The 2004 Arthur Holmes Medal & Honorary Membership is awarded to Stephen Sparks for his pioneering work in volcanology and for confirming geological fluid dynamics as an established discipline.
Professor Stephen Sparks is undoubtedly the world’s foremost volcanologist but it would be wrong to think of his scientific achievements as limited to this branch of Earth Sciences. He has also made major ground-breaking studies of melting in the continental crust and of turbidity currents. He should perhaps be best acknowledged as one of the very few Earth scientists who made Geological Fluid Dynamics a mature discipline, such that theory and physical insight are applied to well-defined geological problems and to a coherent set of natural observations. Last, but not least, he has defined a new and highly efficient style of crisis management during the Soufrière Hills eruption on Montserrat Island.
It is very difficult to single out a small number of landmark papers in Stephen Sparks’ incredibly voluminous output, and I have done an almost random choice. His 1978 study of bubble growth has inspired scores of volcanologists (including myself). He recognised very early the importance of density control on erupted lava composition (his 1980 EPSL and CMP papers), a theme which he has returned to time and time again. His studies of magma chamber replenishment and differentiation with Herbert Huppert probably form the most original, coherent and illuminating whole in the geological literature. He has recently embarked on rather complicated (but well-posed) conduit flow models to account for the vagaries of explosive eruptions.
Steve Sparks’ papers are always a joy to read and to go back to because of their breadth and incredibly clear writing. His influence can be felt in most (if not all) modern volcanologists. The ground-breaking and lasting nature of his work makes him ideally suited to the Holmes medal. He is a true pioneer whose influence will be felt for many decades.