## 3 Results and Discussion  
The results shown in Figure 2a, together with the fact that the variability \(\beta_{W}\) of the OP of seismicity when using local EQ catalogs in various regions of the world [74,77,133] has been made for \(M\geq M_{\textit{thres}}\) with \(M_{\textit{thres}}=3.5\), led us to select for such an analysis in natural time only the EQs with \(M\geq 3.5\). Upon this selection, we have that the average rate of EQs (of \(M\geq 3.5\)) within \(\mathrm{N}_{33}^{46}\mathrm{E}_{20}^{48}\) is around 50 EQs per month. By employing the method of analysis presented in Section 2.3, we found for \(\beta_{W}\) with \(W=300\), 250, 200, 150, and 100, which correspond to time periods of six to two months practically covering the aforementioned lead time of SES activities, the results shown in Figure 4.  
In this figure, we present \(\beta_{W}\) during the almost 20-year period 1 January 2002 to the time of occurrence of the Kahramanmaras, Turkey, EQ doublet on 6 February 2023. In Figure 4e, we present in an expanded time scale the results during the final period from 1 January 2022 to 6 February 2023. Although \(\beta_{W}\) for different values of \(W\) exhibit different dynamics, we observe that _all_\(\beta_{W}\) values studied exhibit local minima during the period from 14 August 2022 to 18 October 2022 whose values lie between \(\beta_{300,min}=0.319\) and \(\beta_{200,min}=0.297\). The ratio \(\beta_{300,min}/\beta_{200,min}\approx 1.07\) falls within the limits found [133] in Japan for the variability minima that preceded all EQs of magnitude \(M\geq 7.6\) since 1984 (cf. this criterion was also found valid; see, e.g., Section 1.5.1 of [38], for the case of the 2015 \(M_{w}\)7.9 Ogasawara EQ, which is the single \(M\geq 7.6\) EQ in Japan after the M9 Tohoku EQ studied in [133]). As stated in the Appendix of [134], for a variability minimum to be of precursory nature, the EQs that lead to the minima \(\beta_{200,min}\) and \(\beta_{300,min}\) should belong to the same _critical_ process before the strong EQ. This fact was secured [134] by inspecting whether 90% of the EQs that led to \(\beta_{200,min}\) are included in the EQs that led to \(\beta_{300,min}\). Turning now to the present case, we examine whether such a critical process is also observed in the present case. For this reason, we inspect from the EQ catalog whether the EQs that lead to a minimum, e.g., \(\beta_{100,min}\), are included in the EQs leading to \(\beta_{150,min}\) or \(\beta_{200,min}\) or \(\beta_{300,min}\). We found that in all combinations \(W^{\prime}<W\), the EQs that lead to \(\beta_{W^{\prime},min}\) of Figure 4e are included in the EQs that lead to \(\beta_{W,min}\) with percentages that exceed 98%. Hence, according to [134], the variability minima of Figure 4e belong to the same critical process that preceded by almost three and a half months (when considering the time lag \(\Delta t_{300}\) since \(\beta_{300,min}\)) the Kahramanmaras, Turkey, EQ doublet. An inspection of Figure 4 reveals that such a critical process leading to simultaneous (within almost two months, i.e., 14 August to 18 October 2022) minima of \(\beta_{W}\) within the aforementioned limits \([0.297,0.319]\) is unique during the almost 20-year period of our study that consists of 241 months. Hence, the probability of observing by chance such a phenomenon could be approximated by \(2/241\approx 1.2\%\), which points to the statistical significance of the critical process identified in Figure 4e. Here, we note that NTA focuses on the identification of precursory behavior before strong EQs. An inspection of Figure 4 reveals that during the study period from 1 January 2002 to the time of occurrence of the Kahramanmaras-Gaziantep \(M_{w}\)7.8 Pazarcik EQ, the only EQ with \(M>7.0\) that occured in the region is the \(M_{w}\)7.3 Halabaya EQ on 12 November 2017 [135]; see Figure 4d.