Earthquake scale & classes

 

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

 
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