The melting of the Thwaites glacier, which is about the size of Britain, is already responsible for 4 percent of sea level rise worldwide. It is known among glaciologists as the “Doomsday Iceberg”. If this ice field were to melt completely, sea level would rise by more than half a metre.
That hasn’t happened yet, but a group of American scientists fear the glacier melt will accelerate in the coming years. They will say this week at a conference in New Orleans. They see in satellite images that the eastern ice shelf, which is floating in front of the Thwaites Glacier, is starting to show more and more cracks. The ice shelf now acts as a kind of dam, slowing the glacier on its way to the sea.
warm ocean current
“What we see is like a car window that has some cracks at first, until you drive over a bump and the entire window suddenly shatters into hundreds of pieces,” said Erin Pettit, assistant professor of glaciology at Oregon State University. Statement.United States. If something like that happened to the ice shelf, the barrier would fall in front of the glacier and would sink into the sea more quickly.
Cracks in this ice shelf are caused by a warm ocean current, by Antarctic standards. Another consequence of this is that ice is increasingly associated with an underwater mountain. Even if the ice shelf lost its grip on that mountain, the glacier could suddenly clear the way to the sea.
“This is disturbing news,” replies Steve Lermitt, who studies Antarctica as an undergraduate lecturer in Earth sciences at Delft University. “We’ve known for some time that the ice in this area is breaking down, but there are now very concrete predictions for the end of this ice shelf.” Lhermitte agrees that the melting of the Thwaites glacier could have a significant impact on sea level rise. “Certainly in the Netherlands.”
horizontal gravity
Ocean waters are as strongly attracted to ice masses as they are in Antarctica – think of it as a kind of horizontal gravity. As a result, sea level in more remote regions, such as the North Sea, is a little lower than you might expect. With less ice around the South Pole, the waters will gradually spread over the oceans. As a result, the Netherlands will receive the brunt of the melting of Antarctica.
In its latest report, published last summer, the Intergovernmental Panel on Climate Change (IPCC) warned explicitly of a scenario in which parts of Antarctica would become unstable. The UN climate team believes this scenario is unlikely, but the impact would be enormous at the same time. If Antarctic glaciers melt and crash into the sea with a thunderous roar, a two-meter rise in sea levels by 2100 looms.
“The collapse of this ice shelf is a first step toward such a worst-case scenario,” Lermitt says. However, he did not believe that such a scenario would suddenly become more likely than before. “This is an area that scientists have been interested in for some time.”
