Earthquake in Haiti and now Chili... a bit too close together?

The two recent earthquakes of serious magnitude have stuck me a bit strange. Sure, it is normal to have low-Richter earthquakes in different areas of the world and in quick succession. But in this case two of these quakes were both over 7.5 on the scale, that is some honestly incredible probability over the course of two months.

I would like your opinion, what is causing this and why?