Simulation of co-seismic gravity change and deformation of Wenchuan Ms8. 0 earthquake

:Surface co-seismic gravity changes and displacements caused by the Wenchuan Ms8. 0 earthquake are calculated on the basis of the half-space dislocation theory and two fault models inversed, respectively, by Institute of Geophysics, CEA and USGS. The results show that 1) the dislocation consists of dip slip and right-lateral strike slip; 2) the co-seismic gravity change shows a four-quadrant pattern, which is greatly controlled by the distribution of the vertical displacements, especially in the near-filed; 3) the gravity change is generally less than 10 × 10− 8 ms− 2 in the far-field, but as high as several 100 × 10− 8 ms− 2in the near-filed. These results basically agree with observational results.