O Registro de Isótopos Estáveis de Hidrogênio em Testemunhos de Gelo da Ilha Rei George, Antártica
Palavras-chave:Glacioquímica, Testemunhos de Gelo, Antártica.
The hydrogen stable isotopic record in four ice cores drilled on King George Island ice field (to the west of the Antarctic Peninsula) are examined. Isotopic composition variations are strongly homogenized, exceptly in the few upper meters of cores drilled above 650-m of elevation. Intensive melting followed by water percolation throughout the snow and firn pack lead to isotopic exchange and consequently strong homogenization. A stratigraphic profile showing several ice layers and a water table detected in the glacier strengthen this hypothesis. Isotopic ratios decrease with elevation, reflecting the strong melting and isotopic fractionation in lower areas.