*Xiaocan Liu¹, Junjie Chen^2,4, Peng Han³, Jiuhou Lei² (1.Institute of geophysics China Earthquake Administrition, Beijing, China, 2. School of Earth and Space Sciences, CAS Key Laboratory of Geospace Environment, University of Science and Technology of China, Hefei, China, 3.Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, China, 4.Department of Earth Sciences, University of Hongkong, Hongkong, China)