We’ve lost A68, the world’s largest iceberg

In 2017 the world’s largest iceberg, known as A68, detached from the Larsen C ice shelf and began drifting along the ocean. Today, it has almost entirely melted away.

The A68 iceberg has melted. Its journey began in 2017 when it broke away from the Larsen C ice shelf in Antarctica. At the time, it was considered the largest iceberg in the world, its surface extending for almost six thousand square kilometres – that’s more than the whole of Brunei – with a mass of over one billion tonnes. Today, satellite images show that today, after a long journey, A68 has almost completely melted away. The iceberg has broken up into smaller fragments which, according to the US National Ice Centre, it isn’t even worth monitoring.

a68 iceberg, antarctica
A satellite image of the A68 iceberg published by the European Space Agency (ESA) © contains modified Copernicus Sentinel data (2020), processed by ESA, CC BY-SA 3.0 IGO

The journey of A68

For a while, A68 didn’t really move much. It then began heading northwards and, at the end of last year, it reached a speed of one kilometre per hour. It had even entered into a collision course with the island of South Georgia, a British territory in the southern Atlantic ocean. Many icebergs end up melting in this region due to local shallows.

However, it wasn’t the shallows that stopped A68. According to the BBC, it was the waves and higher water and air temperatures in the Atlantic that consumed it, causing it to disintegrate into many pieces. “It’s amazing that A68 lasted as long as it did,” said Swansea University Professor Adrian Luckman. “If you think about the thickness ratio – it’s like four pieces of A4 paper stacked up on top of one another. So this thing is incredibly flexible and fragile as it moved around the ocean. It lasted for years like that. But it eventually broke into four-to-five pieces and then those broke up as well.”

The US National Ice Centre, whose role is to monitor icebergs and determine which ones constitute a risk for shipping, decided to cease monitoring A68. Its fragments are now smaller than the standard required to be classed as dangerous.

una veduta dei ghiacci antartici
A68’s journey began in 2017 when it broke off from the Larsen C ice platform © Mario Tama/Getty Images

Glaciologists believe the melting of A68 is a natural event

In 2017, soon after A68 broke off from Larsen C, glaciologists from Midas (a British research project) stated that this was a natural event, not necessarily linked to anthropogenic global warming. This hypothesis seems to still stand to this day, despite the fact that all experts agree that this process nonetheless leads to a series of risks for the world’s ice cover, as it makes the ice increasingly unstable. In any case, A68’s journey has come to an end.

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