(Table S1) Diatom abundance according to ice cycles in ANDRILL AND1-1B drill core ...

• Main Authors: McKay, Robert M, Naish, Tim R, Carter, Lionel, Riesselman, Christina R, Dunbar, Robert G, Winter, Diane M, Sjunneskog, Charlotte, Sangiorgi, Francesca, Warren, Courtney E, Pagani, Mark, Schouten, Stefan, Willmott, Verónica, Levy, Richard H, DeConto, Robert M, Powell, Ross
• Format: Dataset
• Language: English
• Published: PANGAEA 2012
• Subjects: DEPTH, sediment/rock; Cycles; Actinocyclus actinochilus; Fragilariopsis curta; Fragilariopsis cylindrus; Fragilariopsis obliquecostata; Fragilariopsis ritscheri; Fragilariopsis sublinearis; Porosira pseudodenticulata; Stellarima microtrias; Thalassiosira antarctica; Thalassiosira tumida; Fragilariopsis kerguelensis; Rhizosolenia spp.; Rouxia antarctica; Thalassiosira lentiginosa; Thalassiosira oliverana; Thalassiothrix antarctica; Trichotoxon reinboldii; Stellarima stellaris; Thalassionema nitzschioides; Shionodiscus tetraoestrupii; Chaetoceros spp.; Diatoms indeterminata; Drilling/drill rig; Counting, diatoms; MIS; McMurdo Station; International Polar Year 2007-2008 IPY; Antarc*; Antarctic; Antarctica; Ice Sheet; Ice Shelf; International Polar Year; IPY; North Atlantic; Ross Ice Shelf; Ross Sea; Sea ice; Southern Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.816030; https://doi.pangaea.de/10.1594/PANGAEA.816030

The influence of Antarctica and the Southern Ocean on Late Pliocene global climate reconstructions has remained ambiguous due to a lack of well-dated Antarctic-proximal, paleoenvironmental records. Here we present ice sheet, sea-surface temperature, and sea ice reconstructions from the ANDRILL AND-1B sediment core recovered from beneath the Ross Ice Shelf. We provide evidence for a major expansion of an ice sheet in the Ross Sea that began at ~3.3 Ma, followed by a coastal sea surface temperature cooling of ~2.5°C, a stepwise expansion of sea ice, and polynya-style deep mixing in the Ross Sea between 3.3 and 2.5 Ma. The intensification of Antarctic cooling resulted in strengthened westerly winds and invigorated ocean circulation. The associated northward migration of Southern Ocean fronts has been linked with reduced Atlantic Meridional Overturning Circulation by restricting surface water connectivity between the ocean basins, with implications for heat transport to the high latitudes of the North Atlantic. ... : A minimum of 300 valves were counted in each sample at a magnification of 600×. A magnification of 1,000× was used to confirm species identifications. For centric diatoms, a specimen was counted as 'one' if the central area and a portion of the margin could be identified, or if at least one-half of the valve was preserved. For pennate diatoms, each identifiable apex was counted as 'one-half', and the total count for each species was divided by two before relative abundance percentages were calculated. Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150 ...