基于贝叶斯方法的内蒙古地区应力场研究  

Research on Stress Field in Inner Mongolia Based on Bayesian Method

作　　者：张帆[1,2] 崔丰智[2] 郝美仙 杨彦明[2] 李娟[2] 杨晓忠[3] ZHANG Fan;CUI Fengzhi;HAO Meixian;YANG Yanming;LI Juan;YANG Xiaozhong(School of Control and Computer Engineering,North China Electric Power University,2 Beinong Road,Beijing 102206,China;Earthquake Agency of Inner Mongolia Autonomous Region,80 Jirem Road,Hohhot 010010,China;School of Mathematics and Physics,North China Electric Power University,2 Beinong Road,Beijing 102206,China)

机构地区：[1]华北电力大学控制与计算机工程学院,北京市102206 [2]内蒙古自治区地震局,呼和浩特市010010 [3]华北电力大学数理学院,北京市102206

出　　处：《大地测量与地球动力学》2025年第3期252-259,共8页Journal of Geodesy and Geodynamics

基　　金：内蒙古自治区自然科学基金(2024MS04021);内蒙古自治区地震局局长基金(2023GG02)。

摘　　要：利用内蒙古地区728个震源机制解和2793次地震事件的14460条P波极性数据,采用3种不同策略对内蒙古地区应力场进行研究,获得地壳深层应力状态。将内蒙古地区划分为1°×1°网格,分别采用基于初动极性数据的综合震源机制方法、基于震源机制的贝叶斯右手三棱锥方法(BRTM)和极性数据反演结果与震源机制解数据加权融合方法进行反演。结果表明,基于极性数据和基于震源机制的方法具有较好的一致性。由于极性数据更为丰富,可克服震源机制解数据的有限性,获得更多区域的反演结果。将基于极性数据的反演结果与震源机制解数据加权融合后,采用BRTM方法获得125个格点的反演结果,可扩充计算区域和降低结果的不确定性。研究结果显示,内蒙古地区不同区域的应力场在空间上存在较大差异,东部地区主要表现为剪切和拉张特征,大兴安岭主脊表现为剪切特征,两侧盆地表现出拉张特征,东南部的赤峰和通辽一带局部呈现挤压特征,鄂尔多斯地块北缘主要表现出拉张特征,阿拉善地块主要表现出剪切特征;最大主应力方向存在较大差异,而最小主应力方向较为一致。We investigate the crustal stress field in Inner Mongolia using 728 focal mechanism solutions and 14460 P-wave polarity data derived from 2793 earthquakes based on three different strategies.The Inner Mongolia area is divided into 1°×1°grids,and three methods are applied:a composite focal mechanism solution method based on first-motion polarity data,a Bayesian right trihedra method(BRTM)based on focal mechanisms,and a weighted fusion method of polarity and focal mechanism data.The results from polarity-based and focal mechanism-based methods show good consistency.The abundance of polarity data,compared to limited focal mechanism data,enables stress inversion in a wider spatial extent.After weighted fusion of polarity-based results with focal mechanism data,the BRTM successfully obtains stress results at 125 grid points,expanding the coverage and reducing uncertainties.The study reveals significant spatial variations in the stress field across Inner Mongolia area.The eastern regions are dominated by shear and extension,with shearing concentrated along the Daxinganling and extension characterizing the basins on both sides.Localized compression is observed near Chifeng and Tongliao in the southeast.The northern margin of Ordos block exhibits extension characteristics,while the Alxa block displays shear features.The orientations of maximum principal stress exhibit considerable differences,while the minimum principal stress directions remain relatively uniform.

关 键 词：构造应力场 BRTM 震源机制 内蒙古 

分 类 号：P315[天文地球—地震学]