*Kayoko Tsuruga¹, Yoshihiro Sekino¹, Jota Kanda¹, Toshifumi Hayashi¹, Ryuichi Hagita¹, Tetsutaro Aikawa¹, Takuji Hosaka¹, Hiroshi Sugawara¹, Hisatoshi Baba², Kiyoshi Suyehiro¹, Chiharu Aoyama¹, Tetsuro Tsuru¹, Kazuo Nakahigashi¹, Satoshi Ohnishi³, Takao Inamori³, Noriyuki Inoue³, Masazumi Ohnishi⁴, Toru Kuroda⁴, Toshio Iiduka⁴, Norio Murata⁴, Daiki Sugawara⁵, Yoshitaka Uyeda⁶, Kazuhiko Fujita⁶ (1.Tokyo University of Marine Science and Technology, 2.Tokai University, 3.JGI, Inc., 4.GEOSYS, Inc., 5.Kyokuto Boeki Kaisha, Ltd., 6.Seisgadget Ltd.)

*Kayoko Tsuruga¹, Yoshihiro Sekino¹, Jota Kanda¹, Toshifumi Hayashi¹, Ryuichi Hagita¹, Tetsutaro Aikawa¹, Takuji Hosaka¹, Hiroshi Sugawara¹, Hisatoshi Baba², Kiyoshi Suyehiro¹, Chiharu Aoyama¹, Tetsuro Tsuru¹, Kazuo Nakahigashi¹, Satoshi Ohnishi³, Takao Inamori³, Noriyuki Inoue³, Masazumi Ohnishi⁴, Toru Kuroda⁴, Toshio Iiduka⁴, Norio Murata⁴, Daiki Sugawara⁵, Yoshitaka Uyeda⁶, Kazuhiko Fujita⁶ (1.Tokyo University of Marine Science and Technology, 2.Tokai University, 3.JGI, Inc., 4.GEOSYS, Inc., 5.Kyokuto Boeki Kaisha, Ltd., 6.Seisgadget Ltd.)

*Yuichi Kurihara¹, Hikaru Miura¹, Toshihiro Kogure¹, Noriko Yamaguchi², Shogo Higaki³, Aya Sakaguchi⁴, Yuichi Onda⁵, Masayoshi Yamamoto⁶, Kazuya Tanaka⁷, Jota Kanda⁸, Takashi Ishimaru⁸, Yoshio Takahashi¹ (1.Department of Earth and Planetary Science, Graduate School of Science, The university of Tokyo, 2.National Institute for Agro-Environmental Sciences, 3.Radioisotope Center, The university of Tokyo, 4.Faculty of Pure and Applied Science, University of Tsukuba, 5.Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 6.Low Level Radioactivity Laboratory, Kanazawa University, 7.Japan Atomic Energy Agency, 8.Tokyo University of Marine Science and Technology)

*Miho Fukuda¹, Shinnosuke Yamazaki¹, Tatsuo Aono¹, Takashi Ishimaru², Jota Kanda² (1.National Institute for Quantum and Radiological Science and Technology, National Institute of Radiological Science, 2.Tokyo University of Marine Science and Technology)

*Yuichi Kurihara¹, Hikaru Miura¹, Toshihiro Kogure¹, Noriko Yamaguchi², Shogo Higaki³, Aya Sakaguchi⁴, Yuichi Onda⁵, Masayoshi Yamamoto⁶, Kazuya Tanaka⁷, Jota Kanda⁸, Takashi Ishimaru⁸, Yoshio Takahashi¹ (1.Department of Earth and Planetary Science, Graduate School of Science, The university of Tokyo, 2.National Institute for Agro-Environmental Sciences, 3.Radioisotope Center, The university of Tokyo, 4.Faculty of Pure and Applied Science, University of Tsukuba, 5.Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 6.Low Level Radioactivity Laboratory, Kanazawa University, 7.Japan Atomic Energy Agency, 8.Tokyo University of Marine Science and Technology)

*Miho Fukuda¹, Shinnosuke Yamazaki¹, Tatsuo Aono¹, Takashi Ishimaru², Jota Kanda² (1.National Institute for Quantum and Radiological Science and Technology, National Institute of Radiological Science, 2.Tokyo University of Marine Science and Technology)