Bulk and diatom-bound nitrogen isotope ratios, opal, TOC, and TN from ODP Hole 178-1098B ...

• Main Authors: Jones, Colin, Kelly, Roger P, Robinson, Rebecca S
• Format: Dataset
• Language: English
• Published: PANGAEA 2020
• Subjects: Carbon; CDW; circumpolar deep water; Diatom; diatoms; mid-holocene; nitrogen; nitrogen isotope ratios; nitrogen isotopes; Paleoceanography; sediment; Southern Ocean; Stratification; Upwelling; WAP; West Antarctic Peninsula; Sample code/label; Depth, composite; AGE; Opal, biogenic silica; Opal, biogenic silica, standard deviation; Carbon, organic, total; Carbon, organic, total, standard deviation; Nitrogen, total; Nitrogen, total, standard deviation; δ15N, bulk sediment; δ15N, bulk sediment, standard deviation; δ15N, diatom-bound organic matter; δ15N, diatom-bound organic matter, standard deviation; Drilling/drill rig; DSDP/ODP/IODP sample designation; Age model, Domack et al. 2001; Element analyser CHNSO, Costech ECS 4010; Mass spectrometer Delta V; Leg178; Joides Resolution; Antarctic; Antarctic Peninsula; Palmer Deep; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.1594/pangaea.925205; https://doi.pangaea.de/10.1594/PANGAEA.925205

Intense seasonal productivity and carbon drawdown on the West Antarctic Peninsula (WAP) is driven by upwelling of nutrient-rich Circumpolar Deep Water (CDW) and subsequent stratification. CDW influence on the WAP is thought to have varied dramatically during the mid-Holocene, 5-7 ka. Here, we use diatom-bound nitrogen isotopes (δ15NDB), a nutrient utilization proxy, from ODP Site 1098 in Palmer Deep to study variations in the presence of CDW on sub-millennial timescales in the mid-Holocene. CDW intrusion is synchronous with atmospheric warming over Antarctica, suggesting that stronger and/or more southerly Southern Hemisphere westerlies enhanced CDW intrusion onto the WAP shelf. Our results also suggest that bulk sedimentary nitrogen isotopes (δ15Nbulk) do not track the same processes as δ15NDB at this site and that this cannot be explained by changes in diatom assemblages. ...