SUB-GLACIAL LIFE NOW

Lake waters lap at frozen ceilings as they have for about 15 million years in the desolate world that lies beneath. Recently, scientists have found new evidence of life buried deep in within and swimming below ice more than 2 miles thick.

Photo: Courtesy of Bibliotecas Pleyades

 

There are more than 380 sub-glacial freshwater lakes in Antarctica that are potentially homes to thousands of creatures and organisms that we have never seen before. The largest, Lake Vostok, is 160 miles long by 30 miles wide. It sits almost a quarter mile below sea level, has been under exploration for decades. Check out this video about the lake. Evidence of microbes was first found here, (reported in the Journal Science in 1999) in the accretion ice -- the ice formed when the surface of the lake water meets the surface of the overlying glacier.

 

Photo: Christian H. Fritsen, Desert Research Institute. Bacteria inhabiting Lake Vida

 

But now, with new abilities to detect, preserve, and decipher DNA and RNA, scientists have recently found evidence of more than 3,500 unique forms of life (reported in PLOS ONE 07.03.13). While some were found to be similar to those discovered in the ice core samples retrieved for a study in 2008-2009, many were new to view. One microbe, discovered last winter, was so far found to have only 86% of its genetic code in common with any other species recorded in global databases.

 

 

Photo: Courtesy of Fin Portraits

 

Named extremophiles, for their radical affinities for dark, icy environments, about 95% are thought to be bacteria and 5% eukaryotes (more complex organisms). Some of the organisms found are those that colonize the intestines of rainbow trout, lobsters and tubeworms, suggesting that these might be also living in the lake. Some bacteria are the ones that like to hang out in thermal vents. Other fragments of genetic strands found come from mollusks and water fleas.

Diagram: Shtarkman et al. / PLOS ONE

 

The graphic above shows the organisms found at two Lake Vostok sampling sites.

 

So far, the shallowest areas of Lake Vostok appear to have the highest density of organisms, although even here, the population is sparse.

 

Photo: Courtesy of NASA/JPL

 

Earlier this year, (January and February 2013), the Whillans Ice Stream Sub-glacial Access Research Drilling (WISSARD) team drilled about ½ mile into the glacier above Lake Whillans and collected water samples, sediment cores, and resident bacteria from the lake bottom. According to WISSARD, the project marked the “first successful retrieval of clean whole samples from an Antarctic sub-glacial lake”.

 

The image above shows a 20” wide ice borehole through which the Micro-Submersible Lake Exploration Device, NASA’s Jet Propulsion Labs tiny submarine, set out to capture new data.

 

Lake Whillans lies beneath glacial stream that moves about a meter per day vs a meter per year for the surrounding glacier. It is thought to be fed through a network of recently discovered sub-glacial river systems.

 

Some scientists suggest that life forms could have been transported into the lakes from these rivers and/or from the atmosphere before the lakes were sealed up by encroaching glaciers, sometime around 15 million years ago.

 

Photo: Courtesy of the National Oceanic and Atmospheric Administration

 

New life has also been found now, where glaciers have melted and washed away, including glass sponges (hexactinellid) with an estimated Methuselah lifespan of 10,000 years. The are part of the Antarctic seafloor life, known as benthos, that is now changing fast. Scientists have observed a tripled acceleration in the growth and reproduction of the sponges as more glaciers disappear. They’ve also noted an invasion of king crabs. As the sponges and crabs proliferate, they will battle each other. But they are just two species affected by the ice melt. The entire Antarctic ecosystem is changing around them.

 

The new research was detailed July 11 in the journal Current Biology.

Photo: Malclom McMillan/GRL

 

The excitement over newly discovered life is rivaled by our expanding understanding of ice in its formative and ongoing relationship with our planet. A new study, led by geophysicist Malcolm McMillan, at the University of Leeds (UK), shines new light on how Antarctic ice is responding to the environment and how massive sub-glacial floods have impacted land and sea. The most recent flood resulted in the Cook sub-glacial lake draining, unleashing 1.5 cubic miles of water, in torrential flow, over an 18-month period starting in 2007. One hundred square miles of glacier above sunk down in its wake. And since then, the crater has begun to refill with water.

 

"There's a lot of mystery surrounding the continent still that we don't understand," said Hugh Corr, told LiveScience's OurAmazingPlanet. Corr, a study co-author and glaciologist with the British Antarctic Survey explained, "This will be modeled in terms of the ice dynamics and the thermal impacts of this feature, and that will add to the general knowledge of the continent."

 

These and future explorations of the icy worlds of Antarctica are enabling scientists to create models which may offer insights into the geophysical and biological lives of Mars and other frozen planets and moons.

 

Check out the rest of our posts on "Beautiful Cool" this week in Arts/Design, Food/Drink, Mind/Body, Place/Time, Nature/Science, and Soul Impact. And enter our new photo competition. The theme: "Beautiful Cool" (Deadline, July 21st, 2013).