AGU member since 1990. Cecil and Ida Green Professor of Geophysics, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts. Major interest: Earth's structure, composition, and evolution, with focus on subduction systems, mantle convection, and Australasian continental tectonics. Lecturer, University of Botswana, 1983-1984; Postdoctoral Fellow, University of Leeds, United Kingdom, 1990–1992; Research Fellow, Australian National University, Australia, 1992–1995; on MIT faculty since 1996. Visiting/Adjunct faculty positions: Institute de Physique du Globe, Paris, France, 1998 to present; Utrecht University, Netherlands, 2001 to present; Member of the European Geosciences Union, Society for Exploration Geophysicists, Seismological Society of America. Authored approximately 80 refereed publications, 27 in AGU publications; coedited five monographs, three published by AGU. Honors include Doornbos Memorial Prize, International Association for Seismology and Physics of the Earth's Interior (IASPEI); Macelwane Medal (AGU); Fellow, AGU; Packard Foundation Fellow; VICI Innovative Research Award, Dutch National Science Foundation. AGU service: AGU Western Pacific Geophysics Meeting, Program Committee, 1995-1996; AGU Spring Meeting, Program Committee, 1998–2000; Chair, 2005 AGU Joint Assembly; Member, Meetings Committee, 2004 to present; organizer of several special sessions at AGU Spring and Fall meetings; Associate Editor, Journal of Geophysical Research-Solid Earth and G-Cubed; coeditor of three AGU Geophysical Monographs.