HR: 14:50h
AN: C12B-05 INVITED     [PDF]
TI: Fracture Mechanics of Ice Shelves
AU: * Sammonds, P
EM: p.sammonds@ucl.ac.uk
AF: University College London, Dept. Earth Sciences, Gower Street, London, WC1E 6BT United Kingdom
AU: Rist, M
EM: M.A.Rist@open.ac.uk
AF: The Open University, Dept. Materials Engineering, Milton Keynes, MK7 6AA United Kingdom
AB: The importance of large-scale fracture processes has recently been emphasized by the break-up of ice shelves on the Antarctic Peninsula and underlines the need for incorporation of fracture mechanics into models of ice sheet dynamics. Key components for fracture mechanics models include qualitative models of the brittle processes in ice shelf fracture and experimental measurements of fundamental fracture parameters. We have adopted an integrated experimental and theoretical approach which is validated against field and satellite measurements. Our procedure has been first to quantify experimentally and physical behaviour of Antarctic ice core, then to use these measurements in fracture criteria describing the spatial distribution of crevasses, the depth and height of top and bottom crevasse penetration and the effect of tidal flexure. Up to now these have been crack initiation criteria. Here we discuss two extensions to our work: 1) to describe the statistical nature of ice fracture; 2) to describe crack propagation in ice. We find there that the statistical nature of ice shelf fracture can arise from the inhomogeneous size distribution of initiation cracks. We infer that crack propagation in ice can have strong environmental controls. We describe how these aspects of ice fracture can be incorporated into ice shelf models.
DE: 1640 Remote sensing
DE: 1827 Glaciology (1863)
DE: 1863 Snow and ice (1827)
SC: Cryosphere [C]
MN: 2003 Fall Meeting