GRAVITY INVERSION OF DEEP INTERFACES IN THREE GORGES DAM REGION
Wang Jian 1,2) ; Shen Chongyang 1,2) ; Li Hui 1,2) ; Xiao Fan3,4) ; and Liu Xiaoling 5)
1)Key Laboratory of Earthquake Geodesy,Institude of Seismology, CEA, Wuhan 430071;
2)Wuhan Base of Institute of Crustal Dynamics, CEA, Wuhan 430071;3)61365 Troops of PLA, Tianjin 300140;4)Institute of Surveying and Mapping, Information Engineering University,Zhengzhou 450052;5)Hubei Bureau of Surveying and Mapping, Wuhan 430071
Abstract The Parker-Oldenburg iterative inversion method with constant density and variable density model was applied to the Three Gorges dam region. Comparing and analyzing the reversed results with the two models, we can obtain of the accurance undulation the upper, middle and lower crust interfaces(B3,B2,B1). The results indicated that the variable density model’s reverse results is more reliable，the general morphological characteristics of two reverse results are consistent. Between the differences of the inversion results, change of B2 is the most, the maximum difference reaches 4 km; the thickness of the middle crust in the Three Gorges dam is about 9 km which is the thinnest area in the Three Gorges region.
