Riki Miyai¹, Hideki Takami², Daisuke Muraoka², Atsushi Suzuki³, Yukihiro Nojiri⁴, *Mayuri Inoue¹ (1.Department of Earth Sciences, Okayama University, 2.Tohoku National Fisheries Research Institute, 3.Geological Survey of Japan, AIST, 4.Faculty of Science and Technology, Hirosaki University)