Earthquake Scale

Class Magnitude Est. No. p.a. Effects
Minor 2.5 or less 900,000 Usually not felt, but can be recorded by seismograph.
Light 2.5 to 5.4 30,000 Often felt, but only causes minor damage.
Moderate 5.5 to 6.0 500 Slight damage to buildings and other structures. 
Strong 6.1 to 6.9 100 May cause a lot of damage in very populated areas. 
Major 7.0 to 7.9 20 Major earthquake. Serious damage. 
Great 8.0 or greater One every
5 to 10 years
Great earthquake. Can totally destroy communities near the epicenter.