Radionuclides measured on water bottle samples ...

• Main Authors: Geibert, Walter, Rutgers van der Loeff, Michiel M, Hanfland, Claudia, Dauelsberg, Hans-Jürgen
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2002
• Subjects: CTD/Rosette; MultiCorer; In situ pump; ANT-XVI/3; ARK-VIII/3; ANT-X/5; ANT-XI/4; ANT-XII/4; Polarstern; Joint Global Ocean Flux Study JGOFS; Marine Geochemistry @ AWI AWI_MarGeoChem; Paleoenvironmental Reconstructions from Marine Sediments @ AWI AWI_Paleo; Antarctic; Arctic; Pacific; Southern Ocean; The Antarctic; Weddell; Antarc*
• Online Access: https://dx.doi.org/10.1594/pangaea.761951; https://doi.pangaea.de/10.1594/PANGAEA.761951

Actinium is one of the rarest naturally occurring elements on earth. We measured its longest-lived isotope 227Ac (half-life 21.77 yr) for the first time in the water column of the Southeast Pacific, the Central Arctic, the Antarctic Circumpolar Current (ACC) and the Weddell Gyre (WG). Besides the profile in the Southeast Pacific, which confirms earlier findings about the role of diapycnal mixing for 227Ac distribution, we found three other different types of vertical profiles. These profiles point to a prominent role of advection for 227Ac distribution, especially in the Southern Ocean. Depending on the type of profile found, 227Ac is proposed as a tracer for different oceanographic questions. In the Southern Ocean, up to 4.93±0.32 dpm/m**3 227Ac is found close to the sea floor, which is the highest concentration ever observed in the ocean. Close to the sea surface in the WG, 0.46±0.05 dpm/m**3 227Acex (227Ac in excess of its progenitor 231Pa) is detected. We use 227Acex there to determine the upwelling ... : Supplement to: Geibert, Walter; Rutgers van der Loeff, Michiel M; Hanfland, Claudia; Dauelsberg, Hans-Jürgen (2002): Actinium-227 as a Deep-Sea Tracer: Sources, Distribution and Applications. Earth and Planetary Science Letters, 198(1-2), 147-165 ...