Interpretation of the coseismic surface deformation of Wenchuan earthquake based on the theory of disclination and dislocation

Abstract

A combination model of disclination-dislocation which can describe the three-dimensional translational and rotational motion of the fault is given. We used the combined model and the dislocation model to calculate the coseismic horizontal displacement of 102 points of Wenchuan earthquake respectively. The result indicates that the horizontal displacements calculated by the two models are generally in agreement with the GPS observations both in magnitude and direction, but there are some differences in some points. When the magnitudes of horizontal displacements by the two models are close to each other, we calculate their direction residuals by taking the direction of the GPS observations as the true value. It is found that the directions residuals calculated by the two models are concentrated between [-20°, 20°], and the number of points accounts for 84.3% of the total in this interval. In the interval where the direction residuals is smaller, the percentage of the number of the points calculated by the combined model is greater than that calculated by the dislocation model, indicating that the combined model can better explain the surface deformation observation.