We perform researches on the structure and dynamics of the Earth's deep interior through geophysical observations mainly in oceanic regions, and researches on mantle and core convections based on numerical and laboratory simulations. Integrating these researches should enable a better understanding on thermal and mass transports across boundaries in the layered Earth, such as the core-mantle boundary and the Earth's surface, which is indispensable to understanding mechanisms of the Earth’s evolution and dynamics.
Our researches target at mantle upwelling such as mantle plumes, large igneous provinces, and petit spots; mantle downwelling such as subducted slabs and the associated downward flow; and the global-scale structure of mantle and core. A paleomagnetic study and long-term geomagnetic observation are also performed to elucidate geomagnetic field variations.
We investigate the mantle and the core dynamics, and their mutual interactions at the core-mantle boundary based on numerical simulations, laboratory experiments and the observations of the geomagnetic field variations on various time scales. We carry out 3-D mantle convection simulation with realistic earth-like parameters using the Earth Simulator to reveal the basic properties of mantle activities. We also perform geodynamo simulations and laboratory experiments of thermal convection in liquid metals to investigate the core dynamics and the origin of the Earth's magnetic field.
We use broadband ocean bottom seismographs, pressure gauges, ocean bottom electro-magnetometers, and vector tsunameters for geophysical observation on the seafloor. We continue to develop new observation systems in oceanic regions, which are a key to improving our understanding of the mantle-core dynamics and mechanisms of earthquakes and tsunamis.
Director, Department of Deep Earth Structure and Dynamics Research