Constraints on chemical layering of Earth’s mantle from topography of the 660-km discontinuity

With the support from the National Natural Science Foundation of China and Chinese Academy of Sciences as well as Ministry of Science and Technology of China,the research team led by Prof.Ni SiDao(倪四道)at the State Key Laboratory of Geodesy and Earth's Dynamics,Institute of Geodesy and Geophysics,Chinese Academy of Sciences,found the s&smological evidence of small scale topography of the 660-km mantle discontinuity.