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TitleA nuclear magnetic resonance study of Antarctic sea ice brine diffusivity
Publication TypeJournal Article
Year of Publication1999
AuthorsCallaghan, P.T., Dykstra R., Eccles C.D., Haskell T.G., and Seymour J.D.
JournalCold Regions Science and Technology
Volume29
Issue2
Pagination153 - 171
Date Published1999
ISSN0165232X (ISSN)
KeywordsAnisotropy, Antarctica, Arctic engineering, brine, Brine inclusions, Brines, Brownian movement, Diffusion in liquids, diffusivity, Heat convection, nuclear magnetic resonance, nuclear magnetic resonance spectroscopy, Sea ice, Thermodynamic properties
AbstractWe have measured the diffusive motion of water molecules in the brine inclusions of Antarctic sea ice using a specially constructed nuclear magnetic resonance (NMR) apparatus. The method relies on the use of pulsed magnetic field gradients in precise analogy to well established laboratory procedures. One version of the apparatus utilised core samples extracted from the ice sheet which were subsequently analysed on site while a later version utilised a probehead which was inserted into the ice sheet, thus minimising any sample perturbation. The diffusive motion of water molecules in the brine inclusions is found to be strongly anisotropic, and, over short length scales, exhibits a rapidity greatly in excess of that expected for thermal equilibrium Brownian behaviour, an effect which we attribute to convective transport.We have measured the diffusive motion of water molecules in the brine inclusions of Antarctic sea ice using a specially constructed nuclear magnetic resonance (NMR) apparatus. The method relies on the use of pulsed magnetic field gradients in precise analogy to well established laboratory procedures. One version of the apparatus utilized core samples extracted from the ice sheet which were subsequently analyzed on site while a later version utilized a probehead which was inserted into the ice sheet, thus minimizing any sample perturbation. The diffusive motion of water molecules in the brine inclusions is found to be strongly anisotropic, and, over short length scales, exhibits a rapidity greatly in excess of that expected for thermal equilibrium Brownian behaviour, an effect which we attribute to convective transport.
URLhttp://www.scopus.com/inward/record.url?eid=2-s2.0-0033377973&partnerID=40&md5=56c5f47da5cadf66d89c9a13dfb3ad4f
DOI10.1016/S0165-232X(99)00024-5

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