Abstract Based on the finite element method, we use the postseismic GPS observation data from 5 years of the 2015 MW7.8 Nepal earthquake to constrain the rheological structure of the southern Tibet. We use two different boundary structural models to probe the boundary structure of the Indian plate and the Tibetan plateau, which are the vertical boundary structure constrained by the distance between the main front thrust(MFT) and the Indian elastic subduction slab structure, respectively. The results show that both structures can produce south-southwest horizontal motion pattern consistent with the observed data, and can explain the far-field surface displacements well. The vertical deformation obtained by the vertical boundary structure is larger. In contrast, the subduction slab structure can well explain the uplift of the Sino-Nepal border and the north. The optimal results of steady state viscosity ηm and transient state viscosity ηk of the lower crust of the Tibetan plateau are 1×1018 Pa·s and 1×1017 Pa·s, respectively.
ZHANG Jian,ZHAO Bin,WANG Dongzhen et al. Probing the Rheological Structure of Southern Tibet from the Postseismic Deformation of the 2015 MW7.8 Nepal Earthquake[J]. jgg, 2021, 41(8): 827-832.
ZHANG Jian,ZHAO Bin,WANG Dongzhen et al. Probing the Rheological Structure of Southern Tibet from the Postseismic Deformation of the 2015 MW7.8 Nepal Earthquake[J]. jgg, 2021, 41(8): 827-832.
