Robert Stephen John Sparks. Member of AGU since 1987. Professor of geology at the University of Bristol, United Kingdom. Major interests are volcanology, igneous petrology, geohazards and risk assessment, and applying fluid mechanics to understanding geological flows. B.S., honors, 1971, and Ph.D., 1974, at Imperial College, London University; research fellow at Lancaster University (1976–1978); NATO postdoctoral fellow at Graduate School of Oceanography, Rhode Island (1976–1978); lecturer at Cambridge University (1978–1989); professor at University of Bristol (1989 to present). Sherman Fairchild Fellow at California Institute of Technology (1987); Edward Bass Scholar at Yale University (2006–2007). President of the Geological Society of London (1994–1996); president of International Association of Volcanology and Chemistry of Earth's Interior (1999–2003). Author of over 300 refereed publications with 35 in AGU publications. Key papers on ignimbrite facies; eruption column stability, magma chamber convection, and nonlinear dynamics of conduit flows. Fellow of the Royal Society (1988); AGU Fellow (1998); honorary member, Geological Society of America (2000); Wager Medal (IAVCEI, 1978); Bigsby and Murchison medals (Geological Society of London, 1985 and 1998); Arthur Day Medal (Geological Society of America, 2000); Arthur Holmes Medal (European Geosciences Union, 2004); ISI highly cited researcher; D.Sc. (Honoris Causa) at Université Blaise Pascal (1999), Lancaster University (2000), and Institute de Physique de Globe de Paris (2005). Past member of AGU Fellowships Committee (VGP section); current member of Bowen Medal Committee; Chair of Royal Society Hooke Committee; member of ICSU committee on natural hazards; chair of UK 2008 research assessment panel for Earth sciences.