Cryoconite hole connectivity on the Wright Lower Glacier, Mc

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TitleCryoconite hole connectivity on the Wright Lower Glacier, McMurdo Dry Valleys, AntarcticaAbstractCryoconite holes can be important sources and stores of water and nutrients on cold and polythermal glaciers, and they provide a habitat for various forms of biota. Understanding the hydrological connectivity of cryoconite holes may be the key to understanding the transport of nutrients and biological material to the proglacial areas of such glaciers. This paper aims to characterize and explain spatial variability in the connectivity of ice-lidded cryoconite holes on a small, piedmont glacier in the McMurdo Dry Valleys through geochemical analysis of cryoconite hole waters. Solute concentrations in both surface and near-surface ice and cryoconite holes, vary greatly along the glacier centerline, and all sample types displayed similar spatial patterns of variability. Using chloride as a tracer, we estimated variations in cryoconite hole connectivity along the glacier centerline. We found that a previously used mass transfer method did not provide reliable estimates of the time period for which cryoconite hole waters had been isolated from the atmosphere. We attribute this to spatial variability in both the chloride content of the surface ice and surface ablation rates. The approach may, however, be used to qualitatively characterize spatial variations in the hydrological connectivity of the cryoconite holes. These results also suggest that ice-lidded cryoconite holes are never truly isolated from the nearsurface drainage system. Copyright The Author(s) 2016.AcknowledgementsFinancial assistance for S. M. was provided by a University of Otago Postgraduate Scholarship, the Sir Robin Irvine Antarctica New Zealand Doctoral Scholarship and the University of Otago Postgraduate Publishing Bursary. M. S. acknowledges support from the Canadian Arctic-Antarctic Exchange Program (Natural Resources Canada) and an NSERC Discovery Grant. Financial support for S. F. was provided by a University of Otago Research Grant. Logistical support was provided by Antarctica New Zealand. We are grateful for field assistance provided by Lawrence Kees, Laurel Morrison, Dorothea Stumm and Ben Varkalis and to Tracy Connolly for drawing Fig. 1. Fantastic helicopter support was provided by Helicopters NZ pilot Rob McPhail. We are grateful for insightful comments from the two reviewers.Funding DetailsNSERC, Natural Sciences and Engineering Research Council of Canada

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1st AuthorMacDonell, S.AuthorMacDonell, S.Sharp, M.Fitzsimons, S.Year2016JournalJournal of GlaciologyVolume62Number234Pages714-724DOI10.1017/jog.2016.62URLhttps://www.scopus.com/inward/recor.....7412f9749466b1c5576452bd5Keywordsrank5

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TypeArticleCitationMacDonell, S., Sharp, M. and Fitzsimons, S. (2016). Cryoconite hole connectivity on the Wright Lower Glacier, McMurdo Dry Valleys, Antarctica. Journal of Glaciology, 62(234): 714-724 IdentifierMacDonell2016Relevancerank5