孕震过程中重力位、重力、重力梯度变化的数值模拟研究  

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

作　　者：张永志[1] 李辉[2] 

机构地区：[1]中国地震局第二地形变监测中心,陕西西安710054 [2]中国地震局地震研究所,湖北武汉430071

出　　处：《地震》2002年第2期35-41,共7页Earthquake

基　　金："九五"国家科技攻关计划项目 ( 96 -91 3-0 4 -0 1 -0 3)

摘　　要：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。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 in epicentral area is investigated 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 themselves before strong earthquakes. The characteristics of gravity potential, gravity and gravity gradient variation have practical significance in predicting earthquake.

关 键 词：重力位变化 重力变化 重力梯度变化 数值模拟 地震孕育 空间分布 

分 类 号：P315.726[天文地球—地震学]