According to new research led by the British Antarctic Survey (BAS), the Pine Island Ice Shelf in West Antarctica – which holds enough ice to raise sea levels by 0.5 meters if melted – could be much more vulnerable to disintegration than previously thought. The experts showed that two processes – melting and calving – may interact in a dangerous feedback loop, threatening the stability of the shelf and increasing the likelihood of its collapse.
This huge ice shelf controls the flow of ice from the Pine Island Glacier – one of the world’s largest and fastest changing glaciers – into the Amundsen Sea. Currently, the shelf is becoming increasingly fragile due to two processes: enhanced thinning caused by an increase in ice shelf melting into the sea, and a rise in calving events, in which masses of ice break off into icebergs.
“This study highlights the extreme sensitivity of ice shelves to climate change. It shows the interplay between calving and melting can promote disintegration of the Pine Island Ice Shelf, which we already thought was vulnerable to collapse,” explained study lead author Alexander Bradley, an ocean modeler at BAS.
Together with his colleagues, Bradley used advanced ocean modelling techniques to simulate the effects of calving events on melt rate. The analyses revealed that calving events will most likely result in further thinning of the ice shelf, which will in turn make the shelf more vulnerable to calving. The feedback loop between these two processes could lead to the complete disintegration of the ice shelf, which would reduce its ability to stem the flow of ice from the Pine Island Glacier into the sea and cause devastating sea-level rises.
“Complete disintegration of the Pine Island Ice Shelf will have profound consequences not only for the glacier but all of West Antarctica as it is thought to play an integral role in maintaining the stability of the West Antarctic Ice Sheet,” Bradley concluded.
The study is published in the Journal of Geophysical Research: Oceans.
Image Credit: ESA