Effects of Crustal Structure for Estimation of Vertical Load Deformation on the Solid Earth Using GRACE in China Mainland

When the inversion of vertical load deformation on Earth’s surface using GRACE (Gravity Recovery and Climate Experiment) data, the load Love numbers based on PREM (Preliminary Reference Earth Model) are commonly used. But the crustal structure under China mainland especially under Tibet Plateau is quite different from that given by PREM Earth model. New load Love numbers were calculated based on a modified Earth model which accounted for regional crustal structure in China mainland. And the effect of regional crustal structure in China mainland for estimation of vertical load deformation on Earth’s surface using GRACE RL05 data was investigated in this paper. It is found that the effect of crustal difference is very prominent. The relative difference of load Love numbers for vertical deformation can reach about 11% at degree 90. The extreme value of difference in vertical load deformation below 90 degree of spherical harmonic coefficients located at the southeastern Tibet Plateau and the maximum relative difference reaches 10%. The relative difference of the root mean square is about 4%. It is suggesting that an Earth model with a more realistic crustal structue instead of PREM should be used for the estimation of vertical load deformation in China mainland espacially in Tibet Plateau.     

浅议北京戒台寺滑坡坡体变形与地下采空区的关系

本文对北京戒台寺滑坡坡体内部采空区做了较为详细的论述,并进一步分析了地下采空区和坡体变形的关系。调查结果表明,采矿形成的采空区是产生滑坡的主要诱发因素。对分析由地下采空区所引发的地质灾害具有一定的借鉴意义。