利用EGM2008地球重力场模型研究川西地区水平构造应力场
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摘要
利用EGM2008地球重力场模型数据计算川西地区的水平构造应力场。结果显示,采用重力场数据可以快速获得水平构造应力场图像;龙门山断裂带及鲜水河-安宁河断裂带水平构造应力聚集程度较高,构造应力值较大,反映出这些地区地质构造运动活跃;水平构造应力方向从巴颜喀拉块体到华南地块再到川滇块体呈现顺时针方向旋转;构造应力场随着深度的增加呈逐渐减小的趋势,地震活动频率也相应降低;构造应力场等值线密集区构造运动活跃、地震活动频发,表明地震活动与构造应力聚集分布存在一定的对应关系。
We studied the method of computing the horizontal tectonic stress field by the earth gravity field, and then the horizontal tectonic stress field in western Sichuan is computed with the EGM2008. The results show that we can quickly obtain the tectonic stress field using gravity field data. The horizontal tectonic of the Longmenshan and Xianshuihe-Anninghe fault zones is greater, and the accumulation degree is higher than any other area, which reflects that tectonic movement is more active in these areas. The horizontal tectonic stress from the Bayanhar block to the southern China block to the Sichuan-Yunnan block shows clockwise rotation. In the Bayanhar block and southern China block boundary, the strong stop of Sichuan basin in the south China block results in the formation of Longmenshan foreland thrust zone. The tectonic stress field gradually decreases with the increase of depth, and the frequency of seismic activity decreases accordingly. The tectonic stress field is densely distributed with active tectonic activity and frequent seismic activity, which indicates that there is a corresponding relationship between seismic activity and tectonic stress accumulation.
We studied the method of computing the horizontal tectonic stress field by the earth gravity field, and then the horizontal tectonic stress field in western Sichuan is computed with the EGM2008. The results show that we can quickly obtain the tectonic stress field using gravity field data. The horizontal tectonic of the Longmenshan and Xianshuihe-Anninghe fault zones is greater, and the accumulation degree is higher than any other area, which reflects that tectonic movement is more active in these areas. The horizontal tectonic stress from the Bayanhar block to the southern China block to the Sichuan-Yunnan block shows clockwise rotation. In the Bayanhar block and southern China block boundary, the strong stop of Sichuan basin in the south China block results in the formation of Longmenshan foreland thrust zone. The tectonic stress field gradually decreases with the increase of depth, and the frequency of seismic activity decreases accordingly. The tectonic stress field is densely distributed with active tectonic activity and frequent seismic activity, which indicates that there is a corresponding relationship between seismic activity and tectonic stress accumulation.
引文
[1] Zang A,Stephansson O. Stress Field of the Earth’s Crust[M]. London: Springer, 2010
[2] 游永雄. 重力场转换区域构造应力场的研究[J]. 地球物理学报,1994,37(增1):259-271(You Yongxiong. A Research on the Conversion of Gravity to Tectonic Stress Fields [J]. Acta Geophysica Sinica,1994,37(S1):259-271)
