Suspended sediments in Admiralty Bay, King George Island (Antarctica)

Abstract

In February 2000, suspended sediment concentrations were measured at two sampling sites atAdmiralty Bay. One test site was located in front of the Lange Glacier ice cliff, which was sampled on six occasions; the second site, at Martel Inlet, was measured four times. The sample volume at each station was comprised of four levels, from the surface to a maximum depth of 15 m. Variations in the concentration of inorganic matter were analyzed, taking into consideration the distance from the glacier cliff and sampling depth. Sediment concentrations were higher at the Martel Inlet than near Lange Glacier. This was due to several periglacial areas around that inlet. At Martel Inlet, the supply of fine-grained material is mobilized by surface water and transported into the marine environment. The formation of a distinct sediment plume, as suggested by different theoretical models, could not be confirmed at the sampling sites. Temporal variations of sediment concentrations showstrong influence of rain and storm events, which are attributed to an increase of freshwater discharge and denudation. Furthermore, wind-induced resuspension of previously deposited material on the fjord floor was considered as the main reason for the high sediment concentrations, measured at the Martel sampling site.