Richter Magnitude Scale Table

MAGNITUDE INTENSITY EFFECTS ON PEOPLE/BUILDINGS FREQUENCY Est
> 2.0 Micro Not Felt Continual
2.0-2.9 Minor Generally not felt, but recorded

     1,300,000      (per year)

3.0-3.9 Minor Often felt, rarely causes damage

       130,000         (per year)

4.0-4.9 Light Noticeable indoor items shaking, significant damage unlikely

         13,000         (per year)

5.0-5.9 Moderate Can cause major damage to poorly constructed buildings, slight damage to well-designed buildings

       1,319          (per year)

6.0-6.9 Strong Can be destructive to areas 99 miles across in populated areas

         134             (per year)

7.0-7.9 Major Can cause serious damage over larger areas

           5              (per year)

8.0-8.9 Great Can cause serious damage hundreds of miles across

          1               (per year)

9.0-9.9 Great Devastating in areas thousands of miles across 1 per 10 years
10+ Massive Never recorded, widespread damage across very large areas Never recorded

*Based on US Geological Survey documents.