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《地震研究》[ISSN:1000-0666/CN:53-1062/P]

卷:

44

期数:

2021年04期

页码:

635-641

栏目:

出版日期:

2021-11-10

文章信息/Info

Title:

Lithospheric Magnetic Field Distribution in Changning Area,Sichuan Province

作者:

蔡苏苏; 陈 斌

(中国地震局地球物理研究所,北京 100081)

Author(s):

CAI Susu; CHEN Bin

(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China)

关键词:

长宁地区;  岩石圈磁场;  曲面样条;  嵌入体

Keywords:

Changning area;  lithospheric magnetic field;  surface spline;  embedded body

分类号:

P318.2

DOI:

-

摘要:

基于四川长宁地区平均点距为2 km的952个地磁总强度测量数据,经过日变化改正、主磁场剥离以及曲面样条插值等数据处理,得到长宁背斜附近地区的岩石圈磁场分布。结果表明:岩石圈磁场总强度范围为-400～200 nT,中值约为-4.4 nT,90%的数据位于(-4.4±32)nT。长宁背斜内部对应岩石圈正值区域,背斜边界对应负值区。边界区域内最显著的负值区域位于长宁背斜的西北端,背斜东北侧以正值区域为主,背斜南侧以负值区域为主。罗场向斜与建武向斜之间的高地震活动区域对应岩石圈磁场的正值区域。岩石圈磁场空间分布说明长宁背斜东、西部之间存在岩石圈磁场的局部负值嵌入体,该嵌入体或许造成了背斜东、西两部分的地震活动性的差异,背斜东、西部的岩石圈磁场梯度呈现西高东低的差异性分布。

Abstract:

The existing geomagnetic field models cannot provide the fine structure of local lithospheric magnetic field in Changning area,Sichuan province. Relied on geomagnetic total intensity measuremed data on 952 stations with 2 km average interval in this area, through data processing such as diurnal variation correction, main magnetic field stripping and surface spline interpolation, we obtained distribution of lithospheric magnetic field in the area near the Changning anticline.The total intensity of the lithospheric magnetic field ranged from -400 nT to 200 nT, with a median of about -4.4 nT, and 90% of the data lies between(-4.4±32)nT. The inner part of the Changning anticline corresponds to a positive region of lithospheric magnetic field, while the anticline boundary corresponds to a negative region. The most significant negative area in the boundary region is located in the northwest end of the Changning anticline, the northeast of the anticline is dominated by positive region, and the south of the anticline is dominated by negative region. The high seismic activity region between the Luochang syncline and the Jianwu syncline corresponds to a positive region of lithospheric magnetic field. The spatial distribution of the lithospheric magnetic field indicates that there are local negative intercalations of the lithospheric magnetic field between the east and west parts of the Changning anticline, which may block the seismic activity of the two parts of the anticline. At the same time, the lithospheric magnetic field gradient in the east and west of anticline presents a differential distribution of high in the west and low in the east.

参考文献/References:

-

备注/Memo

备注/Memo:

收稿日期:2021-02-26
基金项目:国家重点研发计划“地球物理探测卫星数据分析处理技术与地震预测应用研究”子课题“全球/区域地球物理场精细建模技术”(2018YFC1503504)资助.

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更新日期/Last Update: 2021-11-10