Two icebergs the size of London and Cornwall could pose a threat to shipping, fishing and wildlife.
British scientists are tracking the two icebergs which have broken away from Antarctica and can take decades to melt.
One of them, called A81, was photographed as the scientists were flying off the UK’s Halley base for the season.
The bigger one is A76a which has been described as the size of Cornwall, at over 3,000 sq km.
Its long and thin shape has been compared to a giant ironing board, with a research team tracking it aboard the Royal Research Ship Discovery. One biological oceanographer recalls that it took ’24 hours’ to traverse it.
‘It was directly in our path as we sailed home so we took 24 hours out to go around it,’ Professor Geraint Tarling told the BBC.
The team collected water from around the iceberg to study as the huge flat-topped icebergs had a considerable influence on their environment.
A76a travelled out of Antarctica’s Weddell Sea into the South Atlantic, having originated from the Filchner-Ronne Ice Shelf in May 2021.
Now, it’s heading north, carried by currents and winds towards the Falklands and South Georgia, raising concern that it could become lodged in the continental shelf’s shallow waters.
Alternatively, the iceberg could get trapped within a collection of nearby islets known as Shag Rocks, which is still not ideal.
‘If it does become grounded, our major concern is break-up and the impact of (smaller) icebergs on vessel movements in the area,’ Dr Mark Belchier, the director of fisheries and environment with the government for South Georgia and the South Sandwich Islands, told the BBC.
‘Although the tourist season is coming to an end, our fisheries operate during the winter months so it may impact on their operations,’
According to the scientists, the iceberg could be less disruptive to wildlife if it breaks up over winter when most animals can forage over greater distances and don’t have to keep returning to land to feed their young.
A81 broke away from the Brunt Ice Shelf at the end of January and is expected to follow A76a out into the shipping lanes of the South Atlantic.
The world’s largest iceberg, A23a, measures some 4,000 sq km in area and broke away from the same Filchner-Ronne Ice Shelf as A76a.
Since it broke away in 1986, A23a has spent decades as an ‘ice island’, grounded in the south-central Weddell Sea.
Icebergs of this size pose a threat to ships as they can roll over and lose their snow layers, making them less visible to ships.
Following the loss of RMS Titanic in April 1912, the International Ice Patrol was created to track icebergs.
Now, reports are transmitted twice each day to ships, with continuous computer plots logged of their location.
When icebergs melt, they inject huge volumes of fresh water into the sea, disrupting the ecosystem for some organisms.
The melting also releases mineral dust from when it was part of an Antarctic glacier. This dust is a source of nutrients that will spur life in the open ocean.
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