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dc.contributor.authorGil, Isabelle M.
dc.contributor.authorKeigwin, Lloyd D.
dc.contributor.authorAbrantes, Fatima G.
dc.date.accessioned2010-06-16T13:26:42Z
dc.date.available2010-06-16T13:26:42Z
dc.date.issued2009-12-12
dc.identifier.citationPaleoceanography 24 (2009): PA4101en_US
dc.identifier.urihttp://hdl.handle.net/1912/3645
dc.descriptionAuthor Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 24 (2009): PA4101, doi:10.1029/2008PA001729.en_US
dc.description.abstractDiatom assemblages document surface hydrographic changes over the Bermuda Rise. Between 19.2 and 14.5 ka, subtropical diatom species and Chaetoceros resting spores dominate the flora, as in North Atlantic productive regions today. From 16.9 to 14.6 ka, brackish and fresh water diatoms are common and their contribution is generally coupled with total diatom abundance. This same interval also contains rare grains of ice-rafted debris. Coupling between those proxies suggests that successive discharge of icebergs might have stimulated productivity during Heinrich event 1 (H1). Iceberg migration to the subtropics likely created an isolated environment involving turbulent mixing, upwelled water, and nutrient-rich meltwater, supporting diatom productivity in an otherwise oligotrophic setting. In addition, the occurrence of mode water eddies likely brought silica-rich waters of Southern Ocean origin to the euphotic zone. The persistence of lower-salinity surface water beyond the last ice rafting suggests continued injection of fresh water by cold-core rings and advection around the subtropical gyre. These results indicate that opal productivity may have biased estimates of meridional overturning based on 231Pa/230Th ratios in Bermuda Rise sediments during H1.en_US
dc.description.sponsorshipSupport for this research was provided by the Fundação para a Ciência e Tecnologia through the grant BPD/27214/2006 to I. M. Gil.en_US
dc.format.mimetypetext/plain
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttp://dx.doi.org/10.1029/2008PA001729
dc.subjectBermuda Riseen_US
dc.subjectDiatomen_US
dc.subjectHeinrich event 1en_US
dc.titleDeglacial diatom productivity and surface ocean properties over the Bermuda Rise, northeast Sargasso Seaen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2008PA001729


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