Antarctica: Glaciers in distress – DER SPIEGEL

The good news is that the “satellite image of the week” has been saved at this time. The picture takes us to the Pine Island glacier west of Antarctica this Easter Monday. Here is one of the largest glacier formations in the Western Antarctic Glacier. Covering an area of ​​about 162,000 square kilometers, it is twice as large as Bavaria and makes up ten percent of the ice in Western Antarctica.

The Pine Island glacier carries its cold cargo over 250 kilometers into the Amundsen Sea in a gigantic shelf. Big accidents happen regularly. This is not yet an unusual process, because glacier calving is a natural process. After all, they regain mass through the snow.

However, in recent years researchers have been concerned about how quickly the glacier loses its ice into the ocean. The mass balance has become increasingly negative, with the edge of the ice shelf floating in the ocean, called the grounding line, which has significantly displaced again in recent years. The flow rate has also increased. No glacier in the world currently carries more ice at sea than Pine Island.

The fear in such observations is that the glacier has crossed a point and can no longer sustain it. Then, like a house of cards where you have taken multiple cards, the whole house collapses, a mechanism is set up in motion in which the entire glacier disappears.

Researchers at the University of Northumbria in the UK believe that the Pine Island glacier may indeed be too late. In a study conducted on Focmacasin Cry Cryosphere It seemed, what they looked like These are called tipping points Play a role there.

They identified many of these early warning indicators that contribute to the instability of the ice. This is especially important when the seawater near the glacier warms permanently above 1.2 degrees Celsius. “This could lead to the retreat of the entire glacier, which could start the collapse of the western Antarctic ice sheet,” writes the team study around glacier expert Sebastian Rosier.

Unfortunately, this scene is very realistic. Due to prolonged warming in circadian deep water and altered air in the Amundsen Sea, the ice shelf will be exposed to hot water for a long time. This further exacerbates the temperature changes of this sequence.

“The potential for this region to reach a critical point has already been described in the past, but our study was the first to confirm that the Pine Island glacier actually exceeds this critical limit,” says Rosier.

The researchers developed and used the latest computer models for the study. Such simulations are always fraught with uncertainty and challenge, Rosier agrees. But their algorithm makes it much easier to identify future tipping points, it is said.

The Pine Island glacier is already losing one meter of its two-kilometer-thick ice each year. This is even more so in the area of ​​the thin ice shelf. Pine Island Glacier and its melting Neighboring Dwights Glacier It is already responsible for ten percent of global sea level rise. Ice melting in western Antarctica is estimated to raise sea levels by more than three meters.