定远M_L 4.7地震前后皖北区域重力场的变化特征  

CHARACTERISTICS OF LOCAL GRAVITY VARIATION BEFORE AND AFTER DINGYUAN M_L 4.7 EARTHQUAKE

作　　者：徐如刚[1] 张毅[1] 顾春雷[1] 王雷[1] 朱志春[1] 孙少安 李辉 

机构地区：[1]安徽省地震局,合肥230031 [2]中国地震震研究所,武汉430071

出　　处：《大地测量与地球动力学》2009年第4期38-41,共4页Journal of Geodesy and Geodynamics

基　　金：安徽省地震局科研项目(200827)

摘　　要：利用安徽皖北流动重力监测网2005—2007年的流动重力观测资料,分析了安徽定远ML4.7地震前后皖北区域重力场的动态变化特征。研究结果表明:地震发生在重力负值变化(高值区附近的重力变化)高梯度带上;震前震中附近重力场发生明显减弱,并沿断裂产生重力变化高梯度带;震后重力场呈松驰反向恢复;重力场的动态变化清晰地反映出震源应力场引起的重力源兆变化特征。By use of mobile gravity data in the northern area of Anhui province during 2005 - 2007, the dynamical gravity variation features before and after Dingyuan ME4.7 earthquake are analyzed. The results show that Dingyuan earthquake occurred in the high gradient zone of gravity variation near the area with high negative gravity variation. Before the earthquake, the gravity values around epicenter decreased, at the same time the high gravity gradient belt came into being along active faults;after the earthquake, the gravity field takes on relax and resumption. The dynamic gravity variations clearly reflect the features of source precursor caused by stress field of seismic focus.

关 键 词：定远地震 重力异常 变化特征 流动重力 源兆 

分 类 号：P315.726[天文地球—地震学]