| Class | Magnitude | Hazard |
| 1 | 8 or more High | Extremely High |
| 2 | 7 - 7.9 | Very High |
| 3 | 6 - 6.9 | High |
| 4 | 5 - 5.9 | Moderately High |
| 5 | 4 - 4.9 | Moderate |
| 6 | 3 - 3.9 | Moderately Low |
| 7 | 1 - 3.0 | Low |