伽师及其邻近地区重力场动态演化特征初步分析

通过对伽师及邻近地区2005~2007年5期流动重力测量资料的系统分析,研究了该区域重力场的时空动态演化特征。结果表明,重力变化与构造环境变化有关,地震孕育发生阶段,重力场将有明显的异常变化。地震多发于重力变化正负值交替的零线附近,正负重力异常变化梯度带的附近是物质增减差异剧烈的地区,能量易于积累,从而产生地震。与GPS观测结果相互印证,表明受大的构造背景影响,测区内重力异常的正负值分布反映了区域间的应力挤压作用。

PRELIMINARY ANALYSIS ON DYNAMIC EVOLUTION CHARACTERISTICS OF GRAVITATIONAL FIELD IN JIASHI AND ITS ADJACENT REGION

Analyzing the datum of mobile gravimetric survey in Jiashi and its adjacent region from 2005 to 2007,studied the time and space dynamic evolution characteristics of gravitational field.The result shows that,gravity change is relation with tectonic environment change,during earthquake gestation,gravitational field have obvious anomalous change.Most earthquakes occurred in the region with zero value among the positive and negative value for gravity;In the region with anomalous change grads of positive and negative value for gravity,matter have bigger difference,the energy are liable to accumulate,earthquakes are easy to occur.Contrasting with GPS observation datum,the result shows that,it affected by large tectonic background,and distribution of anomalous positive and negative value for gravity reflected the stress extrusion action in observation region.