Hydrochemical Characteristics of Four Retreating Glacier Forefields Off the Coast of Admiralty Bay (King George Island, Maritime Antarctic)

Abstract

This study examines the impact of geological, marine and anthropogenic sources on metal and metalloid concentrations in the forefields of four glaciers (Ecology, Sphinx, Tower and Windy) on King George Island, Antarctic. Water samples were collected at the beginning and end of the hydrological season (austral summer, December 2021 to February 2022), while snow samples were taken from the remaining snow cover at the start of the season. The study area, underlain by the Llano Point and Zamek formations—comprised mainly of basalt and andesite—reveals significant geological contributions of elements such as Fe, Al and Mg due to active weathering processes amplified by glacial retreat. The research highlights how meteorological condition change-induced temperature and precipitation increases accelerate sediment erosion and weathering, mobilising metals and metalloids from glaciers and snowmelt. Significant concentrations of Cr, V and Ba in collected samples align with the local geological substratum. Statistical analyses (Kruskal–Wallis ANOVA) identified notable differences in Mo and Ba levels between glacier forefields, consistent with geological influences, as these elements occur in varying concentrations within the local basaltic and andesitic bedrock. Seasonal variations were also observed, particularly for Mg and K ions, indicating that meltwater dynamics influence element mobilisation throughout the season. Furthermore, Tower Glacier's eastward exposure explains the higher concentrations of Zn and Cd, suggesting atmospheric deposition as a contributing factor. This study underscores the complex interactions between geological, climatic and atmospheric processes, illustrating how geogenic sources and cryosphere degradation influence the chemical landscape of Antarctic glacier forefields.