## 4 Case Analysis
Nevertheless, further research and discussion are required on how they can be applied in actual earthquake prediction. Occurrence time prediction: If the \(M\geq 4.0\) seismic gap identification threshold, i.e., \(T0=400\) days, is adopted as the start time for earthquake occurrence time \(T\) prediction, parameters \(T1\) (quiet period) and \(T2\) (time interval between the end of the seismic gap and the corresponding earthquake) in Table 1 can be used to calculate the following: \(T=T1+T2\)-\(T0\) (days). The results for No. 1-6 gaps are 419, 573, 377, 605, 1049, and 423 days. The results for the No. 5 seismic gap (1049 days/approximately 35 months) are relatively larger than those for the other five gaps (377-605 days/13-20 months, with an average of 479 days/16 months). Because the results for the No. 5 gap deviate relatively significantly from those of the other gaps (and the corresponding earthquake took place outside the spatial location of the gap), it is not included in the following analysis. For the other five corresponding earthquakes, dynamic \(T\) prediction is performed using \(T0=500\), 600, and 700 days. That way, the predicted occurrence time can be corrected dynamically (every 100 days). Table 2 lists the dynamic prediction results for the occurrence times of earthquakes corresponding to the five seismic gaps (No. 1-4 and No. 6). According to Table 2 when forecasting is started at \(T0=500\) days, the predicted occurrence time \(T\) is 277-505 days (9-17 months). Figure 6: Distributions of \(M\geq 6.7\) earthquakes and earthquakes corresponding to the six seismic gaps in the western Sichuan block in 1970–2022. Gray circles: earthquakes with no seismic gap images. Blue, cyan, green, yellow, pink, and red lines and circles: No. 1–6 seismic gaps and their corresponding earthquakes. The average is approximately 379 days (13 months). Considering \(T0\) = 600 days, the occurrence time \(T\) is within the 177-405 days (6-14 months) range, with an average of 279 days (about 9 months). Finally, when \(T0\) = 700 days, the occurrence time \(T\) is predicted to be 77-305 days (3-10 months). The average is approximately 179 days (6 months). The predicted occurrence time shortens gradually. The average time reduces from about 16 months (1.3 years) to about 6 months (0.5 years). Among the five earthquakes in Table 2, four took place after \(M\geq\) 4.0 earthquakes ended the corresponding seismic gaps, whereas one of them directly ended the seismic gap. Actually, when the earthquake occurrence time is predicted using the proposed method, it is not necessary to consider whether the seismic gap has ended or not. As long as the corresponding earthquake has not yet occurred, dynamic correction can continue. The predicted occurrence time can be shortened until it is close to the predicted earthquake. Therefore, based on the analysis results, if forecasting begins once the \(M\geq\) 4.0 seismic gap is formed (\(T0\) = d\(T\) = 400 days), and dynamic correction is performed every 100 days (or at other intervals), the gap can be used as a predictive index on a time scale of about 1-0.5 years or less. Hypocenter prediction: It is normally located inside or at the margin of the spatial location of the seismic gap. In this paper, the six seismic gap images can be adopted to predict earthquakes mainly in regions inside or at the boundary of the western Sichuan block (Figure 6). Magnitude (intensity) prediction: There are certain statistical correlations between the following parameters: the magnitudes of initial earthquakes surrounding the spatial location of the seismic gap, the quiet period and semi-major-axis length of the gap, and the magnitudes of future earthquakes. The findings of [PERSON] et al. [7] on seismic gaps in mainland China suggested that when the magnitudes of initial earthquakes surrounding the spatial location of a seismic gap are roughly \(M4.0\), it is possible to predict \(M\) > 7.0 earthquakes. In addition, according to [PERSON] et al.