Antarctica iceberg Larsen C held together by 20km of connected ice shelf: Australian Antarctic Division, Hobart

The crack in the Larsen C ice shelf in Antarctica. Researchers from the Australian Antarctic Division anticipate the shelf will "calve" or break away in the next few months. Picture: NASA.
The crack in the Larsen C ice shelf in Antarctica. Researchers from the Australian Antarctic Division anticipate the shelf will "calve" or break away in the next few months. Picture: NASA.

An iceberg described as being “in the top 10” for size will break away from the Antarctic ice shelf in the next few months and is being held together by a flimsy 20-kilometres of connected iceberg.

The Larsen C ice shelf is about 50,000 square kilometres in size and the iceberg poised to break away from the shelf is about 10 per cent of the total ice shelf’s mass.

The shelf and its crack is being monitored by Hobart-based Antarctic research centre the Australian Antarctic Division (AAD) and glaciologist Ben Galton-Fenzi said it followed a pattern of calving icebergs in the same area.

The Larsen A and B cracks “calved” in 1995 and 2002 respectively but Larsen C will be one of the biggest icebergs ever recorded from the station.

Dr Galton-Fenzi said Larsen C had been fascinating because of the rate of the widening crack, that has seen 18-kilometres of ice separate from the shelf in the last couple of weeks.

”It’s interesting for me because because of its close proximity to other ice shelf collapses in the past decades,” Dr Galton-Fenzi said.

Scientists from AAD will monitor the impacts the iceberg will have on the ocean’s ecosystem when the freshwater iceberg melts into the ocean.

Dr Galton-Fenzi said the problem with ice shelf cracks and icebergs was not that they cracked off, which was typical for the continent, but what happened to the icebergs afterwards.

Warmer sea temperatures could lead to the Larsen C iceberg melting into the ocean more quickly that would lead to a significant rise in sea levels, because of the iceberg’s size.

“We have a team in Antarctica now at one of the shelves, monitoring ice melt but we do still rely a lot on remote satellites,” he said.

Dr Galton-Fenzi said it was typical to have icebergs calve off ice shelves in Antarctica but what made Larsen C special was its size.

It is difficult to pinpoint when exactly the iceberg will separate from the shelf but Dr Galton-Fenzi said it was anticipated in the next few months.

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