The impact of subglacial hydrology and ice water interaction on the ice dynamics of Antartica: subglacial lakes and drainage systems

• Applicant: Dr. Christoph Mayer
• Subject Area: Oceanography
• Term: from 2008 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 75671330

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.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1158: Infrastructure area - Antarctic Research with Comparative Investigations in Arctic Sea Ice Areas
• Participating Person: Klaus Grosfeld, Ph.D.