Research
Antarctica phase IV (1997-2000)
EPICA basal ice - eastern Antarctica
Promotor
Professor Roland Souchez
Université Libre de Bruxelles - C.P. 160/03
Département des Sciences de la Terre et de l'Environnement
Avenue F.D. Roosevelt, 50
B-1050 BRUSSELS
Phone: +32 (0)2 650 22 16
Fax: +32 (0)2 650 22 26
E-mail: glaciol@ulb.ac.be
Topics
The subject of this research is to proceed to a detailed interpretation of the composition of the basal ices from the EPICA drilling at the Dome C and role of the possible interactions between the ice cap and the stretches of water detected at its base.
It appeared very clearly these last years that the composition of polar ices records key-parameters of the Earth's climatic environment. As the layers of ice are all the more old for being deeper, a drilling which crosses some 3,000 m of Antarctic ice and reaches the substratum makes it possible to obtain a record extending over a few hundred thousand years. Such is the main purpose of the European project EPICA in Eastern Antarctica, which will allow a particularly precise environmental reconstruction on such a time span.
The methods of absolute dating of the ices do not go beyond 100,000 years and the only method for assessing the age of the deepest ices remains the modelling of the flow of the ice cap.
In this context, the composition of the basal ices provides not only indications on the characteristics of the deformations which underwent the ice cap, but it also makes it possible to understand, like it has been done for the central part of Greenland, the processes which governed its development and which influenced its dynamics. Such information is fundamental for a correct modelling of the flow, which only makes it possible to understand, like it has been done for the central part of Greenland, the processes which governed its development and which influenced its dynamics. Such information is fundamental for a correct modelling of the flow, which only makes it possible to work out a chronological scale beyond 100,000 years.
Near the site chosen for the first major EPICA drilling, namely Dome C in the Eastern Antarctic, radio-echo-surveys revealed the existence of stretch of sub-glacial water. It is thus extremely probable that very particular dynamical conditions, different from those of the centre of Greenland, prevailed and reign at the base of this ice cap because of the interactions between the ice and these stretches of water. The comprehension of these phenomena is essential to the deciphering of the palaeoenvironmental record beyond 100,000 years.
Goals
- To improve the preliminar technical stage of some analytical methods, in order to address the particular characteristics of the basal ices rich in debris and low in gas contents.
- To better the comprehension of the physico-chemical processes which occur at the surface of contact between a glacier and a lake in Antarctica, thanks to the analysis of the composition of the ices which were formed there.
- To gain further comprehension of the physico-chemical processes which occur in Antarctica at the anchoring line, where the glacier looses from the substratum at the seawater interface, thanks to the analysis of the composition of the ices which were formed there.
- To develop the knowledge of the characteristics of Eastern Antarctica fossil ices buried within the ground in areas currently not frozen, in order to be able to determine their genesis. This knowledge could prove to be significant insofar as underground ices preceding the formation of the cap could exist at the base of the EPICA ice core.
Related Projects
- Mass balance of the Antarctic ice
cap (a contribution to EPICA)
Prof. A. BERGER and Dr H. GALLÉE -- Université Catholique de Louvain
Research contract # A4/10/E01 - Dynamics of the Antarctic ice cap
and climate changes (a contribution
to EPICA)
Prof. H. DECLEIR -- Vrije Universiteit Brussel
Research contract # A4/03/E03 - Antarctic shelf-slope dynamics: an
innovative geophysical approach
Dr M. DE BATIST and Dr J.-P. HENRIET -- Universiteit Gent
Research contract # A4/02/G01