Information coming from images shot over the Antarctic ice sheet is quite troubling. As one can see with the naked eye, glaciers are disappearing into the ocean. That is a normal thing to happen, but it is more accelerated than usual, and it complicates matters for us humans, leading to sea level to rise more than expected.
Over six years, half a dozen glaciers have been observed to double the mass they lose to the seas. Thwaites Glacier has been selected as a model for a new study. Scientists are trying to project how much ice the glacier will lose between 50 and 800 years.
That is made difficult by rapid changes in climate change that require scientists to collect more data to make such predictions accurately. Researchers from NASA’s Jet Propulsion Laboratory have given their assistance to the team working on the study. They have provided 500 ice-flow simulations that accounted for climate instability. As one might expect, results varied in the simulations. But many led to instability in the glacier that happened sooner or later.
Alex Robel, assistant professor at Georgia Tech’s School of Earth and Atmospheric Sciences gives us the following insight: “If you trigger this instability, you don’t need to continue to force the ice sheet by cranking up temperatures. It will keep going by itself, and that’s the worry. Climate variations will still be important after that tipping point because they will determine how fast the ice will move.”
Sea Levels To Rising More Than Expected Due To Antarctic Instability
“After reaching the tipping point, Thwaites Glacier could lose all of its ice in 150 years. That would make for a sea level rise of about half a meter (1.64 feet),” Robel added.
An iceberg tends to stand alone. It is also an ice formation that is 90 percent underwater. Water being the critical factor here. Because an iceberg’s mass is already in the water, it will not contribute to a rise in sea level. A glacier is a different matter entirely as a landmass supports this ice formation, which is usually many miles below the ice. So, contrary to the belief of some, Antarctica is not a continent made of ice. It is only covered by it.
Melting of Antarctic glaciers would see that mass transfer from land into the ocean. It is resulting in sea level rise. The region holds eight times as much ice than Greenland and 50 times as much ice as all the glaciers in the world. There is a line where a glacier meets the seafloor on the coast as well as where the ice extends to reach the surface. This is called a grounding line. Some spots are usually found near the base of this line that can cause instability. This is due to the bedrock shifting underneath the ice.
The movement of the bedrock and the ice along the line is accelerated by rising temperatures in the world’s oceans. That causes breaks in the ice sheet, especially closer to the surface, which in turn melts the ice and contributes to the rise of the sea level.
Lena Pierce is a reporter for Great Lakes Ledger. After graduating from Ryerson In Toronto, Lena got an internship at CBC radio in Calgary. Lena was also a beat reporter for the Calgary Flames. Lena mostly cover sports and community events. Contact Lena here.