Using radar waves, science surprises with what lies beneath the ice in Antarctica

Deep beneath the ice in the eastern part of Antarctica, home to the world's largest ice sheets, scientists have recently confirmed the existence of a giant lake of liquid water.

Dubbed Snow Eagle Lake, the researchers believe that the sediments inside the lake may contain all the information about the evolution of the Antarctic ice sheet from its formation to the present.

The body of water located under the ice is about 3.2km, 42km long and 15km wide, covers an area of ​​370 square kilometers and contains 21 cubic kilometers of water. At the bottom of the lake is a layer of non-cohesive sediment. The team believes it has been there for a long time - perhaps before the ice sheet formed.

"According to our observations, the ice sheet has changed dramatically since about 10,000 years ago, although the cause is still unknown," said Don Blankenship, a geophysicist at the Institute of Geophysics.

The strange thing is that although the East Antarctic part is the coldest place on Earth, it is not completely frozen. Instead, there are hundreds of liquid lakes - known as subglacial lakes - that have been discovered hidden deep beneath the ice that has covered the continent for millennia.

According to scientists, there are several factors that allow these lakes to exist. First, it's the mass of the iceberg that creates pressure, which dramatically lowers the freezing point of water particles trapped beneath it.

In addition, the ice itself also acts as an effective insulation, against the cold air above, helping a large amount of water below have favorable conditions to form a flow and reduce the freezing point.

To detect subglacial lakes, scientists typically use high-altitude ice-penetrating radar. Accordingly, the radar signal is transmitted through the ice and bounced back. They then compared the transmitted signal with the return signal, and found signs of what was happening beneath the Antarctic ice sheet.

In the case of Snow Eagle Lake, the first hint to scientists was when they observed a very large dent inside the iceberg, after viewing satellite images. Then, a research team led by geophysicist Shuai Yan of the University of Texas at Austin, began collecting radar data around the area, as well as measurements of the Earth's magnetic field, over a period of time. 3 years, from 2016 to 2019.

After analyzing data from radar, they found a large patch, deep below the ice, emitting a bright light. From there, researchers can confirm this is one of the largest subglacial lakes ever discovered.

The team believes that explaining the lake is "trapped" under the ice in one of the most hostile environments on Earth, could open up new discoveries about the origin, as well as the formation of the lake itself. Green planet from the first days.