Experimental fracture and mechanical properties of Antarctic ice: Preliminary results

摘要: An experimental study of the fracture mechanics and rheology ice from Ronne Ice Shelf, Antarctica, is currently being undertaken. The apparent critical stress-intensity factor (or toughness, K Q) for crack propagation has been measured using a three-point bend method inducing growth perpendicular to axis cylindrical ice-core specimens. Tensile nucleation under applied uniaxial compressive stress also evaluated. Both methods have allowed profile elastic properties with depth through shelf be constructed. Preliminary results indicate that modulus increases firn upper meteoric before reaching constant value in deeper, dense basal marine ice. resistance fracture, as by changes toughness crack-nucleation stress, right layers. A simple model Shelf indicates crevasses form small surface cracks, less than 40 cm deep, which quickly grow depths 40‐60m then remain stable.