*Xiaoqiu Yang¹、Weiren Lin^2,3、Osamu Tadai⁴、Xin Zeng¹ (1.South China Sea Institute of Oceanology, Chinese Academy of Sciences、2.Graduate School of Engineering, Kyoto University、3.Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC)、4.Marine Works Japan Ltd.)