B. L. N. Kennett is Director and Distinguished Professor of Seismology at the Research School of Earth Sciences at the Australian National University, Canberra. Professor Kennett's research interests are directed towards understanding the structure of the Earth through seismological observations. He is the recipient of the 2006 Murchison Medal of the Geological Society of London, and the 2007 Gutenberg Medal of the European Geosciences Union, and he is a Fellow of the Royal Society of London. Professor Kennett is the author of three other books for Cambridge University Press: Seismic Wave Propagation in Stratified Media (1983), The Seismic Wavefield: Introduction and Theoretical Development (2001), and The Seismic Wavefield: Interpretation of Seismograms on Regional and Global Scales (2002). H.-P. Bunge is Professor and Chair of Geophysics at the Department of Earth and Environmental Sciences, Universität Munchen, and is Head of the Munich Geo-Center. Prior to his Munich appointment he spent five years on the faculty at Princeton University, New Jersey. Professor Bunge's research interests lie in the application of high performance computing to problems of Earth and planetary evolution, including core, mantle and lithospheric dynamics. A member of the Bavarian Academy of Sciences, Bunge is also President of the Geodynamics Division of the European Geosciences Union (EGU).