Three years ago, in July 2017, a gigantic iceberg a quarter the size of Wales split off the Larsen C ice shelf in Antarctica. The berg, known as A-68, was the fourth largest iceberg ever, and is currently the biggest in the world. This is despite having shed two pieces, each a few hundred square kilometres, designated A-68B and A-68C. The main body is now called A-68A.
In its first year the iceberg stayed close to the Larsen Shelf, moving no more than about five kilometres, as it was hemmed in by sea ice. In September 2018 strong winds broke A-68 free. Since then it has been moving towards South America, picking up speed. A-68A has now reached the South Orkney islands, more than a thousand kilometres from its starting point.
The European Space Agency’s Copernicus Sentinel-1 radar satellite has been monitoring the berg’s progress. Radar is helpful in tracking even such a large object, as the Antarctic is dark through the winter months and obscured by cloud for much of the rest of the year.
Although it covers over 5000 square kilometres, A-68A is only about two hundred metres thick. As it gets into rougher waters, it may disintegrate into a multitude of smaller bergs; or it may persist long enough to see another birthday.
