台湾海峡两岸地壳相对运动分析

ANALYSIS OF RELATIVE CRUSTAL MOVEMENT BETWEEN BOTH SHORES OF TAIWAN STRAIT

利用1995～2003年福建GPS测站与台北和桃园核心基准站资料,计算了福建GPS各测站与台北和桃园之间的边长及其相对变化,同时利用遗传算法计算了台北和桃园测点的主应变和方向角。计算结果表明,在1995～1997年和2001～2003年间台海两岸的地壳相对运动都处于拉张状态,但两期拉张的主应变大小和方向有较大变化,这种变化可能反映了1999年台湾集集7.6级地震前后应变积累与释放的过程。

On the basis of the data of Fujian GPS stations, TAIW and TWTF key observation stations during 1995 to 2003, the variations and relative variations of the lengths between Fujian GPS stations and TAIW and TWTF stations are calculated, in the meantime, strain tensors of TAIW and TWTF stations are also calculated with genetic algorithm. The results show that the crustal relative movement of Taiwan strait is in the tensile state during both the periods of 1995 to 1997 and 2001 to 2003, but the magnitude and the direction of principal strain in the two periods are with a wide variation that may reflect the process of strain energy from accumulation to release before and after the M7.6 Chi-Chi earthquake in 1999.