An Antarctic reservoir, which contained more water than Sydney Harbour, has mysteriously disappeared. The discovery is by Australian and American scientists who noticed it from satellite images.
A huge lake in East Antarctica has suddenly disappeared. The report came from a team of international, Australian and American researchers, who published the study in Geophysical Research Letters. The basin left only a fractured ice sheet and a depression of about 11 square kilometers. Noting the disappearance were satellite images between winter 2019 and the following summer. It is estimated that the lake contained more water than Sydney Harbour.
The Disappearance of the Antarctic Lake
Dr. Roland Warner of the Australian Antarctic Program Partnership at the University of Tasmania, on the team of researchers, said the event may have been caused by a process known as "hydrofracturing." "We believe that a large crack," Warner said, "opened up in the floating ice shelf and drained the entire lake into the ocean within three days. Hydrofracturing occurs when liquid water, which is denser than ice, puts pressure on cracks in ice shelves to open them up to the ocean below.
The drainage of the Antarctic lake has left a deep, irregular depression in the surface covering about eleven square kilometers. This impressive structure, known as an ice sinkhole, contains the fractured remains of the thick layer of ice that had covered the lake. The event was also captured by a laser instrument on NASA's ICESat-2. Study coauthor Professor Helen Fricker of the Scripps Institution of Oceanography, a member of the ICESat-2 Science Team, said it was a great demonstration of the satellite's capabilities.
An estimated 600 to 750 million cubic meters of water were lost to the ocean. Professor Warner said the event raises new questions about how common these ice-covered lakes are and how they evolve. The team of researchers then also argued that it cannot be concluded that climate change is responsible for the lake's disappearance, but that nonetheless, the study of the formation of these Antarctic basins may be crucial to understanding the Earth's geological evolution.
In the meantime, after other various research, National Geographic has included a fifth ocean, the Antarctic, in its maps, which would have been born recently.
Stefania Bernardini