Physics and geochemistry of lakes in Vestfjella, Dronning Maud Land

• Published in: Antarctic Science
• Main Authors: Leppäranta, Matti, Luttinen, Arto, Arvola, Lauri
• Other Authors: Institute for Atmospheric and Earth System Research (INAR), Natural Sciences Unit, Finnish Museum of Natural History, Biological stations, Lammi Biological Station
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2021
• Subjects: 1171 Geosciences; Antarctica; classification; epiglacial; hydrology; seasonal; supraglacial; SUPRAGLACIAL LAKES; HEAT-BALANCE; SNOW; Antarctic; Basen; Dronning Maud Land; Fossilryggen; Plogen; Vestfjella; Antarc*; Antarctic Science
• Online Access: http://hdl.handle.net/10138/327115

Shallow Antarctic surface lakes belong to the most extreme aquatic environments on the Earth. In Vestfjella, proglacial surface lakes and ponds are characterized by a 2-5 month long period with liquid water and depths <2 m. We give a detailed description of nine seasonal lakes and ponds situating at three nunataqs (Basen, Plogen and Fossilryggen) in western Dronning Maud Land. Their physical and geochemical properties are provided based on observations in four summers. Three main 'lake categories' were found: 1) supraglacial lakes, 2) epiglacial ponds and 3) nunataq ponds. Category 3 lakes can be divided into two subgroups with regards to whether the meltwater source is glacial or just seasonal snow patches. Supraglacial lakes are ultra-oligotrophic (electrical conductivity <10 mu S cm(-1), pH <7), while in epiglacial ponds the concentrations of dissolved and suspended matter and trophic status vary over a wide range (electrical conductivity 20-110 mu S cm(-1), pH 6-9). In nunataq ponds, the maxima were an electrical conductivity of 1042 mu S cm(-1)and a pH of 10.1, and water temperature may have wide diurnal and day-to-day fluctuations (maximum 9.3 degrees C) because snowfall, snow drift and sublimation influence the net solar irradiance. Peer reviewed