## 3 Results  
As the magnitude threshold \(M_{\rm R}\), starting from which the earthquake epicenters are used as objects of FCAZ recognition of strong earthquake-prone areas, was chosen, \(M_{\rm R}=2.5\). The combined catalog contains 10,486 crustal events with \(M\geq 2.5\), which made up the set of recognition objects \(W\). At the first step of the set \(W\), which is a subset of the set of earthquake epicenters shown in Figure 2, the topological filtering algorithm DPS was applied. Three iterations of the algorithm were performed. The optimal values (\(q_{1}=-2.0\), \(q_{2}=-2.5\), \(q_{3}=-2.5\); \(\beta_{1}=0.1\), \(\beta_{2}=0.1\), \(\beta_{3}=0.05\)) of the input parameters of the algorithm were chosen by artificial intelligence blocks [34]. DPS clusters (Figure 3) included 67.2% of the epicenters of earthquakes with \(M\geq 2.5\) used in the problem as objects of FCAZ recognition. In other words, \(|DPS(W)|=67.2\%|W|\). In the second step, the E\({}^{2}\)XT algorithm was applied to the recognized DPS clusters. The optimal values (\(v=-4.0\)\(n\)\(w=-2.25\); the geographical grid spacing is \(0.25^{\circ}\)) of its input parameters were also selected automatically using blocks [31]. In Figure 3, a combination of green and red colors shows the result--the strong earthquake-prone areas in the eastern sector of the Russian Arctic, recognized by the FCAZ method. As can be seen from Figure 3, the recognized FCAZ zones are in good agreement with the location of the epicenters of historical and instrumental earthquakes with \(M\geq 5.0\) (Table 1). In addition, certain potential high seismicity zones (Figure 3) are well confined to the boundaries of the Eurasian, North American, and Okhotsk tectonic plates. In the zone of contact of all three plates and the Okhotsk Plate with the North American Plate (Figure 3), the FCAZ system recognized very large FCAZ zones containing half of the known strong earthquakes (Table 1). This is especially true for the northeastward elongated margin of the Okhotsk Plate, where more than a third of the known events with \(M\geq 6.0\) occurred. Furthermore, FCAZ zones are recognized within the Cherskiy Range, which is one of the main geomorphological structures (Figure 1) of the region. Within this range, a fairly large number of instrumentally registered strong earthquakes are known (Figure 3). The  
Figure 3: FCAZ zones prone to earthquakes in the eastern sector of the Russian Arctic and epicenters of earthquakes with \(M\geq 5.0\). consistency of FCAZ zones with the boundaries of tectonic plates is a significant argument in favor of the reliability of the recognition [9; 54]. Out of 130 events with \(M\geq 5.0\), only 19 (14.6%) epicenters are located outside the FCAZ zones. Note that 14 of them occurred before 1962, i.e., long before the start of systematic instrumental observations of the seismicity of the region. Their epicenters and magnitudes were determined with a significant error [15]. Thus, for six events with \(M=5.0\)-5.2, the magnitude error is \(\pm 0.5\)-0.7, and for eight events, the epicenter coordinates are determined with an error of \(\pm 1\)-2\({}^{\circ}\)[15]. At the same time, exactly half of the latter is located at the very border of the recognized FCAZ zones. Thus, with a high probability, some of the earthquakes that make up \"missed target\" errors may not be such. Let us now consider the epicenters of stronger earthquakes. Out of 54 considered events with \(M\geq 5.5\) 8 epicenters (14.8%) are located outside the zones recognized by the FCAZ method. All such events occurred before 1957, i.e., before the beginning of the instrumental earthquake catalog, and therefore, belong to the historical part of the used catalog of strong earthquakes (Table 1). The coordinates of their epicenters were determined with an error from 0.5\({}^{\circ}\) to 2\({}^{\circ}\). At the same time, half of the events have magnitudes \(M=5.5\)-5.8, estimated with an error of \(\pm 0.3\)-0.5.