The 2016 Robert Wilhelm Bunsen Medal is awarded to Tetsuo Irifune for outstanding contributions in experimental high-pressure mineral physics and petrology, as well as pioneering developments in high-pressure technology.
Tetsuo Irifune’s seminal research on high-pressure mineralogy, petrology and geochemistry has changed perceptions of how the deep mantle works, introducing entirely new concepts to the international community. His series of experimental studies on phase transitions and density changes in subducting slabs and mantle materials has greatly contributed to our understanding of the dynamics of subducting slabs, and his work on water in the mantle foreshadowed the present burgeoning interest in the Earth’s deep water cycle. His study of phase relations in hydrous phases tested ideas that now underpin interpretations of deep seismic structure, and he has experimentally constrained the effect of water on thermal expansivity and phase relations in the transition zone, as well as the stability of hydrous phases in the deep lower mantle. Further important contributions involve applications of synchrotron X-ray observations performed in situ to precisely determine phase boundaries and key physical properties, such as sound velocities, at pressure and temperature conditions of the Earth’s mantle. These studies revealed the nature of the major seismic discontinuities and tightly constrained the chemical compositions of the mantle transition zone and the lower mantle. However, the impact of his innovative approaches to experimental petrology extends far beyond the arena of high-pressure mineral physics. From his pioneering use of sintered diamond anvils in multi-anvil experiments to his novel synthesis of superhard nano-polycrystalline diamonds, he has vastly expanded the reach in pressure-temperature space of large-volume experiments, as well as opened industrial uses for the world’s hardest bulk material. In summary, Tetsuo Irifune is an extraordinarily skilled and creative experimental petrologist and mineralogist with the insight to interpret results in terms of global geophysics. His work has consistently been at the forefront of research in mineral physics, with impacts extending from mantle geochemistry to seismology and geodynamics. He represents the international mineralogical sciences at their best, both as a scientist and a citizen of the community.