## 3 Results
At the same time, the hazardous areas of \(\approx 10\%\) are outlined in Figure 3.  
In the eastern sector of the Russian Arctic, it is impossible to perform control experiments of the \"seismic history\" type [29], which substantiate the reliability of FCAZ recognition by demonstrating the stability of the recognized zones in space and time. This is due to the lack of recognition objects (earthquake epicenters with \(M\geq 2.5\)) to perform control experiments on in such a large territory as the studied region of the eastern sector of the Russian Arctic. As mentioned above, there were no strong events in the region that could form material for conducting a pure experiment (checking the correspondence between the recognized FCAZ zones and the epicenters of earthquakes that occurred after the end of the catalog, which is a set of recognition objects). To substantiate the reliability and optimality of the recognized FCAZ zones (Figure 3), we compared them with the zones recognized using other (smaller) values of the \(M_{\rm R}\) threshold, which determines a set of objects. In other words, the number of recognition objects varied. Figures 4-7 show the FCAZ zones prone to strong earthquakes in the eastern sector of the Russian Arctic, mapped using thresholds: \(M_{\rm R}=2.0\), \(M_{\rm R}=1.5\), \(M_{\rm R}=1.0\), and \(M_{\rm R}=0.5\), which determine the set \(\overline{W}\). Figure 4: FCAZ zones prone to earthquakes (calculated at \(M_{\rm R}=2.0\)) in the eastern sector of the Russian Arctic and earthquake epicenters with \(M\geq 5.0\). Designations as in Figure 3.  
Figure 5: FCAZ zones prone to earthquakes (calculated at \(M_{\rm R}=1.5\)) in the eastern sector of the Russian Arctic and earthquake epicenters with \(M\geq 5.0\). Designations as in Figure 3.  
Figure 6: FCAZ zones prone to earthquakes (calculated at \(M_{\rm R}=1.0\)) in the eastern sector of the Russian Arctic and earthquake epicenters with \(M\geq 5.0\). Designations as in Figure 3.  
From Figures 5-7, it can be seen that FCAZ zones recognized using \(M_{\rm R}=1.5\), \(M_{\rm R}=1.0\), and \(M_{\rm R}=0.5\) have almost the same number of \"missed target\" errors as the main variant (Figure 3). Outside the recognized zones are located 20 out of 130 earthquake epicenters with \(M\geq 5.0\), 11 out of 54 with \(M\geq 5.5\), and five out of 27 with \(M\geq 6.0\). It should be noted that the area of these zones is 25-30% larger than the area of FCAZ zones in Figure 3. That is, in the case of low values of the \(M_{\rm R}\) threshold, the number of false alarms increases, which negatively affects the recognition reliability. In this case, the values \(M_{\rm R}=1.5\), \(M_{\rm R}=1.0\), and \(M_{\rm R}=0.5\) are significantly less than the magnitude \(M_{\rm c}\) (completeness magnitude) in the catalog [56; 57; 58]. This means, with such values of \(M_{\rm R}\), the set of recognition objects is an incomplete sample of earthquake epicenters, with a high probability containing numerous errors in the values of seismicity parameters. The latter affects the result of FCAZ recognition. The high seismicity zones recognized using \(M_{\rm R}=2.0\) (Figure 4) are comparable in area to the main FCAZ zones (Figure 3). The area difference is less than 1%. At the same time, we note that these zones have the following number of \"missed target\" errors: 22 earthquake epicenters with \(M\geq 5.0\), 14 with \(M\geq 5.5\), and seven with \(M\geq 6.0\), which is significantly more than the main variant. Zone analysis in Figures 3-7, the results of comparison of their areas, and statistics of \"missed target\" errors show that the FCAZ zones recognized using the threshold \(M_{\rm R}=2.5\) with the smallest area of false alarms are in the best agreement with the epicenters of known strong earthquakes in the studied region. This substantiates the reliability of the interpretation of high seismicity zones shown in Figure 3 as earthquake-prone areas with \(M\geq 5.5\) in the eastern sector of the Arctic zone of the Russian Federation.