The Expedition PS97 from Punta Arenas to Punta Arenas

In total, 46 scientists work on board in 6 different groups in various geological, oceanographic, geodetic, and biological disciplines. During the Polarstern expedition PS97 we plan to focus on marine geological work in different working areas along the southern Chilean continental margin, the southern rim of the Falkland Plateau, the central North Scotia Ridge, and the northern margin of the Antarctic Peninsula in the area of the South Shetland Islands. In addition, we plan for two North-South transects across the western and central Drake Passage.

The Drake Passage forms the major geographical constraint for the flow of the Antarctic Circumpolar Current and plays an essential role in the modern ocean circulation patterns and global climate. Despite its importance for modern and likely also future climate, little is known about past climatic and oceanographic changes on longer, geological time-scales in this region. Therefore, the principle scientific goal is to enhance understanding of the paleoceanographic role of the Drake Passage during Quaternary global climate variations at orbital and sub-orbital time-scales.

Further research conducted during the expedition will cover the exploration of ultra-high resolution paleoclimate archives off southern Chile and the South Shetland Islands, development of biomarker-based sea-ice reconstructions, and unravelling the glacial extent of the Pacific margin of the Patagonian ice-sheet and its deglaciation history. For this purpose we also plan to work on offshore islands at the southern Chilean continental margin. Besides obtaining long piston cores and surface sediments, we plan to perform geophysical surveys at suitable locations (primarily along the Chilean margin) for planned IODP (International Ocean Discovery Program) proposals. Sediment sampling will be accompanied by bathymetric, sediment echo-sounding, and oceanographic surveys. The oceanographic work will improve our understanding of the understudied Cape Horn Current and the westernmost Drake Passage.

In addition to paleo-oceanographic and paleo-climatic research questions, it is planned to carry out physico-chemical and biological-oceanographical investigations. A major focus of the planned expedition is to understand how trace metal limitation and cycling operates and how global change will impact the Southern Ocean ecosystem.