A massive new iceberg has started to move away from Antarctica, new satellite images show.
The pictures, taken by the Deimos1 satellite, show clear water between the berg, which is about a quarter the size of Wales, and the Larsen C Ice Shelf.
There are also signs that it is breaking up with a major new crack carving out a significant chunk of the ice.
Icebergs can remain in place for decades because they are ground on small hills rising up from the sea bed.
There are fears that if it breaks up into numerous small pieces that are too small to track they could pose a significant hazard to shipping.
A68, which is about 5,800 square kilometres in size and weighs around a trillion tonnes, is one of the largest ever known, although it is only about half the size of the record holder, which broke off the Ross Ice Shelf in 2000.
After the berg calved from Larsen C, Rod Downie, head of polar programmes at environmental charity WWF, said: “The sheer scale of this natural calving event is impressive – we will need to redraw the map of the Antarctic Peninsula.
“And whilst this is Antarctica doing what Antarctica does, it demonstrates just how fragile the polar regions are.
“The polar regions drive our oceans and atmosphere. But west Antarctica has experienced some of the most rapid rates of warming on the planet in recent decades, and that’s not good news for iconic species such as Adélie or emperor penguins.
“This demonstrates why we need to urgently and globally tackle climate change head on, starting in the UK with the UK Government outlining how we plan to meet our international commitments to reduce carbon emissions.”