泾阳4.8级地震前后重力变化探析

系统分析了泾阳Ms4．8地震前后陕西关中地区流动重力观测资料，探讨了重力场的时空变化及其映震特征。结果表明：①震前在震中区附近形成较显著地重力负异常区，且与沉降区基本吻合。②泾阳地震震中区既是重力变化梯度带，也是重力异常的正值区到负值区的过度带。③由于震源区应力作用方式是以水平为主的左旋走滑运动，震前局部重力异常不显著。

Exploration and analysis of gravity variation before and after the Jingyang Ms 4. 8 earthquake

The mobile gravity observation data before and after the Jingyang M_S 4.8 earthquake in GuanZhong region of Shaanxi province had been systematically analyzed,and the characteristics of variation in time and spatial domains and reflection earthquake had been studied.We have the following understanding from the results.First,there was notable gravity negative anomaly area in epicenter area before the earthquake.It was coincided with subsidence area.Second,the epicenter area was gradient area of gravity anomaly i.e.transitional area from positive to negative of gravity anomaly.Third,partial gravity anomaly before earthquake was not obvious because stress action pattern was left-slip movement of horizontal.