*Katsumi Kasai¹, Kazuhisa Goto¹, Hideaki Yanagisawa² (1.The University of Tokyo, 2.Tohoku Gakuin University)

*Kazuhisa Goto¹, James Goff², Joji S. Malodali³, Nilesh Kumar⁴, Takashi Ishizawa⁵, Katsumi Kasai¹, Koki Nakata¹ (1.Department of Earth and Planetary Science, The University of Tokyo, 2.University of New South Wales, 3.Mineral Resource Department, 4.University of the South Pacific, 5.Tohoku University)

*Kenta Minamidate¹, Kazuhisa Goto², Haruki Imura², Katsumi Kasai², Dai Takahashi², Takashi Ishizawa³ (1.Graduate School of Science, Tohoku University, 2.Department of Earth and Planetary Science, The University of Tokyo, 3.International Research Institute of Disaster Science, Tohoku University)

*Takashi Ishizawa¹, Kazuhisa Goto², Koki Nakata², Savelinga Faoliu³, Penikolo Vailea³, Katsumi Kasai², James Goff^4,5 (1.Tohoku University, 2.The University of Tokyo, 3.Tonga Geological Services, 4.University of New South Wales, 5.University of Southampton)

*Koki Nakata¹, Takashi Ishizawa², James Goff³, Savelinga Faoliu⁴, Penikolo Vailea⁴, Katsumi Kasai¹, Yusuke Yokoyama¹, Yosuke Miyairi¹, Kazuhisa Goto¹ (1.The University of Tokyo, 2.Tohoku University, 3.University of New South Wales, 4.Tonga Geological Services)