Stunning video footage of an enormous crack in the Larsen C ice shelf in Antarctica was released this week by the British Antarctic Survey.

A huge iceberg more than 5,000 sq km, almost the size of Delaware, is ready to break off from the ice shelf, satellite observations this month show.

The aerial footage of the massive crack was taken by BAS scientists as they flew over Larsen C on their way to collect science equipment.

Scientists have been keeping an eye on the growing rift in Larsen C for years after the collapse of the Larsen A ice shelf in 1995 and the break-up of the Larsen B shelf in 2002.

It is not unusual for ice shelves to produce iceberg every few decades. Scientists are not sure whether the expected iceberg break off from the Larsen C is an effect of climate change, however the BAS said “there is good scientific evidence that climate change has caused thinning of the ice shelf.”

The iceberg that breaks off will not itself raise sea levels, but it still plays a big role. If the shelf continues to break up after the iceberg detaches, the glaciers that flow off the land behind it could speed up its passage towards the ocean, which could have an effect on sea levels, causing global waters to rise by 10cm.

“The stability of ice shelves is important because they resist the flow of the grounded ice inland,” said BAS ice and ocean modeler Dr. Paul Holland. “After the collapse of Larsen B, its tributary glaciers accelerated, contributing to sea-level rise.”

Last month, scientists at Swansea University in Wales, England warned about the “inevitable” iceberg break off from the Larsen C. Scientists from the UK Midas project led by Swansea University said the rift rapidly grew in December. In January, only 12 miles of ice (20km) was keeping the iceberg from floating away.