Biogenic opal estimation of deep-sea sediment cores from the Scotia Sea ...

• Main Authors: Sprenk, Daniela, Weber, Michael E, Kuhn, Gerhard, Rosén, Peter, Frank, Martin, Molina-Kescher, Mario, Liebetrau, Volker, Röhling, Heinz-Gerd
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2013
• Subjects: International Marine Global Change Study IMAGES; Antarc*; Antarctic; Scotia Sea; Sea ice; Southern Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.789348; https://doi.pangaea.de/10.1594/PANGAEA.789348

We present biogenic opal flux records from two deep-sea sites in the Scotia Sea (MD07-3133 and MD07-3134) at decadal-scale resolution, covering the last glacial cycle. Besides conventional and time-consuming biogenic opal measuring methods, we introduce new biogenic opal estimation methods derived from sediment colour b*, wet bulk density, Si/Ti-count ratio, and Fourier transform infrared spectroscopy (FTIRS). All methods capture the biogenic opal amplitude, however, FTIRS - a novel method for marine sediment - yields the most reliable results. 230Th normalization data show strong differences in sediment focusing with intensified sediment focusing during glacial times. At MD07-3134 230Th normalized biogenic opal fluxes vary between 0.2 and 2.5 g/cm2/kyr. Our biogenic opal flux records indicate bioproductivity changes in the Southern Ocean, strongly influenced by sea ice distribution and also summer sea surface temperature changes. South of the Antarctic Polar Front, lowest bioproductivity occurred during the ... : Supplement to: Sprenk, Daniela; Weber, Michael E; Kuhn, Gerhard; Rosén, Peter; Frank, Martin; Molina-Kescher, Mario; Liebetrau, Volker; Röhling, Heinz-Gerd (2013): Southern Ocean bioproductivity during the last glacial cycle - new detection method and decadal-scale insight from the Scotia Sea. Geological Society of London, special issue: Palaeoenvironments and Earth-Surface Processes, 381(1), 245-261 ...