Salinity evolution and mechanical properties of snow-loaded

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TitleSalinity evolution and mechanical properties of snow-loaded multiyear sea ice near an ice shelfAbstractSea ice often forms attached to floating ice shelves. Accumulating snow can depress its freeboard, creating a flooded slush layer that may subsequently freeze to form snow ice, rejecting brine as it freezes. The resulting salinity profile determines the mechanical properties of the sea ice. We provide measurements of snow-loaded, multiyear sea ice from summer to winter. Brine from a slush layer is not completely expelled from the sea ice when the slush refreezes to form snow ice. Measurements of sea ice salinity and temperature indicate that the fate of this brine depends on the permeability of the sea ice below it. The sea ice in this study was also deformed by a nearby ice shelf over eleven years at a strain rate = (-8 ± 3) x 10-4 yr-1 (or 3 x 10-11s-1). From transects of sea ice thickness and structure we estimate an effective Young's modulus at medium scales for sea ice mostly composed of snow ice of 0.1 GPa < E < 0.4 GPa, suggesting that this eleven year old sea ice cover has similar mechanical properties to warm first year sea ice. This is important for the parameterisations needed to simulate multiyear sea ice in the complex region near an ice shelf. Copyright 2013 Antarctic Science Ltd.AcknowledgementsWe thank Brian Staite, Euan Paterson and the 2009 Scott Base winter team for assistance in the field. This work, part of New Zealand's contribution to the IPY, was funded by the Foundation for Research, Science and Technology and a University of Otago postgraduate scholarship. The Rt Hon William R. Chandler also donated generously to the project. Logistical support was provided by Antarctica New Zealand. We thank Mike Williams and Jean-Louis Tison for their comments and Jeff Scanniello for information on the breakout history at Cape Armitage prior to 2003. We also gratefully acknowledge the constructive comments of the reviewer.

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1st AuthorGough, A.AuthorGough, A.Mahoney, A.Langhorne, P.Haskell, T.Year2013JournalAntarctic ScienceVolume25Number6Pages821-831DOI10.1017/S0954102013000217URLhttps://www.scopus.com/inward/recor.....c6e08b03f0698fe05b46ae40dKeywordsbrineevolutionfloating iceice coverice shelfpermeabilitysalinitysea icesnowstrain ratesummerwinter, rank5Author Keywordsice structurepermeabilityslush layersnow icewords brine rejection

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TypeArticleCitationGough, A., Mahoney, A., Langhorne, P. and Haskell, T. (2013). Salinity evolution and mechanical properties of snow-loaded multiyear sea ice near an ice shelf. Antarctic Science, 25(6): 821-831