*Yukihiro Nakatani¹, Hiroshi Yakiwara¹, Shuichiro Hirano², Reiji Kobayashi², Hiroki Miyamachi², Shigeru Nakao², Yusuke Yamashita³, Kazunari Uchida⁴, Takeshi Matsushima⁴, Hiroshi Shimizu⁴, Kazuo Nakahigashi⁵, Tomoaki Yamada⁶, Hideji Abe⁷, Masanao Shinohara⁷ (1.Nansei-Toko Observatory for Earthquakes and Volcanoes, Kagoshima University, 2.Graduate School of Science and Engineering, Kagoshima University, 3.Disaster Prevention Research Institute, Kyoto University, 4.Institute of Seismology and Volcanology, Faculty of Science, Kyushu University, 5.Tokyo University of Marine Science and Technology, 6.Japan Meteorological Agency, 7.Earthquake Research Institute, the University of Tokyo)