One of the largest icebergs in the world, A-68, is on the move and new footage compiled from satellite images tracks its more than 155 mile (250km) journey towards South Georgia.
Since it calved from Antarctica’s Larson C ice shelf two years ago, the iceberg has rotated 270 degrees and drifted 155 miles north, carried by the ocean current known as the Weddell Gyre.
At 2,239 sq miles (5,800 sq km) it is roughly the size of Delaware (2,490 sq m / 6,450 sq km), or four times the size of Greater London 580 sq m (1,500 sq m), and its volume is twice that of Lake Erie.
Iceberg calving is a natural phenomenon – as inland glaciers supply coastal ice shelves with new ice, older ice is pushed out to sea.
A growing body of evidence suggests rising water and air temperatures caused by global warming are triggering instabilities along the coasts of Antarctica and Greenland, accelerating melting and increases the rates of calving.
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One of the largest icebergs in the world, A-68, is on the move and new footage compiled from satellite images tracks its more than 155 mile (250km) journey towards South Georgia. At 2,239 sq miles it is roughly the size of Delaware (2,490 sq miles), or four times the size of Greater London 580 sq miles, and its volume is twice that of Lake Erie
Glacier expert Adrian Luckman, a geography professor at Swansea University in Wales, published an animation of the glacier’s movements between January 6, 2018 and July 10, 2019 on his blog.
‘For an object weighing around one trillion tonnes, Iceberg A68 appears to be quite nimble,’ Professor Luckman wrote on his blog.
‘Following a year of staying close to its parent ice shelf, in mid-2018 A68 became caught in the Weddell Gyre, a clockwise ocean current, which spun it through 270 degrees and carried it 250km north.
‘The iceberg is 100 miles (160 km) in length yet only 656 ft (200 m) thick – a similar ratio to a credit card – so it is surprising how little damage it has sustained in its journey so far.’
Since it calved from Antarctica’s Larson C ice shelf two years ago, the iceberg has rotated 270 degrees and drifted 155 miles north, carried by the ocean current known as the Weddell Gyre. Pictured: A-68 in it begins to break away from it’s starting position
At 2,239 sq miles (5,800 sq km) it is roughly the size of Delaware (2,490 sq m / 6,450 sq km), or four times the size of Greater London 580 sq m (1,500 sq m), and its volume is twice that of Lake Erie. Pictured: A-68 where it currently resides Iceberg calving is a natural phenomenon – as inland glaciers supply coastal ice shelves with new ice, older ice is pushed out to sea
For more than a year after it initially calved, A-68 remained mostly motionless, grounded on the Bawden Ice Rise, a shallow seabed near the edge of the Larsen ice shelf.
Last Autumn, the iceberg began to disengage from the seafloor, spin and drift. Over the last year, A-68 has begun to move at an accelerated pace.
When it first split, scientists expected the iceberg to quickly break apart and disintegrate, but it has remained mostly intact.
Satellite records for A-68, which weighs more than one trillion metric tons, suggest is the sixth largest iceberg currently floating in Earth’s oceans.
A growing body of evidence suggests rising water and air temperatures caused by global warming are triggering instabilities along the coasts of Antarctica and Greenland, accelerating melting and increases the rates of calving Pictured: A-68’s position back in November 2017
Glacier expert Adrian Luckman, a geography professor at Swansea University in Wales, published an animation of the glacier’s movements between January 6, 2018 and July 10, 2019 on his blog. Pictured: A-68’s position in July, 2018
Left: A ‘temperature anomaly’ on 20 July 2018, when it was almost 20 °C warmer than the mean over the Weddell Sea and Larsen Ice shelf. Right: Sentinel-1 SAR satellite imagery from 29 August 2018 shows that to the north of the iceberg the wind is pushing the sea ice northwards faster than the iceberg is rotating
In early July 2017, a huge crack in Antarctica’s Larsen C ice shelf caused a massive iceberg – dubbed A-68 – to break free.
In September 2018, scientists tracking A-68 with satellites revealed it had begun to spin and swing northward after becoming lodged on the sea bed.
When A-68 separated from Larsen C, it revealed an ocean hidden under the ice shelf for 120,000 years, and a team of scientists are now studying the region to uncover some of the hidden ecosystem’s mysteries.
Led by the Cambridge-based British Antarctic Survey (BAS), the group will study tiny animals, microbes and plankton on the seafloor to see how they cope with severe changes to their environment.
WHAT IS THE A-68 ICEBERG AND WHAT CAUSED IT TO BREAK AWAY FROM ANTARCTICA?
In July 2017, a huge crack in Antarctica’s Larsen C ice shelf caused a trillion ton iceberg – the third biggest ever recorded – to break off from the icy southern continent.
The huge chunk of ice, dubbed iceberg A-68, measures 5,800 square kilometres (2,240 square miles), making it around the size of Delaware, or four times the area covered by Greater London.
Since A-68 broke away, it has remained unclear what will happen to the giant mass, with fears it could break up into pieces too small to track on satellite, and drift into shipping lanes.
In July 2017, a huge crack in Antarctica’s Larsen C ice shelf caused a trillion ton iceberg – the third biggest ever recorded – to break off from the icy southern continent. These detailed images were captured by instruments aboard Nasa’s Landsat 8 satellite
Experts have found that cracks are still growing on Larsen C, and if they continue to grow, it’s possible that the ice shelf could collapse.
If all of Larsen C collapses, the ice it holds back might add another 4 inches (10 cm) to global sea levels over the years.
Many scientists argue that a calving event was not necessarily due to climate change.
Instead, it may simply reflect the natural growth and decay cycle of an ice shelf.
