The Haiti earthquake occurred at a fault that runs right through Haiti and is situated along the boundary between the Caribbean and North American plates, which are rocky slabs that cover the planet and fit together like a giant jigsaw puzzle. These two plates constantly creep past one another, about 0.8 inches (20 mm) a year, with the Caribbean plate moving eastward with respect to the North American slab. - See more at: http://www.livescience.com/9797-devastating-haiti-earthquake-questions-answers.html#sthash.x9toIya1.dpuf