1. Institute of Geology and Geophysics, Chinese Academy of Sciences, Key Laboratory of Earth and Planetary Physics , Beijing 100045 , China
2. University of Chinese Academy of Sciences, College of Earth and Planetary Sciences , Beijing 101408 , China
3. Institute of Geology and Geophysics, Chinese Academy of Sciences, Heilongjiang Mohe Observatory of Geophysics , Beijing 100045 , China
4. University of California at Santa Cruz, Institute of Geophysics and Planetary Physics , Santa Cruz, CA 95064 , USA