Scratch marks on the ocean floor off western Greenland mark the passing of the largest icebergs ever known to have existed. At more than 950 metres from top to bottom, these behemoths would dwarf anything we see today and make the 30-metre-high berg that sank the Titanic look like an ice cube. The scratch marks date back to the last ice age, more than 12,000 years ago.
The gouges were found in sonar images of the sea floor made by Antoon Kuijpers of the Geological Survey of Denmark and Greenland, in Copenhagen, and his colleagues. They measured the furrows…
