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*
王 粲1,2,袁洁浩1,王振东1

(1.中国地震局地球物理研究所,北京 100081; 2.USGS,Menlo park,CA 94025,USA)

岩石圈磁场; CHAMP卫星; 地磁总强度:卫星磁异常; 地质构造

Analysis of the Magnetic Anomalies in China and its Adjacent Areas from the CHAMP Satellite Geomagnetic Total Intensity Data in 2008
WANG Can1,2,YUANG Jiehao1,WANG Zhendong1

(1.Institute of Geophysics,China Eearthquake Administration,Beijing 100081,China)(2.USGS,Menlo park,CA 94025,USA)

lithospheric magnetic field; CHAMP satellite; geomagnetic total intensity; satellite magnetic anomalies; tectonics

备注

CHAMP卫星10年的观测任务提供了大量高精度的地磁观测数据。利用2008年CHAMP卫星地磁总强度F观测数据,通过地磁指数及地方时阈值为参数选取地磁活动较为平静期间的卫星观测资料,并利用地磁参考模型去除主磁场和外源场成分,获得了中国及邻区地磁异常分布。结果 表明:卫星磁异常的分布特征与地质构造有较好的对应关系,塔里木盆地、四川盆地、松辽盆地、印度地台及华北平原部分地区表现为正磁异常,青藏高原和阿尔泰造山带地区表现为负磁异常。

The CHAMP satellite mission provided reliable measurements for both global and regional lithospheric magnetic fields.Based on the CHAMP satellite scalar magnetic field data in 2008,we derived the scalar magnetic anomalies in China and its adjacent areas.In order to extract the lithospheric magnetic anomalies,satellite magnetic data was selected to obtain the least-disturbed data,and we chose the satellite observation data through quiet period of magnetic activity based on the magnetic index and local threshold.Then the main magnetic field,magnetospheric field,ionospheric field and induction fields were corrected,and some unrealistic observed data were deleted.The CHAMP magnetic anomalies showed good relationship with the lithospheric structure in China and adjacent areas,the high positive magnetic anomalies are mainly located at the old platform and huge basin areas,such as the Songliao basin,Sichuan basin and Tarim basin,while the negative anomalies located in fold zones,such as Tibet plateau and Altai orogenic belt.