Aftershocks may last for months

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 US Geological Survey said.

“The frequency of events will diminish with time, but damaging earthquakes will remain a threat.” Yesterday’s quake had a magnitude of 4.4, the Geological Survey said.

That makes it much less powerful than the 7.0-magnitude quake that struck ten 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 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 yesterday, including at the port, where critical supplies are being shipped in.

The city’s south pier was operating, though slowly. Authorities pushed yesterday 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 three million Haitians affected by the quake.

About 120 to 140 flights a day were coming into the single-runway Port-au-Prince airport, compared with 25 a day just after the quake struck last week. The USNS Comfort, a US naval hospital off the coast, received about 240 patients over 36 hours, said Captain James Ware, the commanding officer. “Most of those individuals are critical care types of injuries,” he told CNN’s “American Morning” show.