Research on Characteristics of Focal Rupture of the Zhangbei-Shangyi Earthquake by Means of Deformation Field Obtained by Spaceborne D-INSAR

摘要

In the last ten years, the D-InSAR (Differential Interferometric Synthetic Aperture Radar) technique has proved very useful; it has been a new space observation technique with great potential. Investigating seismic focus rupture information using D-InSAR is a scientific issue to which more attention is being paid. In this paper, the basic theory of seismic focus dislocation models is discussed briefly. Based on a map of the interferometric deformation field of the Zhangbei-Shangyi earthquake from Jan. 10, 1998, and applying the seismic focus dislocation model within elastic half-space medium; some geometrical and kinematical characteristics of the main seismic fault are deduced. Results were as follows: the seismic break surface of the Zhangbei-Shangyi earthquake is left-slip and thrust fault, striking in SEE-NWW 272°with dip angle 46°; rupture direction is unilateral faulting from SEE to NWW; length of rupture zone is 9km, width is 8km, and depth is 8km, the displacement vector of three directions are 290mm, 560mm and 0mm.