基于直立长方体模型的山体隆升与重力变化关系数值模拟  

Simulation of the Relationship between the Surface Deformation and the Gravity Variation Based on Vertical Cuboid

作　　者：梁晨昊 申重阳[1] 王嘉沛 LIANG Chenhao;SHEN Chongyang;WANG Jiapei(Key Laboratory of Earthquake Geodesy,Institute of Seismology,China Earthquake Administration,Wuhan 430071,China)

机构地区：[1]中国地震局地震研究所地震大地测量重点实验室,湖北武汉430071

出　　处：《地震研究》2021年第2期162-169,共8页Journal of Seismological Research

基　　金：国家自然科学基金项目(41674018)资助。

摘　　要：基于形变与密度变化耦合运动理论,利用时变场内重力垂直梯度的计算方法,采用直立长方体模型,根据青藏高原平均降升速率,模拟计算在艾黎地壳均衡模式下,地表形变所引起重力及其垂直梯度的变化。结果显示,在山体抬升过程中,伴随着地表的隆升,重力值亦逐渐减小,导致其减小的原因为介质体密度减小与测点的高度增加。伴随着山体最高点抬升了5 cm,在最高点处重力变化为-14μGal,对应的重力梯度约为-2.6 E。重力垂直梯度与静态场重力梯度存在一定的差异,其原因为在重力梯度场中加入了时间效应。Based on the coupling theory of deformation and density variation, the vertical gradient of gravity in time-varying field is calculated.By the help of the vertical cuboid and average uplift rate of the Tibetan plateau, the process of the mountain movement is simulated, and the variation of gravity and its vertical gradient caused by surface deformation is simulated in accordance with the Airy equilibrium model.The results show that in the process of mountain uplift, the gravity value gradually decreases.It is speculated that the gravity decrease is caused by the decrease of medium density and the increase of the height of the measuring point.The mountaintop where the maximum gravity value appears rises for 5 cm, as a result, the maximum gravity changes for-14 μGal, and the corresponding gravity gradient is about-2.6 E.Due to the time effect in the gravity gradient field, there is a certain difference between the vertical gravity gradient and the static gravity gradient.

关 键 词：耦合运动 地表形变 重力变化 重力垂直梯度 

分 类 号：P315.721[天文地球—地震学]