NASA Photo Reveals Rift in Antarctic Ice Shelf

A rift in the middle of the ice in the Pine Island Glacier could point to a new mechanism for the collapse of this and potentially other glaciers contributing to global sea level rise. Researchers think the rift was caused by the same warm ocean waters that have been spilling into the cavities below many Antarctic ice shelves. As the ice shelves have thinned, the glaciers have flowed more quickly to the sea adding once land-bound ice to the ocean. Rifts naturally form along the edges of an ice shelf. Rifts can spread across an ice shelf eventually causing an iceberg to break off causing the glacier to speed its flow pushing more ice to the sea raising global sea levels. Previous research has suggested that the warmer water from global warming can follow a seasonal cycle, meaning the water under the ice shelf is warmer at some times of the year than others. When the ice first hits the ocean it melts according to the temperature of the water.

This rift photographed above during NASA's Operation Ice Bridge back in Nov. This is the second to form in the center of the ice shelf in the past three years. The first resulted in an iceberg that broke in 2015. (NASA)

NASA's airborne Ice Bridge mission flew directly over it during its recent Antarctic campaign, gathering valuable data that could help researchers better understand how the rifts formed and evolved. The question for the future of the Pine Island Glacier is whether rifts will keep forming in these valleys further inland. If they do more and more icebergs could break off at a quicker pace diminishing the ice shelf and speeding the retreat of the glacier.