When is an earthquake considered a big one? Is it at 5 on the Richter scale?

Answer 1

Descriptor Richter Magnitudes Earthquake Effects Frequency of Occurrence
Micro Less than 2.0 Microearthquakes, not felt. About 8,000 per day
Very minor 2.0-2.9 Generally not felt, but recorded. About 1,000 per day
Minor 3.0-3.9 Often felt, but rarely causes damage. 49,000 per year (est.)
Light 4.0-4.9 Noticeable shaking of indoor items, rattling noises. Significant damage unlikely. 6,200 per year (est.)
Moderate 5.0-5.9 Can cause major damage to poorly constructed buildings over small regions. At most slight damage to well-designed buildings. 800 per year
Strong 6.0-6.9 Can be destructive in areas up to about 100 miles across in populated areas. 120 per year
Major 7.0-7.9 Can cause serious damage over larger areas. 18 per year
Great 8.0-8.9 Can cause serious damage in areas several hundred miles across. 1 per year
Rare great 9.0 or greater Devastating in areas several thousand miles across. 1 per 20 years

I hope this helps.

Answer 2

Each number is ten time larger than the previous number (logarithmic). Six is ten times more intense than 5, etc. Therefore, 7 is a big one and there is a practical limit. Earthquakes affect entire large land areas especially above the epicenter (ground zero) that may be many miles below the surface. However, there are also local effects at a distance because certain ground/soil types either magnify or dampen the available energy. Also, duration is important when the frequency of the quake is similar to the natural frequency of a structure and adds energy like pushing a child on a swing until the child flies over the bar!

Answer 3

Well, I grew up in "earthquake country" and anything over a 6.0 people usually consider a "big one." Any 5-range earthquake will most definitely get your attention and make you nervous, but not necessarily scared. Also, there are "shakers" and "rollers." "Shakers" feel more violent than "rollers" even if they are of equal strength.

Let's just say I don't much miss experiencing earthquakes.

Answer 4

6 above is considered big.

Answer 5

7 is terrifying. Anything above that is definitely Apocalyptical.

Answer 6

Please visit my slide show at
http://asia.pg.photos.yahoo.com/ph/quake
to know more about the release of energy wise Richter scale and its effects

Answer 7

6.5 and higher

9 is off the hook