A group of scientists is gathering today in the U. K. to discuss a thick piece of ice that's cracking in Antarctica, which is of the size of Delaware.
The ice shelf is called Larsen C, and it now has a 90-mile crack running through it. The big rift (裂缝) is slicing the ice shelf from top to bottom. But this is not just another sad climate change story. It's more complicated. "A lot of things are going on deep inside the ice," says Adrian Luckman, a glaciologist.
Luckman says climate change is certainly influencing this region. Larsen C used to have two neighbors to the north, Larsen A and Larsen B. As the air and water warmed, those ice shelves started melting and then disappeared in 1995 and 2002. But the crack in Larsen C seems to have happened on its own, for different reasons.
Larsen C has many cracks. All ice shelves do. This particular crack has been around since at least the 1960s. The unusual part is that in 2014, this crack — and only this crack — started growing quickly. Why?
"Well, that is a little bit of a mystery and that's why it drew itself to our attention," says Luckman. One puzzling aspect is how it managed to cut through areas of softer ice that bind (连接) the ice from neighboring glaciers into one giant sheet. Starting in 2014, that soft ice did very little to slow down this rift.
Scientists are split on how important this crack is for the stability of the whole ice shelf. Some say if this giant section breaks off, it won't make a difference. Others disagree.
"Ice shelves are the gates of Antarctica in a way, and the gatekeepers of Antarctica. The ice shelves are already floating, so if they fall apart it does not immediately affect sea levels. It's what they hold back -water from all the inland glaciers — that could be problematic. If all the water packed in those glaciers made their way to the sea, it could significantly raise global sea levels," says Ala Khazendar, a geophysicist.
