The ice walls of floating glaciers in the Antarctic are fundamental and vital for the global climate according to a new study published in the magazine Nature. These walls, in fact, prevent the rise in temperature of the Antarctic sea itself and the melting of the ice.
In the deep sea around the South Pole, in fact, a large amount of thermal energy is stored and the floating glaciers act as a “wall” so that this thermal energy does not spread in the Antarctic, which would naturally cause even more melting ice.
Researchers have analyzed in particular the Getz Glacier in West Antarctica. This glacier has a floating part with a thickness of 300-800 meters. Below this part is sea water that connects to the surrounding ocean.
Researchers have found that ocean currents are blocked by the edge of the glacier and this limits the amount of hot water that can reach the continent: “Now, we understand that only a small amount of current can make its way under the glacier. This means that about two-thirds of the thermal energy that rises to the continental shelf from the deep sea never reaches the ice,” the researchers say.
The study was conducted by an international team led by Swedish researchers. Anna Wåhlin, Professor of Oceanography at the University of Gothenburg and lead author of the study, explains that the increase in melting ice in areas near the Antarctic coast could be caused by hot, salty ocean currents circulating on the continental shelf causing the glaciers themselves to melt from below.
Céline Heuzé, another researcher involved in the study at the same university, comments on the results: “What we found here is a crucial feedback process: ice shelves are the best protection against hot water intrusion. If the ice gets thinner, more ocean heat enters and melts the ice shelf, which becomes even thinner, etc.”. This is worrying, as the ice shelves are already thinning due to global warming of the air and oceans”.