地球磁异常网格第3版(EMAG2v3)海平面数据质量评估——以东南亚Sulu海及北极Kolbeinsey脊南段为例

Quality evaluation of sea level data in the Earth Magnetic Anomaly Grid at 2 Arc Minute Resolution Version 3(EMAG2v3):taking the Sulu Sea in Southeast Asia and the southern section of the Kolbeinsey Ridge in the Arctic as an example

为了对地球磁异常网格第3版(EMAG2v3)海平面数据的质量进行评估,搜集整理了东南亚Sulu海和北极Kolbeinsey脊南段2个区块约30万km2的航磁异常数据,应用克里金插值法、相关分析法进行数据的对比分析.其中克里金差值法用于比较2个区块的航磁异常数据与EMAG2v3海平面数据的横向分辨率,而相关分析法是为了计算相关系数,进而判断二组数据之间的相关性程度.通过对航磁异常数据与EMAG2v3海平面数据之间相关系数及差值特征的综合分析,探讨了EMAG2v3海平面数据中Sulu海和Kolbeinsey脊南段2个区块磁力数据的质量.研究结果表明,EMAG2v3海平面数据适用性较强,但和航磁数据相比,其横向分辨率仍然较低,故认为EMAG2v3海平面数据的质量总体不高,对于较大比例尺的磁测工作,最好是依靠航空测量和海洋测量的数据,其效果会更好.

In order to evaluate the quality of the sea level data in the Earth Magnetic Anomaly Grid at 2 Arc Minute Resolution Version 3(EMAG2v3),the authors collected and collated the aeromagnetic anomaly data of two blocks(i.e.,the Sulu area of the Southeast Asia and the southern section of the Kolbeinsey Ridge in the Arctic)with a total area of 300000 km2.Kriging interpolation and correlation analysis were applied for the comparative analysis of the data.The kriging difference method is used to compare the lateral resolution of the aeromagnetic anomaly data and the sea level data in the EMAG2v3 of the two blocks,and the correlation coefficient is calculated using the correlation analysis method to determine the degree of correlation between the two sets of data.Then,through comprehensive analysis of the features of these correlation coefficients and differences between the aeromagnetic anomaly data and the sea level data in the EMAG2v3,the quality of the magnetic data of the Sulu Sea and the southern section of the Kolbeinsey Ridge was evaluated in the database EMAG2v3.The results showed that the sea level data in the EMAG2v3 are more applicable,but have lower lateral resolution compared to the aeromagnetic data.Therefore,the overall quality of the sea level data in the EMAG2v3 is still low and for larger scale magnetic survey it would be better to rely on data from aeromagnetic and marine measurements,which would be more effective.