## 4 Discussion and Conclusions  
The methodological basis of the used approach to data analysis is the general property of synchronization of the behavior of the constituent parts of complex systems as they approach critical states [18]. The goal of all methods used is to search for synchronization effects by estimating the coherence of seismic noise in different areas of a seismically active region. In this paper, a phenomenological approach is applied to the study of complex multicomponent systems, which include Earth's crust, based on the general property of increasing the radius and the degree of strong coherence of random fluctuations in the parameters of a complex system as it approaches a sharp change in its properties as a result of its own dynamics. As a result of studying long-term continuous records of low-frequency seismic noises on a network of broadband seismic stations covering the study area, it was possible to establish the characteristic time points for changing trends in the coherence of seismic noise properties. The described approach to the analysis of continuous seismic noise records has a long history of application in various regions of the planet, both at the regional and global levels, which is reflected in publications [5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17]. Using the presented methodological approach to processing data from continuous recording of microseismic oscillations at the network of stations on the Kamchatka Peninsula and the authors' conceptual model of the seismic noise behavior based on empirical data and general ideas about the behavior of complex dynamic systems in critical conditions, a study was made of spatiotemporal variations in noise parameters for 2011-2021 in connection with five earthquakes with \(M_{w}=7.2\)-8.3. According to the distribution maps of the noise statistical parameters, the manifestation of decreased \(\alpha^{*}\), \(\Delta\alpha\), and \(\beta\) values and increased \(En\) values in the areas of future strong earthquake sources during months to years was found (Figure 4). In 2011-2018, the earthquake hazard area was located in the northern part of the region in the latitude range 54-58\({}^{\circ}\) N, in which four strong earthquakes occurred (Table 3). Since 2019, there have been changes in the spatial distribution of noise parameters, and the danger area in 2019-2021 was located to the southern part of the region (latitude range 50-54\({}^{\circ}\) N). The source of the North Kuril earthquake with \(M_{w}\) = 7.5 occurred on 25 March 2020, near this area. Thus, the conceptual model of the relationship between the changes in noise parameters and the preparation of strong earthquakes has found convincing confirmation in spatiotemporal variations in seismic noise parameters and occurred seismic events with magnitudes 7.2-8.3 for the Kamchatka region in the data for 2011-2021. Using this model, according to the observations for 2011-2016 in the author's publications made an early prediction of the area (54-58\({}^{\circ}\) N) of future subsequent earthquakes, including the Near Islands Aleutian earthquake on 17 July 2017, with \(M_{w}\) = 7.7. According to observations at of the end of 2021 and in accordance with the model, the danger area for strong earthquakes in the southern part of the region remains. Before the Sea of Okhotsk, Near Islands Aleutian and North Kuril earthquakes with \(M_{w}\geq 7.5\) (Table 3), a noise parameter synchronization effect was found by increased values of the spectral measure of coherent behavior of noise parameters' time series constructed from the data from the entire network and for groups of stations least affected by volcanic activity and sea waves. A property of this type of synchronization is an increase in the measure of spectral coherence \(\
u(\tau,\omega)\geq 0.3\) during the time period from several months to a few years before seismic events.