基于实测重力数据的秦岭地区均衡异常与垂向构造应力分析  

Isostatic Anomaly and Vertical Tectonic Stress Analysis by Gravity Observations in Qinling Area

作　　者：袁华清 吴云龙[1] 许闯 张毅[1] 王振宇 YUAN Huaqing;WU Yunlong;XU Chuang;ZHANG Yi;WANG Zhenyu(Institute of Seismology,China Earthquake Administration,Wuhan 430071,China;School of Civil and Transportation,Guangdong University of Technology,Guangzhou 510006,China;Institute of Earthquake Forecasting,China Earthquake Administration,Beijing 100036,China)

机构地区：[1]中国地震局地震研究所,湖北武汉430071 [2]广东工业大学土木与交通工程学院,广东广州510006 [3]中国地震局地震预测研究所,北京100036

出　　处：《武汉大学学报（信息科学版）》2022年第6期972-978,共7页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金(41974096,41974014,41931074);广东省自然科学基金(2022A1515010396)。

摘　　要：确定秦岭地区准确的均衡异常与垂向构造应力对认识该地区深部构造特征、动力学机制等具有重要意义。目前,高精度重力数据是获取均衡异常与垂向构造应力的重要手段之一。采用高精度重力/GPS联测数据,得到秦岭地区的自由空气重力异常与布格重力异常,反演均衡异常与垂向构造应力。研究结果表明,均衡面深度在40~49 km之间,莫霍面深度范围为39~48 km,垂向构造应力大小在-28~24 MPa之间。秦岭北侧的渭河盆地处于不均衡状态;四川盆地北部的均衡异常与垂向构造应力几乎为零,地壳处于均衡状态;在秦岭出现局部的负均衡异常,表明存在一定的地壳运动。Objectives:It is important to determine the isostasy anomaly and the vertical tectonic stress for understanding the deep tectonic features and dynamics in Qinling area.At present,high-precision observation gravity data is one of the important means to obtain the isostasy anomaly and the vertical tectonic stress.Methods:The free-air gravity anomaly and the Bouguer gravity anomaly are computed by using gravity and GPS data,and the isostasy anomaly and the vertical tectonic stress are further inferred.Results:The results show that the isostasy depth is 40-49 km,the Moho depth is 39-48 km and the vertical tectonic stress carried by the crust is-28-24 MPa.Conclusions:The Weihe Basin on the northern of Qinling area is in a non-isostatic state.The isostasy anomaly and the vertical tectonic stress are approximately zero in the Northern Sichuan Basin,which indicates the basin is in an isostatic state.The local negative isostasy anomaly in Qinling indicates that there is existence crustal movement.

关 键 词：莫霍面深度 均衡面深度 垂向构造应力 秦岭地区 均衡异常 

分 类 号：P223[天文地球—大地测量学与测量工程]