地磁正常场的选取与地磁异常场的计算SELECTIONS OF THE .PDF

地磁正常场的选取与地磁异常场的计算 高金田 1 安振昌 2, 1 顾左文 1 韩炜 1 詹志佳 1 姚同起 1 1 中国地震局地球物理研究所，北京 100081 2 中国科学院地质与地球物理研究所，北京 100029 摘要：根据 2003 年中国地磁观测数据（包括 135 个地磁测点和 35 个地磁台）以及我国邻近地区 38 个 IGRF 计 算点的地磁数据，计算中国地磁异常场的分布．选取两种地磁场模型作为地磁正常场，一是国际参考地磁场的球谐 模型，二是中国地磁场泰勒多项式模型．根据各个测点的磁异常值（观测值减去模型计算值 ），用球冠谐分析方法 计算地磁异常场的球冠谐模型，并绘制 2003 年中国地磁异常图（ΔD, ΔI, ΔF, ΔX, ΔY, ΔZ ）．分析和讨论了中 国地磁异常场． 关键词：地磁场 地磁正常场 地磁异常场 泰勒多项式方法 球冠谐分析方法 中国地区 文章编号：0001-5733(2005)01-0056-07 中图分类号：P318 收稿日期：2004-02-17，2004-09-20收修定稿 SELECTIONS OF THE GEOMAGNETIC NORMAL FIELD AND CALCULATIONS OF THE GEOMAGNETIC ANOMALOUS FIELD GAO Jin-Tian1 ,AN Zhen-Chang 2,1 ,GU Zuo-Wen1 ,HAN Wei1 ,ZHAN Zhi-Jia1 ,YAO Tong-Qi1 1 Institute of Geophysics，China Earthquake Administration，Beijing 100081, China 2 Institute of Geology and Geophysics, Chinese Academy of Sciences ，Beijing 100029, China Abstract ：According to the geomagnetic observation data in China for 2003, including 135 geomagnetic stations and 35 geomagnetic observatories, and the geomagnetic data of 38 IGFR calculated points in China’s adjacent regions, the distribution of the geomagnetic anomalous field in China was calculated. The two kinds of geomagnetic models are selected as the geomagnetic normal field: one is the spherical harmonic model of the international geomagnetic reference field, and the other is the Taylor polynomial model of the geomagnetic field in China ． Based on the geomagnetic anomaly values (the observed value minus the model calculated value) at various stations, the spherical cap harmonic model of the geomagnetic anomalous field was calculated by using the spherical cap harmonic analysis method. The geomagnetic anomaly charts （ΔD, ΔI, ΔF, ΔX, ΔY and ΔZ ）in China for 2003 are drawn ．