A three-dimensional viscoelastic LDDA method is put forward on the basis of the two-dimensional elastic LDDA method and a corresponding computer program is developed. Both the method and the program, verified by a num...A three-dimensional viscoelastic LDDA method is put forward on the basis of the two-dimensional elastic LDDA method and a corresponding computer program is developed. Both the method and the program, verified by a numerical frictional experiment composed of two blocks, are correct and reliable. Simultaneously, using this program, the present velocity field of the eastern Asia area, which is induced by the collision of the Indian shield against the Asian plate, is investigated. The primary result shows that the velocity field in magnitude is largest near the colliding boundary and attenuates fast away from it. The Tibet plateau moves northeast, the North China plain and the southeastern Asia moves eastward and southeastward, respectively. The attenuation of the velocity field across Qilianshan is nonlinear, its direction changes from the northeast nearly to the east, its gradient is 0.05 mma-1km-1 and 0.007 mma-1km-1 to the southwest and the northeast of Qilianshan, respectively. The attenuation of the velocity field is almost linear across the Longmenshan fault, its gradient is 0.01 mma-1km-1 and its direction is toward the southeast. The remarkable deformation caused by collision extends to the east longitude 115 and to the north latitude 45. The velocity field obtained by the method is basically consistent with the data from the Global Positioning System. The relative slip rate along the Bangong-Nujiang-Lancangjiang fault is 0.5 mm/a, the Jinshajiang fault, 0.8 mm/a, while the Tanlu fault hardly moves. It is shown that the method proposed in this paper could be employed to study the geodynamic problems with faults.展开更多
文摘A three-dimensional viscoelastic LDDA method is put forward on the basis of the two-dimensional elastic LDDA method and a corresponding computer program is developed. Both the method and the program, verified by a numerical frictional experiment composed of two blocks, are correct and reliable. Simultaneously, using this program, the present velocity field of the eastern Asia area, which is induced by the collision of the Indian shield against the Asian plate, is investigated. The primary result shows that the velocity field in magnitude is largest near the colliding boundary and attenuates fast away from it. The Tibet plateau moves northeast, the North China plain and the southeastern Asia moves eastward and southeastward, respectively. The attenuation of the velocity field across Qilianshan is nonlinear, its direction changes from the northeast nearly to the east, its gradient is 0.05 mma-1km-1 and 0.007 mma-1km-1 to the southwest and the northeast of Qilianshan, respectively. The attenuation of the velocity field is almost linear across the Longmenshan fault, its gradient is 0.01 mma-1km-1 and its direction is toward the southeast. The remarkable deformation caused by collision extends to the east longitude 115 and to the north latitude 45. The velocity field obtained by the method is basically consistent with the data from the Global Positioning System. The relative slip rate along the Bangong-Nujiang-Lancangjiang fault is 0.5 mm/a, the Jinshajiang fault, 0.8 mm/a, while the Tanlu fault hardly moves. It is shown that the method proposed in this paper could be employed to study the geodynamic problems with faults.
