# Integrated Earthquake Catalog III: Gakkel Ridge, Knipovich Ridge, and Svalbard Archipelago
## 3 Results  
### Merging Catalogs  
As shown in (Table S1, see Supplementary), in the studied region, a significant majority of events are registered by European seismic networks, the data of which are collected in the composite ISC catalog. The number of earthquake records in the ISC catalog is approximately three times greater than the total number of events in the Russian catalogs. Moreover, the data on earthquakes presented in [29] was specified based on the analysis and combination of all available seismic bulletins of Russian and European seismic networks using modern velocity models of the environment. Thus, in the task of merging earthquake catalogs, the following priority sources of earthquake data were chosen (Table 1, Figure 3):  
1. Earthquakes from the Morozov catalog (4 events);
2. Earthquakes from the ISC catalog (16,937 events);
3. Earthquakes from catalogs of ARC (2404 events), SBH (2404 events), and ARKH (1493), with preference given to data from the ARC catalog in overlapping areas. Before the merging process, each of the source catalogs (Table 1) was checked for internal duplicates. Statistical analysis did not reveal any anomalous groups of close events (Figure S3, see Supplementary). At each stage, the merging of catalogs is performed in two steps. First, the metric parameters (1) are determined. For this, the metric (1) _Ro_ between the nearest events from two source catalogs with standard parameters \(\sigma_{T}=0.05\) min, \(\sigma_{X}=\sigma_{Y}=15\) km is calculated. The threshold value of the metric \(Ro=10\) is used for the preliminary duplicate identification, which corresponds to the time and space difference \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Stage** & \begin{tabular}{c} **Main** \\ **Catalog** \\ \end{tabular} & \begin{tabular}{c} **Additional** \\ **Catalog** \\ \end{tabular} & \begin{tabular}{c} **Metric Parameters** \\ **\(\sigma_{T}\)**min, \(\sigma_{X}\)**km, \(\sigma_{Y}\)**km** \\ \end{tabular} & \begin{tabular}{c} **Threshold Value** \\ **of the Metric** \\ \end{tabular} & \begin{tabular}{c} **Estimation of the** \\ **Number of Errors** \\ \end{tabular} & \
\begin{tabular}{c} **Number of** \\ **Duplicates** \\ \end{tabular} &
\begin{tabular}{c} **Merged** \\ **Catalog** \\ \end{tabular} \\ \hline
1 & \begin{tabular}{c} ARC \\ 2403 events \\ \end{tabular} & \begin{tabular}{c} SHB \\ 2634 events \\ \end{tabular} & \
\begin{tabular}{c} 0.054; \\ 22.5; \\ 21.3 \\ \end{tabular} & 12 & 0.7\% & 502 &
\begin{tabular}{c} ARC\_SHB \\ 4535 events \\ \end{tabular} \\ \hline
2 & \begin{tabular}{c} ARC\_SHB \\ 4535 events \\ \end{tabular} & \begin{tabular}{c} ARKH \\ 1492 events \\ \end{tabular} & \
\begin{tabular}{c} 0.048; \\ 23.9; \\ 22.8 \\ \end{tabular} & 14 & 0.3\% & 1136 &
\begin{tabular}{c} RUS \\ 4891 events \\ \end{tabular} \\ \hline
3 & \begin{tabular}{c} ISC \\ 16,937 events \\ \end{tabular} & \begin{tabular}{c} RUS \\ 4891 events \\ \end{tabular} & \
\begin{tabular}{c} 0.05; \\ 28.3 \\ 24.7 \\ \end{tabular} & 17.5 & 0.9\% & 3906 &
\begin{tabular}{c} ISC\_RUS \\ 17,922 events \\ \end{tabular} \\ \hline
4 & \begin{tabular}{c} Morozov \\ 4 events \\ \end{tabular} & \
\begin{tabular}{c} ISC\_RUS \\ 17,922 events \\ \end{tabular} & & & & 4 &
\begin{tabular}{c} N\_ARCTIC0 \\ 17,922 events \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Scheme and compilation parameters of the integrated catalog. Figure 3: Assembly diagram of the integrated catalog of the studied region. At each stage, the main catalog is marked with a bold frame. The stage numbers are given in ellipses and correspond to Table 2.  
Standard deviations \(\sigma_{T}\), \(\sigma_{X}\), and, \(\sigma_{Y}\) of the variables \(DT\), \(DX\), and \(DY\) are calculated for the pre-identified duplicates (Figures 4, 6 and 8). In the next step, a threshold value of the metric is determined and the final duplicate identification takes place (Figures 5, 7 and 9). The catalogs for the studied region consist of a mixture of data from a large number of agencies.