According to data just released by scientists, this year’s earthquake in Haiti was caused by a previously unknown fault.
This discovery, could be the first sign of a larger system of seismic faults in the area, the scientists say,
The Enriquillo fault, which runs through Port au Prince, was originally blamed. But new evidence has shown that it was not linked to the event.
Eric Calais from Purdue University in Indiana, presented the findings at an scientific meeting of the American Geophysical Union’s Meeting of the Americas in Foz do Iguacu,Brazil. He explained that the earthquake was more complicated than previously thought.
The first “give-awaysi” sign was the fact that there was no surface break along the previously known Enriquillo fault. This resulted in a search for other faults or fractures in the Earth’s crust, which may have moved and caused the event.
The devastating earthquake in January 2010 killed more than 200,000 people and left 1.5 million homeless. Working through the devastation, it has taken scientists several months to gather data and evidence about what really shifted the earth.
Using equipment,including GPS and radar, and other techniques Dr Calais and his fellow scientists were able to show that the “pattern of motion was incompatible with slippage on a vertical fault such as the Enriquillo”.
Calculations showed that a fault that was slightly oblique to the Enriquillo and dipped 60 degrees to the north.
This previously unmapped fault was only brought to scientists’ attention by the earthquake itself, it may be one part of a larger system of seismic faults.
Dr Calais explained that searching for and studying this system was crucial in order to define “the long-term hazard level in Haiti”.