There is a huge void hiding under the Antarctic ice, becoming more and more cautious by the day, a new study reveals using satellite data.
The cavity is huge, about two-thirds of the surface of Manhattan and a height of about 300 meters. It rises at the bottom of the Thwaites Glacier in West Antarctica, and it quickly allows the melting of ice above it.
Scientists believe there may be some gaps between the Thwaites Glacier and the foundations below it, where ocean waters could enter and melt the ice glacier over it. But even they discovered the immensity and speed of the growth of the gap. [Top 10 Ways to Destroy Earth]
For starters, the gap is big enough to hold 15 billion tons (13.6 billion tons) of ice once, but much of that ice has been melting over the past three years, according to NASA.
"For years we have been suspected that the Thwaites are not firmly associated with the foundation under it," says researcher Eric Rigot, a professor of Earth Sciences at the University of California, Irvine, and a leading scientist in Radar Science and Engineering at the Laboratory Laboratory for the dip of NASA in Pasadena, California, said in a statement.
Scientists spotted the hidden cavity thanks to the new generation of satellites, said Rignot. These satellites, which are part of NASA Operation IceBridge, have a radar that penetrates the ice. The researchers also used data from the constellation of Italian and German spacecraft, which are equipped with an instrument for synthetic openings for synthetic openings (SAR), which can measure how much surface area the surface shifts between the images.
These tools found that the field had shifted significantly from 1992 to 2017, scientists found.
"[The size of] the cavity beneath the glacier plays an important role in melting, "says researcher Pitro Milillo, a JPL scientist at the Department of Radar Science and Engineering," as more heat and water are placed under the glacier, melts faster. "
Thwaites Glacier is the size of Florida, and is currently responsible for about 4 percent of the global sea rise. If the entire glacier melts, the resulting water could increase ocean levels by more than 2 feet (65 centimeters), researchers say. In addition, the glacier acts as a backdrop for adjacent glaciers, which means it slows the speed at which they lose ice. If these glaciers melt, sea levels can increase an incredible 8 meters (2.4 meters), says the research team.
Although the Thwaites Glacier is one of the hardest places on Earth to achieve, more of its secrets will soon be discovered. This summer, the National Science Foundation of the United States and the British Council for Scientific Research on Natural Resources open the international Thwaites Glacier Collaboration, a five-year field project that aims to reach the bottom of the glacier processes and functions.
Thwaites Glacier, curiously, does not melt in a unified way.
"We are discovering different withdrawal mechanisms," Milillo said. For example, the front part of a 100 km (160 km) glacier has different withdrawal rates in its ground line (where sea ice meets the ocean's foundation), depending on where you look. [In Images: IceBridge Investigates Antarctica]
Satellites found that a huge cavity lies underneath the western part of the glacier, the one beyond the Western Antarctic Peninsula, researchers say. Basically, this means that the glacier at this site is exposed to the tide and flow of the tide, causing the ice on the ground line to retreat and progress through a region about 2 to 3 miles long (3-5 km).
However, there is more seizure of progress than the end. The glacier is retiring at a stable rate of about 0.4 to 0.8 km per year since 1992, researchers say. This has made the melting point of this part of the glacier disturbingly high, researchers say.
Meanwhile, "on the east side of the glacier, grounding takes place through small channels, perhaps one kilometer [0.6 miles] wide, like fingers beneath the glacier to melt from below, "Milillo said. Here, the land-trapping rate doubled from about 0.6 km per year from 1992 to 2011 to 1.2 miles (1.2 km ) year from 2011 to 2017, he said.
Despite this high rate of withdrawal, melting rates are still larger on the west side, where the gap lies.
These findings show the complexity of the ice-ocean interactions. We hope that upcoming international cooperation will help researchers to merge the different systems of work under and around the glacier, researchers say.
"Understanding the details of how the ocean melts away this glacier is essential for the project[ing] its impact on sea levels will increase in the coming decades, "said Rigot.
The study was published yesterday (January 30th) in the journal Science Advances.
Originally published on Science Live.