Dating the Anthropocene in deep-sea sediments: how much carbon is buried in the Irminger Basin?

• Published in: Global and Planetary Change
• Main Authors: Fontela, Marcos, Francés, Guillermo, Quintana, Begoña, Álvarez-Fernández, María Jesús, Nombela, Miguel Ángel, Alejo, Irene, Pedrosa, M. C., Pérez, Fiz F.
• Other Authors: Ministerio de Economía y Competitividad (España)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2019
• Subjects: Deep-sea sedimentation rate; Subpolar North Atlantic; Irminger Basin; Carbon sink; Geochronology; Anthropocene; North Atlantic
• Online Access: http://hdl.handle.net/10261/177615; https://doi.org/10.1016/j.gloplacha.2019.02.008; https://doi.org/10.13039/501100003329

31 pages, 5 figures. Evaluation of biogeochemical processes in Anthropocene deep-sea sediments require accurate dating techniques. Here we show the results of an approach using high resolution low level background gamma spectrometry with two simultaneous hyper-pure germanium (HPGe) detectors. The quantitative role of the deepest zones (>3000 m depth) of the Irminger Basin (Subpolar North Atlantic Ocean) as a carbon sink during the Anthropocene is evaluated combining a chronology based in the natural radionuclide 210Pb with sedimentological analysis and elemental composition. The average sedimentation rate of the central Irminger is 1.28 ± 0.18 mm·yr−1, with a mean weighted flux to the sediment for inorganic and organic carbon of 46 ± 15 g·Cinorg·m−2·yr−1 and 8 ± 1 g·Corg·m−2·yr−1. The biogenic fraction of the mass flux is increased since the XXth century. The contribution of the deepest zones of the Irminger Basin to the Anthropocene carbon sequestration in the North Atlantic Ocean is considerable at basin-scale. For this work M. Fontela was funded by the Spanish Ministry of Economy and Competitiveness through the BOCATS project supported by the Spanish Government. Peer reviewed