ANTARCTICA: The world\u2019s largest and oldest iceberg A23a is on the move. <\/p>\n\n\n\n
After decades of being grounded on the seafloor and more recently spinning on the spot, the mega-iceberg has broken free from its position north of the South Orkney Islands and is now drifting in the Southern Ocean.<\/p>\n\n\n\n
The colossus A23a, which is double the size of Greater London and weighs nearly a trillion tonnes, calved from Antarctica\u2019s Filchner Ice Shelf in 1986, and remained grounded on the seabed in the Weddell Sea for over 30 years before beginning its slow journey north in 2020.<\/p>\n\n\n\n
The iceberg\u2019s journey has been marked by intriguing scientific events. For months, the iceberg was trapped in a Taylor Column, an oceanographic phenomenon where rotating water above a seamount traps objects in place. This dynamic kept A23a spinning in one spot delaying its expected rapid drift north.<\/p>\n\n\n\n