Affiliation: | Department of Natural Environmental Science, Faculty of Science, Kochi University, Akebono-cho, Kochi 780-8520, Japan (email:;),Aso Volcanological Laboratory, Faculty of Science, Kyoto University, Aso, Kumamoto 869-1400, Japan,;Disaster Prevention Research Institute, Kyoto University, Gokasyo, Uji 616-0011, Japan,;Department of Earth and Planetary Sciences, Faculty of Science, Kobe University, Nada-ku, Kobe 657-8501, Japan, and;Department of Earth and Planetary Sciences, Faculty of Science, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan |