WAMSISE · West Antarctic Margin Signatures of Ice Sheet Evolution

West Antarctic Margin Signatures of Ice Sheet Evolution

The evolution of the Antarctic ice sheets has been widely debated. According to several studies a continent-wide ice sheet first developed during the early Oligocene and subsequently it experienced many cycles of advance and retreat. Tectonic, oceanographic, climatic and ice dynamic processes have been pointed to as the primary factors controlling this oscillation. However, their relative influence is still controversial. Middle Miocene growth of the Antarctic ice sheet has been related to intensification of the Antarctic Circumpolar Current. It was followed by warm episodes during the Miocene Climate Optimum (∼17-14 Ma) and during the Pliocene when collapse of the West Antarctic Ice Sheet has been suggested. However, the stratigraphic signature of such a collapse has not been recognized on West Antarctic continental margins. The main aim of WAMSISE is examine the record of ice sheet evolution on West Antarctic continental margins from middle Miocene to present and clarify the factors controlling the major sedimentary changes and their global implications. To date, the research developed under WAMSISE has been focussed on the middle Miocene ice sheet oscillation over the Ross Sea continental shelf. The insights suggest ice sheet advance on the continental shelf during short time intervals prior to the Miocene Climate Optimum, which was followed by widespread marine-based ice sheet advance on the Ross Sea during the Middle Miocene Climate Transition (∼14 Ma). Additional work developed in the Drake Passage and Scotia Sea reveals a link between the regional variability of the bottom-water flows and the Antarctic ice sheets dynamics from late Miocene to present.

Data: CORDIS, © European Union