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SO223T (TransGeoBiOc)

Pusan (S Korea) – Suva (Fiji)

09.09.2012 – 08.10.2012


The RV SONNE cruise TransGeoBiOc was a joint research cruise of the MARUM (Dr. Mahyar Mohtadi, Marine Sedimentology group), the University of Cologne (Prof. Dr. Hartmut Arndt, Zoological Institute, General Ecology group) and the University of Oldenburg (Dr. Katharina Pahnke, Institute for Chemistry and Biology of the Marine Environment, Marine Isotope Geochemistry group).

To date, the causes of the glacial/interglacial variations in atmospheric CO2 are still poorly understood. It has been proposed for example, that atmospheric CO2 was sequestered into an abyssal water mass located in the Pacific during glacials for thousands of years and then ventilated rapidly through intermediate waters that circulated through the Southern Ocean during the last glacial termination. In the case of the so-called deep-water reservoir hypothesis however, there is no clear evidence that an isolated deep-water reservoir rich in CO2 was released during the last glacial termination.We are drawn to these recent observations as a means of explaining the enigmatic nature of the glacial/interglacial CO2 changes. If indeed there is an additional source of CO2 that contributes to the glacial/interglacial variability in addition to CO2 dissolved in deep water reservoirs, a strategically important place to test this idea is near the source of that carbon. The back arc of the Mariana system near the Island of Rota is an ideal location to investigate the deglacial signature from intermediate water depths near one of the active volcanic systems. This expedition aims to obtain a suite of cores from sites near the Island of Rota that can yield biogenic carbonate through the last glacial termination to investigate whether there were sources of CO2 released from the North Pacific volcanic systems that contributed to the distinctive glacial/interglacial CO2 cycles.

Chief Scientist:

Dr. Mahyar Mohtadi


+49 421 21865660


+49 421 21865653

Cruise track of SO223T
Slicing the Multi-core sediments from offshore Rota Island