Swastika Bhaumik, Faculty of Geosciences and MARUM, University of Bremen, Bremen, Germany, Anette Meixner, Faculty of Geosciences and MARUM,University of Bremen, Bremen, Germany, Eva Meckel, Constructor University Bremen, Germany, Department of Physics and Earth Sciences, Bremen, Germany, Andrea Koschinsky, Constructor University, Department of Physics and Earth Sciences, Bremen, Germany and Simone Kasemann, University of Bremen, Faculty of Geosciences, Bremen, Germany