Dissolved neodymium isotopes in the Mediterranean Sea
In: ISSN: 0016-7037, 2022
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International audience ; The neodymium isotopic composition (ε Nd ) of seawater is one of the most important geochemical tracers to investigate water mass provenance, which can also serve as a proxy to reconstruct past variations in ocean circulation. Nd isotopes have recently also been used to reconstruct past circulation changes in the Mediterranean Sea on different time scales. However, the modern seawater ε Nd dataset for the Mediterranean Sea, which these reconstructions are based on, is limited and up to now only 160 isotopic measurements are available for the entire basin. The lack of present-day data also limits our understanding of the processes controlling the Nd cycle and Nd isotopic distribution in this semi-enclosed basin. Here we present new ε Nd data from 24 depth profiles covering all Mediterranean sub-basins, which significantly increases the available dataset in the Mediterranean Sea. The main goal of our study is to better characterize the relationship between the dissolved Nd isotope distributions and major water masses in the Mediterranean Sea and to investigate the impact and relative importance of local non-conservative modifications, which include input of riverine particles and waters, aeolian-derived material and exchange with the sediments at continental margins. This comprehensive ε Nd dataset reveals a clear ε Nd - salinity correlation and a zonal and depth gradient with ε Nd systematically increasing from the western to the eastern Mediterranean basin (average ε Nd = -8.8 ± 0.8 and -6.7 ± 1 for the entire water column, respectively), reflecting the large-scale basin circulation. We have evaluated the conservative ε Nd behaviour in the Mediterranean Sea and quantified the non-conservative components of the ε Nd signatures by applying an Optimum Multiparameter (OMP) analysis and results from the Parametric Optimum Multiparameter (POMP) analysis of Jullion et al. (2017). The results of the present study combined with previously published Nd isotope values indicate that dissolved ε Nd .
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Dissolved neodymium isotopes in the Mediterranean Sea
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| Autor/in / Beteiligte Person: | Montagna, Paolo ; Colin, Christophe ; Frank, Martin ; Störling, Tjördis ; Tanhua, Toste ; Rijkenberg, Micha J. A. ; Taviani, Marco ; Schroeder, Katrin ; Chiggiato, Jacopo ; Gao, Guohui ; Dapoigny, Arnaud ; Goldstein, Steven L. ; Institute of Polar Sciences Venezia-Mestre (CNR-ISP) ; National Research Council of Italy ; Lamont-Doherty Earth Observatory (LDEO) ; Columbia University New York ; Géosciences Paris Saclay (GEOPS) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) ; Helmholtz Centre for Ocean Research Kiel (GEOMAR) ; Department of Geology Lund ; Skane University Hospital Lund ; Royal Netherlands Institute for Sea Research (NIOZ) ; Universiteit Utrecht / Utrecht University Utrecht ; Biology Department (WHOI) ; Woods Hole Oceanographic Institution (WHOI) ; Stazione Zoologica Anton Dohrn (SZN) ; Istituto di Scienze Marine Venezia (ISMAR-CNR) ; Istituto di Science Marine (ISMAR ) ; Université Paris Cité (UPCité) ; Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE) ; Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) ; Géochrononologie Traceurs Archéométrie (GEOTRAC) ; Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS) ; The research leading to this paper was funded by the French National Research Agency under the “Investissements d'avenir” programme (Grant number ANR-11-IDEX-0004-17-EURE-0006) and the INSU LEFE-IMAGO PALMEDS Project. P. Montagna gratefully acknowledges the Marie Curie International Outgoing Fellowship (Grant agreement 219607, MEDAT-ARCHIVES) for providing financial support at LDEO and is also indebted to L. Pena, Y. Cai and N. Frank for introducing him to the neodymium isotope measurements. Micha Rijkenberg was supported by the Netherlands Organization for Scientific Research (NWO) (Grant number 822.01.015, GEOTRACES, the biogeochemical cycles of bioessential trace metals and isotopes in the Mediterranean Sea and Black Sea). Thanks are also extended to the captains, crews, chief scientists, and scientific parties of oceanographic cruises Medcor (December 2008 ; Captain: Vincenzo Lubrano Lavadera), Arcadia (March-April 2010 ; Captain: Vincenzo Lubrano Lavadera) and Record (November 2013 ; Captain: Emanuele Gentile) onboard R/V Urania, Meteor 84/3 (April 2011 ; Captain: Thomas Wunderlich) onboard R/V Meteor and MedBlack GEOTRACES 64PE370 (May-June 2013 ; Captain: Pieter Kuijt) and 64PE374 (July-August 2013 ; Captain: Pieter Kuijt) onboard R/V Pelagia. We gratefully acknowledge Mohamed Ayache and Jean-Claude Dutay for providing the model data to produce Fig. 10, Fig. 11. This manuscript benefited from constructive suggestions by four anonymous reviewers and the Associate Editor Karen H. Johannesson. Article finalized and submitted at the time of the Covid-19 pandemics. This is ISMAR-CNR Bologna scientific contribution number 2034. ; ANR-11-IDEX-0004,SUPER,Sorbonne Universités à Paris pour l'Enseignement et la Recherche(2011) ; ANR-17-EURE-0006,IPSL-CGS,IPSL Climate graduate school(2017) |
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| Zeitschrift: | ISSN: 0016-7037, 2022 |
| Veröffentlichung: | HAL CCSD ; Elsevier, 2022 |
| Medientyp: | academicJournal |
| ISSN: | 0016-7037 |
| DOI: | 10.1016/j.gca.2022.01.005 |
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