Author(s): Mark Shortt; Peter Sammonds; Eleanor Bailey
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Abstract: We present results from consolidation experiments on saline ice conducted at the Hamburgische Schiffbau-Versuchsanstalt (HSVA) Large Ice Model Basin (LIMB) in Hamburg, Germany. The aim was to investigate the strength and physical characteristics of freeze-bonds developed in a range of conditions encountered in rafted and ridged sea ice, by employing: 1) free floating ice compared with submerged ice and, 2) the presence or absence of a liquid layer. Stacks of two 1m2 blocks of saline ice were used: 1) free-floating and submerged beneath the water surface and, 2) with a 3 mm liquid layer and with direct contact between the ice blocks. There were a total of four experiments, each left to consolidate for five days, during which the temperature and salinity evolutions were measured. By the end of the consolidation period the two direct contact experiments had consolidated sufficiently for full cored samples to be taken. Conversely, those experiments that contained a liquid layer were too weak to survive coring, despite an apparent freezing of the brine within the layer deduced via salinity measurements. Cored samples from each experiment were taken, from which salinity profiles were determined. The compressive strengths of samples from the direct contact experiments were also measured and compared to level ice. Both consolidated samples were weaker in compression than the level ice. The sample from the submerged experiment was considerably weaker than the sample from free-floating ice. The observations from the two liquid layer experiments support the necessity to distinguish between thermodynamic and full mechanical consolidation.
Year: 2018