(Table 2) Annual mass fluxes, 230Th composition and organic geochemistry of sediment trap samples in the South Altantic ...

• Main Authors: Walter, Hans-Jürgen, Rutgers van der Loeff, Michiel M
• Format: Dataset
• Language: English
• Published: PANGAEA 2001
• Subjects: Latitude of event; Longitude of event; Event label; DEPTH, water; DATE/TIME; Date/time end; Duration, number of days; Total, flux per year; Opal, biogenic silica; Carbon, organic, total; Calcium carbonate; Organic matter, particulate; Terrigenous; Thorium-230 excess; Thorium-230 excess, standard deviation; Thorium, flux; Thorium, flux, standard deviation; Protactinium-231 excess; Protactinium-231 excess, standard deviation; Protactinium-231, flux; Protactinium-231, flux, standard deviation; Protactinium-231/Thorium-230 excess; Protactinium-231/Thorium-230 excess, standard deviation; Comment; Mooring long time; Trap; Trap, sediment; Element analyser CHN; Alpha spectrometry; Calculated; ANT-VIII/2; ANT-IX/3; ANT-IX/2; ANT-VIII/3; Polarstern; Marine Geochemistry @ AWI AWI_MarGeoChem; Paleoenvironmental Reconstructions from Marine Sediments @ AWI AWI_Paleo; Silicon Cycling in the World Ocean SINOPS; Austral; Bouvet; Bouvet Island; Southern Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.57910; https://doi.pangaea.de/10.1594/PANGAEA.57910

The scavenging of 231Pa and 230Th was investigated in the Atlantic Sector of the Southern Ocean by combining results from sediment trap and in situ filtration studies. We present the first high-resolution profile of dissolved 230Th and 231Pa in surface waters across the ACC, showing a dramatic southward increase of both radionuclides around the southern ACC Front at 533S. High dissolved 231Pa/230Th ratios combined with low 230Th/231Pa fractionation factors (F) in these surface waters result in extremely high 231Pa94/230Th94 ratios of material collected in the shallow traps. Particulate 231Pa94/230Th94 ratios in a shallow trap near Bouvet Island increase continuously during the productive period in austral summer, and drop back in the low flux period. This behavior, following the Rayleigh fractionation principle, is interpreted to be due to an increase in the dissolved 231Pa/230Th ratio in the euphotic zone resulting from preferential scavenging of 230Th relative to 231Pa, even in opal-dominated regions. In ... : Supplement to: Walter, Hans-Jürgen; Geibert, Walter; Rutgers van der Loeff, Michiel M; Fischer, Gerhard; Bathmann, Ulrich (2001): Shallow vs. deep-water scavenging of 231Pa and 230Th in radionuclide enriched waters of the Atlantic sector of the Southern Ocean. Deep Sea Research Part I: Oceanographic Research Papers, 48(2), 471-493 ...