# Integrated Earthquake Catalog III: Gakkel Ridge, Knipovich Ridge, and Svalbard Archipelago
## 3 Results
### Magnitude Unification in the Integrated Earthquake Catalog
#### 3.2.2 Knipovich and Gakkel Ridges
Ratios (**a**,**b**) are constructed using Knipovich (gray dots) and Gakkel (black dots) ridges data. In (**c**), correlations of \(ML^{\rm BER}\) with \(mb^{\rm ISC}\) (blue) and \(MW^{\rm GCMT}\) (black) are very similar. The Y-axis for \(mb^{\rm ISC}\) is shifted to 0.2 in accordance with the ratio between \(mb^{\rm ISC}\) and \(MW^{\rm GCMT}\) shown in (**a**). Dots are observations, lines are the best shift-type fits. The 95% confidence intervals are not shown since they are less than 0.1. Figure 16: Correlation ratios for different magnitudes with \(M\)W\({}^{\rm GCMT}\) (black), \(mb\)\({}^{\rm ISC}\) (blue), and \(ML\)\({}^{\rm BER}\) (red) in the sub-region of Knipovich Ridge. The Y-axes for \(M\)W\({}^{\rm GCMT}\), \(mb\)\({}^{\rm ISC}\) and \(ML\)\({}^{\rm BER}\) are shifted relative to each other in accordance with the basic ratio between the magnitudes shown in Figure 15. Dots are observations, lines are the best shift-type fits. The 95% confidence intervals are not shown since they are less than 0.1. Figure 17: Correlation ratios for \(MD\)\({}^{\rm BER}\) and \(mb\)\({}^{\rm IDC}\), \(mb\)\({}^{\rm EDIC}\) with \(M\)W\({}^{\rm GCMT}\) (black), \(mb\)\({}^{\rm ISC}\) (blue), and \(ML\)\({}^{\rm BER}\) (red) in the sub-region of Knipovich Ridge. Y-axes for \(M\)W\({}^{\rm GCMT}\), \(mb\)\({}^{\rm ISC}\) and \(ML\)\({}^{\rm BER}\) are shifted relative to each other in accordance with the basic ratio between the magnitudes shown in Figure 15. Black crosses in (**b**–**d**) are the population mean of \(ML\)\({}^{\rm BER}\) and \(mb\)\({}^{\rm ISC}\). Ratios for \(mb\)\({}^{\rm IDC}\)\(mb\)\({}^{\rm EDIC}\) are constructed using the Knipovich and Gakkel ridges data. Dots are observations, lines are the best shift-type fits. The 95% confidence intervals are not shown since they are less than 0.1. The catalog of the Gakkel Ridge sub-region contains 2089 events. The magnitude \(MW^{\rm GCMT}\) is determined for 138 events, while the magnitudes \(mb^{\rm DSC}\) and \(mb^{\rm NEIC}\) are known for 1053 events. A large number of earthquakes (561) have a \(ML^{\rm FCIAR}\) magnitude, accounting, together with \(MW^{\rm GCMT}\), \(mb^{\rm DSC}\), and \(mb^{\rm NEIC}\), for almost 84% of the events. The magnitude \(MW^{\rm GCMT}\approx mb^{\rm DSC}\) + 0.2 (Figure 15a). The magnitude ratios, only using events from the Gakkel Ridge, are shown in Figure 19. We constructed ratios with \(MW^{\rm GCMT}\) and \(mb^{\rm DSC}\). The  
Figure 18: Correlation ratios for various magnitudes with \(MW^{\rm GCMT}\)(black), \(mb^{\rm DSC, NEIC}\) (blue), and \(ML^{\rm BER}\) (red) in the sub-region of Knipovich Ridge. Y-axes in (**b**,**c**) for \(MW^{\rm GCMT}\), \(mb^{\rm DSC}\) are shifted relative to each other in accordance with the basic ratio between the magnitudes shown in Figure 15. All ratios are shift type, excluding \(MS^{\rm MOS}\) (**d**), where we use linear relation. Dots are observations, lines are the best fits. Ratios are constructed using the Knipovich and Gakkel ridges data. Ratios (**f**-**h**) are poorly determined, and dashed lines show 95% confidence intervals. \(ML^{\text{FCIAR}}\) magnitude was not used due to insufficient statistics (for most events with \(ML^{\text{FCIAR}}\) it is the only determined magnitude). For local magnitudes \(ML^{\text{BER}}\), \(ML^{\text{DNK}}\), and \(ML^{\text{KOLA}}\) (a total of 45 events), ratios obtained for the Knipovich Ridge events were used, but we considered them unreliable. For 21 events, the ratios were poorly determined due to the small statistics (Figures 18e and 19h). For seven events, the ratios were not determined. In total, the unified magnitude was poorly determined for 3.5% of the events. Statistics and formulas for converting magnitudes in the Gakkel Ridge sub-region are given in Figure 16:0  
Figure 16:1 Correlation ratios for various magnitudes with \(MW^{\text{CCMT}}\) (black), and \(mb^{\text{SC}}\) (blue) in the sub-region of Gakkel Ridge.