Shu-Kun Hsu, National Central University, Department of Earth Sciences, Kanagawa, Japan, Leo T Armada, University of the Philippines, National Institute of Geological Sciences, Quezon, Philippines, Yi-Ching Yeh, Department of Earth Sciences, National Central University, Taoyuan City, Taiwan, Carla B. Dimalanta, National Institute of Geological Sciences, University of the Philippines, Quezon City, Philippines, Ching-hui Tsai, National Central University, Center for Environmental Studies, Jhongli, Taiwan and Teresito Bacolcol, Philippine Institute of Volcanology and Seismology, Quezon City, Philippines