Hydrological systems from the Antarctic Peninsula under climate change: James Ross archipelago as study case

摘要

Hydrological systems of the ice-free areas of the James Ross archipelago (NE Antarctic Peninsula) provide a unique opportunity for studying recent environmental changes associated with the current Global Warming. Geochemical, hydrological, sedimentological, and magnetic studies were carried out on different lake systems and ephemeral ponds from post-Holocene periglacial environments to characterize their natural variability. Significant differences between the lakes were observed based on physicochemical analyses, and can be attributed to several characteristics and processes taking place (geochemical, diagenetic, biological, etc.) in individual lake catchments. Seymour-Marambio Island's lakes exhibit high total dissolved solids (similar to 3.300 mg L-1) due to the high rate of evaporation in the region, whereas trace elements show differences in the lithological source. Lakes from Vega and James Ross islands are comparatively diluted, with the highest pH values up to 10.2. Within Vega Island, trace elements discriminate lakes into sectors which show statistical differences due to variations in lithological sources. Dissolved sources can be divided according to their kinetics into: high-rate processes which occur during summer months (evaporation, salt precipitation, atmospheric precipitation, melting processes) and low-rate processes (mineral weathering, giving a long-term signature). The present multidisciplinary study contributes to a better understanding of Antarctic lake systems, and can be used as a baseline dataset for further studies investigating the impact of recent climate changes on the biological and geochemical characteristics of these pristine ecosystems in the future.