A huge chunk of ice from a north Greenland glacier, almost double the size of Manhattan, is on the verge of breaking off, stunned scientists say.

Although the exact date of calving is not known, scientists are worried about the climatic implications of this astounding phenomenon. Almost a year ago, another ice island around four times the size of Manhattan broke off from one of Greenland's major glaciers.

That fracturing, the largest in Greenland's recorded history, was taken as another sign of rapid climate change in the Arctic. Since then, scientists have been intensified monitoring of Greenland glaciers with the help of satellite imagery.

Wales Online reported that Dr Alun Hubbard, a reader at Aberystwyth University's Centre for Glaciology, returned from the Petermann Glacier in northwest Greenland a month ago, but did not see the stark images documenting the changes until this week.

The recently released photographs, which were taken in July, showed stark changes in different areas of the Petermann Glacier.

In a statement released by the Byrd Polar Research Center, Hubbard stated that although he knew what to expect in terms of ice-loss from satellite imagery, he was still unprepared for the gob-smacking scale of the breakup, which rendered me speechless. ... What the breakup means in terms of inland ice acceleration and draw-down of the ice sheet remains to be seen, but will be revealed by the GPS data recovered, which we are now processing at Aberystwyth.

Apart from the Petermann Glacier, scientists are also monitoring a second glacier in the region called the Humboldt glacier.

Check out the startling images of the Petermann Glacier captured through satellite imagery below: