At least 50 years ago, a hole was opened in the Antarctic ice. Now scientists know why

Antarctica Doubles its extension During the southern winter, if we take into account the enormous layer of ice that surrounds it. But this expansion is not completely homogeneous, and in this ice, desert oases sometimes form in the form of holes in the ice through which sea water reaches the surface.

Some of these gaps are more interesting than others.

solve the puzzle. An international team of researchers It has been solved In the mystery of the mysterious hole in the Arctic ice sheet, the so-called Maud Polynya Mountain (Maud Rise Polynya). This hole resulted from a series of interactions between winds, ocean currents, and the formation of the sea floor in the area.

Maud Polynya Summit. Polynyas are openings in ice sheets above the polar oceans. This is polynyawhich at its greatest extent covers an area equivalent to the size of Castilla-La Mancha (about 80,000 km²), owes its name to its location on a seamount. Maud called Rise.

The analysis occurred when the polynya opened during the southern winters of 2016 and 2017, but it is not the first time an opening has been discovered in the region. This hole in the ice already existed It was discovered by satellites For three consecutive winters, between 1974 and 1976.

Since then, the crater has formed only sporadically. Until a few years ago.

The secret of this polina. The mystery lies in the position of this polynya. This type of formation is natural in the coastal region, where the wind pushes the ice that covers the waters of the continental ice, forming a gap through which liquid water emerges from the ocean.

However, Maud Polynya Mountain is located kilometers from the coast, making its presence difficult.

A combination of factors. The team responsible for Unravel this puzzle It took advantage of the latest events of this phenomenon to study it in depth. They noted that during this time the currents surrounding the Weddell Sea (where Maud Peak is located) intensified.

These currents brought warmer, saltier water from below to the surface, mixing it with the water in these upper layers. It is then possible to explain how the ice on the surface melts, but there is a problem.

The melting ice consists mainly of fresh water. When this dissolves, it should reduce the salinity thus ending the process. According to the team, there must have been another phenomenon that caused the polynya to continue opening to reach its extension; There must be something that contributed to the increased salinity in the mixture.

Ekman Transport. They found this something In Ekman transferIt is a phenomenon in which water moves at a 90-degree angle in the direction of surface winds, as the team explains. This displacement can affect ocean currents and water salinity.

Details of the study were published recently In an article In the magazine Advancement of science.

Change direction. Interest in the phenomenon of polynya is not arbitrary. These openings in the ice have effects on how heat and carbon dioxide are transferred between the ocean and the atmosphere, for example.

“The imprint of a polynya can remain in the water for many years after it is formed. They can change how the water moves and how currents transport heat to the continent. “The dense water that forms here could spread throughout the World Ocean.” He explained in a press release Sarah Gill, co-author of the study.

In Chataka | 50 kilometers of underwater volcanoes under the Antarctic ice. The new discovery of the Italian expedition

Image | NASA Earth Observatory, / Lauren Dauphin, from MODIS, with data from NASA EOSDIS/LANCE and GIBS/Worldview