*Hidenori KUMAGAI1, Hiromi WATANABE2, Takuya YAHAGI3, Shigeaki KOJIMA4, Shun'ichi NAKAI5, Shin TOYODA6, Jun-ichiro ISHIBASHI7
(1.Submarine Resources Research Project, JAMSTEC, 2.Japan Agency for Marine-Earth Science and Technology, 3.Graduate School of Frontier Sciences, The University of Tokyo, 4.Atmosphere and Ocean Research Institute, The University of Tokyo, 5.Earthquake Research Institute, University of Tokyo, 6.Department of Applied Physics, Faculty of Science, Okayama University of Science, 7.Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University)