Life Hidden Half-Mile Beneath Antarctic Ice
Antarctica may be the coldest place on Earth, but that doesn't mean life won't find a way to survive. Researchers recently found a rich microbial ecosystem living underneath Antarctica's thick ice sheet, where no sunlight has been felt for millions of years.
Nearly 4,000 species of microbes inhabit Lake Whillans, which lies beneath 2,625 feet (800 meters) of ice in West Antarctica, researchers reported in the journal Nature.
"We were able to prove unequivocally to the world that Antarctica is not a dead continent," John Priscu of Montana State University, who led the US project called WISSARD in sampling the sub-ice environment, said in a statement.
"It's the first definitive evidence that there's not only life, but active ecosystems underneath the Antarctic ice sheet," added lead author Brent Christner, "something that we have been guessing about for decades."
There are more than 200 known lakes beneath the Antarctic Ice Sheet. Some of them - like Lake Whillans - are connected by rivers and streams, while others are deep, isolated basins. The new Lake Whillans discovery gives scientists hope that these other waterways also house hidden life.
Researchers drilled through Lake Whillans in January 2013 after years of planning and more than $10 million spent by the National Science Foundation. The team, called WISSARD (Whillans Ice Stream Subglacial Access Research Drilling), used a custom hot water drill to bore a whole into the ice sheet and take water samples.
The results show evidence for 3,931 species of single-celled life in Lake Whillans.
"We were surprised about the number of organisms," Christner told Live Science. "It's really not that different than the number of organisms in a lake on the surface."
These single-celled organisms are called Archaea - one of the three domains of life, the others being Bacteria and Eukaryotes - and convert ammonium and methane into the energy required for growth. Unlike organisms exposed to sunlight, they have to use minerals in the water and lake muck for the energy needed to "fix" carbon dioxide.
"These are opportunists that are using every available energy source," Christner added.
The team now plans to track down the origin of Lake Whillans, whether it is from ice, rivers, or was trapped in place in the old ocean sediments.
Also, the findings of Lake Whillans may provide a unique glimpse into how life may survive on other planets, such as within Mars' ice cap.