Antarctic ice sheet expansions in the Middle Miocene and Pliocene

• Other Authors: Langebroek, Petra
• Language: English
• Published: Niedersächsische Staats- und Universitätsbibliothek 2008
• Subjects: 550; 16,13; ggo geo; Antarctic; The Antarctic; Antarc*; Ice Sheet
• Online Access: http://webdoc.sub.gwdg.de/ebook/dissts/Bremen/Langebroek2008.pdf; http://elib.suub.uni-bremen.de/diss/docs/00011291.pdf; http://d-nb.info/992948908/34; http://nbn-resolving.de/urn:nbn:de:gbv:46-diss000112917

This study focuses on the interactions between climate and ice sheets in order to obtain a better understanding of the processes involved. Two periods in the geological past are explored; the Middle Miocene and the mid-Pliocene. For both periods, foraminiferal oxygen-isotope records from deep-sea sediment cores as well as stratigraphical data, suggest a global sea-level lowering. The magnitude of these reductions in sea level indicate large-scale ice-sheet build-up. However, the origin of these events and even the geographic locations of the ice sheets, are still under discussion. The ice sheet-climate model developed in this study provides a tool to test some of the hypotheses brought forward to explain the ice-sheet expansion events. It describes the Antarctic ice sheet and is forced by a climate component based on energy and mass balances. Further more, the model computes the oxygen-isotopic composition of the ice-sheet, thereby providing the possibility to compare numerical results directly to deep-sea sediment records. Numerical experiments focus on the interactions between atmospheric CO2, temperature, ice volume (sea-level equivalent) and the isotopic composition of sea water. Univ., Diss--Bremen, 2008