摘要
偏应力场的定量研究结果对于揭示区域构造运动具有重要意义.本文使用重力与GPS联合观测数据计算青藏高原东北缘的重力势能,估计其产生的水平偏应力,并与全球应变率图(GSRM)进行对比分析,发现研究区域的重力势能分布形态总体具有青藏高原高、鄂尔多斯块体低的特点.重力势能最高值位于青藏高原北部,量值为1.53×10^(14) N/m,最低值位于秦岭南部,量值为1.45×10^(14) N/m.由重力势能差异引起的偏应力在青藏高原北部、鄂尔多斯块体南部和秦岭东段较大,最大值达14 MPa左右,位于青藏高原与阿拉善块体交界处.
A quantitative study on the deviatoric stress field of the Northeast Qinghai-Tibet Plateau is of vital importance to reveal the tectonic motion of this region.Based on the in-situ gravity and GPS observations,the current study calculates the gravity potential energy of the study area and evaluates the induced horizontal deviatoric stress,which is then analyzed and compared to the Global Strain Rate Map(GSRM).The results indicate that the gravity potential energy of the study area is featured by a characteristic of high values at the Qinghai-Tibet Plateau and low values at the Ordos Block.The highest value of gravity potential energy locates at the northern Qinghai-Tibet Plateau,with a magnitude of 1.53×10^(14)N/m,whereas the lowest value of gravity potential energy locates at the southern Qinling Orogen,with a magnitude of 1.45×10^(14)N/m.The deviatoric stress induced by the difference of gravity potential energy is relatively large at the northern Qinghai-Tibet Plateau,southern Ordos Block,and eastern Qinling Orogen.The largest stress occurs at the conjunction region between the Qinghai-Tibet Plateau and the Alax Block,with a magnitude of about 14 MPa.
作者
王振宇
付广裕
刘泰
郭凌冬
陈伟
房婷婷
WANG Zhen-yu;FU Guang-yu;LIU Tai;GUO Ling-dong;CHEN Wei;FANG Ting-ting(Institute of Geophysics,CEA,Beijing 100081,China;School of Geophysics and Information Technology,China University of Geosciences,Beijing 100191,China;Key Laboratory of Earthquake Forecast,Institute of Earthquake Forecasting,CEA,Beijing 100036,China)
出处
《地震》
CSCD
北大核心
2022年第2期1-13,共13页
Earthquake
基金
国家自然科学基金项目(41874003)
中国地震科学实验场专项(2019CSES0101)
中国地震局地震预测研究所基本科研业务费专项(CEAIEF20220212)
关键词
青藏高原东北缘
重力势能
动力地形
水平偏应力
the Northeast Qinghai-Tibet Plateau
Gravity potential energy
Dynamic topography
Horizontal deviatoric stress
