The Agulhas Ridge - Cruise No. MSM 19/2 - October 23 - November 30, 2011 - Walvis Bay (Namibia) - Cape Town (South Africa) (English)

Cruise Leg MSM 19/2 with RV Maria S. Merian, leaving Walvis Bay on 23.10., returning to Cape Town on 30.11.2011, comprised seismic reflection studies of the Agulhas Ridge, a topographic anomaly within the Agulhas-Falkland Fracture Zone in the South Atlantic. The Agulhas Ridge rises more than 2000 m above the surrounding seafloor and hence forms an obstacle for the exchange of water masses between high and lower latitudes. A deformation of the post-Oligocene sediments has provided indications for a tectono-magmatic reactivation of the Agulhas Ridge in post-Oligocene times. A detailed study and analysis of the structure of the Agulhas Ridge and the surrounding Cape and Agulhas Basins via seismic data and a correlation with results from ODP Leg 177 Sites 1088, 1089, and 1090 was needed to supply information on the Tertiary development of the Agulhas Ridge and its influence on the path of the Antarctic Bottomwater. Seismic profiles were gathered, which capture the structure of the Agulhas Ridge and the basins down to basement and possible sediment drifts. In total ~5400 km of high resolution seismic reflection data were recorded. Bathymetric and Parasound data were recorded parallel to the seismic profiling. Parasound data were used to pick significant locations for petrological sampling, which will be the focus of the following cruise MSM 19/3. To complement the seismic and geological studies CTD measurements at 3 locations and ADCP measurements across the whole working area were carried out.