Variations of water stable isotopes (δ18O) in two lake basins, southern Tibetan Plateau
| Autor: | Daniel R. Joswiak, Tandong Yao, Jing Gao |
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| Rok vydání: | 2014 |
| Předmět: |
Shore
Hydrology geography geography.geographical_feature_category Plateau 010504 meteorology & atmospheric sciences Stable isotope ratio δ18O Glacier 010502 geochemistry & geophysics 01 natural sciences Glacial period Precipitation Meltwater Geology 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Annals of Glaciology. 55:97-104 |
| ISSN: | 1727-5644 0260-3055 |
| Popis: | δ18O measurements based on systematic sampling and isotopic modeling have been adopted to study the controls of stable isotopes in lake water in two lake basins (lakes Yamdrok-tso and Puma Yum-tso) at two different elevations on the southern Tibetan Plateau. Temporally, δ18O values in precipitation and lake water display a seasonal fluctuation in both lakes. Spatially, δ18O values in the two lake basins increase by 10% from the termini of glaciers to the lake shores, by ∽1% from the lake shores to the lake center and by 0.4% from the water surface to depth in these lakes. The clear annual δ18O variations indicate that lake water mixes sufficiently in a short time. Model results show that glacial meltwater and surface lake-water temperature are not the dominant factors in the balance process of stable isotopes in lake water. Equilibrium δ18O values decrease by 0.8% for Yamdrok-tso lake and 0.6% for Puma Yum-tso lake when glacial meltwater contributions to these lakes shrink by 60%. δ18O ratios increase rapidly during the initial stages and take a longer time to approach the equilibrium value. |
| Databáze: | OpenAIRE |
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