Claude P. Jaupart

Institut de Physique du Globe de Paris

2015 Harry H. Hess Medal Winner

Claude Jaupart was awarded the 2015 Harry H. Hess Medal at the AGU Fall Meeting Honors Ceremony, held on 16 December 2015 in San Francisco, Calif. The medal is for “outstanding achievements in research on the constitution and evolution of the Earth and other planets.”


Claude Jaupart has made major contributions to several areas of solid Earth science. His contributions include understanding the physics of volcanic eruptions, igneous processes in magma chambers and intrusions, geodynamics, in particular related to mantle convection and the role of continents, and heat flow in the Earth. His work ranges from geophysical fluid dynamics to behavior of elastic materials to heat transport problems.

Claude’s contributions to volcanology and magma physics have been exceptional. His research includes elucidating how stress fields control dike emplacement; insights into crystallization of magmas, magma convection, conduit flows, degassing dynamics of magma chambers and eruptions, formation of layered intrusions, development of overpressures in magma chambers, formation of magma chambers, evolution of lava lakes, and the rheological behavior of bubbly magmas; and understanding of magma fragmentation. A seminal contribution concerns the thermal and dynamical behavior of the Earth including heat flow measurements on continents, radioactivity within the continental crust and lithosphere, interpretation of heat flow measurements on continents and oceans, convection in the mantle, and viscous melts and lava flows. Claude has had a career-long commitment to measuring the heat flow through the Canadian cratons. His discovery of low mantle heat flux is one of the most important pieces of observational work on the continents.

Claude’s research is characterized by a highly rigorous quantitative approach to science. He sees understanding observations and data as the key rationale for modeling, experimentation, and analysis. All of his research places observations and data at the forefront, even in his more theoretical endeavors. Claude adopts a holistic approach combining elegant laboratory experiments, astute development of theoretical models, and a deep knowledge and respect for observations. His primary motivation is to understand the natural world through his deep knowledge of the underlying physics. He is technically outstanding, applying rigorous mathematics to his modeling and analysis of data. He has tremendous creative ability to think of the right clever experiment or insightful development of a model and a flair for identifying the right questions and key issues.

Claude is widely known for being kind, courteous, generous with his time, and insightful of colleagues. He has nurtured several outstanding graduate students, many of whom are independently making significant contributions. He has provided leadership of French geoscience and is Institut de Physique du Globe de Paris director for the second term. Claude Jaupart is an outstanding recipient of the Hess Medal because of the breadth, depth, and quality of his scientific contributions.

—Stephen Sparks, University of Bristol, Bristol, United Kingdom


The American Geophysical Union, the Hess Medal, and Steve Sparks are all so prestigious that I have been inflated to the bursting point. This medal carries special significance because of Harry Hess’s considerable achievements and breadth of research. I have spent countless hours poring over his landmark papers on seafloor spreading and on the Stillwater complex. His studies typify what is so exciting about our science, the intimate connections between the compositions of minerals and rocks, geological activity, and the deep churning of our planet. It is a great privilege to be associated with him.

My scientific development has been due to the energetic push and inspiration from a few remarkable scientists. It all began when I joined John Sclater’s group at the Massachusetts Institute of Technology, where the level of scholarship and enthusiasm was intoxicating. John kept his group on a permanent high with his constant support for new ideas and emphasis on the large-scale picture. I moved back to France at Claude Allègre’s urging to develop research on the physics of magmatic and volcanic processes at Institut de Physique du Globe de Paris. Claude provided far-field scientific vision and fought hard for what was then a burgeoning field. I met Steve Sparks and Herbert Huppert at almost the same time. Their groundbreaking studies of magmatic and volcanic processes had been eye-openers and have remained a constant source of inspiration. A fantastic field trip to Santorini volcano and a wonderful stint at the University of Bristol in their company solidified my resolve. I also had the good fortune to forge a lasting partnership with Jean-Claude Mareschal. We embarked on a 3-decades-long heat flow program that yielded an exceptional data set and powerful constraints on the thermal structure and evolution of continents. None of these would have happened without Jean-Claude, his nimble mathematics, his steadfastness and unselfishness, not to mention his encyclopedic knowledge of jazz music that kept us alert when we were logging deep boreholes.

The natural world has so many wonders to offer in so many different guises that exciting research topics abound. Definitive answers have rarely come from a single scientific discipline, but it is clear that the development of geological fluid dynamics has had a profound impact. I have been very fortunate to see this happening and am deeply grateful to AGU and to the many friends and colleagues who made this possible.

—Claude Jaupart, Institut de Physique du Globe de Paris and Université Paris-Diderot, Paris, France