*Yuka YOKOYAMA¹, Nozomi NAKAMURA¹, Izumi SAKAMOTO¹, Hisanori BABA¹, Asahiko TAIRA² (1. Tokai Univ., 2. IORD, Tokai Univ.)

*Nozomi HATANO¹, Ritsuho KAWANO², Kohki YOSHIDA², Ryosuke FUKUCHI³, Hiroyasu ASAHI³, Ken SAWADA^3,4 (1. Natural Environment Division, Nagano Environmental Conservation Research Institute, 2. Faculty of Science, Shinshu University, 3. Graduate School of Science, Hokkaido University, 4. Department of Earth and Planetary Sciences, Faculty of Science, Hokkaido University)

*Ryosuke FUKUCHI¹, Ken SAWADA², Hiroyasu ASAHI¹, Nozomi HATANO³ (1. Graduate School of Science, Hokkaido University, 2. Department of Earth and Planetary Sciences, Faculty of Science, Hokkaido University, 3. Natural Environment Division, Nagano Environmental Conservation Research Institute)

*Hiroko OKAZAKI¹, Hiroomi NAKAZATO², Toru TAMURA^3,4 (1. Fukada Geological Institute, 2. NARO, 3. AIST, 4. Univ. Tokyo)

*Takeshi NAKAJIMA¹ (1. Geological Survey of Japan, AIST)

*Miwa Yokokawa¹, Ren Nagano¹, Kazuma Matsunami¹, Atsuki Fukuoka¹ (1. Osaka Institute of Technology)

*Tetsuji MUTO¹, Junhui WANG^2,3 (1. Department of Environmental Sciecnce, Nagasaki University, 2. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), 3. College of Geoscience, China University of Petroleum (Beijing))

*Osamu TAKANO¹, Shuichi TOKUHASHI, Takeshi NAKAJIMA² (1. JAPEX, 2. Geological Survey of Japan, AIST)

*KEN SAWADA¹, Hiroyasu ASAHI¹ (1. Faculty of Science, Hokkaido University)

*Takanori Noguchi¹, Shun Chiyonobu¹, Hiroyuki Arato¹, Koudai Satou², Hirokazu Madokoro², Takeshi Nagayoshi² (1. Graduate School of International Resource Sciences Akita Univ. (Division of Earth Resource Science), 2. Akita Prefectural Univ.)

*Ryo MATSUMOTO¹, Lika TAKEUCHI², Hiroshi NAKAGAWA³, Tokiyuki SATO⁴, Yasufumi IRYU⁵, Hiroki MATSUDA⁶, Junko KOMATSUBARA⁷, Michio SATO⁸, Satoshi YAMAMOTO⁹ (1. Gas Hydrate Research Laboratory, Meiji University, 2. Japan Science and Technology Agency, 3. GEOWINDOW Co. Ltd., 4. Graduate School of International Resource Sciences, Akita University, 5. Dept of Earth Science, Faculty of Science, Tohoku University, 6. Faculty of Science, Earth Sciences Course, Kumamoto University, 7. AIST, 8. Meiji University, School of Agriculture , 9. Ryukyu University Faculty of Physics and Earth Sciences)