# Earthquake Shake Detecting by Data Mining from Social Network Platforms
## 3 Results and Discussions
Furthermore, Nantou County is a farming region and a tourism destination for people. Hence, a small number of people use PPT BBS. Meanwhile, most citizens are older in the region and make less posts, and therefore useful messages are considerably less. Therefore, from the useful message of the disaster information content, only the \"feeling of the earthquake shaking and little shocking\" type of disaster information was reported. Except for the underestimated location near the epicenter, the intensity scale at other places follows the official report by the CWB. Figure 5: The intensity distribution analyzed by our approach for the earthquake occurring on 6 February 2016. In this study, the author used two events to show results; however, the author in total selected five earthquakes to examine for this investigation. A total of 5167 posts were collected and the analysis of the disaster information was made using the proposed model to estimate the intensity scale level in the region. Figure 8 illustrates the locations of the epicenters of all five earthquakes (red pentagram). Figure 6: The intensity scale distribution reported by the CWB for the earthquake occurring on 27 March 2013. Figure 7: The intensity distribution analyzed by our approach for the earthquake occurring on 27 March 2013. Table 3 provides the characteristics of the origin time, epicenter, and the magnitude of the five earthquakes. The five events are all inland or close-by coast earthquakes because the seismic effect is more evident and is discussed by more people. To understand the proposed model, the estimated intensity scale level and the official reported scale level for all investigated earthquakes are summarized in Table 4. The result shows the estimated intensity scale level in different regions for the five events and is compared with the CWB official report. The result indicates that the proposed model agrees well with the CWB official report. The highlighted cell represents the difference in the derived value in contrast to the regular cell. The percentage of the successful estimation by the proposed model was 60%-83%. If the author removes the region without data, the percentage of successful estimation is between 79% and 87.5%. Case 1 shows the percentage of those successful estimated to be 65% and increases up to 73.3% after removing two regions without effective posted messages. In the case where the earthquake occurred at the mountain area in Nantou County, the disaster contrasts slightly with the downtown area. Meanwhile, the most semantic analysis of the disaster information message shows that only the \"the feeling of the shaking at somewhere\" was reported. However, the shaking feeling will vary between people and buildings and cause slight discrepancy between the estimated value and the CWB report. Case 2 shows a successful rate of 76.5%. The inconsistent region in the seismic shaking scale is underestimated except for Taipei and Taichung cities. The overestimate could be attributed to the higher buildings or the geological conditions at Taipei and Taichung cities. However, the result shows that the disaster information could be more serious than the physical measurement (peak ground velocity). It indicates that the disaster management is very important during the earthquake event. Cases 4 and 5 show the results of off-land earthquakes and the percentage of success to be 71%. The \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Case** & **Year** & **Month** & **Day** & **Hour** & **Min** & **Latitude** & **Longitude** & **Depth** & **Magnitude** \\ \hline
1 & 2013 & 3 & 27 & 10 & 03 & 121.05 & 23.90 & 19.4 & 6.2 \\
2 & 2013 & 10 & 31 & 20 & 02 & 121.35 & 23.57 & 15.0 & 6.4 \\
3 & 2016 & 2 & 6 & 03 & 57 & 120.54 & 22.92 & 14.6 & 6.6 \\
4 & 2016 & 5 & 12 & 12 & 29 & 122.02 & 24.69 & 12.0 & 5.7 \\
5 & 2017 & 2 & 11 & 01 & 12 & 120.14 & 22.87 & 16.2 & 5.7 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Catalog of the earthquakes used in this study.