Washington ― More than 3 million people in Haiti are estimated to have been affected by the earthquake that struck January 12. Registering at magnitude 7.0, it is the most violent earthquake to hit that island nation in a century. Deaths, injuries and damage are yet to be tallied.
(Media-Newswire.com) - Washington ― More than 3 million people in Haiti are estimated to have been affected by the earthquake that struck January 12. Registering at magnitude 7.0, it is the most violent earthquake to hit that island nation in a century. Deaths, injuries and damage are yet to be tallied.
According to experts, magnitude 7 earthquakes ― considered “severe” by seismologists ― occur around the world 12 to 15 times each year. What made the Haiti earthquake especially devastating?
In addition to the magnitude ( strength ) of an earthquake, an earthquake’s location relative to population centers and its depth under the earth are determining factors for the damage that may result, according to Michael Blanpied, associate coordinator of the Earthquake Hazards Program at the U.S. Geological Survey ( USGS ).
In a recorded interview for USGS, Blanpied said the epicenter for the Haiti earthquake was just 10 miles ( 15 kilometers ) from the capitol city of Port-au-Prince, where nearly 1 million people live. He also noted that Haiti, which suffers from widespread poverty, has not constructed many buildings resistant to earthquakes. Compounding the problem, he said, is that the earthquake has been followed by at least six aftershocks of moderate magnitude that have further damaged already weakened buildings and imperiled rescue efforts.
The initial earthquake is estimated to have occurred just 6.2 miles ( 10 kilometers ) under the earth’s surface. Shaking from relatively shallow earthquakes is more severe, Blanpied said. In addition, soft ground amplifies the shaking, which increases the threat of destruction to the buildings above it.
Landslides, which could bury buildings and claim more victims, remain a possibility, Blanpied said. “The only positive thing about this earthquake is that, because it did occur on land, it did not generate a tsunami,” he said. Tsunamis are huge ocean waves capable of traveling miles inland on land masses. The 2004 Indian Ocean tsunami, generated by an undersea earthquake, killed some 300,000 people.
Haiti is no stranger to earthquakes. The nation, which occupies the western part of the island of Hispaniola and is situated between Puerto Rico and Cuba, has experienced numerous slight to moderate earthquakes in the recent past.
“The island is caught between two tectonic plates,” Blanpied explained. “The North America and the Caribbean tectonic plates are sheering the island, crushing it, grinding it. And as that occurs, earthquakes pop off. … This is quite an earthquake-prone region.”
According to the USGS, at least 1,783 deaths worldwide resulted from earthquake activity in 2009. The deadliest earthquake of that year was a magnitude 7.5 event that killed approximately 1,117 people in southern Sumatra, Indonesia, on September 30. The most powerful earthquake for 2009 ― registering at magnitude 8.1 ― occurred September 29 in the Samoa Islands region. The tsunami it generated killed 192 people.
More information about earthquakes is available at the USGS Earthquake Hazards Program Web site.
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