Water from an Antarctica Lake
In an amazing feat of science and engineering, a National Science Foundation (NSF)-funded research team has successfully drilled through 2,600 feet of Antarctic ice to reach a subglacial lake and retrieve water and sediment samples that have been isolated from direct contact with the outside world for many thousands of years. Scientists and drillers with the interdisciplinary Whillans Ice Stream Subglacial Access Research Drilling project (WISSARD) announced January 28th that they had used a customized clean hot-water drill to directly obtain samples from the waters and sediments of subglacial Lake Whillans. Upon study this may reveal an unique perspective on life and how it evolves.
Whillans Ice Stream is one of about a half-dozen large, fast-moving rivers of ice pouring from the West Antarctic Ice Sheet into the Ross Ice Shelf. The ice stream is the subject of different glaciological studies, one of which is looking at subglacial lakes that researchers believe may be speeding the movement of the ice as they periodically fill and drain.
In total around 250-300 subglacial lakes are currently known in Antarctica. There are currently three projects to directly sample subglacial lakes in Antarctica. These are the British led Subglacial Lake Ellsworth project, the U.S. led Whillans Ice Stream Subglacial Access (WISSARD) and the Russian led Lake Vostok program.
This water exists because geothermal heat flow from below, coupled with pressure, movement, and the insulating nature of the ice sheet above, is great enough to maintain some areas at the base of the ice sheet above the freezing point, even in the extreme cold of Antarctica. In topographic depressions there are hundreds of lakes, both large and small; some are isolated, but many are interconnected by water channels and large areas of saturated sediments, the water eventually running out into the Southern Ocean as the ice sheet becomes a floating ice shelf.
The samples may contain microscopic life that has evolved uniquely to survive in conditions of extreme cold and lack of light and nutrients. Studying the samples may help scientists understand not only how life can survive in other extreme ecosystems on Earth, but also on other icy worlds in our solar system.
The WISSARD teams' accomplishment, the researchers said, "hails a new era in polar science, opening a window for future interdisciplinary science in one of Earth's last unexplored frontiers."
WISSARD targeted a smaller lake (1.2 square miles in area), where several lakes appear linked to each other and may drain to the ocean, as the first project to obtain clean, intact samples of water and sediments from a subglacial lake.
The achievement is the culmination of more than a decade of international and national planning and 3 1/2 years of project preparation by the WISSARD consortium of U.S. universities and two international contributors.
The WISSARD team will now process the water and sediment samples they have collected in hopes of answering seminal questions related to the structure and function of subglacial microbial life, climate history and contemporary ice-sheet dynamics. This information may also foretell how life may exist on other worlds where similar under ice water bodies may exist.
Video surveys of the lake floor and measurements of selected physical and chemical properties of the waters and sediments will allow the team to further characterize the lake and its environs.
A team of engineers and technicians directed by Frank Rack, of the University of Nebraska-Lincoln, designed, developed and fabricated the specialized hot-water drill that was fitted with a filtration and germicidal UV system to prevent contamination of the subglacial environment and to recover clean samples for microbial analyses. In addition, the numerous customized scientific samplers and instruments used for this project were also carefully cleaned before being lowered into the borehole through the ice and into the lake. The key is to collect a good sample without contamination and without contaminating the sub glacial lake.
Following their successful retrieval, the samples are now being carefully prepared for their shipment off the ice and back to laboratories for numerous chemical and biological analyses over the coming weeks and months.
For further information see Whillans.
Sub Glacial Lake image via Wikipedia.