| Based on observations
since 1900 |
||
| Descriptor | Magnitude | Average Annually |
| Great | 8 and higher | 1 |
| Major | 7-7.9 | 18 |
| Strong | 6-6.9 | 120 |
| Moderate | 5-5.9 | 800 |
| Light | 4-4.9 | 6,200 (estimated) |
| Minor | 3-3.9 | 49,000 (estimated) |
| Very Minor | <3.0 | Magnitude
2 - 3: about 1,000 per day Magnitude 1-2: about 8,000 per day |