An integrated data quality evaluation of Earth magnetic anomaly grid EMAG2v3 and global gravimetric database V29: A case study of the Aegir ridge in the Arctic

To evaluate the qualities of the marine magnetic data in the Earth magnetic anomaly grid EMAG2v3 and the marine gravity data in global gravimetric database V29, this study selected the magnetic and gravity data of the Aegir axial rift and its adjacent areas within a range of about 150 km from EMAG2v3 and V29, respectively to conduct comparative research. This study systematically collected the anomaly data of the study area from EMAG2v3 and V29 for comparison with the measured gravity and magnetic data of the study area. First, this study gridded and whitened the EMAG2v3 data, V29 data, and measured gravity and magnetic anomaly data to obtain the corresponding images. Then, this study analyzed the correlations between the EMAG2v3 data and the shipborne magnetic data and between the V29 data and the shipborne gravity data, obtaining the magnetic and gravity correlation diagrams and corresponding correlation coefficients. By comparing the correlation coefficients and differences between the two kinds of magnetic data and the two kinds of gravity data, this study conducted an integrated evaluation of magnetic the gravity data of the study area from EMAG2v3 and V29, respectively. As indicated by the results, EMAG2v3 incorporates many shipborne magnetic data, with the shipborne magnetic anomaly data showing higher quality than the data from the EMAG2v3 for areas with dense survey lines. The results also show that the shipborne gravity anomalies showed roughly the same variations as those from V29, indicating the same lateral resolution of the two types of anomaly data.