Maps redrawn as trillion-ton Antarctic iceberg finally breaks off
A TRILLION-TON iceberg four times the size of London has separated from Antarctica and could pose a hazard to shipping.
Scientists monitoring Nasa’s Aqua MODIS satellite announced yesterday that the huge section in the Larsen C Ice Shelf had finally completely severed, leaving the 2,200-square-mile mass of ice free to float on the open sea.
Expected to be designated “A68”, the iceberg is believed to be among the 10 largest recorded. It broke away between Monday and yesterday, leaving the ice shelf 12 per cent smaller and “redrawing the map of the Antarctic for ever”. The scientific community disagrees over the extent to which the event was caused by man-made climate change. However, it is agreed the severance will not raise sea levels, as the iceberg was already afloat.
While it could remain in one piece, British scientists closely monitoring the shelf believe it is more likely to fragment into countless smaller pieces.
Given its enormous size and potential to split up into smaller, more mobile chunks, the latest berg to calve from Antarctica will be closely watched for any potential risk to shipping.
Prof Adrian Luckman, from Swansea University, said: “We have been anticipating this event for months, and have been surprised how long it took for the rift to break through the final few kilometres of ice. We will continue to monitor both the impact of this calving event on the Larsen C Ice Shelf, and the fate of this huge iceberg.
“The iceberg is one of the largest recorded and its future progress is difficult to predict. Some of the ice may remain in the area for decades, while parts of the iceberg may drift north into warmer waters.”
The researchers said the calving was a “natural event”, but one that puts the remainder of the ice shelf in a vulnerable position. There are concerns that Larsen C, which sits beside the Antarctic Peninsula, part of British Antarctic Territory, could follow the example of its neighbour Larsen B, which disintegrated in 2002 after a similar event.
Future collapses may be years or even decades away. However, any further losses of ice could result in glaciers flowing directly into the ocean, causing a “modest” rise in sea levels.
The huge crack that created the new iceberg grew over several years. However, between May 25 and 31, the rift grew by 10 miles. Between June 24 and 27, the movement of the ice sped up again, reaching a rate of more than 32ft per day in some sections.
Dr Martin O’leary, a glaciologist from Swansea University and member of the Midas project team, which carries out Antarctic research, said: “This is the furthest back that the ice front has been in recorded history. We’re going to be watching very carefully for signs that the rest of the shelf is becoming unstable.”
Rod Downie, of the WWF, said that at the very least the calving was a reminder of how quickly the poles can change. He said: “The sheer scale of this natural calving event is impressive. We will need to redraw the map of the Antarctic Peninsula. And while this is Antarctica doing what Antarctica does, it demonstrates just how fragile the polar regions are.”