It is the size of a city. And it is covered by more than three kilometers of ice. Its sediments could shed light on what the frozen continent was like before it froze. The giant lake beneath Antarctica may offer clues to the future.
Snow Eagle Lake was discovered by polar research aircraft. It is located in a 1.6 km deep canyon. where? In the highlands of Antarctica’s Princess Elizabeth Land, a few hundred km from the coast.
Changes in the ice
“It has a record of the entire history of the East Antarctic ice sheet. Including its inception more than 34 million years ago. Also, its evolution through the glacial cycles since then.” So says Don Blankenship, a researcher at the University of Texas Geophysical Institute. He is one of the authors of the paper published in the journal ‘Geology’. “The ice sheet changed significantly about 10,000 years ago. We have no idea why,” he adds.
how did they find it? A smooth depression was detected in satellite images of the ice sheet. For three years they systematically surveyed the site with ice-penetrating radar. They used sensors that measure minute changes in the Earth’s gravity and magnetic field.
Revealing sediments
“I literally jumped when I first saw that bright radar reflection.” So explains Shuai Yan of UT Austin’s Jackson School of Geosciences. He saw lake water that, unlike ice, reflects radar like a mirror. He then constructed a detailed image of Snow Eagle Lake located at the base of a canyon.
The giant lake beneath Antarctica is about 48 km long, 16 km wide, and 200 meters deep. The sediments at the bottom of the lake are about 300 meters deep. It is hoped to obtain a sample of the lake sediments.
“This lake has been accumulating sediments for a long time. Perhaps from when Antarctica was ice-free up to the time it froze over.” Quite a trip back in time.
