Seriously?
This is SD?
Well, all I can say is: earthquakes have existed since the earth has, and their frequency has varied with the ages.
So no, there is no reason for quakes to "destroy the earth" on a whim, like "hey, today I feel swell, lets destroy Japan in one go!"
Earthquakes are happenning everywhere and all the time.
And its not 100+ in 2011, its over a thousand, maybe more, couldn't find a more precise figure. The hundred plus must be those above a certain magnitude.
Also, look at
this.You'll get a good idea of how frequent earthquakes are.