Richter scale of earthquake magnitude

magnitude level category effects earthquakes per year

less than 1.0 to 2.9 micro generally not felt by people, though recorded on local instruments more than 100,000

3.0-3.9 minor felt by many people; no damage 12,000-100,000

4.0-4.9 light felt by all; minor breakage of objects 2,000-12,000

5.0-5.9 moderate some damage to weak structures 200-2,000

6.0-6.9 strong moderate damage in populated areas 20-200

7.0-7.9 major serious damage over large areas; loss of life 3-20

8.0 and higher great severe destruction and loss of life over large areas fewer than 3