Data_Sheet_1_Modeling δD-δ18O Steady-State of Well-Sealed Perennially Ice-Covered Lakes and Their Recharge Source: Examples From Lake Untersee and Lake Vostok, Antarctica.pdf

• Main Authors: Benoit Faucher, Denis Lacelle, David A. Fisher, Klemens Weisleitner, Dale T. Andersen
• Format: Dataset
• Language: unknown
• Published: 2020
• Subjects: Solid Earth Sciences; Climate Science; Atmospheric Sciences not elsewhere classified; Exploration Geochemistry; Inorganic Geochemistry; Isotope Geochemistry; Organic Geochemistry; Geochemistry not elsewhere classified; Igneous and Metamorphic Petrology; Ore Deposit Petrology; Palaeontology (incl. Palynology); Structural Geology; Tectonics; Volcanology; Geology not elsewhere classified; Seismology and Seismic Exploration; Glaciology; Hydrogeology; Natural Hazards; Quaternary Environments; Earth Sciences not elsewhere classified; Evolutionary Impacts of Climate Change; freezing; ice-covered lakes; Antarctica; FREZCHEM; McMurdo Dry Valleys; Untersee; Lake Vostok; Anuchin Glacier; Antarc*
• Online Access: https://doi.org/10.3389/feart.2020.00220.s001; https://figshare.com/articles/Data_Sheet_1_Modeling_D-_18O_Steady-State_of_Well-Sealed_Perennially_Ice-Covered_Lakes_and_Their_Recharge_Source_Examples_From_Lake_Untersee_and_Lake_Vostok_Antarctica_pdf/12487850

Perennially ice-covered lakes that are tightly sealed from the atmosphere represent a unique group of polar lakes. In these lakes, the δD-δ 18 O evolution of the water column and steady-state conditions are controlled by rates of recharge and freezing at the bottom of the ice cover. We developed a recursive model (FREEZCH9) that takes into account the changing salinity in the water column as a result of freezing and mixes the recharge water to the residual water in well-sealed perennially ice-covered lakes. Our model is tested against datasets from Lake Vostok and is used to assess the δD-δ 18 O mass balance of Lake Untersee and evaluate if the lake is in isotopic steady-state. Our FREEZCH9 simulations fit well with the predicted δD-δ 18 O values of Lake Vostok’s upper water column and the overlying accreted ice. Simulations with FREEZCH9 also suggests that Lake Untersee is in isotopic steady-state and that its two input sources (i.e., subaqueous terminus melting of the Anuchin Glacier and subglacial meltwater) have similar δD-δ 18 O composition. Our modeling demonstrates that Lake Untersee most likely did not receive additional input from surface streams during the last 300–500 years. FREEZCH9 may be also used to determine if any groundwater systems of the McMurdo Dry Valleys are fully or partially recharged by subglacial lakes.