Measurements and numerical simulation of fabric evolution along the Talos Dome ice core, Antarctica

We present measurements of fabrics and microstructures made along the Talos Dome ice core, a core drilled in East Antarctica in the framework of the TALDICE project. Fabric and average grain size data are analyzed regarding changes in climatic conditions. In particular, the fabric strength increases sharply going downward from Holocene to Wisconsin ice. Following (Durand et al., 2007), this change is associated with a positive feedback between variations in ice viscosity, due to variations in dust content, and the impact of a shear stress component, increasing with depth. A ViscoPlastic Self-Consistent modeling approach is used to simulate the fabric evolution for a “perfect dome” configuration. The discrepancies between the measured and the simulated fabrics highlight the depth ranges where shear strongly affects the fabric strengthening. Finally, the grain size and fabric analyses show the occurrence of dynamic recrystallization mechanisms (continuous and discontinuous) along the core.

► High resolution fabric and grain size evolution are measured along the Talos Dome ice core.
► Fabric strengthening is associated with feedback between viscosity changes and shear.
► VPSC modeling of fabric evolution helps to validate the TALDICE-1 dating estimations.
► Evidence is shown of a non-isotropic fabric in firn.
► Evidences of dynamic recrystallization are observed along the core.