This Nasa photo released on Thursday shows what scientists on Nasa's IceBridge mission photographed in a view of a massive rift in the Antarctic Peninsula's Larsen C ice shelf on Nov 10.
Ice shelves are the floating parts of ice streams and glaciers, and they buttress the grounded ice behind them. When ice shelves collapse, the ice behind accelerates towards the ocean, where it then adds to sea-level rise.
Larsen C neighbours a smaller ice shelf that disintegrated in 2002 after developing a rift similar to the one now growing in Larsen C.
The IceBridge scientists measured the Larsen C fracture to be about 113km long, more than 91m wide and about 0.5km deep.
The crack completely cuts through the ice shelf but it does not go all the way across it. Once it does, it will produce an iceberg roughly the size of the state of Delaware (nine times the size of Singapore).