ScienceNews reports: The wind is helping to awaken one of Antarctica’s sleeping giants. Warm ocean waters, driven inland by winds, are undercutting an ice shelf that holds back a vast glacier from sliding into the ocean, researchers report November 1 in Science Advances.
Totten Glacier is East Antarctica’s largest glacier, with a drainage basin encompassing about 550,000 square kilometers, an area about the size of France. Its floating front edge, the Totten ice shelf, sticks out like a tongue over the water and acts as a buttress for the giant glacier, slowing its movement toward the ocean. If the entire land-based glacier destabilizes and slips into the sea, it could raise global sea level by at least 3.5 meters.
Satellite and on-the-ground studies have previously shown that Totten Glacier and its buttressing ice shelf are thinning. Last year, scientists determined that the ice shelf is being melted from below by warm water. The ice shelf floats within a pool of its own cold meltwater that sits atop a deeper, saltier and warmer layer; the two layers generally don’t mix, like oil and water. The warmer layer periodically rises up, becoming shallow enough to access grooves in the seafloor that extend beneath the ice shelf. But what controls the inflow of that warm water was unknown. [Continue reading…]