Evidence for physical and chemical stratification in Lake Untersee (central Dronning Maud Land, East Antarctica)

Lake Untersee is the largest freshwater lake in the interior of East Antarctica. It is a perennially ice-covered, max. 169 m deep, ultra-oligotrophic lake. In contrast to earlier studies, we found clear evidence for physical and chemical stratification in the summer of 1991–92. However, the stratifi...

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Bibliographic Details
Published in:Antarctic Science
Main Authors: Wand, U., Schwarz, G., Brüggemann, E., Bräuer, K.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1997
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Online Access:http://dx.doi.org/10.1017/s0954102097000060
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102097000060
Description
Summary:Lake Untersee is the largest freshwater lake in the interior of East Antarctica. It is a perennially ice-covered, max. 169 m deep, ultra-oligotrophic lake. In contrast to earlier studies, we found clear evidence for physical and chemical stratification in the summer of 1991–92. However, the stratification was restricted to a trough, c. 500 m wide and up to 105 m deep, in the south-western part of the lake. There, the water body was distinctly stratified as indicated by sharp vertical gradients of temperature, pH, dissolved oxygen, and electrical conductivity. The water column was anoxic below 80 m. The chemical stratification is also indicated by changes of ionic ratios. Moreover, there was some evidence for methanogenesis and bacterial sulphate reduction in Lake Untersee.