Earthquake Magnitude Scale
Magnitude |
Earthquake Effects |
Estimated Number Each Year |
2.5 or less |
Usually not felt, but can be recorded by seismograph. |
900,000 |
2.5 to 5.4 |
Often felt, but only causes minor damage. |
30,000 |
5.5 to 6.0 |
Slight damage to buildings and other structures. |
500 |
6.1 to 6.9 |
May cause a lot of damage in very populated areas. |
100 |
7.0 to 7.9 |
Major earthquake. Serious damage. |
20 |
8.0 or greater |
Great earthquake. Can totally destroy communities near the epicenter. |
One every 5 to 10 years |
Earthquake Magnitude Classes
Earthquakes are also classified in categories ranging from minor to great, depending on their magnitude.
Class |
Magnitude |
Great |
8 or more |
Major |
7 - 7.9 |
Strong |
6 - 6.9 |
Moderate |
5 - 5.9 |
Light |
4 - 4.9 |
Minor |
3 -3. |
http://www.geo.mtu.edu/UPSeis/magnitude.html
|
|