Scientists have discovered in Antarctica the bottom of an ancient sea at a depth of two kilometers; if the ice shelves "propping up" the underlying ice begin to melt rapidly, a huge ice sheet could slide into the ocean and raise the water level, according to an article published in the journal Nature Geoscience.
The results of the study were obtained as a result of the joint work of specialists from the British National Antarctic Research Center (BAS), the Universities of Aberdeen, Exeter and York. British polar explorers used radars to compile an under-ice map for an under-explored area of the mainland adjacent to the Weddell Sea (West Antarctica) and found that there is a hidden basin the size of a small European country (about 20 thousand square kilometers). Its depth in some places is up to two kilometers.
Scientists have come to the conclusion that there was once a sea on this site that stretched 200 kilometers into the interior of the modern continent. This is indicated, firstly, by the composition of the rocks on the surface of the subglacial basin (these are marine sediments) and the relief of the basin wall, which was once a sea coast with fjords, determined by density by radars.
“The terrain surveys that we carry out with radar from an airplane helps to study the topography of the rocky base of the continent … The topography of the underlying surface greatly affects how the ice moves and how it will move in the future,” said the head of the air detachment BAS Fausto Ferraccioli (Fausto Ferraccioli).
According to scientists, if the ice shelf holding back large masses of ice begins to melt quickly, the ice that is now "resting" in this basin will begin to "slide" into the sea and rapidly melt, raising the water level.
Last Wednesday, the journal Nature published a study by scientists from the Alfred Wegener Institute for Polar Research (AWI), who calculated that the rate of melting of the Filchner-Ronne Ice Shelf in the Weddell Sea by the end of the century could rise to 10 time. Martin Siegert, author of a study on the under-ice basin at the University of Edinburgh, believes that if the ice shelf melts in this scenario, the consequences could be catastrophic.
“Now it is difficult to give specific numbers, but, in all likelihood, when these huge masses of ice are set in motion, the sea level can rise by several centimeters, in turn, forcing the surrounding ice to melt … A chain reaction can start, as a result of which the ocean level will continue to climb rapidly,”said Sigert, quoted in a posting on the BAS website.