Antarctica Is Home to the World’s Largest Wetland

Antarctica’s vast ice sheet bottom is wet, forming Earth’s largest wetland, possibly hosting microbial life within the glaciers. Credit: Image by British Antarctic Survey

While to most observers, Antarctica is a barren wasteland, there are many who see it as something completely different. There’s a rich network of rivers and enormous lakes, which happen to be covered by ice.

Thanks to radar imagery, John Priscu managed to see through the ice. The ice is several thousand meters thick at some points, and sandwiched in between the ice and rock, there are river systems that rival the Amazon in spatial extent feed lakes, and possibly fuel an entire hidden biosphere.

Scientists examine the iron-tinged ice at Blood Falls, Antarctica. Credit: John Priscu

Priscu presented at the Center for Dark Energy Biosphere Investigation, sites where he highlighted a few subglacial lakes, where exotic chemical mixtures and unique physical phenomenons converge to create bizarre environments.

At the bottom of the Taylor Glacier, there is an icefall several stories tall and streaked with orange and red bands, known as Blood Falls. Over time, subglacial water lost its oxygen and got saltier, creating a viscous liquid brine. Water emerging from the base of the glacier contains Fe²⁺ due to anaerobic microbes. When the solution emerges, it’s quickly oxidized, which is why the icefall is red with rust.

Satellite imagery has provided evidence of an active hydrologic cycle. At Adventurer Trench, the ice has moved up and down as subglacial lakes fill up and drain. The changes are as much as nine meters in two years and the flat surface indicates that there is a subglacial lake far below.

The whole bottom of the Antarctic ice sheet is wet, and it’s Earth’s largest wetland. There could even be microbial life throughout the glaciers themselves.