The crack that is threatening to calve off one of the largest icebergs ever seen has grown a worrying 27 kilometers (17 miles) in length in the last two months alone. The ice shelf is now perilously close to fully breaking free, which is expected to occur in the next month or so, due to the enormous stress placed on the last remaining 17 kilometers (20 miles) tethering the shelf to the rest of the ice.
Around twice the size of Hawaii, the Larson C ice shelf is the fourth largest ice shelf in Antarctica, and while it is already floating on the ocean, and so won’t itself contribute to sea level rise itself, the consequences following the calving could be dramatic. The shelf sits on the outer edge, effectively holding back glaciers that are on land and trying to flow into the ocean.
It is thought that when the shelf finally breaks free, it will allow the glaciers covering the land in this region of Antarctica to slip into the ocean, which is predicted to elevate sea levels by an estimated 10 centimeters (3.9 inches). Considering that over the last two decades the global sea level has only risen by roughly 6.6 centimeters (2.6 inches), this would be a dramatic rise in sea levels.
Climate change is not actually thought to be the direct cause of the calving, though it is most likely a contributing factor. Rising global temperatures are, however, contributing to the melting of ice that is still covering the land not only in Antarctica, but also around the globe.
This is not the only huge crack forming in the Antarctic ice shelves, though. The British Antarctic Survey (BAS) this month was forced to move their state of the art Halley VI research station as it was threatened by the development of another crack in the Brunt Ice Shelf. Over 50 meters deep in places, and 30 kilometers long, it has long been dormant, until in 2012 when it started to expand.
The BAS has now released an incredible drone video showing the astonishing extent and strange beauty of the massive chasm in the Brunt Ice Shelf as it stretches to the horizon.
