Tomoo Katsura
Commendation
For outstanding research on the physical and chemical properties of mantle materials through large-volume high-pressure-temperature experiments, particularly with synchrotron radiation, and prominent contribution to mineral physics and study of the Earth’s deep interior.
A list of five representative papers
- Chanyshev, A., Ishii, T., Bondar, D, Bhat, S. Kim, E.-J., Farla, R., Nishida, K., Liu, Z., Wang, L., Nakajima, A., Yan, B., Tang, H., Chen, Z., Higo, Y., Tange, Y., Katsura, T., Depressed 660-km discontinuity caused by akimotoite-bridgmanite transition, Nature, 601, 69-73, 2022
- Ishii, T., Huang, R., Myhill, R., Fei, H., Koemets, I., Liu, Z., Maeda, F., Yuan, L., Wang, L., Druzhbin, D., Yamamoto, T., Bhat, S., Farla, R., Kawazoe, T., Tsujino, N., Kulik, E., Higo, Y., Tange, Y., Katsura, T., Sharp 660-km discontinuity controlled by extremely narrow binary post-spinel transition. Nature Geoscience 12, 869- 872, 2019.
- Fei, H., Wiedenbeck, M., Yamazaki, D., Katsura, T., Small effect of water on upper-mantle rheology based on silicon self-diffusion coefficients, Nature, 498, 213-215, 2013.
- Yoshino, T., Manthilake, G., Matsuzaki, T., Katsura, T., Dry mantle transition zone inferred from the electrical conductivity of wadsleyite and ringwoodite, Nature 451, 326-329, 2008.
- Yoshino, T., Matsuzaki, T., Yamashita, S., Katsura, T., Hydrous olivine unable to account for conductivity anomaly at the top of the asthenosphere, Nature 443, 973–976, 2006.
Major achievements
Dr. Katsura developed the multi-anvil high-pressure apparatus and its experimental techniques, particularly in combination with synchrotron-based X-ray observation. Using these unique techniques, he precisely determined the olivine-wadsleyite phase relations and estimated the temperature at the 410-km seismic discontinuity. He then estimated the temperature distribution in the mantle by measuring the high-pressure thermal expansion coefficients of mantle minerals. He also determined the post-spinel transition boundary precisely to explain the high reflectivity of the 660-km discontinuity. He then determined the akimotoite-bridgmanite transition boundary to show that this transition causes the depression of the 660-km seismic discontinuity. On the other hand, he measured the electrical conductivity of mantle minerals under pressure and elucidated their conduction mechanism to constrain the water distribution in the mantle. His precise determination of elemental self-diffusion coefficients in olivine questioned the hypothesis of hydration softening of the upper mantle.
He has contributed to the geoscience community through his efforts in setting up high-pressure apparatuses in large facilities and developing innovative experimental techniques. Using these apparatuses and techniques, he has achieved the above-mentioned original and outstanding scientific results in high-pressure mineralogy and physics of the Earth’s interior.
Nominator
Takashi Yoshino