Rapid environmental changes in the Ross Sea Embayment using a geochemical approach

• Main Author: Monien, Donata
• Format: Thesis
• Language: unknown
• Published: Univ. Bremen 2010
• Subjects: Antarc*; Antarctic; Ice Sheet; Ice Shelf; McMurdo Ice Shelf; Ross Ice Shelf; Ross Sea
• Online Access: https://epic.awi.de/id/eprint/52116/; https://media.suub.uni-bremen.de/handle/elib/2851; https://hdl.handle.net/10013/epic.4e8228c1-4f4d-433a-a3a4-aa3e8abffd69

Enhanced glacier and polar ice sheet melting during the last decades is one of the major focuses of geosciences. The understanding of the effects of future global warming is important due to raising sea level. Antarctic ice masses play a key role in global climate. Melting of Antarctic ice would result in a sea level rise of about ~3-6 m due to the West Antarctic Ice Sheet and 60 m due to the East Antarctic Ice Sheet. Because of its marine-based nature, especially the West Antarctic Ice Sheet is sensitive to rising temperatures. Additionally, the Ross Sea, as a part of the west Antarctic system, and its shelf are a key region stabilizing the west Antarctic ice masses. It is thus essential to understand the processes and changes in this area in order to interpret the past and predict the future climate developments. Sedimentary archives are a unique opportunity to get insights into past climate variability and the ice response due to increased temperature (~3°C), as the earth had experienced in the last 14 Ma since the mid Miocene cooling. The multi-national drilling program ANDRILL (ANtarctic geological DRILLing, McMurdo Ice Shelf project, MIS) focuses on the changes of climatic influences on the West Antarctic Ice Sheet during the past ~14 Ma. During austral summer 2006/07, an approximately 1300 m long sedimentary succession beneath the northwestern Ross Ice Shelf was cored. In this study geochemical investigations were carried out and interpreted using a multiproxy approach. The results of major element measurements from X-ray fluorescence on discrete samples and high-resolution non-destructive XRF analyses on split-cores, using an XRF core scanner, total organic carbon, total inorganic carbon, opal, and mineral data, as well as optical microscope and visual colour reflectance investigations were used to reveal different processes controlling the depositional environment in the southern Ross Sea. Provenance analyses reveal three main sources for fine-grained terrigenous sediments at the MIS site. First, ...