Glaciologists were waiting patiently for the other shoe to drop.

They had known that there was a large crack in the Pine Island Glacier in Antarctica since 2011 and that the crack was continuing to expand. On Monday, a German satellite confirmed that the crack breached the lacier and a giant chunk broke away.

The resulting iceberg is estimated to be about 278 square miles in area, a little less than the size of New York City's five boroughs. The satellite images were taken by the German Aerospace Center, courtesy of their TerraSAR-X satellites.

Angelika Humbert, an ice researcher at the Alfred Wegener Institute in Germany, says it's too early to tell whether the iceberg breaking off was a result of climate change. "The creation of cracks in the shelf ice and the development of new icebergs are natural processes," she said in a statement.

However, she adds that the glacier's ice had been flowing more quickly than other glaciers in western Antarctica. "The wind now brings warm sea water beneath the shelf ice," she said. "Over time, this process means that the shelf ice melts from below."