What Does the Richter Scale Really Mean?

What Does the Richter Scale Really Mean?

Earthquakes are measured using the Richter Scale. Here's a breakdown of what the numbers really mean:

Less than 2.0: Micro
Microearthquakes, not felt.
About 8,000 per day

2.0-2.9: Very minor
Generally not felt, but recorded.
About 1,000 per day

3.0-3.9: Minor
Often felt, but rarely causes damage.
49,000 per year (est.)

4.0-4.9: Light
Noticeable shaking of indoor items, rattling noises. Significant damage unlikely.
6,200 per year (est.)

5.0-5.9: Moderate
Can cause major damage to poorly constructed buildings over small regions. At most slight damage to well-designed buildings.
800 per year

6.0-6.9: Strong
Can be destructive in areas up to about 100 miles across in populated areas.
120 per year

7.0-7.9: Major
Can cause serious damage over larger areas.
18 per year

8.0-8.9: Great
Can cause serious damage in areas several hundred miles across.
1 per year

9.0 or greater: Rare, Very Great
Devastating in areas several thousand miles across.
1 per 20 years

12.0:
Would be strong enough to split the earth in half.