Table 1 Spatial grid size and search area and time for the back-projection analysis
Step number | Grid size in horizontal direction (°) | Area for grid search (latitude/longitude) | Grid size in vertical direction (km) | Depth range for grid search (km) | Time range for grid search (s) |
|---|---|---|---|---|---|
1 | 0.1 | N32.9750–33.4750/E131.0825–131.5825 | 10 | 0–30 | 30–40 |
2 | 0.05 | N33.0750–33.4750/E131.1825–131.5825 | 5 | 0–20 | 32–40 |
3 | 0.025 | N33.1500– 33.4000/E131.2075–131.4575 | 2.5 | 0–15 | 32–38 |
4 | 0.0125 | N33.1875–33.3375/E131.2700–131.4200 | 1.25 | 0–15 | 32–35.5 |