Hydrogeochemistry of the deglaciated lacustrine systems in Antarctica: Potential impact of marine aerosols and rock-water interactions

• Published in: The Science of the total environment 2020-03, Vol.706, p.135822-135822, Article 135822
• Main Authors: Magesh, N.S., Botsa, Sathish Mohan, Dessai, Soniya, Mestry, Mamta, Leitao, Tara Da Lima, Tiwari, Anoop
• Format: Article
• Language: English
• Subjects: Antarctica; Hydrogeochemistry; Lake water; Larsemann Hills; Marine aerosols; Rock-water interaction
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2019.135822

The deglaciated lacustrine systems in Grovnes, Larsemann Hills, East Antarctica was assessed for its solute dynamics and hydrogeochemical interactions. These pristine high latitude lacustrine systems serve as a natural laboratory to understand the interaction between hydrosphere, lithosphere and atmosphere thus providing valuable insights on the functioning of major biogeochemical cycles. A total of 14 fresh water lakes were identified and the water samples were analysed for its physico-chemical characteristics. The abundance of anions and cations in the lake water samples were in the following order of Cl− > HCO3– > SO42− > NO3− and Na+ > Mg2+ > Ca2+ > K+ respectively. Moreover, the lakes exhibit slightly alkaline condition due to dissolution of alkaline earth metals and atmospheric fallout. Na+-Cl−–HCO3– and Na+-Cl− are the commonly noticed water type in the study area and higher concentration of Na+-Cl− were due to the effect of sea spray through marine aerosols. Reverse ion exchange is noticed in most of the lakes due to saline influence. Three major mechanisms such as rock dominance, precipitation/snow and evaporation/sea spray controls the lake water geochemistry in the study area. Silicate weathering and evaporite dissolution also contribute ionic load to the lake water. Significant positive correlations (p