Greenland iceberg double the size of Manhattan breaks off

An iceberg twice the size of Manhattan has broken off the Petermann Glacier in northern Greenland..

An iceberg twice the size of Manhattan has broken off the Petermann Glacier in northern Greenland, scientists have revealed. 

While glaciers do naturally calve icebergs, the rate and extent of which the Petermann Glacier has been active has concerned experts. 

The Petermann Glacier is land-anchored and contains a floating river of ice known as an ice tongue. 

Two years ago another ice island broke free from the tongue. That one measured 100 square miles and came from the same glacier. 

The most recent break was seen by Nasa's Aqua satellite, which passes over the North Pole several times each day to document changes. 

Trudy Wohlleben of the Canadian Ice Service says that this time of year is vital: "At this time of year, we're always watching the Petermann glacier," she said as broken bergs can float into shipping lanes and oil platforms in the North Atlantic and Grand Banks. 

This new massive chunk is not expected to raise sea levels since it was already part of an ice shelf that was attached to land but extended over water. A good example akin to this is an ice cube which melts in a glass of water without raising the level of water in the container. 

Still, "the floating extension (of the glacier) is breaking apart," Eric Rignot of Nasa's Jet Propulsion Laboratory said in a statement. "It is not a collapse, but it is certainly a significant event" which could signal problems in the future. 

Climate change is seen as a major factor in the current state of the glaciers in the region.