Newly discovered city-sized lake may hold key to Antarctica’s rise and fall

Faye Saulsbury
19th June, 2022

The discovery was made in Princess Elizabeth Land, the last unsurveyed sector of Antarctica. Professor Martin Siegert, Co-Director of the Grantham Institute, speaks to I,Science.

Lake Snow Eagle was discovered 3.2 kilometres under the East Antarctic Ice Sheet by an international team including researchers from Imperial College. The sub-glacial lake contains a thick layer of unconsolidated sediment, likely to be older than the ice sheet itself. These sediments could be key to finding out what Antarctic climate was like 34 million years ago, before it was covered in ice, which could in turn help predict the impacts of future Antarctic change on sea level.

Estimated to be 370 square kilometres in area – roughly the size of the Isle of Wight – the sub-glacial lake is one of the largest in Antarctica.

“Five years ago, there were no data at all – nothing – for Princess Elizabeth Land,” says Prof Martin Siegert, co-author of the study and Co-Director of the Grantham Institute at Imperial College London. “Now, using airborne geophysical techniques, we have a first complete survey of the bed of the Antarctic ice sheet… there’s no big area that has no data anymore.” This means Lake Snow Eagle is likely the last discovery of its kind.

Knowing Antarctica’s sub-glacial topography – the lay of the land underneath the ice – is critical to understanding the global-reaching effects of climate change. When he began his career 30 years ago, Prof Siegert says his purpose was to build a picture of the then-unexplored continent. Now, he says, “there’s another motive, and that is to understand what processes are going on in Antarctica.”

“If I was starting my career again now, it wouldn’t be about exploring unknown places. It would be about understanding how Antarctica is changing [as a result of climate change], and what that’s going to mean for sea level. You can only really understand the processes if you have a proper depiction of the sub-glacial topography across the continent, which we now do.”

Professor Martin Siegert, co-author of the study and Co-Director of the Grantham Institute at Imperial College London

Moving forward, scientists hope to sample the lake’s sediments in order to piece together the global implications of a shrinking ice sheet.

“As carbon dioxide levels [in the atmosphere] keep going up and up – as the Earth keeps getting warmer – we’re looking at major disruption from sea level rise. We’re looking at the Netherlands maybe only having 100 years left,” says Prof Siegert. “This is profound. Everyone needs to know about this.”

_______

Faye Saulsbury is the Co-Editor-in-Chief of I,Science, and is an MSc Science Communication Student at Imperial College London