[3] 曹学伟. 基于大地测量资料的区域构造应力场反演及模型研究[D]. 青岛:山东科技大学,2010 (Cao Xuewei. Study on Inversion of Regional Tectonic Stress Field and Models Based on Geodesy Data [D]. Qingdao:Shandong University of Science and Technology,2010)
[4] 郭飞霄,肖云,苗岳旺. 利用EGM2008模型和地面实测重力资料反演川滇地区构造应力场[J].大地测量与地球动力学,2015,35(3):445-448 (Guo Feixiao,Xiao Yun,Miao Yuewang. Inversion of Tectonic Stress Field in Sichuan-Yunnan Area Using EGM2008 Model and Ground Gravity Observation [J]. Journal of Geodesy and Geodynamics, 2015,35(3):445-448)
[5] 向文,李辉. 重力场与构造应力场内在关系的理论研究[J]. 地壳形变与地震,1999,19(1):32-37(Xiang Wen,Li Hui. Study on the Inner Relation of Gravity to Tectonic Stress Fields[J]. Crustal Deformation and Earthquake,1999,19(1):32-37)
[6] 李忠亚,胡敏章,李辉. 华北地区重力势能差水平构造应力分布特征[J]. 大地测量与地球动力学,2017,37(9):908-912(Li Zhongya,Hu Minzhang,Li Hui. Research on Horizontal Tectonic Stress Distribution Contributed by Gravitational Potential Energy Differences in North China Area [J]. Journal of Geodesy and Geodynamics, 2017,37(9):908-912)
[7] 祝意青,闻学泽,孙和平,等.2013年四川芦山MS7.0地震前的重力变化[J].地球物理学报,2013,56(6):1 887-1 894(Zhu Yiqing,Wen Xueze,Sun Heping,et al. Gravity Change before the Lushan,Sichuan,MS=7.0 Earthquake of 2013 [J]. Chinese Journal of Geophysics,2013,56(6):1 887-1 894)
[8] 祝意青,刘芳,李铁明,等.川滇地区重力场动态变化及其强震危险含义[J].地球物理学报,2015,58(11):4 187-4 196(Zhu Yiqing,Liu Fang,Li Tieming,et al. Dynamics Variation of the Gravity Field in the Sichuan-Yunnan Region and Its Implication for Seismic Risk[J]. Chinese Journal of Geophysics,2015,58(11):4 187-4 196)
[9] NGA(2010). Earth Gravitational Model 2008 (EGM2008)[EB/OL].http://earth-info.Nga.mil/GandG/wgs84/gravitymod/egm 2008/index.html
[10] Sandwell D T,Smith W H F.Global Marine Gravity from Retracked Geosat and ERS-1 Altimetry: Ridge Segmentation versus Spreading Rate[J]. J Geophy Res, 2009, 114:B01411
[11] 章传银,郭春喜,陈俊勇,等. EGM2008地球重力场模型在中国大陆适用性分析[J].测绘学报,2009,38(4):283-289 (Zhang Chuanyin,Guo Chunxi,Chen Junyong,et al. EGM2008 and Its Application Analysis in Chinese Mainland[J]. Acta Geodaetica et Cartographica Sinica,2009,38(4):283-289)
[12] 邓起东,高翔,杨虎. 断块构造、活动断块构造与地震活动[J]. 地质科学,2009,44(4):1 083-1 093(Deng Qidong,Gao Xiang,Yang Hu. Fault-Block Tectonics,Active Fault-Block Tectonics and Earthquake Activity[J]. Chinese Journal of Geology,2009,44(4):1 083-1 093)
[13] 孟文,陈群策,吴满路,等.龙门山断裂带现今构造应力场特征及分段性研究[J].地球物理学进展,2013,28(3):1 150-1 160(Meng Wen,Chen Qunce,Wu Manlu,et al. Research on Segmentation and Characteristic of Tectonic Stress Field of Longmenshan Fault Zone[J]. Progress in Geophysics,2013,28(3):1 150-1 160)
[14] 丁开华. 青藏高原中东部地区的现今地壳形变研究[D]. 武汉:武汉大学,2010 (Ding Kaihua. Research on Present-Day Crustal Deformation of Central and East Qinghai-Tibet Plateau[D]. Wuhan:Wuhan University,2010)
[15] 赵静,江在森,牛安福,等.川滇菱形块体东边界断层闭锁程度与滑动亏损动态特征研究[J].地球物理学报,2015,58(3):872-885(Zhao Jing,Jiang Zaisen,Niu Anfu,et al. Study on Dynamic Characteristics of Fault Locking and Fault Slip Deficit in the Eastern Boundary of the Sichuan-Yunnan Rhombic Block [J]. Chinese Journal of Geophysics,2015,58(3):872-885)
[2] 游永雄. 重力场转换区域构造应力场的研究[J]. 地球物理学报,1994,37(增1):259-271(You Yongxiong. A Research on the Conversion of Gravity to Tectonic Stress Fields [J]. Acta Geophysica Sinica,1994,37(S1):259-271)
