Antarctic's Pine Island Glacier Enters Irreversible Melt, Sea Levles May Rise by 1 cm

The Antarctic Pine Island Glacier, one of the biggest single contributors to rising sea levels, has gone into a self-sustaining retreat threatening to contribute a 3.5-10 mm rise in sea levels in the next 20 years.

Researchers arrived at this figure after combining data retrieved from state-of-the-art ice-flow models and field observations. They notice that the Pine Island Glacier grounding line was engaged in an unstable 40 km retreat.

"At the Pine Island Glacier we have seen that not only is more ice flowing from the glacier into the ocean, but it's also flowing faster across the grounding line - the boundary between the grounded ice and the floating ice," Dr. G. Hilmar Gudmundsson, a researcher on the project, was quoted in Planet Earth Magazine.

Based on their observations, the Pine Island Glacier is shrinking and this recession of the glacier will take place over several kilometers. When compared to the current observations, this irreversible melting will trigger a three to five-fold ice mass loss,  equivalent to 3.5-10 mm rise in sea level over the next twenty years.

Due to the accelerated rate of the sea ice melting, the Pine Island Glacier that covers 160,000 sq km in West Antarctica is under a constant watch along with its associated sea ice shelf.  During the last decade, PIG has receded nearly ten kilometers and alone contributed to nearly 25 percent of the ice loss from west Antarctica. The sea levels could rise up to five meters if the  entire West Antarctic Ice Sheet melts.

Tony Payne, Professor of Glaciology in the University's School of Geographical Sciences said, "Over the last 30 years, Pine Island Glacier was the major contributor to sea level rise from Antarctica however it is unclear whether this will continue into the future.  We have shown that the glacier's current retreat will indeed continue for many decades."

A research conducted earlier by the British Antarctic Survey revealed that in the last few years the rate at which PIG ice shelf was melting was a result of the underground ridge's erosion and sea ingress and not due to human driven global warming.  

 This research was documented in Nature Climate Change.