'Megaberg' weighing 1,000,000,000 tonnes and twice the size of London breaks apart and set loose

A 1,000,000,000 tonne 'megaberg' believed to be twice the size of London is on the move once again.

The colossal iceberg - known to scientists as A23a - originally broke off from the Antarctic coastline all the way back in 1986 and spent the following 30 years wedged into the floor of the Weddell Sea due to its size.

However, A23a was later spotted drifting north back in 2020 after becoming unanchored from the seafloor.

The mega iceberg would again find itself stuck once again earlier this year, after becoming trapped in vortex back in spring.

The world's largest iceberg is drifting north once again (Getty Stock Images)

The vortex is known as a ' Taylor Column' and occurs when rotating water traps an object in place, which meant 1,000,000,000 tonne chunk of ice spent several months spinning around aimlessly in the freezing sea.

But it would seem that A23a is nothing if not determined as the iceberg has now broken free again and is now back to drifting through the Southern Ocean.

Speaking about the update, which was confirmed by the British Antarctic Survey (BAS) on Friday, oceanographer Dr Andrew Meijers said: "It's exciting to see A23a on the move again after periods of being stuck.

"We are interested to see if it will take the same route the other large icebergs that have calved off Antarctica have taken."

Experts currently expect the iceberg will eventually drift into the Atlantic Ocean, however, there is no risk of A23a crashing into any passing vessels or nearby islands anytime soon as the warmer waters will cause the ice to melt.

Iceberg A23a is currently of interest to scientists and researchers due to its ability to influence the surrounding eco-system.

Last year, BAS crew onboard the RRS David Attenborough were able to study the iceberg up close in order to gain further understanding of A23a as well as gather samples.

"We know that these giant icebergs can provide nutrients to the waters they pass through, creating thriving ecosystems in otherwise less productive areas. What we don’t know is what difference particular icebergs, their scale, and their origins can make to that process," biogeochemist and researcher Laura Taylor said of the ongoing project, which is known as BIOPOLE.

"We took samples of ocean surface waters behind, immediately adjacent to, and ahead of the iceberg’s route. They should help us determine what life could form around A23a and how it impacts carbon in the ocean and its balance with the atmosphere."