Drift bodies in the Prydz Bay Region - a tool to understand the interplay of Antarctic currents and warm and cold periods

• Main Authors: Nielsen, Ricarda, Uenzelmann-Neben, Gabriele
• Format: Conference Object
• Language: unknown
• Published: 2018
• Subjects: Amery Ice Shelf; Antarc*; Antarctic; Cooperation Sea; Ice Sheet; Ice Shelf; Prydz Bay
• Online Access: https://epic.awi.de/id/eprint/48196/; https://hdl.handle.net/10013/epic.90515552-ec45-481e-be3f-ee96dad2d08a

The Antarctic Circumpolar Current (ACC) is a massive ocean current and believed to have had a major impact on climate since the late Eocene/early Oligocene. However, its pathway, spatial extent in relation to climate variability and possible regional changes during warm and cold periods are still hardly understood although several models exist. In addition, questions concerning its interactions with and effect on the adjacent Antarctic Slope Current (ASC) and the Antarctic Divergence (AD) are not solved yet. The Prydz Bay/Cooperation Sea area provides a perfect setting to study spatial and temporal changes of the ACC, the ASC and the AD due to the spatial limitations by the southern Kerguelen Plateau in the Northwest. The plateau acts as a northern barrier for the ACC and narrows its path through the Princess Elizabeth Trough. In the south, Prydz Bay has been massively impacted by the advance and retreat of the Amery Ice shelf during warm and cold periods. We have studied the deposition and accumulation history of the Wild drift, the Wilkins drift and the surrounding deep sea in detail by interpreting over 50000 km of multi-channel seismic reflection data in a pseudo 3D-image. Lithology and age information from various ODP Sites were incorporated. We aim to provide a detailed reconstruction model of the prevailing currents, and the interplay of ice sheet dynamics, climate changes and oceanic circulation in the Prydz Bay/Cooperation Sea area during the early Oligocene to the Quaternary. First results suggest onset of a drift formation in the early Oligocene and major changes during warm periods with intensification of currents and ice retreat prior to the Miocene Climatic Optimum. Differences in the seismostratigraphic pattern point towards a shift of the material sources, depending on cold or warm periods and suggest an interplay between down-slope, i.e., ice sheet driven input versus along-slope, i.e., current controlled sediment transport during the Miocene.