Department of Geophysical Sciences, University of Chicago, Chicago, Ill.

Frank M. Richter was awarded the 2009 Harry H. Hess Medal at the AGU Fall Meeting Honors Ceremony, held on 16 December 2009 in San Francisco, Calif. The medal is for “outstanding achievements in research in the constitution and evolution of Earth and other planets.”
Citation
The AGU Harry H. Hess Medal serves to highlight and honor “outstanding achievements in research of the constitution and evolution of Earth and sister planets.” There can be no doubt that Frank Richter’s research throughout his career clearly falls within this medal’s scope. Frank has made fundamental contributions to the Earth sciences through the application of simple but rich physical and chemical modeling and experimental investigations across a remarkably diverse spectrum of the geological sciences. Frank’s mode of research is to identify critical problems, develop a fundamental, first principles—based understanding, and then to delve deeply into the broader consequences and implications for the Earth sciences. This approach has characterized his work ranging from applying fluid dynamics to investigations of mantle dynamics and the driving forces of plate tectonics, mantle convection as it affects the thermal and chemical evolution of the mantle, mantle melting and melt segregation, diffusion-advection models for the Sr isotope evolution of deep-sea sediments and seawater, 40Ar/39Ar thermochronometry exploiting the multidomain diffusion of Ar in K-feldspar, compositional and isotopic effects of multicomponent diffusion during silicate melting, and more recently kinetic isotope fractionation by mass transport due to diffusion or evaporation. At each stage of his career, Frank’s research has contributed or defined the state of the art in each of these areas. Many of his papers are classics and are (or should be) required reading for anyone embarking on research in each of the areas that his research has touched upon.
Take a moment to reflect on the list of areas in which Frank has made seminal contributions. It is remarkable. His approach is to identify an Earth science—related problem where he can make a significant contribution, work single-mindedly until he succeeds to some satisfying degree, and then move on once he feels that further efforts would not yield results as significant as those he has already achieved. This mode of declaring success and moving on helps explain the remarkable diversity of his contributions, and the impossibility of classifying Frank as a fluid dynamicist, geodynamicist, geochemist, experimental petrologist, or cosmochemist. All of these apply and would characterize some phase in his career. These are not dalliances but are fully engaged intellectual pursuits to deeply understand some fundamental property of the natural world by developing mathematical models based on rigorous experimental and analytical approaches to better understand how physics and chemistry affect the evolution of natural systems. Frank is also a careful listener and reader, whose questions and input can often be transformative of the research of his friends and colleagues. I, for one, believe I am better scientist as a result of interactions with Frank over the years, and I am most grateful for his generosity and critical input.
—DAVID B. ROWLEY, University of Chicago, Chicago, Ill.
Response
For many reasons I am delighted to receive the Harry H. Hess Medal. First, I take it as an expression of affection and some measure of admiration by Dave Rowley and those who supported my nomination. Second, while I never met Harry Hess, he had a profound influence on my early research. My Ph.D. dissertation and my first published paper were both entitled “Dynamical models for seafloor spreading” which acknowledges Hess in that the term seafloor spreading is the commonly used reference to his seminal ideas regarding processes in the ocean basins. Another work that was important to my developing models for the driving mechanism of plate tectonics is the paper “Seismology and the new global tectonics,” by Isaacs, Oliver, and Sykes. This paper, which is not remembered as much as it should be, provided a very well argued synthesis that made it easy to imagine the role of the cold subducted lithosphere in driving plate motions.
Dave Rowley noted that I have changed the focus of my research more than a few times. These changes did not spring from some especially fertile imagination but in almost every case were in-spired by scientific collaboration with a mentor or a friend. I am grateful to Joe Pedlosky for introducing me to fluid dynamics and for his integrity and excellence in scientific research. Sometimes the new direction came from a challenge, as when Ed Stolper asked, “Frank, if you’re so smart, why don’t you explain uphill diffusion?” That question led to my continued interest in many aspects of diffusion, further inspired by collaborations with Bruce Watson and Yan Liang. Dan McKenzie got me involved with dynamical models of melt segregation. Don DePaolo introduced me to pore water chemistry and the chemical evolution of seawater. Mark Harrison encouraged Oscar Lovera and me to develop multidomain models for 40Ar/39Ar thermochronometry of feldspar minerals. Andy Davis is responsible for my interest in certain aspects of cosmochemistry. In almost every case the progression was from an abstractly posed question to a rewarding collaboration in which each of us brought something distinctive to the task of addressing that question.
I don’t want to leave you with the impression that I can’t at least sometimes change emphasis on my own. My shift to experimental petrology and building a lab with various sorts of furnaces was my own initiative. It came about because smoking was banned in our building at a time when I was never without a lit pipe in my mouth. I could not give up my cherished pipe, and the only solution was to change to a field where I could demand a fume hood. Experimental petrology was an obvious choice, and some of you may remember that for years I had a computer, a phone, and an ashtray inside the fume hood. I eventually did give up smoking, but it appears I gave up one addiction, smoking, for another, laboratory experiments.
This being San Francisco reminds me of another Harry—Dirty Harry—and his iconic phrase: “Go ahead, make my day.” You and AGU really have made my day, and for that I thank you very much.
—FRANK M. RICHTER, Department of Geophysical Sciences, University of Chicago, Chicago, Ill.