Der Einfluss subglazialer Hydrologie und der Eisschild-Wasser-Wechselwirkung auf die Eisdynamik der Antarktis:Subglaziale Seen und Drainagesysteme
Dr. Christoph Mayer
Bayerische Akademie der Wissenschaften
Kommision für Erdmessung und Glaziologie
For a very long time the subglacial regime underneath the Antarctic Ice Sheet was isolated from the atmospheric environment and there is still only rather limited knowledge about the physical conditions in this boundary layer. Due to the large ice thicknesses ice temperatures at the ice sheet bottom reach the pressure melting point in many regions, and recently a large number of subglacial lakes and abundant water was detected underneath the Antarctic Ice Sheet. This fact has a number of important consequences, e.g., on the dynamic conditions of the ice sheet, but also for potential sources of life forms in extreme environments. The proposed project aims on providing answers on several of the major issues connected with the interaction between subglacial water bodies, the overlying ice and drainage at the ice sheet bottom and across the ice sheet's boundaries. A challenging approach is proposed for the coupling of already existing numerical models of highresolution ice dynamics and subglacial lake circulation. This will be completed by developing means for the implementation of drainage mechanisms into the coupled model. A considerable effort is taken in order to evaluate the models reliability for the best known ice-lake system of subglacial Lake Vostok. With a working numerical model system at hand a number of very important questions will be tackled which are crucial for evaluating the recent and future physical/dynamical condition of the Antarctic Ice Sheet. Namely, the relevance of subglacial water bodies for the dynamic situation of the ice sheet will be investigated, starting from large subglacial lakes and reaching down to local drainage systems. Also the significance of lake existance for the onset of ice streams and the influence of major subglacial water bursts on the adjacent oceanic circulation will be investigated within this project. A synthesis of the investigated mechanisms and their impacts will provide a totally new insight into the dynamic status and the sensitivity of large parts of the Antarctic Ice Sheet.
Beteiligte Person: Dr. Klaus Grosfeld, Ph.D.
Förderung von 2008 bis 2012