Using novel methods to track British and Irish Ice Sheet dynamics since the Late Pleistocene, along the west Porcupine Bank, NE Atlantic

• Published in: Quaternary Science Reviews
• Main Authors: O'Reilly, Luke, Lim, Aaron, Titschack, Jürgen, Moore, Niamh, O'Connor, O, J, Appah, John, Fentimen, Robin, Butschek, Felix, Harris, Kimberley, Vennemann, Torsten, Wheeler, Andrew, J
• Other Authors: University College Cork (UCC), Center for Marine Environmental Sciences Bremen (MARUM), Universität Bremen, Laboratoire de Planétologie et Géosciences UMR_C 6112 (LPG), Le Mans Université (UM)-Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Université de Lausanne = University of Lausanne (UNIL)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: Quaternary North-east Atlantic Sedimentology-marine cores Ice-rafted debris Palaeoceanography British-Irish ice sheet (BIIS); [SDE.MCG]Environmental Sciences/Global Changes; Ice Sheet; North East Atlantic
• Online Access: https://univ-angers.hal.science/hal-04278626; https://univ-angers.hal.science/hal-04278626/document; https://univ-angers.hal.science/hal-04278626/file/1-s2.0-S0277379122000944-main.pdf; https://doi.org/10.1016/j.quascirev.2022.107463

International audience Extensive research has been undertaken to elucidate the glacial history of the British Irish Ice Sheet (BIIS)in the NE Atlantic. BRITICE-CHRONO has compiled terrestrial and marine based evidence, to provide anempirical reconstruction of ice sheet expansion and retreat during the Late Pleistocene. Across the Irishmargin, particular focus has been given to seafloor sediments which contain ice-rafted debris (IRD).However, there are few publications on IRD from areas proximal to the maximum extent of the BIIS,which would offer further insights on the behaviour of the ice sheet during (de)glacial events. Previousexploratory surveys of the west Porcupine Bank (wPB) visually identified IRD on the seafloor and thesepresent a new study site to investigate the extent of the BIIS and the course of its icebergs. Moreover,there are uncertainties about the effects of icebergs on the marine life and cold-water corals occupyingthe nearby Porcupine Bank Canyon. Assessing a sediment core containing an IRD analogue for the wPBwould thus, have a dual purpose. In the past however, coring missions of the wPB using traditional coringmethods (i.e. piston and gravity cores) were unsuccessful. Here, we utilized a novel ROV-mountedvibrocoring procedure to capture a 0.75 m IRD-bearing sediment core from the wPB. Then furthernovel analytical methods (computed tomography-based IRD-detection) were used to quantify IRD every0.02 cm to provide the highest resolution record of BIIS related IRD to date. From this, several fluxes ofIRD deposition onto the wPB between 31.6 and 9 ka BP were revealed and corroborated by other publishedrecords from across the NE Atlantic. It was shown that the wPB IRD fluxes occur simultaneouslywith other parts of the margin. The IRD signal also shows that iceberg calving occurred on the wPBduring the Younger Dryas. Grain-size analysis of the core allowed for a reconstruction and interpretationof the palaeoenvironmental conditions during these IRD flux events and shows that BIIS-derived ...