Vast Antarctic iceberg 'could threaten shipping'

Satellite image of the PIG iceberg (Image: Nasa)
UK researchers will closely monitor the movement of the iceberg as it travels through the Southern Ocean

UK researchers have been awarded an emergency grant to track a vast iceberg in Antarctica that could enter shipping lanes.

Latest images show several kilometres of water between the iceberg, estimated to be about 700 sq km (270 sq miles), and the glacier that spawned the block.

The £50,000 award will fund a six-month project that will also predict its movement through the Southern Ocean.

The icy giant broke away from the Pine Island Glacier (PIG) in July.

"From the time it had been found that the crack had gone all the way across in July, it had stayed iced-in because it was still winter (in Antarctica)," explained principal investigator Grant Bigg from the University of Sheffield.

Rift in PIG
A Nasa aircraft was the first to detect the expanding crack across the Pine Island Glacier in 2011

"But in the last couple of days, it has begun to break away and now a kilometre or two of clear water has developed between it and the glacier.

"It often takes a while for bergs from this area to get out of Pine Island Bay but once they do that they can either go eastwards along the coast or they can… circle out into the main part of the Southern Ocean.

Prof Bigg told BBC News that one iceberg was tracked going through The Drake Passage - the body of water between South America's Cape Horn and Antarctica's South Shetland Islands.

If the iceberg did follow this trajectory, it would bring the Singapore-size ice island into busy international shipping lanes.

Eyes in the sky

The team of scientists from Sheffield and the University of Southampton will use data from a number of satellites, including the German TerraSAR-X, which first alerted researchers at the Alfred Wegener Institute to the July calving.

PIG is described as the longest and fastest flowing glacier in the Antarctic, with vast icebergs being calved from ice shelf every 6-10 years. Previous notable events occurred in 2007 and 2001.

Scientists first noticed a spectacular crack spreading across the surface of the PIG in October 2011.

Map of Antarctica showing Pine Island Glacier

As well as tracking the movement of the iceberg, Prof Bigg explained that the team also planned to predict its path through the Southern Ocean.

"Part of the project is to try to simulate what we think the berg might do, given the... wind fields being experiencing in the region recently.

He added that the team would attempt to predict possible tracks into the coming 12 months or so.

If the berg did move towards or into shipping lanes then a warning would be issued via the services of numerous ice hazard agencies around the world.

See how the giant berg took shape

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