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dc.contributor.authorDrenzek, Nicholas J.  Concept link
dc.coverage.spatialCariaco Basin
dc.coverage.spatialSaanich Inlet, British Columbia
dc.date.accessioned2007-07-06T17:38:05Z
dc.date.available2007-07-06T17:38:05Z
dc.date.issued2007-06
dc.identifier.urihttps://hdl.handle.net/1912/1736
dc.descriptionSubmitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2007en
dc.description.abstractThis thesis employs compound-specific stable carbon and radiocarbon isotopic analysis of organic biomarkers to (a) resolve petrogenic from pre-aged vascular plant organic carbon (OC) in continental margin sediments, (b) investigate the underlying mechanisms controlling the anomalously old ages that are often observed for the terrestrial component of sedimentary OC, and (c) address the associated consequences for biomarker-based climate reconstructions. In Chapters 2 and 3, coupled molecular isotope mass balances demonstrate that the amount of petrogenic OC residing on the Beaufort Shelf (Arctic Ocean) and the Eel River Margin (coastal California) has been previously overestimated due to the presence of significantly ‘pre-aged’ terrestrial OC. However, even though the contribution of organic matter emanating from sedimentary rocks may be smaller, these results reinforce the emerging notion that it is not completely oxidized during weathering and subsequent seaward transport. In Chapter 4, comparison of the down-core radiocarbon profiles for certain vascular plant biomarkers extracted from Cariaco Basin (Caribbean Sea) and Saanich Inlet (coastal British Columbia) sediments with the radiocarbon evolution of atmospheric carbon dioxide reveals that the vast majority of the terrestrial OC experiences multi-millennial residence times on land prior to entering the sea. Most of the remaining inventory is deposited in sediments within one or two decades, providing direct evidence that very little terrestrial organic matter is rapidly transferred to the marine environment. With this in mind, the striking modulation in the signal amplitude of a biomarker-based tropical paleoaridity record presented in Chapter 5 was instead used to evaluate the role of low versus high latitude forcing in abrupt paleoclimate oscillations during the last full glacial cycle. Seasonal variations in the position of the Intertropical Convergence Zone were interpreted to be a response to both high latitude adjustments in meridional overturning circulation and precessionally-driven modifications in local insolation. Finally, Chapter 6 addresses the broader implications of multi-millennial terrestrial residence times for paleoclimate records based on vascular plant biomarkers.en
dc.description.sponsorshipThe scientific analyses described herein were funded by the National Science Foundation through grants OCE-9907129 (T.I.E.), OCE-052626800 (T.I.E.), OCE- 0137005 (T.I.E. and K.A.H.), DEB-0447281 (K.A.H.), and the Stanley Watson Chair for Excellence in Oceanography (T.I.E.). N.J.D.’s tuition and stipend were supported by the graduate fellowships from the Stanley Watson Foundation, Schlanger Ocean Drilling Program, and Environmental Protection Agency’s Science to Achieve Results (STAR) Program, as well as by the WHOI Academic Programs Office.en
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen
dc.publisherMassachusetts Institute of Technology and Woods Hole Oceanographic Institutionen
dc.relation.ispartofseriesWHOI Thesesen
dc.subjectCarbonen_US
dc.subjectCoastal sedimentsen_US
dc.subjectNew Horizon (Ship) Cruiseen_US
dc.subjectHermano Gines (Ship) Cruiseen_US
dc.subjectClifford A. Barnes (Ship) Cruiseen_US
dc.titleThe temporal dynamics of terrestrial organic matter transfer to the oceans : initial assessment and applicationen
dc.typeThesisen
dc.identifier.doi10.1575/1912/1736


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