Laura J Cobden¹, Michael Afanasiev², Frederic Deschamps³, Fabienne Stockmann⁴, Christine Thomas⁵, Sebastian Rost⁶ and Andreas Fichtner², (1)Utrecht University, Utrecht, Netherlands, (2)ETH Zurich, Department of Earth Sciences, Institute of Geophysics, Zurich, Switzerland, (3)Academia Sinica, Taipei, Taiwan, (4)University of Münster, Münster, Germany, (5)University of Münster, Institute of Geophysics, Münster, Germany, (6)The University of Leeds, Leeds, United Kingdom