Walter Menapace¹, Alexander Rösner¹, *Miho Asada^2,3, Christian Dos Santos Ferreira¹, Norbert Kaul⁴, Achim Kopf¹, SO251b onboard scientific party (1.MARUM, Center for Marine and Environmental Science, 2.Japan Society for the Promotion of Science, 3.Japan Agency for Marine-Earth Science and Technology, 4.Department of Geosciences, University of Bremen)