[3] 曹学伟. 基于大地测量资料的区域构造应力场反演及模型研究[D]. 青岛:山东科技大学,2010 (Cao Xuewei. Study on Inversion of Regional Tectonic Stress Field and Models Based on Geodesy Data [D]. Qingdao:Shandong University of Science and Technology,2010)
[4] 郭飞霄,肖云,苗岳旺. 利用EGM2008模型和地面实测重力资料反演川滇地区构造应力场[J].大地测量与地球动力学,2015,35(3):445-448 (Guo Feixiao,Xiao Yun,Miao Yuewang. Inversion of Tectonic Stress Field in Sichuan-Yunnan Area Using EGM2008 Model and Ground Gravity Observation [J]. Journal of Geodesy and Geodynamics, 2015,35(3):445-448)
[5] 向文,李辉. 重力场与构造应力场内在关系的理论研究[J]. 地壳形变与地震,1999,19(1):32-37(Xiang Wen,Li Hui. Study on the Inner Relation of Gravity to Tectonic Stress Fields[J]. Crustal Deformation and Earthquake,1999,19(1):32-37)
[6] 李忠亚,胡敏章,李辉. 华北地区重力势能差水平构造应力分布特征[J]. 大地测量与地球动力学,2017,37(9):908-912(Li Zhongya,Hu Minzhang,Li Hui. Research on Horizontal Tectonic Stress Distribution Contributed by Gravitational Potential Energy Differences in North China Area [J]. Journal of Geodesy and Geodynamics, 2017,37(9):908-912)
[7] 祝意青,闻学泽,孙和平,等.2013年四川芦山MS7.0地震前的重力变化[J].地球物理学报,2013,56(6):1 887-1 894(Zhu Yiqing,Wen Xueze,Sun Heping,et al. Gravity Change before the Lushan,Sichuan,MS=7.0 Earthquake of 2013 [J]. Chinese Journal of Geophysics,2013,56(6):1 887-1 894)
[8] 祝意青,刘芳,李铁明,等.川滇地区重力场动态变化及其强震危险含义[J].地球物理学报,2015,58(11):4 187-4 196(Zhu Yiqing,Liu Fang,Li Tieming,et al. Dynamics Variation of the Gravity Field in the Sichuan-Yunnan Region and Its Implication for Seismic Risk[J]. Chinese Journal of Geophysics,2015,58(11):4 187-4 196)
[9] NGA(2010). Earth Gravitational Model 2008 (EGM2008)[EB/OL].http://earth-info.Nga.mil/GandG/wgs84/gravitymod/egm 2008/index.html
[10] Sandwell D T,Smith W H F.Global Marine Gravity from Retracked Geosat and ERS-1 Altimetry: Ridge Segmentation versus Spreading Rate[J]. J Geophy Res, 2009, 114:B01411
[11] 章传银,郭春喜,陈俊勇,等. EGM2008地球重力场模型在中国大陆适用性分析[J].测绘学报,2009,38(4):283-289 (Zhang Chuanyin,Guo Chunxi,Chen Junyong,et al. EGM2008 and Its Application Analysis in Chinese Mainland[J]. Acta Geodaetica et Cartographica Sinica,2009,38(4):283-289)
[12] 邓起东,高翔,杨虎. 断块构造、活动断块构造与地震活动[J]. 地质科学,2009,44(4):1 083-1 093(Deng Qidong,Gao Xiang,Yang Hu. Fault-Block Tectonics,Active Fault-Block Tectonics and Earthquake Activity[J]. Chinese Journal of Geology,2009,44(4):1 083-1 093)
[13] 孟文,陈群策,吴满路,等.龙门山断裂带现今构造应力场特征及分段性研究[J].地球物理学进展,2013,28(3):1 150-1 160(Meng Wen,Chen Qunce,Wu Manlu,et al. Research on Segmentation and Characteristic of Tectonic Stress Field of Longmenshan Fault Zone[J]. Progress in Geophysics,2013,28(3):1 150-1 160)
[14] 丁开华. 青藏高原中东部地区的现今地壳形变研究[D]. 武汉:武汉大学,2010 (Ding Kaihua. Research on Present-Day Crustal Deformation of Central and East Qinghai-Tibet Plateau[D]. Wuhan:Wuhan University,2010)
[15] 赵静,江在森,牛安福,等.川滇菱形块体东边界断层闭锁程度与滑动亏损动态特征研究[J].地球物理学报,2015,58(3):872-885(Zhao Jing,Jiang Zaisen,Niu Anfu,et al. Study on Dynamic Characteristics of Fault Locking and Fault Slip Deficit in the Eastern Boundary of the Sichuan-Yunnan Rhombic Block [J]. Chinese Journal of Geophysics,2015,58(3):872-885)