中国及邻近地区CHAMP卫星磁异常的分布特征  

Distribution of the magnetic anomaly for the CHAMP satellite in China and adjacent areas

作　　者：康国发[1] 高国明[1] 白春华[2] 王军[1] 邵丹[1] 

机构地区：[1]云南大学地球物理系,昆明650091 [2]中国科学院地质与地球物理研究所,北京100029

出　　处：《地球物理学报》2010年第4期895-903,共9页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(40864002)资助

摘　　要：本文利用CHAMP卫星磁测资料建立的新一代高阶地磁场模型POMME-4.2S,计算中国及邻区400 km高度的卫星磁异常及其垂直梯度,给出7个磁场分量的分布图,比较了截断水平对磁异常分布的影响,初步分析了磁异常与岩石圈构造的关系.主要结果表明,在四川盆地、塔里木盆地和松辽盆地等主要磁异常区,△Z异常中心的南北两边出现△X的异常中心,东西两边出现△Y的异常中心.在球谐模型为90阶时,磁异常分布的基本形态已经确定,更高的模型阶数对磁异常只有微小调整.在磁异常较强的地区,磁异常及其垂直梯度同步变化.卫星磁异常与地形变化、断裂带分布、莫霍面深度和岩石圈厚度没有直接的对应关系,而与居里等温面深度、磁性层厚度有明显的相关性.居里等温面深、磁性层较厚的地区显示正磁异常,居里等温面浅、磁性层较薄的地区显示负磁异常.Based on the new and higher degree geomagnetic model POMME-4.2S from CHAMP 〖JP2〗satellite data, we have calculated the satellite magnetic anomaly and its vertical gradient at 400 km 〖JP〗altitude in China and adjacent areas. The distributions of seven magnetic components are shown. In addition, we also compared the impact of the truncation level on the magnetic anomaly and analyzed the relationship of the anomaly and the lithospheric structure. The results indicate that, the ΔX （ΔY） magnetic anomalies foci appear on the south （west） and north （east） sides of that of ΔZ, in the main magnetic anomaly areas of Sichuan, Tarim and Songliao basins. The configuration of the magnetic anomaly distribution is determined when the spherical harmonic model is up to 90 degrees, and only a minor modification to the magnetic anomaly is available for higher degrees. The anomaly and its vertical gradient are varying synchronously in the strong magnetic anomaly areas. The satellite magnetic anomaly has no direct corresponding relations with the topographic change, the zone of rupture, the depth of Moho and the thickness of the lithosphere. However, this anomaly is connected with the depth of the Curie isotherm surface and the thickness of the magnetic layer, which is positive （negative） in the areas of deeper （shallower） Curie isotherm surface and thicker （thinner） magnetic layer.

关 键 词：CHAMP卫星 地磁场模型 岩石圈磁场 空间分布 中国地区 

分 类 号：P318[天文地球—固体地球物理学]