There were two severe earthquakes off the coast of Gisborne in March and May 1947, each generating large tsunamis in the surrounding area.
| When | Sat May 17 1947 7:06 PM |
| Where | 45 km east of Tolaga Bay |
| Shaking | Severe |
| Magnitude | 6.9 |
| Depth | 12 km |
| Quality | best |
| Extreme | 0 | |
| Severe | 0 | |
| Strong | 0 | |
| Moderate | 2 | |
| Light | 1 | |
| Weak | 0 | |
| Total | 4 |
| Extreme | 0 | |
| Severe | 0 | |
| Strong | 0 | |
| Moderate | 2 | |
| Light | 1 | |
| Weak | 0 | |
| Total | 4 |