Pre-Last Glacial Maximum glaciations in the Barents Sea: seismic investigations

• Main Author: Alexandropoulou, Nikolitsa
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: UiT Norges arktiske universitet 2024
• Subjects: DOKTOR-004; Barents Sea; Bear Island; Svalbard; Barentshav*; Sea ice
• Online Access: https://hdl.handle.net/10037/34515

The main objective of this PhD thesis is to improve understanding of the evolution of pre-Last Glacial Maximum Barents Sea glaciations through the study of glacial deposits from the continental margin using 3D and 2D seismic reflection data. Paper 1 presents a new chronostratigraphic framework, covering the last ∼2.7 Ma, for the Svalbard-Barents Sea margin, using 2D seismic data to extend available ages from sediment cores along the entire 1000 km long margin. This high-temporal-resolution framework was then used to study the evolution of ice sheets in the Barents Sea since ∼2.7 Ma, allowing comparison along the entire margin in a wider regional perspective. In Paper 2, the chronological framework was then used to, for the first time, differentiate glacigenic sediments deposited on the SW Barents Sea continental margin during the Late Saalian (∼0.2 - 0.13 Ma) and Weichselian (<∼0.123 Ma) glacial periods, providing new insights into the evolution and dynamics of Barents Sea ice sheets during these two most recent glaciations. Finally, in Paper 3, recently acquired 3D seismic data on the outer part of the Bjørnøyrenna (Bear Island Trough) was exploited to investigate the interaction of glacial processes, fluid flow, and gas hydrate systems on the SW Barents Sea margin over successive periods of ice advance and retreat during the Quaternary period. Hovedmålet med denne doktorgradsavhandlingen er å forbedre forståelsen av utviklingen av istider i Barentshavet før siste glasiale maksimum gjennom studier av breavsetninger fra kontinentalmarginen ved å bruke 3D og 2D seismiske refleksjonsdata. Artikkel 1 presenterer et nytt kronostratigrafisk rammeverk som dekker de siste ~2.7 Ma for Svalbard-Barentshavmarginen, basert på 2D seismiske data hvilket utvider tilgjengelige stratigrafiske aldre fra sedimentkjerner langs hele den 1000 km lange marginen. Rammeverket med høy temporal oppløsning ble deretter brukt til å studere utviklingen av isdekker i Barentshavet siden ~2.7 Ma, noe som muliggjorde sammenligning langs ...