In West Antarctica, Pine Island Glacier and Thwaites Glacier have been melting at alarming rates, according to satellite imagery over the ice continent. If Thwaites collapses and melts, it would result in up to a six to nine feet rise in global sea levels.
Researchers from the United States, France, the Netherlands, Belgium, and Austria recently published their study in the journal Proceedings of the National Academy of Sciences. Both ice shelves in the Amundsen Sea Embayment have been two of the fastest-changing glaciers in Antarctica.
For decades, changing oceanic and atmospheric conditions have caused enhanced ocean-induced melting of their floating ice shelves. As a result, the glaciers' calving fronts have retreated and the ice shelves have thinned.
The combination of these conditions makes the glaciers prone to marine ice sheet instability, as stated in the study. The continuous loss of ice shelves equates to sea-level rise.
Melting Glaciers & Rising Sea Levels
Indrani Das from the International Thwaites Glacier Collaboration and Lamont-Doherty Earth Observatory at Columbia University shared that global sea levels have been rising nearly 1.4 inches every year. Thwaites Glacier is responsible for up to 5 percent of overall sea rise levels. If both glaciers destabilize, Das said, "a lot of neighboring areas would also fall apart, causing a widespread collapse." This could then result in a huge sea level rise.
A combination of satellite images and models analyze the rate of both glaciers weakening. However, the authors wrote, an accurate projection of future damage remains uncertain.
Glaciers typically have crevasses that form on top of less brittle ice. However, images from 1997 revealed that the lack of crevasses has been expanding rapidly.
As the ice shelves melt, it causes a feedback process, which only triggers the damage to work at a faster rate. Formerly, this was unaccounted for in ice sheet models when looking for solutions for sea level rise to slow down.
For now, the glaciers completely collapsing would not be possible since there is very little melting at the surface level. Brent Goehring from Tulane University explained that most of the melting occurs underwater where the ocean is at warmer temperatures.
Monitoring Antarctic Glaciers
However, the rate of damage has experts worried about how climate change is affecting the two glaciers. Images of Pine Island in 2016 revealed initial damage to the southern shear zone tearing apart compared to images in 1999. In the same year damage in the Thwaites was traced in a large removal of its eastern ice shelf.
In February this year, satellite images revealed that a large rift from the damage zone developed across Pine Island and caused an unprecedented retreat of the ice shelf front. The retreat is causing further destabilization of the glacier's ice shelf.
Goehring said that the team is "moving as fast as we can to understand how much and how fast" the rate of damage is as well as assessing every factor contributing to glacier damage. The team continues to monitor the two major glaciers via satellite, extensive mapping, and ice sheet models.
READ: Melting Thwaites Glacier to be Analyzed By Scientists By Digging a Hole Through It
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