## 4 Statistical Analysis of Earthquakes
### Analysis of Other Earthquakes  
Five Ms \(\geq\) 6.0 earthquakes and seven 6.0 \(>\) Ms \(>\) 5.0 earthquakes were selected in this study, as listed in Table 2 (the negative values represent pre-earthquake date, positive values represent post-earthquake date, the symbol/means no anomaly was observed). Among them, the 29 November 2019, Ms 5.4 earthquake off the east coast of Honshu, Japan, was not investigated due to data quality issues. The anomaly perturbation time of different data for the earthquakes can be summarized as follows (negative values represent pre-earthquake time, positive values represent post-earthquake time):  
1. In this study, there was no anomaly perturbation when all the data were judged as /. As can be seen from the Table 2, it was recognized that there were no seismic anomaly perturbations before or after the 8 June 2022, Ms5.2 earthquake, the 23 September 2021, Ms5.5 earthquake, both near the Lake Baikal, Russia, or the 12 July 2020, Ms5.1 earthquake in the Guye District, Tangshan, Hebei, China. Therefore, all five Ms \(\geq\) 6.0 earthquakes exhibited anomalies; three of the six 6.0 \(>\) Ms \(>\) 5.0 earthquakes exhibited anomalies before or after the time of the earthquake occurrence.
2. As can be seen in Table 2, the data of horizontal east-west component exhibited anomalies more frequently and the data of the vertical component exhibited anomalies only once in the geomagnetic three-component vector data. Meanwhile, the anomaly perturbation time of the horizontal east-west component was also slightly longer than the others.
3. The anomaly perturbations of polarization observations were judged as/more frequently. The anomaly perturbation of polarization perturbation amplitude exhibited anomalies more frequently in Table 2. Among all of the seismic examples with perturbation anomalies, the polarization time-series data exhibited anomalies less frequently, while the polarization perturbation amplitude time series was perturbed more frequently than the polarization time-series data.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline  & & & **The Anomaly** & **The anomaly** & **The Anomaly** & **The Anomaly** & **The Anomaly** & **The Anomaly** & **The Anomaly** \\  & & & **Perturbation** & **Terme of** & **Time of** & **Time of** & **Perturbation** & **Perturbation** \\  & & & **Horizontal** & **Horizontal** & **Time of** & **Time of** & **Time of** & **Time of** \\  & & & & **North-South** & **East-West** & **Component** & **Correlation** & **Polarization** \\  & & & & **Component** & **Component** & **(Z)** & **(N)** & **Amplitude** \\ \hline \multirow{3}{*}{1} & 14 October 2022 & Lake Baikal region, & & & & & \\  & 08:53-53 & Russia & & & & & & \\  & 2 & 202-24 & Russia & & & & & \\  & 23 May 2022 & Off the east coast of & & & & & \\  & 10:01-03 & Honshu, Japan & & & & & \\  & 4 & 25 September 2021 & East of Lake Baikal, & & & & \\  & 01:01-26 & Russia & & & & & \\  & 5 & 1 May 2021 & Off the east coast of & & 15 days to & & & \\  & & 09:27-26 & Honshu, Japan & & & 30 days & & \\  & 21 December 2020 & Off the east coast of & & & & & \\  & 6 & 112:39 & Honshu, Japan & & & & \\  & 7 & 12 July 2020 & Gaye District, & & & & & \\  & 06:36-25 & Tangshan, Hebei, China & & & & & \\  & 8 & 20 April 2021 & Off the east coast of & & 6 days to & & & \\  & 04:39-05 & Honshu, Japan & & & 26 days & 26 days & & \\  & 9 & 25 November 2019 & Farm from the east coast & & & & & \\  & 12:01-36 & of Honshu, Japan & & & & & \\  & 18 June 2019 & Off the west coast of & & & & & \\  & 12:22-21 & Honshu, Japan & & & & 12 days & 12 days & 12 days & 12 days \\  & 11 & 18 May 2019 & Ningjiang District, & & & & & \\  & 60:26-48 & Songyuan city, Jilin & & & & & \\  & 11 April 2019 & Far from the east coast & & & & & \\  & 16:18:23 & of Honshu, Japan & & & & & \\ \hline \end{tabular}
\end{table}
Table 2: Polarization method-based research on magnetic field data associated with other 12 earthquakes in Northeast Asia.