What Are The Causes Of The Haiti Earthquake

On January 12, 2010, a Mw7.0 earthquake struck the Port-au-Prince region of Haiti (Figure A), killing more than 200,000 people, leaving more than 1.5 million homeless, and destroying most governmental, technical, and educational infrastructure throughout this region of 3 million people. It was also strongly felt in the Dominican Republic but caused no damage there because of the significant distance between major urban centers and the epicenter. The event caused an estimated $8 billion in damages in Haiti, ~120% of the country's GDP. No other earthquake of such moderate magnitude has ever caused so many causalities and such extensive damage. This was because the earthquake occurred in a heavily populated region of a very poor country with substandard
Haiti - and the island of Hispaniola as a whole - lies on the boundary between two major tectonic plates, Caribbean and North America, which slide past each other at a speed of about 2 cm/year (Figure D). This relative motion causes the build up of pressure on several faults lines across the island. When the pressure exceeds the mechanical resistance of a fault section, the rock yields, resulting in a sudden break of the fault and the radiation of seismic waves away from this rupture: this is an earthquake. Historical archives tell us that this process occurred a number of times since Columbus first landed on Hispaniola (Figure A). Southern Haiti was struck on September 15, 1751, November 21, 1751, and June 3, 1770 by major events, with magnitude estimated between 7.0 and 7.5, which severely affected Port-au-Prince. They were followed on May 7, 1842 by a magnitude 8.0 earthquake that struck the northern part of Haiti and Dominican Republic, with tremendous damage to the cities of Port de Paix and Cap Haitien. The most recent large events in Hispaniola is a series of magnitude 7.5 to 8.1 earthquakes between 1946 and 1953 offshore the northeastern coast of the Dominican