said , though the extent of damage that any earthquake causes depends on many factors , including its depth , proximity to dense population centers , and the strength of structures where it hits . An American adoption service provider in Haiti wrote in a blog that the aftershock Wednesday sent `` a wall tumbling down on our heads . '' Save the Children said its staff `` heard already-weakened structures collapsing '' as a result . Yet the 7.0-magnitude quake was more than 40 times stronger than the 5.9-magnitude aftershock , researchers said . While each new earthquake can slow relief efforts , those efforts were advancing Friday , including at the port , where critical supplies are being shipped in . Full coverage | Twitter updates The city 's south pier was operating , though slowly . Authorities pushed Friday to clear the bottlenecks at the port . The north pier remained unusable , and the south pier is the smaller of the two . Bottlenecks at all points of entry -- the airport , roads , and ports -- have delayed food and medical aid to the estimated 3 million Haitians affected by the quake . About
Port-au-Prince , Haiti -LRB- CNN -RRB- -- Another aftershock rocked Haiti on Friday . Buildings shook . People looked around to see what else might fall . Then they returned to what they had been doing . At a park in the capital that has become a tent city , a group of kids resumed their soccer game . Aftershocks have become a way of life in this devastated country along with so many other life-threatening challenges . The aftershocks -- smaller earthquakes that follow a more powerful one -- `` will continue for months , if not years , '' the U.S. Geological Survey said . `` The frequency of events will diminish with time , but damaging earthquakes will remain a threat . '' The quake Friday morning had a magnitude of 4.4 , the Geological Survey said . That makes it much less powerful than the 7.0-magnitude quake that struck 10 days ago , leaving widespread death and destruction in its wake . An earthquake on Wednesday was the strongest aftershock so far , with a magnitude of 5.9 . An earthquake that size is strong enough to cause `` considerable '' damage , the Geological Survey