*Subhajit Ghosh^1,2、Arijit Laik²、Santanu Bose^2,3、Nibir Mandal⁴ (1.Earthquake Research Institute, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-Ku, Tokyo 113-0032、2.Department of Geology, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India、3.Department of Geology, Presidency University, 86/1 College Street, Kolkata 700073, India、4.Department of Geological Sciences, Jadavpur University, Kolkata 700032, India)