Affiliation: | Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University, Hakozaki 6-10-1, Fukuoka 812–81, Japan;Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia;National Research Institute for Earth Science and Disaster Prevention, Tennodai 3-1, Tsukuba, Ibaraki 305, Japan |