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Huge iceberg 3.5 times larger than London is melting, releasing billions of tonnes of fresh water into ocean

A68A iceberg approaching the island of South Georgia (14 December 2020). The left hand part of the image are clouds. Credit: MODIS image from NASA Worldview Snapshots. See SWNS story SWNNiceberg; A mega iceberg that was once three and a half times larger than London has released a whopping 152 billion tonnes of fresh water into the ocean as it melts, according to a study. Researchers say the megaberg melted the equivalent of 61 million Olympic sized swimming pools which could have a devastating impact on the marine habitats. Known as A68A it measured 5719 square kilometres, quarter the size of Wales, and melted enough water to fill Loch Ness 20 times.
A huge iceberg three-and-a-half times larger than London is melting, releasing huge amounts of water in the ocean as it melts. (SWNS)

A huge iceberg that was once three-and-a-half times the size of London is melting, releasing 152 billion tonnes of fresh water into the ocean, a study has found.

According to researchers, the 'megaberg' has melted the equivalent of 61 million Olympic-sized swimming pools, or enough to fill Loch Ness 20 times, with a potentially devastating effect on marine habitats.

Experts used satellite images to track the iceberg, which has been dubbed A68A, after it snapped off from the Larsen-C Ice Shelf in Antarctica in July 2017.

When it first broke off from the ice shelf, it was the largest iceberg on Earth and the sixth-largest on record.

It stayed the same size for around two years but started to melt as it drifted and entered seas around the sub-Antarctic island of South Georgia.

The iceberg has melted as it drifted towards South Georgia Island. (Google Maps)
The iceberg has melted as it drifted towards South Georgia Island. (Google Maps)

At its peak the huge iceberg, which measured 5,719sq km - or quarter the size of Wales - was melting at a rate of seven metres per month.

Such a colossal release of water is likely to damage the island's fragile habitat, experts have warned.

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Laura Gerrish, mapping specialist at British Antarctic Survey, said: "A68A was an absolutely fascinating iceberg to track all the way from its creation to its end.

"Frequent measurements allowed us to follow every move and break-up of the berg as it moved slowly northwards through iceberg alley and into the Scotia Sea where it then gained speed and approached the island of South Georgia very closely."

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Anne Braakmann-Folgmann, PhD candidate at the University of Leeds, said: "This is a huge amount of melt water, and the next thing we want to learn is whether it had a positive or negative impact on the ecosystem around South Georgia.

"Because A68A took a common route across the Drake Passage, we hope to learn more about icebergs taking a similar trajectory, and how they influence the polar oceans."

Tommaso Parrinello, CryoSat Mission Manager at the European Space Agency, said: "Our ability to study every move of the iceberg in such detail is thanks to advances in satellite techniques and the use of a variety of measurements.

"Imaging satellites record the location and shape of the iceberg and data from altimetry missions add a third dimension as they measure the height of surfaces underneath the satellites and can therefore observe how an iceberg melts."

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