Samuel Bowring and Hans Keppler each received the 2010 N. L. Bowen Award at the 2010 AGU Fall Meeting, held 13–17 December in San Francisco, Calif. The award recognizes “out-standing contributions to volcanology, geochemistry, or petrology.”
Hans Keppler and his research have profoundly influenced our understanding of the physical and chemical properties of fluids in Earth’s interior, their interactions with melts and solids, and their controlling influence on geochemical budgets and material properties, all with a global perspective.
In his research, Hans combines experimental innovation with technical skill to pursue in situ observations of critical phenomena and in situ measurements of properties of nonquenchable materials. One of Hans’s important contributions has been measuring and systematizing bulk hydroxyl/water solubility in important minerals in the upper mantle and transition zone. He combined these data on individual minerals into a model for the maximum water content of rocks at these depths. In a recent paper in Science he elegantly provided an explanation for the existence of the asthenosphere by considering the water budget, an approach that explains the rather sharp upper boundary of the asthenosphere combined with a relatively diffuse lower boundary.
In closing, let me return to my opening comment, namely, that Hans and his research have had an impact on our science. About 15 years ago, I had the good fortune to spend a year in Bayreuth working with Hans and Dave Rubie. Being 20 years older than Hans, I thought I would be the teacher and he the student. Not so. I remember clearly working through some aspects of thermodynamics as applied to our research. It was absolutely clear to me that Hans knew the answers to the questions with which I was struggling. It was Hans who was the teacher and I the student, as he patiently led me to discover the answers for myself and, in so doing, helped me embrace a much deeper understanding than would have been possible had he simply provided the resolution without my participation in the process.—David Kohlstedt, University of Minnesota, Minneapolis
Thank you, David, very much indeed. Naturally, I feel deeply honored by the Bowen award, for two reasons. One is that the award is named after Norman Bowen, with whom I share many common beliefs, such as the belief in the need to carefully study simple systems and to fully understand the physicochemical principles behind Earth processes. The other is that this is an award of AGU. I owe a lot to America, and I would not be the person I am had I not spent 2 years as a postdoc at California Institute of Technology, working with Peter Wyllie and also with George Rossman.
In later years I benefited enormously from working with several people. I could now mention many names, but I will just mention two: Andy Shen, who introduced me to externally heated diamond anvil cells, and, of course, David Kohlstedt, who showed me the importance of water in olivine. When David came to Bayreuth, it was around the time of his fiftieth birthday. I looked at him and thought, “Wow, I have never seen anything like this before—a professor who is 50 years old and who is still doing his experiments all by himself!” This apparently left a long-lasting impression on me; today, my fiftieth birthday is not so far away, and I am still sometimes doing experiments all by myself—I hope that Norman Bowen would not be too disappointed about the way I do my experiments.
Thank you all again!—Hans Keppler, Bayerisches Geoinstitut, Bayreuth, Germany