The 2007 Arthur Holmes Medal & Honorary Membership is awarded to Claude Jaupart for his fundamental research concerning the fluxes of energy in the Earth with specific reference to volcanic systems.
Claude Jaupart has made major and highly original contributions to physical volcanology, igneous processes, geodynamics and heat flow in the Earth. Claude has applied his deep knowledge of physics and fluid dynamics to make major advances in understanding dynamic processes and heat transfer. He is an able mathematician and outstanding experimentalist with an intuitive feel of how nature works. He has combined these skills with an encyclopaedic knowledge of earth sciences and an appreciation of the importance of collecting high quality field data. In volcanology his contributions include: understanding how the dynamics of bubbly magmas in conduits leads to episodic degassing behaviour at basaltic volcanoes, the role of magma permeability in controlling transitions between explosive and effusive eruptions, the non-linear dynamics of conduit flows from magma chambers, the role of compressibility in bubbly magmas and lavas, convection in lava lakes, the influence of volcanic edifices on the propagation of dykes and formation of magma chambers, and magma chamber control of eruption dynamics. He has also made important contributions to igneous processes and the origin of igneous layering, in particular in his work on the kinetics of crystallization and compositional convection. His research papers are characterized by mathematical and physical rigour, elegant and insightful experiments, and close links between the models and observations of geological, geophysical, petrological and geochemical data. In geodynamics Claude has made highly original and important contributions on heat transfer in the Earth through his field measurements of heat flow, laboratory measurements of thermal conductivities, and modeling studies of mantle convection. He is the World leading figure in heat flow studies and his work in Canada has set a new standard; combined with his theoretical knowledge he has constrained the heat flow in continents and related these measurements to Earth history. His ideas on the geotherm in ancient cratons have been vindicated from mantle nodule data. He has made important contributions to understanding mantle convection, in his pioneering work on convection in fluids with strongly temperature-dependent viscosity and models of lateral convection in the mantle below continents. Claude is a polymath in the true tradition of Arthur Holmes and is one of the outstanding European earth scientists of the last several decades.
Claude Jaupart has received several awards: from the French academy of sciences; the Geological Society of London; the International Association for Volcanology and Chemistry of the Earth’s Interior. He is a Fellow of the American Geophysical Union, Honorary Fellow of the European Union of Geosciences and member of the Institut Universitaire de France.