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| Titel |
Stratigraphy of Lake Vida, Antarctica: hydrologic implications of 27 m of ice |
| VerfasserIn |
H. A. Dugan, P. T. Doran, B. Wagner, F. Kenig, C. H. Fritsen, S. A. Arcone, E. Kühn, N. E. Ostrom, J. P. Warnock, A. E. Murray |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 9, no. 2 ; Nr. 9, no. 2 (2015-03-04), S.439-450 |
| Datensatznummer |
250116761
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| Publikation (Nr.) |
 copernicus.org/tc-9-439-2015.pdf |
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| Zusammenfassung |
| Lake Vida, located in Victoria Valley, is one of the largest lakes in the
McMurdo dry valleys and is known to contain hypersaline liquid brine sealed
below 16 m of freshwater ice. For the first time, Lake Vida was drilled to a
depth of 27 m. Below 21 m the ice is marked by well-sorted sand layers up
to 20 cm thick within a matrix of salty ice. From ice chemistry, isotopic
composition of δ18O and δ2H, and ground penetrating radar
profiles, we conclude that the entire 27 m of ice formed from surface
runoff and the sediment layers represent the accumulation of surface
deposits. Radiocarbon and optically stimulated luminescence dating limit the
maximum age of the lower ice to 6300 14C yr BP. As the ice cover
ablated downwards during periods of low surface inflow, progressive
accumulation of sediment layers insulated and preserved the ice and brine
beneath, analogous to the processes that preserve shallow ground ice. The
repetition of these sediment layers reveals hydrologic variability in
Victoria Valley during the mid- to late Holocene. Lake Vida is an exemplar
site for understanding the preservation of subsurface brine, ice, and sediment
in a cold desert environment. |
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