Hidden Lake the Size of Texas Found Below Antarctic Ice Sheet Could Hold 34 Million Year Old Secrets

The East Antarctic Ice Sheet, the largest ice sheet in the world, long withheld a profound secret under its 4-million-square-mile expanse of ice. While scientists scrabbled and grubbed around its white wonderland, beneath its thick icy veil secretly bubbled a lake, the size of Las Vegas. The huge reservoir of liquid water babbled beneath a jagged canyon frosted with a 2-mile thick layer of ice overhanging in the highlands of Princess Elizabeth Land. After discovering it in May 2022, scientists jumped with joy as the lake seemed to be an excellent potential candidate that could offer clues to Antarctica’s 34-million-year history. They named it “Lake Snow Eagle” and published detailed findings in the journal Geology.

“We confirm the existence of a major subglacial lake, herein referred to as Lake Snow Eagle (LSE), for the first time using recently acquired aerogeophysical data,” researchers noted in the paper. The team used highly sophisticated airborne instruments to detect the presence of this lake. They believed that the sediment inside this lake could provide valuable information about the history and evolution of the East Antarctic ice sheet. Just the same way as the human body stores all the memories and experiences of an individual, the freshwater of this lake seemed to be a treasure trove of valuable information about the history of formation of East Antarctica.

"This lake is likely to have a record of the entire history of the East Antarctic Ice Sheet, its initiation over 34 million years ago, as well as its growth and evolution across glacial cycles since then. Our observations also suggest that the ice sheet changed significantly about 10,000 years ago, although we have no idea why," geophysicist Don Blankenship of The University of Texas at Austin's Institute for Geophysics, said in a press release.

Although East Antarctica, as it appears on the surface, is mostly blanketed by a thick veneer of ice. But dotted here and there beneath this ice is a chain of liquid water reservoirs, called “subglacial lakes.” East Antarctica hosts nearly 379 subglacial lakes, which can be formed due to several different factors. Sometimes, the heavy mass of the ice sheet pressurizes the lower layers, lowering their freezing point and eventually turning them into liquid. Other times, geothermal heat spewing from the Earth’s fiery mantle rises and contacts the ice below, forming meltwater. Another factor could be salt. If somehow a segment of ice contains water rich in salts, the salt content can automatically cause the surrounding ice to melt into brine.

Scientists recruited a high-tech ice-penetrating radar to detect Lake Snow Eagle after some satellite images revealed large depressions on the surface. These radars work by sending waves down the icy borehole. The waves rush down to the bottom of the hole and return with a reflection. Liquids usually have brighter and stronger reflections than solid bedrock. So when they sent down the radar into the suspicious location, the radar’s reflection was more like a mirror, which indicated that there was a huge reservoir of liquid water somewhere below. Adding to the deformation on the surface, the clues led them to analyze the radar data further and deeper.

The data was analyzed by a research team. led by geophysicist Shuai Yan of the University of Texas at Austin. The team worked relentlessly to collect the radar’s data from the region, as well as measurements of Earth's magnetic field, over three years, from 2016 to 2019. "I literally jumped when I first saw that bright radar reflection," Yan described in the press release. The newly-discovered lake was about 30 miles long, 9 miles wide, and 650 feet deep. At the bottom of the lake was a bulky 1000-feet layer of sediment, accumulated over the years. This ancient sediment is a time capsule that holds the potential of taking scientists through a period when Antarctica had no ice at all, to when it slept into a deep freeze.