Jean-Paul Montagner is Professor of Geophysics at the Institut de Physique du Globe, Université Paris-Diderot and has taught graduate-level courses in anisotropic seismology at Caltech (2001-2002) and IPG-Paris (2003–2005). He was awarded the Inge Lehmann Medal of the American Geophysical Union in 2021, and the Beno Gutenberg Medal of the European Geosciences Union in 2010, and he has published 160 peer-reviewed papers and ten books or book chapters. David Mainprice is a CNRS Director of Research in the Geosciences Department at the University of Montpellier. He is an expert in crystallography and anisotropic properties of minerals. He was the director of Electron microscopy facility at the CNRS at the University of Nantes. At the University of Montpellier, he was the director of UMR, director of Electron microscopy facility and member of the CNRS National Committee. He was awarded the Crosby distinguished lectureship in the Department of Earth, Atmospheric and Planetary Sciences at MIT, Cambridge, USA. Recent distinctions include Elected Fellow of the American Geophysical Union (2012) and the Paul G. Silver award of the Amercian Geophysical Union (2017). He is the author of over 150 publications in peer-reviewed international journals.