Preliminary results of planktonic foraminifera and other oceanographic proxies in push cores of the Flemish Pass

• Main Authors: Pérez-Rodríguez, Irene, Papachristopoulou, Eirini, Covadonga Orejas, Thornalley, David
• Format: Conference Object
• Language: unknown
• Published: Zenodo 2021
• Subjects: Ortega; Labrador Sea; Neogloboquadrina pachyderma; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.5281/zenodo.5572646; https://zenodo.org/record/5572646

Foraminifera and other palaeoceanographic proxies found in 3 push cores sediments collected from the Flemish Pass are being analysed. Based on radiometric dating of the radionuclides 210 Pb, 226 Ra, 137 Cs and 241 Am, a preliminary age model was calculated and extrapolated to the successions, suggesting that the sediments could have been deposited during the last 500 years. This chronology will be validated by radiocarbon data. The planktonic foraminifera analysis shows that all three cores contain assemblages dominated by the polar species Neogloboquadrina pachyderma , and they all display a relative decrease of the aforementioned species towards the top, probably related to the current global warming. However, there are differences among the three settings: 1) The core located in the north rim of the Flemish Pass shows a very high proportion of ice rafted debris, suggesting a high influence of icebergs discharges. 2) The core located in a central position within the Flemish Pass shows quite stable counts of planktonic foraminifera, indicating that this portion of the basin has been under a steady influence of the Labrador Current. 3) The core located in the south rim of the Flemish Pass shows an increase on the abundance of N. pachyderma from 15cm-15.5cm depth, suggesting a superficial water cooling. This core is closest to the boundary between the Gulf Stream and Labrador Current. Hence, the cooling may suggest an increased influence of the Labrador Current during the industrial era, consistent with published results from a nearby core (Thornalley et al., 2018). D.J.R. Thornalley, D.W. Oppo, P. Ortega, J.I. Robson, C.M. Brierley, R. Davis, I.R. Hall, P. Moffa-Sanchez, N.L. Rose, P.T. Spooner, I. Yashayaev & L.D. Keigwin (2018). Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years. Nature, https://doi.org/10.1038/s41586-018-0007-4.