One of the biggest icebergs ever recorded, a trillion-ton behemoth more than seven times the size of New York City, has broken off of Antarctica, triggering disagreement among scientists over whether global warming is to blame.

The event, captured by satellite, happened sometime in the past few days when the giant chunk snapped off an ice shelf.

 

While such "calving" of icebergs is not unusual, this is an especially big one. It covers an area of roughly 2,300 square miles (6,000 square kilometers), more than twice the size of Luxembourg. Its volume is twice that of Lake Erie, according to Project MIDAS, a research group based in Britain.

 

It broke loose from the Larsen C ice shelf, which scientists had been monitoring for months as they watched a crack grow more than 120 miles (200 kilometers) long.

 

Scientists say global warming has caused a thinning of such shelves, but they differ on whether the latest event can be blamed on climate change.

 

The iceberg is considered unlikely to pose any threat to shipping. And since the ice was already floating, the breakup won't raise sea levels in the short term, the project said in a statement.

 

But it removed more than 10 percent of the ice shelf, and if that eventually hastens the flow of glaciers behind it into the water, there could be a "very modest" rise in sea level, the project said.