Permalink : http://hdl.handle.net/2115/45430

KEYWORDS : Ice;firn;multiscale modeling;microstructure;recrystallization;stratigraphy;subglacial environment

The dynamics of polar ice sheets is strongly influenced by a complex coupling of intrinsic structures. Some of these structures are extremely small, like dislocation walls and micro-inclusions; others occur in a wide range of scales, like stratigraphic features; and there are also those collossal structures as large as megadunes and subglacial lakes. Their significance results from their interactions with the ice-sheet flow and the environment through an intricate Structure-Form-Environment Interplay (SFEI). Glaciologists are not unaware of the SFEI issue, as particular details of the problem are well documented in the literature. Nevertheless, many aspects of the SFEI remain unclear and a comprehensive perspective of the problem is missing. Here we present some selected results of a joint investigation of these structures via fieldwork, theoretical modeling, and experiments. The basic strategy is to conceive the Antarctic ice sheet as a heterogeneous system of structured media that interact in a hierarchical fashion via the SFEI. Special emphasis is given to snow and firn structures, interactions between microstructure, stratigraphy and impurities, and the interplay between subglacial structures and the overlaying ice.