STUDY ON THE CRUSTAL HORIZONTAL MOVEMENT IN FUJIAN AND ITS NEIGHBOURING SEA REGION IN 1994 TO 1997 BASED ON SEVERAL KINDS OF GPS SURVEYING DATA
ZHOU SHUO-YU;WU YUN;QIN XIAO-JUN ;SHUAI PING;SHI SHUN-YING; DENG GAN-JIN;ZHOU XING (Institute of Seismology, China Seismology Bureau, Wuhan 430071, China) LIU XU-YAN;LING JI-HUA (Seismology Bureau of Fujian Province, Fuzhou 350003, China)
This paper provides a foundation for studying dynamics of marginal sea on the southeast of China mainland. It is based on the data from GPS observation metwork of China continent and Fujian region as well as the data of IGS (International GPS Service) tracing stations around China continent during the years of 1994 to 1997. Two mechanics models of blocks movement and intra-block deformation are established. Velocity and strain rate fields of present-day crustal horizontal movement in Fujian and its neighbouring sea region are firstly studied. The results indicate that Fujian and its neighbouring sea region as a whole horizontally moves towards southeast or east-southeast namely towards sea, not only in China continent frame-work or in around China continent frame work, but also relative to Taiwan. The average velocity is 11.2 + 3.0mm/ a (by Fujian GPS network) or 14.0 ± 4.0mm / a (by China GPS network). Meanwhile, in Fujian area there is a northwest movement directing from sea to hinterland. The average velocity is 3.0 ± 2.6mm / a. The principal compressive axis of regional strain rate field lies in NW (NWW)-SE (SEE). The collision of indian plate and Euro-Asian plate affects Fujian and its neighbouring sea region by several blocks' side-transferring in China continent. The obduction and jam of Philippines-sea plate to Taiwan (southeast margin of Euro-Asia continent) also affects this region. The jointly affection still exists today. The former is stronger than the latter while the velocity field of the former is homogeneous and the one of the latte is not homogeneous.