Tue. May 24, 2016 1:45 PM - 3:15 PM 201A (2F)

Convener:*Jun Korenaga(Department of Geology and Geophysics, Yale University), Hitoshi Kawakatsu(Earthquake Research Institute, University of Tokyo), James Gaherty(Lamont Doherty Earth Observatory), Kiyoshi Baba(Earthquake Research Institute, University of Tokyo), Chair:Hitoshi Kawakatsu(Earthquake Research Institute, University of Tokyo), James B Gaherty(Lamont Doherty Earth Observatory)

The operation of plate tectonics is what makes the Earth a unique planet in the solar system, but why plate tectonics takes place is still unresolved, creating a considerable bottleneck in the theory of planetary evolution at large. A key to this long-standing question is believed to be in the suboceanic mantle, in particular its lithospheric and asthenospheric components, because the defining characteristic ofplate tectonics is the subduction of oceanic plates. Our understanding of the structure and dynamics of suboceanic mantle is, however, yet to be advanced to address the origin of plate tectonics. For example, it is still difficult to answer how strong oceanic plates actually are and what observations can possibly constraint it. In this session, we call for contributions from relevant disciplines including mantle dynamics,rock mechanics, marine geophysics, and global seismology, to discuss the status quo and explore new research directions. Given this exploratory nature, contributions with unusual angles (e.g., ones with only indirect connection, or proposals for innovative observation) are strongly encouraged.