| Magnitude |
Force |
Earthquake effects |
Frequency |
| Less than 2.0 |
Micro |
Microearthquakes, not felt. |
About 8,000 per day |
| 2.0-2.9 |
Minor |
Generally not felt, but recorded. |
About 1,000 per day |
| 3.0-3.9 |
Very Light |
Often felt, but rarely causes damage. |
49,000 per year (est.) |
| 4.0-4.9 |
Light |
Noticeable shaking of indoor items, rattling noises. Significant damage unlikely. |
6,200 per year (est.) |
| 5.0-5.9 |
Moderate |
Can cause major damage to poorly constructed buildings over small regions. |
800 per year |
| 6.0-6.9 |
Strong |
Can be destructive in areas up to about 160 kilometres (100 mi) across in populated areas. |
120 per year |
| 7.0-7.9 |
Major |
Can cause serious damage over larger areas. |
18 per year |
| 8.0-8.9 |
Great |
Can cause serious damage in areas several hundred miles across. |
1 per year |
| 9.0-9.9 |
Extreme |
Devastating in areas several thousand miles across.
|
1 per 20 years |
| 10.0+ |
Epic |
Never recorded.
|
Extremely rare (Unknown) |
