1. State Key Laboratory of Geodesy and Earth’s Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, No. 340, Xudong Street, Wuhan 430077, China, zwli@whigg.ac.cn
2. Department of Earth and Environmental Sciences, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180
3. China Earthquake Networks Center, No. 5, Sanlihenanheng Street, Xicheng District, Beijing 100045, China
4. Department of Earth Sciences, University of Minnesota, 100 Church Street S.E., Minneapolis, Minnesota 55455
5. Also at Ultimate Vision Technology, Beijing 100190, China.