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Saturday, March 6, 2010

Haiti versus Chile

During our recent EarthView programs, we have been discussing the tragic earthquake in Haiti, in which over 200,000 people are thought to have lost their lives. The more recent earthquake in Chile was over 500 times stronger, as measured by the Richter scale, and although it caused extensive damage and killed many people, the number of deaths is thought to be far under 1,000. To understand why the results are so different, it is helpful to understand both the human and the physical geography. Several physical and human factors come together to explain the disparity.

Depth. The earthquake in Haiti was centered 7 miles below the surface; the Chile earthquake was 21 miles below its epicenter.

Situation. The epicenter of an earthquake is the point on the surface directly above the center of the movement. In Chile, the epicenter was at some distance from the country's second-largest city -- Concepcion -- rather than in the immediate vicinity of the largest city, which was the case in Haiti.

Experience. Chile is located along a very active subduction zone, where the Pacific plate is pushing under the South America plate, creating tremendous tension that is relieved quite frequently by earthquakes. Many of the strongest earthquakes ever recorded have taken place in Chile. For this reason, modern buildings are designed with a combination of strength and flexibility that minimizes damages, and communities are well-organized to provide emergency preparedness and response. Haiti's last major earthquake took place over 200 years ago, so preparation was minimal.

Poverty. A history of colonial and post-colonial extraction of its resources, combined with internal and external political strife, have left Haiti far more impoverished than any other country in the Western Hemisphere. Survival in Haiti in the best of times is challenging; even if the country were to have attempted to be prepared for earthquakes, the financial resources have simply been unavailable.

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