[S-CG50] Dynamics in mobile belts

Thu. Jun 3, 2021 9:00 AM - 10:30 AM Ch.21 (Zoom Room 21)

convener:Yukitoshi Fukahata(Disaster Prevention Research Institute, Kyoto University), Hikaru Iwamori(Earthquake Research Institute, The University of Tokyo), Kiyokazu Oohashi(Graduate School of Sciences and Technology for Innovation, Yamaguchi University), Chairperson:Akinori Hashima(Japan Agency for Marine-Earth Science and Technology), Kiyokazu Oohashi(Graduate School of Sciences and Technology for Innovation, Yamaguchi University)

The dynamic behaviors of mobile belts are expressed across a wide range of time scales, from the seismic and volcanic events that impact society during our lifetimes, to orogeny and the formation of large-scale fault systems which can take place over millions of years. Deformation occurs on length scales from microscopic fracture and flow to macroscopic deformation to plate-scale tectonics. To gain a physical understanding of the dynamics of mobile belts, we must determine the relationships between deformation and the driving stresses associated with plate motion and other causes, which are connected through the rheological properties of the materials. To understand the full physical system, an integration of geophysics, geomorphology, geology, petrology, and geochemistry is necessary, as is the integration of observational, theoretical and experimental approaches. In particular, rheological properties, which are physically affected by fluids in the crust and chemical reactions assisted by fluids, can be resolved only through such an interdisciplinary approach. After the 2011 great Tohoku-oki earthquake, large-scale changes in seismic activity and regional scale crustal deformation were observed, making present-day Japan a unique natural laboratory for the study of the dynamics of mobile belts. This session welcomes presentations from different disciplines, such as seismology, geodesy, tectonic geomorphology, structural geology, petrology, geochemistry and hydrology, as well as interdisciplinary studies, that relate to the dynamic behaviors of mobile belts.

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9:00 AM - 9:15 AM

[SCG50-01] 3D numerical simulation of island arc deformation due to steady plate subduction: Effects of a bend along a trench axis

*Yutaro Mori¹, Yukitoshi Fukahata² (1.Graduate School of Science, Kyoto University, 2.Disaster Prevention Research Institute, Kyoto University)

9:15 AM - 9:30 AM

[SCG50-02] Effect of the Philippine Sea slab–overriding plate contact on the stress field in the Southwest Japan arc

*Akinori Hashima¹, Takashi Iidaka¹ (1.Earthquake Research Institute, The University of Tokyo)

9:30 AM - 9:45 AM

[SCG50-03] A Framework to Understand Deformation in Japanese Islands: Inter-arc Deformation and Intra-arc Deformation

*Yukitoshi Fukahata¹, Tomohisa Okazaki² (1.Disaster Prevention Research Institute, Kyoto University, 2.RIKEN)

9:45 AM - 10:00 AM

[SCG50-04] Visualization of crustal deformation in a high-strain shear zone by geodetic, geomorphologic, and geologic approaches

★Invited Papers

*Masakazu Niwa¹, Koji Shimada¹, Tsuyoshi Watanabe¹, Akira Goto¹, Shinya Hiratsuka¹ (1.Tono Geoscience Center, Japan Atomic Energy Agency)

10:00 AM - 10:15 AM

[SCG50-05] Deciphering 3-dimensional crustal movements before and after the 2011 Tohoku-oki earthquake using principal component analysis

Shuntaro Fukaya², *Takeshi Sagiya¹ (1.Disaster Mitigation Research Center, Nagoya University, 2.Graduate School of Environmental Studies, Nagoya University)

10:15 AM - 10:30 AM

[SCG50-06] Effects of a crustal heterogeneity in the postseismic deformation of 2008 Iwate-Miyagi Nairiku Earthquake

*Youichiro Takada¹, Yoshiki Takei², James Daniel Paul Moore³, Mako Ohzono⁴ (1.Faculty of Science, Hokkaido University, 2.Graduate School of Science, Hokkaido University, 3.Nanyang Technological University, Earth Observatory of Singapore, 4.Earthquake Research Institute, University of Tokyo)