Haiti quake reveals previously unknown fault

IGUAÇÚ FALLS, Brazil — The devastating quake that slammed Haiti on January 12 occurred on a previously unrecognized fault zone, report scientists who are still trying to determine the implications for the region’s long-term seismic risk.

The newly discovered fault hasn’t been officially named yet but is informally known as the Léogane fault, after one of the Haitian cities that sits directly atop it, study leader Eric Calais told Science News.

Just after the magnitude-7 temblor struck, scientists presumed that the epicenter of the quake was located on the well-known Enriquillo fault, says Calais, a geophysicist at Purdue University in West Lafayette, Ind. In fact, Calais notes, he and his colleagues published a paper in 2008 suggesting that the Enriquillo fault, which runs east-west through a long valley south of Port-au-Prince, Haiti, was ripe for a magnitude-7.2 quake.