A deflection process for the stress field of the Jiashi strong earthquake sequence
伽师强震系列应力场的转向过程

The Central Moment Tensor (CMT) solutions of Jiashi strong earthquake sequence issued by Harvard University are used to inverse the regional stress field. The systematic cluster analysis of the CMT solutions shows the time_sequence features of three periods. Further analysis of the stress field for the focal region indicates that the variations took place in the period from March 1, 1997 to Jan. 4, 2003. Since Feb. 24, 2003, the direction of basic stress field was recovered. Thus a complete process from the initial variation of the basic stress field to the final recovery of the basic stress field finished. Combining the stressed conditions and tectonic background of the region, the genesis for the stress field variation of the strong earthquake sequence is discussed. We suggest that the Jiashi strong earthquake sequence has the characteristics of body fracture.