This earthquake followed two earlier shakes of magnitude 5.7 and 5.8 in the previous two days. It caused damage to buildings on both sides of Cook Strait.
| When | Sun Jul 21 2013 5:09 PM |
| Where | 20 km east of Seddon |
| Shaking | Extreme |
| Magnitude | 6.5 |
| Depth | 16 km |
| Quality | best |
| Extreme | 5 | |
| Severe | 28 | |
| Strong | 301 | |
| Moderate | 1319 | |
| Light | 3355 | |
| Weak | 502 | |
| Total | 5510 |
| Extreme | 5 | |
| Severe | 28 | |
| Strong | 301 | |
| Moderate | 1319 | |
| Light | 3355 | |
| Weak | 502 | |
| Total | 5510 |