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dc.contributor.authorBhatia, Maya P.  Concept link
dc.contributor.authorDas, Sarah B.  Concept link
dc.contributor.authorKujawinski, Elizabeth B.  Concept link
dc.contributor.authorHenderson, Paul B.  Concept link
dc.contributor.authorBurke, Andrea  Concept link
dc.contributor.authorCharette, Matthew A.  Concept link
dc.date.accessioned2011-11-22T17:12:38Z
dc.date.available2012-04-01T08:32:54Z
dc.date.issued2011-10-01
dc.identifier.citationJournal of Glaciology 57 (2011): 929-941en_US
dc.identifier.urihttps://hdl.handle.net/1912/4895
dc.descriptionAuthor Posting. © International Glaciological Society, 2011. This article is posted here by permission of International Glaciological Society for personal use, not for redistribution. The definitive version was published in Journal of Glaciology 57 (2011): 929-941, doi:10.3189/002214311798043861.en_US
dc.description.abstractThe Greenland ice sheet (GrIS) subglacial hydrological system may undergo a seasonal evolution, with significant geophysical and biogeochemical implications. We present results from a new isotope-mixing model to quantify the relative contributions of surface snow, glacial ice and delayed flow to the bulk meltwater discharge from a small (∼5 km2) land-terminating GrIS outlet glacier during melt onset (May) and at peak melt (July). We use radioactive (222Rn) and stable isotopes (18O, deuterium) to differentiate the water source contributions. Atmospherically derived 7Be further constrains meltwater transit time from the glacier surface to the ice margin. We show that (1) 222Rn is a promising tracer for glacial waters stored at the bed and (2) a quantitative chemical mixing model can be constructed by combining 222Rn and the stable water isotopes. Applying this model to the bulk subglacial outflow from our study area, we find a constant delayed-flow (stored) component from melt onset through peak melt. This component is diluted first by snowmelt and then by increasing glacial ice melt as the season progresses. Results from this pilot study are consistent with the hypothesis that subglacial drainage beneath land-terminating sections of the GrIS undergoes a seasonal evolution from a distributed to a channelized system.en_US
dc.description.sponsorshipThis research was supported by the WHOI Clark Arctic Research Initiative (E.B.K., S.B.D., M.A.C.), the WHOI Ocean Ventures Fund (M.P.B.), the US National Science Foundation ARC-05200077 (S.B.D.), NASA (S.B.D.), the Natural Sciences and Engineering Research Council of Canada (M.P.B.) and the WHOI Climate Change Institute (M.P.B.).en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherInternational Glaciological Societyen_US
dc.relation.urihttps://doi.org/10.3189/002214311798043861
dc.titleSeasonal evolution of water contributions to discharge from a Greenland outlet glacier : insight from a new isotope-mixing modelen_US
dc.typeArticleen_US
dc.identifier.doi10.3189/002214311798043861


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