisms and processes of sediment deposition into the basin. Depth, temperature and transmissivity (turbidity) were recorded in water column profiles by a Seacat SBE 19 profiler. Vertical casts were lowered into Linnévatnet at static mooring sites over a three-week period. A local automated meteorological station recorded air temperature, wind direction and velocity, precipitation, and solar radiation. Additionally, an automated camera recorded images of the lake inlet to document changes in the inflow stream and the occurrence of surface sediment plumes. Preliminary results suggest that Linnévatnet displays density currents including overflows, interflows, and underflows. We observed sediment plumes with fluctuating breadths and depths, which may be constrained by meteorological conditions and local morphologies. The water column profiles displayed a relationship between inlet water temperatures and suspended sediment concentrations, however wind and wave action also played an integral role in sediment transport patterns. No density current stratifications were observed in any water column profiles during strong northerly winds.