*Shinji Ohsawa¹, Kazuhiro Amita², Keika Horiguchi³, Kohei Kazahaya⁴, Hiroshi A. Takahashi⁴, Noritoshi Morikawa⁴ (1.Institute for Geothermal Sciences, Graduate School of Science, Kyoto University, 2.Graduate School of Engineering Science, Akita University, 3.Meteorological Research Institute, Japan Meteorological Agency , 4.Geological Survey of Japan, AIST)