Huge iceberg poised to break off Antarctica, changing the map of the world as we know it

A huge iceberg roughly the side of the US state of Delaware is set to break off Antarctica, threatening to affect the Larsen ice shelf and change the map of the world.

A huge iceberg measuring 5,000 square kilometres, roughly the side of the US state of Delaware, is set to break off the Antarctic Peninsula. When this happens, the ice shelf Larsen C – a floating platform of ice formed by the flow of land-based glaciers or ice sheets into the ocean – located in West Antarctica will loose more than 10 per cent of its extension, effectively changing the map of the world as we know it.

Scientists from Project MIDAS, a UK-based Antarctic research project monitoring the effects of climate change in the area, revealed that the long-running rift in the shelf grew suddenly during the second half of December 2016. Today, only a mere 20 kilometres of ice is keeping the iceberg from floating free in the Southern Ocean: though global warming could be the cause, scientists say they don’t as of yet have evidence supporting this.

Iceberg Antartica
NASA’s Operation IceBridge has been studying how polar ice has evolved over the past eight years, flying 12-hour research flights over West Antarctica at the start of the melt season © Mario Tama/Getty Images

Moving towards disintegration?

Researchers have warned that the loss of such a vast amount of ice may make Larsen C’s configuration more unstable. Previous research and experience shows that, following the break-off, Larsen C may eventually face the same destiny as its neighbours Larsen A, which collapsed in 1995, and most importantly Larsen B, which disintegrated in 2002 following a similar rift-calving episode.

“The calving of this large iceberg could be the first step of the collapse of the Larsen C ice shelf, which would result in the disintegration of a huge area of ice into a number of icebergs and smaller fragments,” glaciologist David Vaughan, Director at the British Antarctic Survey, said in a statement.

Whilst scientists are unsure about the likelihood, or speed, of the shelf’s disintegration, they warn the episode will certainly make the shelf less stable. “In the ensuing months to years we would expect further calving events, and maybe an eventual collapse – but it’s a very hard thing to predict, and our models say it will be less stable; not that it will immediately collapse,” Adrian Luckman, lead professor at Project MIDAS, told BBC News.

Rising sea levels, an uncertain future

Being part of an ice shelf, the breaking of the iceberg wouldn’t directly cause sea levels to rise. However, scientists fear that an ice-shelf reduction of such proportion may accelerate the flow of glaciers from land towards the ocean. Should all the ice held back by Larsen C flow into the ocean, this could raise sea levels up to 10 centimetres.

Reassuringly, scientists confirm that for now this remains only a very remote possibility that could present itself in the far-away future. According to a study by Nature Climate Change, the ‘holding-back’ effect of Larsen C is only a passive one, therefore its calving wouldn’t affect ice flow from the land.

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