"If there is a little bit more retreat, this last 'ice buttress' could collapse and we'd likely lose about half the total ice shelf area in the next few years," he said.
 
Ice melt
 
The western Antarctic Peninsula has experienced the biggest temperature increase on Earth over the past 50 years, with a rise of 0.5 degrees Celsius (0.9 degrees Farenheit) per decade.

"We believe the Wilkins has been in place for at least a few hundred years, but warm air and exposure to ocean waves are causing a breakup," Scambos said.

Scientists says the breakup of the ice shelf is caused by global warming [AFP/ BAS]

Scientists do not expect the ice shelf to further disintegrate in the next few months, due to the Antarctic summer drawing to a close.

"This unusual show is over for this season... But come January, we'll be watching to see if the Wilkins continues to fall apart," Scambos said.

More than 13,000 square km of ice shelves, which float at the coastal regions of the thicker Antarctica ice sheet, have broken up over the past half-century.

Six ice shelves have completely disintegrated in the past 30 years.

The break-up of the ice shelves has not significantly increased sea levels as they are already floating.

But scientists warn that continued disintegration of Antarctic ice shelves could threaten the thicker ice sheet, risking a significant increase in the level of the world's oceans.

According to calculations, the present rise in sea levels by three millimetres per year could increase to 1.4 metres by the end of the century.