低磁纬度地区磁异常化极方法及应用

Reduction to the pole and its applications in area of low magnetic latitude

1. 中国地质大学,北京100083;2. 中国地质大学,广东广州510760

1. China University of Geosciences, Beijing 100083, China;2. Guangzhou Marine Geological Survey, MLR, Guangzhou 510760, China

化极作为一种重要的数据处理方法, 很早就受到地球物理工作者的重视和研究, 并已取得了不少研究成果。但在低磁纬度地区, 作大面积化极换算并进行地质解释的工作仍处于探索阶段。采用频率域局部扇形约束函数改造化极因子的化极方法对南沙中部海磁数据的化极处理结果表明, 该方法具有处理变倾角、低纬度资料的能力, 数值恢复精度较高, 在综合解释中, 显示了良好的地质解释效果。

As an important data processing method, reduction to the pole attracted the attentions of geophysicists many years ago and has been studied for such a long period of time that a lot of research results have been achieved. In area of low magnetic latitude, however, reduction calculation over large data area and geologic interpretation of the resulted data are still in its infancy. In this paper we used a partial sector constrained function to reconstruct the factor of reduction to the pole in frequency domain. Results from data processing performed on real marine magnetic data from central part of Nansha, South China Sea showed that the reduced data is of high precision. The proposed method has the capability of tackling variable inclinations in area of low magnetic latitude. Desired geologic results have been achieved.