Structural grain parameters from image analysis of large area scan macroscope images from the NEEM ice core

Grain parameters (size and shape) are derived by extraction and parametrisation of grain boundary networks from large area scan macroscope images from the NEEM ice core. Images have been taken in reflecting light (LASM) in the NEEM camp on the freshly drilled core, prepared as polished thick sections. A dedicated method of automatic image analysis was developed by Tobias Binder (PhD DFG-funded, 2014, AWI, Bremerhaven and IWR, Heidelberg) and applied to the images. Grain size and shape parameters, if based on reliable statistics viz. several hundreds of grains per section, help to characterise "shape preferred orientation" (SPO) as complementary information to crystal preferred orientation measurements (CPO or fabrics) with respect to the solid state deformation of polar ice.