I won't copy the article here, but some of the interesting points:
- proximity to the boundaries of the Caribbean plate means natural hazards are expected
- there are two major parallel faults - the Enriquillo and the Septentrional - crossing Haiti in an east-west direction
- the earthquake rupture may actually increase the stress and earthquake probability on adjacent segments of the Enriquillo fault
- the aftershock sequence has been rather active
- there are NO permanent seismograph stations in Haiti
The graphic below, from the article, is quite good. Makes me glad that when I worked in western Jamaica in 1999, on the westward extension of the same fault that was responsible for the Haiti quake, all was seismically quiet, although a major quake hit the area in 1957.