The first three months of 2010 have been violent ones in the Western Hemisphere, marked by two massive earthquakes in two different areas. The earthquakes in Haiti and Chile have each been widely covered by the news media, but though the events occurred relatively close to each other geographically, there are significant geological differences between the two natural disasters.
Scale: Haiti's quake, which shook the impoverished nation on Jan. 12, occurred along a transform fault where the Caribbean and North American plate boundaries were sliding past each other, causing the 7.0 magnitude earthquake on the Richter Scale that killed over 200,000 people and displaced 1.3 million. Neither the population of the area nor the building codes were prepared for the event, as a major earthquake had not occurred in Haiti since 1860.
The earthquake in Chile on Feb. 27 was of an even greater magnitude, measuring 8.8 on the Richter Scale. It was caused by the Nazca Plate sliding underneath the South American Plate, a different kind of plate movement than what was observed at the Haiti epicenter.
The largest recorded earthquake in history, a 9.6 on the Richter Scale, occurred in Chile in 1960 and was followed 25 years later by an 8.0 magnitude earthquake. In response, the government insisted that rebuilding efforts conform to guidelines, an action that may have saved thousands of lives this year.
Loss of Life: The loss of life and property in Chile was significant, with at least 700 people killed and 500,000 homes damaged, but not nearly as extensive as in Haiti. The large discrepancy between the Chile and Haiti death tolls is probably due to the fact that Chile is no stranger to large earthquakes, and has awareness programs and stricter building codes in place than were in existence in Haiti.
Aftershocks: Aftershocks struck both Haiti and Chile in the weeks that followed the actual earthquakes, frightening the populations of both and putting fragile structures in even more danger of collapsing. Haiti was struck by 59 aftershocks in the six weeks following the initial earthquake, all of which were greater than 4.5 in magnitude.
The New York Times reported on March 12 that there had already been over 300 aftershocks from the Chile quake. The United States Geological Survey has measured 229 of these as being greater than 5.0 in magnitude and 18 larger than 6.0, impeding the rebuilding process as well as the inauguration ceremony of Sebastián Piñera, Chile's new president.
