The devastating earthquake that rocked Haiti in January was unleashed by a previously undetected fault line — not the well-known one scientists initially blamed, according to an analysis of new data.
It is unclear how dangerous the new, unmapped fault might be or how its discovery changes the overall earthquake-hazard risk for Haiti, said Eric Calais, a professor of geophysics at Purdue University in West Lafayette, Ind.
He said the analysis shows that most, if not all, of the geologic movement that caused January’s magnitude-7.0 earthquake occurred along the newly uncovered fault, not the well-documented Enriquillo fault.
Calais, who presented the findings this week at a scientific conference in Brazil, said they suggest Haiti’s seismic zone is far more complex than scientists had anticipated.
But the new fault’s profile, including the possibility that it merges with the Enriquillo fault at some depth, won’t be known until scientists study the region.
The discovery is the sort of revelation that often comes after big earthquakes, when scientists descend on quake-ravaged sites to conduct intensive research, said U.S. Geological Survey geophysicist Bruce Presgrave, adding, “It’s part of the learning process of science.”
