Grain growth of natural and synthetic ice at 0 °C ...

• Main Authors: Fan, Sheng, Prior, David J, Pooley, Brent, Bowman, Hamish, Davidson, Lucy, Wallis, David, Piazolo, Sandra, Qi, Chao, Goldsby, David L, Hager, Travis F
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Copernicus GmbH 2023
• Subjects: Priestley; Priestley Glacier; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.17863/cam.100595; https://www.repository.cam.ac.uk/handle/1810/355723

Abstract. Grain growth can modify the microstructure of natural ice, including the grain size and crystallographic preferred orientation (CPO). To better understand grain-growth processes and kinetics, we compared microstructural data from synthetic and natural ice samples of similar starting grain sizes that were annealed at the solidus temperature (0 ∘C) for durations of a few hours to 33 d. The synthetic ice has a homogeneous initial microstructure characterized by polygonal grains, little intragranular distortion, few bubbles, and a near-random CPO. The natural ice samples were subsampled from ice cores acquired from the Priestley Glacier, Antarctica. This natural ice has a heterogeneous microstructure characterized by a considerable number of air bubbles, widespread intragranular distortion, and a CPO. During annealing, the average grain size of the natural ice barely changes, whereas the average grain size of the synthetic ice gradually increases. These observations demonstrate that grain growth in ...