Phosphorus burial in the ocean over glacial-interglacial time scales

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doi: 10.5194/bg-6-501-2009
Author(s): Tamburini, Federica; Föllmi, Karl B.
Author Affiliation(s): Primary:
ETH Zürich, Geologisches Institut, Zurich, Switzerland
Other:
Université de Neuchâtel, Switzerland
Volume Title: Biogeosciences
Source: Biogeosciences, 6(4), p.501-513. Publisher: Copernicus GmbH on behalf of the European Union, Katlenburg-Lindau, International. ISSN: 1726-4170
Note: In English. Includes supplement, http://www.biogeosciences.net/6/501/2009/bg-6-501-2009-supplement.pdf; published in Biogeosciences Discussion: 18 December 2008, http://www.biogeosciences-discuss.net/5/5133/2008/bgd-5-5133-2008.html; accessed in February, 2010. 62 refs.; illus., incl. 3 tables
Summary: The role of nutrients, such as phosphorus (P), and their impact on primary productivity and the fluctuations in atmospheric CO2 over glacial-interglacial periods are intensely debated. Suggestions as to the importance of P evolved from an earlier proposal that P actively participated in changing productivity rates and therefore climate change, to most recent ones that changes in the glacial ocean inventory of phosphorus were important but not influential if compared to other macronutrients, such as nitrate. Using new data coming from a selection of ODP sites, we analyzed the distribution of oceanic P sedimentary phases and calculate reactive P burial fluxes, and we show how P burial fluxes changed over the last glacial-interglacial period at these sites. Concentrations of reactive P are generally lower during glacial times, while mass accumulation rates (MAR) of reactive P show higher variability. If we extrapolate for the analyzed sites, we may assume that in general glacial burial fluxes of reactive P are lower than those during interglacial periods by about 8%, because the lack of burial of reactive P on the glacial shelf reduced in size, was apparently not compensated by burial in other regions of the ocean. Using the calculated changes in P burial, we evaluate their possible impact on the phosphate inventory in the world oceans. Using a simple mathematical approach, we find that these changes alone could have increased the phosphate inventory of glacial ocean waters by 17-40% compared to interglacial stages. Variations in the distribution of sedimentary P phases at the investigated sites seem to indicate that at the onset of interglacial stages, shallower sites experienced an increase in reactive P concentrations, which seems to point to P-richer waters at glacial terminations. All these findings would support the Shelf-Nutrient Hypothesis, which assumes that during glacial low stands nutrients are transferred from shallow sites to deep sea with possible feedback on the carbon cycle.
Year of Publication: 2009
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 24 Surficial Geology, Quaternary Geology; Arabian Sea; Arctic Ocean; Atlantic Ocean; Atmospheric transport; Carbon; Carbon cycle; Carbon dioxide; Cenozoic; Climate change; Deep-sea environment; East Pacific; Equatorial Pacific; Geochemical cycle; Geochemistry; Glacial environment; Indian Ocean; Inorganic materials; Interglacial environment; Japan Sea; Leg 108; Leg 112; Leg 117; Leg 128; Leg 130; Leg 184; Marine environment; North Atlantic; North Pacific; Northwest Pacific; Norwegian Sea; ODP Site 1143; ODP Site 1144; ODP Site 658; ODP Site 680; ODP Site 724; ODP Site 798; ODP Site 806; ODP Site 907; Ocean Drilling Program; Oki Ridge; Ontong Java Plateau; Organic compounds; Pacific Ocean; Paleoclimatology; Phosphorus; Quaternary; Sedimentation; Shelf environment; Shelf-Nutrient Hypothesis; South China Sea; South Pacific; Southeast Pacific; Transport; West Pacific; World ocean
Coordinates: S110354 S110354 W0780436 W0780436
N204457 N204457 W0183451 W0183451
N691459 N691459 W0124154 W0124154
N182742 N182743 E0574709 E0574708
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N092143 N092143 E1131707 E1131707
N370218 N370218 E1344759 E1344758
N001906 N001907 E1592142 E1592140
Record ID: 2010078415
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from Copernicus Gesellschaft, Katlenburg-Lindau, Germany