1. Research Center for Coastal Lagoon Environments; Shimane University, Nishikawatsu-cho 1060; Matsue Shimane 690-8504 Japan
2. AIG Collaborative Research Institute for International Study on Eruptive History and Informatics, 8-19-1 Nanakuma, Jonan-ku; Fukuoka 814-0180 Japan
3. Geo-Environmental Hazards & Quaternary Geology Research Center; Korea Institute of Geoscience & Mineral Resources, Gwahak-ro 124, Yuseong-gu; Daejeon 34132 Korea