Experimental fracture and mechanical properties of Antarctic ice preliminary results

• Main Authors: Rist, M. A., Sammonds, P. R., Murrell, S. A. F., Meredith, P. G., Oerter, Hans, Doake, C. S. M.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 1996
• Subjects: Annals of Glaciology; Antarc*; Antarctic; ice core; Ice Shelf; Ronne Ice Shelf
• Online Access: https://epic.awi.de/id/eprint/2650/; https://hdl.handle.net/10013/epic.13234

An experiment study of the fracture mechanics and rheology of ice from the Ronne Ice Shelf is currently being undertaken. The apparent critical stress-intensity factor (or apparent fracture toughness, K{Q}) for crack propagation has been measured using a three-point bend method for inducing crack growth perpendicular to the axis of cylindrical ice-core specimens. Tensile crack nucleation under applied uniaxial compressive stress has also been evaluated. Both methods have allowed a profile of ice elastic and fracture properties with depth through the ice shelf to be constructed. The resistance to fracture, as measured by changes in apparent fracture toughness and crack-nucleation stress, increases with depth right through the firn and meteoric ice layers. A simple fracture mechanics model applied to the Ronne Ice Shelf indicates that crevasses form from small surface cracks, less than 40 cm deep, which quickly grow.