Ocean – ice sheet interaction in West Antarctica: First results from core-log seismic integration in the Amundsen Sea Sector

• Main Authors: Gille-Petzoldt, Johanna, Gohl, Karsten, Uenzelmann-Neben, Gabriele, Klages, Johann Philipp
• Format: Conference Object
• Language: unknown
• Published: 2021
• Subjects: Amundsen Sea; Antarc*; Antarctic; Antarctica; Bellingshausen Sea; Ice Sheet; Ice Shelf; West Antarctica
• Online Access: https://epic.awi.de/id/eprint/53779/; https://hdl.handle.net/10013/epic.7592e695-b80a-4bcc-adae-219654eaace3

Throughout past decades, the West Antarctic Ice Sheet (WAIS) reacted increasingly sensitive to ocean and atmospheric forcing resulting in increased ice shelf thinning, accelerated ice flow and grounding line retreat. Its future stability therefore remains to be a critical unknown in global climate projections. In order to evaluate the threat of a potential future partial or full WAIS disintegration, reliable information on past ice sheet dynamics and its interaction with oceanic processes is essential for calibrating and improving such future projections, particularly for periods in earth’s past that were warmer than present and thus may serve as analogues for projected future scenarios. However, information on past ice sheet dynamics and interaction with ocean circulation processes in the Amundsen Sea sector, a key area for understanding past and present WAIS stability, are scarce. During the International Ocean Discovery Program (IODP) Expedition 379, sediment cores covering those critical periods were recovered at two sites on the Amundsen Sea continental rise. Those nearly continuous late Miocene-Pleistocene records are located on a seismic network allowing for a regional horizon correlation and seismic sequence characterization by applying core-log seismic integration. The sediment records provide insight into a large sediment drift and further enable comparison to other Amundsen and Bellingshausen Sea drift bodies by seismic correlation. The results of the core-log seismic integration with synthetic seismogram calculation are used to correlate key seismic horizons, e.g. prominent boundaries between Miocene and Pliocene, mid-Pliocene as well as Pliocene and Pleistocene. They may further allow statements about variations in sediment deposition and transport activity related to past ice sheet dynamics