孕震过程中重力位、重力、重力梯度变化的数值模拟研究

简要介绍了为探索和解释地震前后重力变化的各种孕震模式,推导了由孕震引起的密度变化和位移与地面重力位、重力、重力梯度之间的变化关系。摸拟计算了孕震位移和密度变化引起的重力位、重力、重力梯度变化的空间分布并分析了重力位、重力、重力梯度变化的空间分布特征。与此同时,采用广义司托克斯云积分和有限差分方法对云南丽江7. 0级地震前重力位、重力、重力水平梯度进行了计算。结果表明,强震前重力位、重力、重力梯度有其自身的变化特征,这对预测强震有实际意义。

The variation of gravity potential, gravity and gravity gradient caused by deformation and density variation

In this paper, gravity potential, gravity and gravity gradient variation caused by movement and density variations of deformation models are discussed. With a spherical model, the variation of gravity potential, gravity and gravity gradient caused by deformation and density variation model occurred inepicentral area is investiga ted and derived. At the same time, variation of gravity potential, gravity and gravity gradient are calculated with stock formulas and differential method before Lijiang M_S = 7. 0 earthquake, 1996 with gravity data observed from 1992 to 1995 repetitively. The results show that gravity potential, gravity and gravity gradient vary with some laws by them selves before strong earthquakes. The characteristics of gravity potential, gravity and gravity gradient variation have practical significance in predicting earthquake.