Dipl. Geol. S. Krüger
Dr. D. C. Leuschner
Prof. Dr. W. Ehrmann
PD Dr. G. Schmiedl

Cooperation:
PD Dr. A. Mackensen, Dr. H. Grobe, Dr. G. Kuhn, Dr. F. Niessen
Alfred-Wegener-Institut für Polar- und Meeresforschung, Bremerhaven
PD Dr. B. Diekmann
Alfred-Wegener-Institut für Polar- und Meeresforschung, Potsdam

The project aims to describe the exchange of deep and bottom water masses between the South Atlantic / Southern Ocean and the Indian Ocean during the Pliocene to late Quaternary. This project is a multi-proxy study with sedimentological, geochemical, sediment physical and micropaleontological investigations along a NW-SE core transect between the South African continental margin and the Conrad Rise (Polarstern cruise ANT XI/4). Main target is to evaluate the significance and timing of the oceanic transmission of Antarctic and Northern hemisphere climate signals into the Indian Ocean at Milankovitch and millennial time scales. 

1) How did the deep and bottom water circulation at the transition zone between the Atlantic and Indian oceans evolve since the Pliocene? Is the advection of North Atlantic Deep Water into the Indian Ocean coherent with the onset and intensification of northern hemisphere glaciation and how did the contribution of southern deep water masses change during this time?

2) How did the proportion of northern-derived deep water (NADW) and southern-derived deep water (LCDW, AABW) change at lower bathyal to abyssal depth of the ACC during the last glacial-to-interglacial cycle? Emphasis will be laid on different glacial (stages 2, 4), interglacial (stages 5.5, Holocene), and transitional (stage 3) boundary conditions. Assessment of the importance of polar deep water signals at low latitudes of the Indian Ocean by comparison of the new data sets with existing data sets from the Arabian Sea and adjacent areas.

3) Are the short-term changes in deep-water convection coherent with atmospheric changes recorded in polar ice cores adjacent to the main deep-water formation sites? Is the asynchrony of Antarctic and Greenland climate change during the last glacial period, observed in ice cores, also reflected in the advection of northern versus southern deep water masses?

4) Is the deep-water signal masked by regional environmental signals independent from the deep-water advection? Assessment of the contribution of wind-transported sediment material and reconstruction of regional changes in productivity.