Vertical Distributions of Some Trace Metals in Lake Nurume, Antarctica

Abstract

The concentration of some trace metals (Fe, Mn, Cu, Zn, Pb, Cd) in Lake Nurume was measured vertically. The concentration of trace metals in surface water decreases with increasing depth to the intermediate water layer. This fact may be ascribed to snow melt added to the surface water. The water layer, which retains reduced environment throughout the year, is found at a depth deeper than 10 m in the pond. This structure is thought to be an important factor of the vertical distribution of trace metals. The Mn concentration maximum was found at a boundary layer between oxidative and reductive layers. In the reductive layer, Fe and Mn are more abundant than in the oxidative layer, because of the increased solubility. The concentration profile of trace metals in the bottom sediment did not show any significant change down to a depth of 80 cm below the water-sediment interface. The fact may suggest that the material supplied from the same source was deposited in a stable environment.