The USGS says the 5.2 aftershock's epicenter was located 15.8 kilometers (9.8 miles) north-northwest of Port-de-Paix, and had a depth of 10 kilometers.
It struck at about 3 p.m. local time on Sunday. The quake and three aftershocks, including the 5.2-magnitude aftershock, are what seismic experts consider to be “small to moderate.”
"It was an aftershock. It was at the same location," said Paul Caruso, a geophysicist with the USGS. "This is the first significant aftershock".
At the time, emergency teams were bringing relief to victims of Saturday's quake, which toppled cinderblock homes and rickety buildings.
“There exists the possibility to have an earthquake up to a magnitude of 8,” said Claude Prépetit, who heads Haiti’s Bureau of Mines and Energy.
Prépetit, a geological engineer,said the only reason there weren’t more deaths and destruction is because the quake was a 5.9 on the Richter scale. But the deaths and damage to buildings even with a 5.9 quake, he said, show “Haiti’s vulnerability, and the situation of the buildings isn’t good at all.”
Haiti's civil protection agency issued a statement saying that houses were destroyed in cities of Port-de-Paix, Gros-Morne, Chansolme and Turtle Island by Saturday's temblor.