*3.2.4. Distribution of the maximum water level*

The numerical results for the distributions of the maximum water level *η*max for 0.0 s ≤ *t* ≤ 2.0 × 103 s, are shown in **Figure 23(a)**–**23(d)**, where the crater locations are depicted with white circles off the north of Sakurajima, off Hayato, off Ryugamizu, and off Kurokami‐cho, respectively. The still water depth at the crater, *h*, is assumed to be 1.0 × 102 m in all the cases, such that the value of the submarine explosive index concerning tsunami generation, *V*w, is about 4.5 × 104

**Figure 23.** The distributions of the maximum water level for 0.0 s ≤ *t* ≤ 2.0×103 s, for different crater locations. The crater locations depicted with white circles, are as follows: (a) off the north of Sakurajima, (b) off Hayato, (c) off Ryugamizu, and (d) off Kurokami‐cho.

(unit length in meter). The tsunamis propagation starts at *t* = 0.0 s. In every case, the maximum water level *η*max decreases at (*x, y*) ≈ (20.0 km, 14.0 km), for the still water depth is deeper, i.e., about 200 m at the location.

**Figure 23** indicates that there are three areas where *η*max increases, irrespective of the crater location, i.e., near the northern shore of Sakurajima, the bay head off Hayato, and near the western shore of the Ohsumi Peninsula, for the still water depth suddenly decreases toward the land near these three areas.

As shown in **Figure 23(a)**, the tsunamis generated off the north of Sakurajima, travel toward the north, after reflecting at the northern shore of Sakurajima; while as shown in **Figure 23(b)**, the tsunamis generated off Hayato, propagate toward the south, after the reflection at the bay‐head shore. In the cases shown in **Figure 23(c)**, and **23(d)**, however, the tsunamis generated off Ryugamizu, and Kurokami‐cho, propagate toward the east, and west, respec‐ tively, where the maximum wave height of these components is larger.
