Geochemical Linkages Among Glaciers, Streams and Lakes Within the Taylor Valley, Geochemical Linkages Among Glaciers, Streams And Lakes Within The Taylor Valley, Antartica
- John C. Priscu
Published Online: 16 MAR 2013
Copyright 1998 by the American Geophysical Union.
Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica
How to Cite
Lyons, W. B., Welch, K. A., Neumann, K., Toxey, J. K., Mcarthur, R., Williams, C., Mcknight, D. M. and Moorhead, D. (1998) Geochemical Linkages Among Glaciers, Streams and Lakes Within the Taylor Valley, Geochemical Linkages Among Glaciers, Streams And Lakes Within The Taylor Valley, Antartica, in Ecosystem Dynamics in a Polar Desert: the Mcmurdo Dry Valleys, Antarctica (ed J. C. Priscu), American Geophysical Union, Washington, D. C.. doi: 10.1029/AR072p0077
- Published Online: 16 MAR 2013
- Published Print: 28 JAN 1998
Print ISBN: 9780875908991
Online ISBN: 9781118668313
- Desert ecology—Antarctica—McMurdo Dry Valleys
Aquatic systems in the Taylor Valley, Antarctica have characteristics of other desert aquatic systems in that the amount of water is limited and highly variable during the year. As part of the McMurdo Dry Valleys LTER, we have examined the major element chemistry of the three largest lake basins in order to investigate the geochemical “continuum” and the geochemical processes occurring within the Taylor Valley. During the summer, meltwater is generated from the glaciers and flows through streams to perennially ice-covered lakes in the valley bottom. As water moves through the system, solute concentrations increase by orders of magnitude. The glacier data suggest that some amount of salt is recycled from the soils and blown by winds onto the glaciers. Spatial differences in glacier chemistry have been observed and these, along with characteristics of the glacial meltwater streams, result in differences in stream chemistry within the valley. Dissolution of evaporite salts within the stream channels, as well as the weathering of Si minerals appear to be significant geochemical processes especially in the longer streams. The differences in modern day stream chemistry would lead to different chemical evolutionary pathways for the different lakes. High interannual variability of stream flow has also been observed which leads to differences in the amount of fresh water and solutes entering into the lakes each season. In addition, seasonal chemical changes occur within the lakes due to the inflow of fresh water and biological activity. For example, changes in calcite saturation in the lakes have been observed through the austral summer period. Based on our work, it appears that long-term systematic monitoring of stream and lake hydrology and chemistry is needed in order to quantitatively evaluate water and solute balances for the lakes, as well as to understand lake dynamics.