Environment

The earthquake occurred at a relatively shallow depth, which allowed it to retain more of its' energy as it hit the land, thus making it more catastrophic. Since the earthquake was located so close to the capital, with 3.5 million living there, there were more casualties.  
The earthquake was born out of 250 years of stress. A 2007 study concluded that the worst-case scenario would be a 7.2 magnitude earthquake.

Movement

President René Préval made a personal appeal for humanitarian aid, and many organizations responded, including the United Nations. The Red Cross focused on bringing aid to victims of the quake, bringing supplies to relief centers, but water and food took days to pass around, due to the lack of distributors. This resulted in more casualties. 
The US navy, in itself, delivered 27000 gallons of water, 532440 bottles of water, 111082 meals, and 4100 kg of medical supplies. 17 ships, 48 helicopters, and 12 airplanes had been assigned to the disaster. 
As a sidenote, social networking such as Twitter and Facebook were used to coordinate ground crew.

Interaction

The earthquake resulted in at least 52 aftershocks measuring 4.5 or higher. In the first 9 hours after the quake, 32 aftershocks of at least 4.2 were recorded. On January 20th, the strongest aftershock, measuring 5.9 was witnessed. An estimated 316,000 people were dead as a result of it all. Another 1,000,000 are homeless.
Immediately after the first earthquake, citizens were issued a tsunami warning, but was quickly cancelled. Two weeks later, it was confirmed that a tsunami had hit a small fishing town, as a result of an underwater slide, and three were washed out and pronounced dead.  

Because of the mass destruction of buildings, Haiti lacked the essential services, i.e hospitals, communication systems, etcetera. The earthquake seriously damaged a harbor, making it useless for rescue missions. Concrete debris was littered on the street, making land vehicles virtually unusable. 

Region

Haiti is located on the north side of the Caribbean plate, on a boundary with the North American plate. Since the North American plate is moving west and the Caribbean plate east, the plates gather friction, and eventually there is enough pressure to result in an earthquake, namely this one. The plates move 20 millimeters per year, which may not seem like very much, but was enough to create this 7.0 magnitude earthquake.

 

Place/Location

The earthquake happened on January 12th, 2010, at coordinates 18.457°N, 72.533°W. The earthquake was concentrated 13 kilometers below the surface, near the town of Léogâne, which is around 25 kilometers west of Haiti's capital, Port-au-Prince.