A massive 6,000 square kilometre iceberg is about to snap off the Antarctic and head for shipping lanes in the South Atlantic.
Scientists are watching for signs the iceberg is detached from the Antarctic ice field.
Only a five-kilometre-wide frozen bridge is holding the millions of tons of ice to the land mass and is expected to snap any time soon.
When it does, the iceberg will crash into the sea and start a slow journey across the Weddell Sea to the South Atlantic which could take years to complete.
The team of scientists and geologists have targeted satellites with special radar antennas to study the iceberg. The radar sensors map the iceberg and calculate how much is hidden below water.
200 metre cliffs of ice
The workings show the iceberg is 190 metres high, with 30 metres floating above the sea, although the height tops 210 metres in places.
The volume of ice is thought to be 1,155 cubic kilometres.
Scientists are unsure when and if the iceberg will float away from the southern continental land mass.
The most important factor is the depth of the Weddell Sea near where the berg is calved from the ice field.
With a draught of around 160 – 180 metres, the base could catch or drag on the ocean floor, slowing movement or even changing the direction of trav400el.
Fears ice island may ground
“The icebergs often shoal and pivot or spin around their grounding point, resulting in stop and go motion or a change in direction. So, the iceberg from Larsen C could take some time before it escapes the shallow western Weddell Sea,” said Dr Anna Hogg from Leeds University.
“It’s not impossible it could simply become stuck on some high-rise topography on the ocean floor. We’ve seen that before where an iceberg becomes a semi-permanent ice island in the Weddell Sea.”
The iceberg will be named after breaking away from the polar ice cap.
The last large iceberg to break off Antarctica was measured from space as 26 km by 13 km – about the size of a major city, but is minute compared with the one about to calf.