Accumulation rates of bulk sediment and opal in surface sediments of the South Atlantic

• Main Authors: Geibert, Walter, Rutgers van der Loeff, Michiel M, Usbeck, Regina, Gersonde, Rainer, Kuhn, Gerhard, Seeberg-Elverfeldt, Jens
• Format: Dataset
• Language: English
• Published: PANGAEA 2005
• Subjects: Agulhas Basin; ANT-IX/2; ANT-IX/3; ANT-V/4; ANT-VI/3; ANT-VIII/3; ANT-X/5; ANT-X/6; ANT-XI/4; ANT-XII/4; ANT-XVIII/5a; ANT-XX/2; Area/locality; Atka Bay; Atlantic Ridge; AWI_MarGeoChem; AWI_Paleo; Barents Sea; Biogenic silica; flux; Bulk sediment; Calculated; Camp Norway; Comment; Cosmonauts Sea; CTD/Rosette; CTD-RO; DEPTH; sediment/rock; Eastern Weddell Sea; Southern Ocean; Elevation of event; Event label; Filchner Trough; Giant box corer; GKG; Gravity corer (Kiel type); Halley Bay; Indian-Antarctic Ridge; Indian Ocean; Kapp Norvegia; KL; Latitude of event; Lazarev Sea; Longitude of event; Lyddan Island; Marine Geochemistry @ AWI; Maud Rise; Measured; Antarc*; Antarctic; Cosmonauts sea; Weddell Sea
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.230042; https://doi.org/10.1594/PANGAEA.230042

A set of 114 samples from the sediment surface of the Atlantic, eastern Pacific and western Indian sectors of the Southern Ocean has been analyzed for 230Th and biogenic silica. Maps of opal content, Th-normalized mass flux, and Th-normalized biogenic opal flux into the sediment have been derived. Significant differences in sedimentation patterns between the regions can be detected. The mean bulk vertical fluxes integrated into the sediment in the open Southern Ocean are found in a narrow range from 2.9 g/m**2 yr (Eastern Weddell Gyre) to 15.8 g/m**2 yr (Indian sector), setting upper and lower limits to the vertically received fraction of open ocean sediments. The silica flux to sediments of the Atlantic sector of the Southern Ocean is found to be 4.2 ± 1.4 * 10**11 mol/yr, just one half of the last estimate. This adjustment represents 6% of the output term in the global marine silica budget.