STUDY OF THE CHARACTERISTICS OF CRUSTAL STRESS-FIELD IN EAST CHINA BYINVERSION OF NODAL-PLANE DATA

We combine a search procedure with an optimization procedure to invert for the average stress tenser and apply this method to the study of t he crustal stress field using the data from nodal plane solutions of P wave first motion. From the analysis of data from Haicheng, Tangshan, Xingtai, Anyang, Liyang, Taiwan, Fujian and Guangdong, we have obtain ed the characteristics of the crustal stress field of East China: the directions of the principal pressure stress always possess a small dip angle but the azimuths vary from ENE (in northern East China) to ESE (in the southern part). This pattern is probably related to the effect s of convergence of the northwestern Pacific plate from the east-north east and the Philippine plate from the east-southeast.