Preliminary Study on the Seismogeological Characteristics of the High Spatial Resolution Lithospheric Magnetic Field in Jin Ji Meng and Jing Jin Ji Regions
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摘要: 应用高精度、高密度地面磁测资料,计算获取研究区域F要素高空间分辨率岩石圈磁场数值模型,主要研究模型空间分布特征、与地震地质构造的相关性、历史地震震中在模型中的分布规律与位置特征。研究发现,研究区模型空间结构复杂,局部异常特征表现强烈,总体具有与地形、地层关系密切的分区特征;强磁异常区走向与断裂构造体系总体一致;5级以上历史地震多发生于模型低幅值区、负值区、“0”值线、高梯级带等特殊位置。Abstract: The high spatial resolution lithospheric magnetic field numerical model (ΔF) of F elements in the study area is calculated by using the high-precision and high-density ground-based magnetic survey data, and then it is analyzed comprehensively. The main contents include:the spatial distribution characteristics of the model, the correlation with the seismogeological structure, the distribution law and location characteristics of the historical epicenter in ΔF. It is found that the spatial structure of ΔF in the study area is complex, and the local anomaly features are strong, which are closely related to the topography and strata as a whole; the strike of the strong magnetic anomaly area is generally consistent with the fault structural system; the historical earthquakes with m ≥ 5 occur in the low amplitude area, negative value area, "0" value line, high gradient belt and other special locations.
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图 1 研究区野外测点示意图
(绿色圆点为地磁总强度加密区测点,红色圆点为地磁矢量约束点,黑色虚线框内部为研究区范围)
Figure 1. Schematic diagram of field survey points in the study area
(green dot is the survey point of the total intensity of geomagnetic densification area, the red dot is the constraint point of geomagnetic vector, and the black dotted box is the research area)
表 1 研究区历史地震震中部位ΔF数值统计结果
Table 1. Basic statistical results of ΔF value at the epicenter of historical earthquakes in the study area
项目 震级 5级以上 6级以上 7级以上 地震总数/个 85 20 4 震中位置处ΔF均值/nT -70.6 -75.6 -60.2 震中位置处ΔF平均幅值/nT 82.9 91.0 60.2 位于ΔF负值区的震中个数与占比/(个,%) 70,82.4% 17,85.0% 4,100.0% ΔF低幅值(小于平均幅值)区震中个数与占比/(个,%) 51,60.0% 11,55.0% 4,100.0% ΔF高幅值(大于2倍平均幅值)区震中个数与占比/(个,%) 10,11.8% 2,10.0% 0,0.0% ΔF“0”值线附近(两侧各15km范围内)震中个数与占比/(个,%) 50,58.8% 8,40.0% 2,50.0% ΔF高梯级带处震中个数与占比/(个,%) 70,82.4% 16,80.0% 3,75.0% -
陈斌, 袁洁浩, 王粲等, 2017.流动地磁监测数据处理流程.地震研究, 40(3):335-339, 510-511. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dzyj201703002 杜劲松, 胡正旺, 陈超等, 2017.大陆岩石圈大尺度磁性结构与板内地震空间分布之间的关联性.2017中国地球科学联合学术年会论文集. 冯丽丽, 王粲, 陈斌等, 2015.基于MF6, EMM2010和CGRF2010模型的中国大陆地壳磁异常特征.地震学报, 37(6):997-1010. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dizhen201506010 顾左文, 陈斌, 高金田等, 2009.应用NOC方法研究中国地区地磁时空变化.地球物理学报, 52(10):2602-2612. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dqwlxb200910020 韶丹, 贾宁, 孙哲, 2015.陕西地壳磁异常特征研究.地震研究, 38(3):396-400, 517. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dzyj201503009 宋成科, 倪喆, 苏树朋等, 2017.岩石圈磁场异常变化与岩石圈结构的关系.地震研究, 40(3):357-361, 510. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dzyj201703006 王粲, 袁洁浩, 王振东, 2017.基于2008年CHAMP卫星地磁总强度数据分析中国及邻区地磁异常特征.地震研究, 40(3):399-403. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dzyj201703014 文丽敏, 康国发, 白春华等, 2017.云南地区地壳磁异常与地质构造.地球物理学报, 60(9):3493-3504. 徐文耀, 2003.地磁学.北京:地震出版社. 徐文耀, 白春华, 康国发, 2008.地壳磁异常的全球模型.地球物理学进展, 23(3):641-651. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dqwlxjz200803002 徐晓雅, 林凤仙, 石宝文等, 2017.新疆地区岩石圈磁异常的样条模型.云南大学学报(自然科学版), 39(S2):187-191. 张忠龙, 赵育飞, 顾健, 2017.小江断裂带及邻区岩石圈磁场变化特征分析.地震研究, 40(3):372-376, 511. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=dzyj201703009 Hemant K., Mitchell A., 2009. Magnetic field modelling and interpretation of the Himalayan-Tibetan Plateau and adjoining north Indian Plains. Tectonophysics, 478(1): 87-99. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=f5510be98215705f94d1edc52dd3549b Ou J. M., Du A. M., Thebault E., et al., 2013. A High resolution lithospheric magnetic field model over China. Science China: Earth Science, 56(10): 1759-1768. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=HYC201405070000004230