The Marine Isotope Geochemistry research group is involved in several sub-projects of the international GEOTRACES programme. GEOTRACES aims to document the distribution of trace elements and their isotopes in the global ocean in order to better understand their sources, sinks and internal cycles (GEOTRACES Science Plan, 2006; www.geotraces.org). Trace elements and their isotopes fulfil crucial functions in the ocean: they are important micronutrients, indicators of the origin and transport routes of material flows and water masses and important indicators for reconstructing past conditions and changes in the ocean.

In the sub-Antarctic and polar South Pacific, we are investigating the distribution of neodymium isotopes in the water column and in marine sediments in order to characterise the isotopic signature of the deep water and reconstruct past circulation changes (Dr. C. Basak, H. Fröllje, K. Pahnke, in co-operation with Dr. R. Gersonde and Dr. F. Lamy, AWI Bremerhaven).

In the western subtropical to tropical Pacific, we measure the neodymium isotopy and concentration of rare earth elements in the water column to investigate the different sources and cycles of trace elements in the Pacific (M. Behrens, P. Böning, K. Pahnke).