【摘要】 根据GPS点观测结果计算得出山西断陷带各地段 1999～ 2 0 0 3年的水平形变场存在差别 ,并有瞬时变化 ,应变场也有同样的情况。山西断陷带内的M≥ 4地震多发生在GPS点位移速率矢量较大的地区 ,且随着震级增大形变特征也愈显著。地震区的最小主应变速率和最大剪应变速率一般都较大 ;最小主应变轴的优势方向各时间段差别较大。山西断陷带的主体走向与最小主应变速率轴夹角较小 ,与最大主应变速率轴夹角相对较大 ,在最小和最大主应变速率轴代表的主压应力和主张应力共同作用下 ,山西断陷带的主体应变发生右旋张剪活动。更多还原

【Abstract】 In different sections of the Shanxi fault subsidence zone there are differences and temporal variation of horizontal deformation field and strain field calculated from GPS observations.In Shanxi fault subsidence zone,the earthquakes of %M%≥4 occured in the areas where the displacement rate vectors of GPS sites are larger and the larger the magnitudes of earthquakes are, the more distinct the ground deformation features are.In addition the minimal principal strain rate and maximal shear strain rate in seismic region is comparatively larger .In the Shanxi fault subsidence zone the differences of the dominant directions of the minimal principal strain axis are obvious in different periods.The angle between the dominant strike of Shanxi fault subsidence zone and the minimal principal strain rate axis is small,and that with the maximal principal strain rate axis is large.Under the joint action of the principal compressive stress and principal tensile stress represented by the minimal and maximal principal strain rate axes,the right-lateral dominant tenso-shear activity ought to take place in Shanxi fault subsidence zone.更多还原