Japan Geoscience Union Meeting 2016

Presentation information

International Session (Oral)

Symbol S (Solid Earth Sciences) » S-IT Science of the Earth's Interior & Techtonophysics

[S-IT11] Geodynamic evolution of northeast Asia and western Pacific

Tue. May 24, 2016 1:45 PM - 3:15 PM A05 (APA HOTEL&RESORT TOKYO BAY MAKUHARI)

Convener:*Gaku Kimura(Department of Earth and Planetary Science of the Graduate School of Science, The University of Tokyo), Jonny Wu(Department of Geosciences, National Taiwan University), Timothy Byrne(University of Connecticut), Kyoko Okino(Ocean Research Institute, University of Tokyo), Chair:Jonny Wu(Department of Geosciences, National Taiwan University), Kyoko Okino(Ocean Research Institute, University of Tokyo)

2:15 PM - 2:30 PM

[SIT11-03] Dynamic of the Japan subduction system

Claudio Faccenna1, Hitoshi Kawakatsu2, *Thorsten W Becker3, Francesca Funiciello1, Adam Holt3 (1.Dip. Scienze Univrsità Roma TRE, Roma (Italy), 2.Earthquake Research Institute, Univ. of Tokyo, Tokyo (Japan), 3.Dept. Earth Science, Univ. Southern California Los Angeles (CA))

Keywords:subduction, Mariana-Izu-Bonin, geodynamic modeling

The geometry of the Mariana-Izu-Bonin (IBM)-Japan slab consists of a large cusp where the undulation of the trench is accompanied by a corresponding variation in slab dip, varying form sub-vertical beneath the Marianas to shallow dipping beneath Japan. The origin and the cause of these variations are still poorly understood.We reconstruct the backarc extensional system of the Philippine plate, showing that the triple junction between the IBM, Ryuku, and Japan migrated northward during the last 40 Ma reaching its present-day position. We balance back the subduction system on time, starting from recent tomographic models and using an absolute reference frame plate reconstruction model. Our kinematic model suggests that the evolution and the geometry of the Japan slab is controlled by the interaction with the surrounding slabs. We test this hypothesis with simple laboratory experiments. Our preliminary results suggest that the slab geometry is influenced by local and plate-scale mantle flow.