自2006年起,北京地区一些流动重力测点测值在趋势变化的基础上加速变化,昌平和顺义等测点附近重力场非均匀性变化增强。以北京昌平重力观测点为中心增加2条重力剖面观测线,并进行3期观测,分析重力场演化特征,采用地下水重力效应经验公式、自由空气改正关系式,分别改正地下水位、地壳形变对重力典型变化点的影响。研究表明:重力变化是地下水位、地壳形变影响的结果,重力剖面观测区及附近重力变化比较平稳,变化均在误差范围内,排除该异常是地震前兆异常的可能。
The mobile gravity measured value had changed on the basis of trend changes in Beij ing since 2006 ,the non-uniformity of the variation of the gravitational field has enhanced in Changping and Shunyi measuring points near region.First,two gravity profiles observation lines to the Beijing Changping gravity observation point were added and three gravity obser-vations was did.Then,the gravity evolution characteristics were analyzed.The influence of the groundwater level and crustal deformation on gravity typical change point was corrected. Finally,it was shown that the gravity change was the influence results of the change of groundwater level and crustal deformation,the gravity profile observation area and its rela-tively gravity change was relatively stable,the gravity change was in its error range,the gravity anomaly wasn′t seismic anomaly in Beijing.