Scientists have been watching the Antarctic Peninsula melt for decades, but are still just figuring out why.
The prevailing conclusion until recently had been that rising air temperatures were causing the melt.
But it may be the water — warm water, according to research published in this week's journal Science.
The study by researchers at Swansea University, Durham University and the British Antarctic Survey says that warming in the waters around Antarctica has corresponded with the "widespread acceleration of glacier retreat." In addition, the melt is worse in the southern region, where some of the waters are relatively warmer, than it is in the cooler water of the northwest region.
Lead author Alison Cook found in a previous study that rising air temperatures alone could not account for the degree of glacier retreat that has been occurring, according to The Washington Post.
A patch of water known as the Circumpolar Deep Water, seems to be the force driving the more rapid glacial melting in the southwestern Antarctic Peninsula, the study concluded. In some areas, portions of the glaciers extend outward into the ocean like shelves or wings. The warmer water could be weakening these ice shelves from below, causing them to break off, and dramatically increase the rate at which the glacier retreats.