Upcoming journey to ice-entombed lake will be no easy trek
The plan sounds like something from an adventure novel.
Just after Christmas this year, a team of scientists that includes NIU‚Äôs Ross Powell and Reed Scherer, with colleagues from nine other major universities, will begin a major research project in the Antarctic.
The operations team will use Giant Caterpillar tractors to pull sleds loaded with fuel, food, supplies, computers and a $3 million hot-water drill more than 600 miles across the Ross Ice Shelf, while braving potential crevasses and wind speeds as high as 100 mph along the way. Also in tow will be a suite of sophisticated oceanographic equipment ‚Äď custom-made to squeeze down a 1-foot-wide drill hole and take precise scientific measurements beneath the ice.
The team will set up camp and drill through a half mile of ice, penetrating Subglacial Lake Whillans. The ancient, ice-entombed lake likely holds never-before-seen organisms, along with other unknown secrets that could shed light on ice sheet dynamics.
‚ÄúOne of the big questions that hangs over humanity is what is going to happen in the near future as a result of global warming,‚ÄĚ says Powell, a professor in NIU‚Äôs¬†Department of Geology and Environmental Geosciences. ‚ÄúOur data is going to provide key information to help scientists predict what will happen.‚ÄĚ
The adventure begins in November, when the researchers will head to the Antarctic. But in a sense, the journey started last month at a fabled body of water in the United States: Lake Tahoe.
Tahoe tests help assess quake risks
Over the past few weeks, researchers and engineers involved in the Antarctic expedition have been testing their custom-made scientific instruments from a barge anchored in the nation‚Äôs second deepest lake.
Several coring devices and other instruments were tethered to an above water bank of computers, providing for real-time data, and lowered into the lake via a crane on the barge.
‚ÄúDespite some substantial winds that kicked up nearly every afternoon on the lake, the testing was very successful,‚ÄĚ Powell says. ‚ÄúWe now have a strong understanding about how the drill and science operations can be handled and integrated at our Antarctic field sites. We also learned how to tweak our instrumentation to collect reliable scientific data.‚ÄĚ
Additionally, the team gathered core samples from the lake bottom and other data to help regional scientists gain a better understanding of an ancient underwater landslide that caused a tsunami-like episode there. With traces of three major earthquake faults lying along the lake floor, California and Nevada researchers are seeking to assess future risks.
NIU and DOER Marine, a San Francisco Bay robotics engineering firm, hope to return to Tahoe again this fall to test a newly developed, 28-foot-long robotic submarine that could retrieve high quality fault-line images from the lake depths. The submarine, or sub-ice rover, will be used in future Antarctic expeditions to investigate melting near the base of the West Antarctic Ice Sheet.
Unlocking secrets beneath the ice
The equipment already tested at Lake Tahoe is being shipped to Antarctica in anticipation of the upcoming trek across the Ross Ice Shelf. The expedition is part of an even larger science program known as WISSARD, for Whillans Ice Stream Subglacial Access Research Drilling.
NIU joins the University of California at Santa Cruz (UCSC) and Montana State University (MSU) as lead institutions on the multi-year program. Funded by the National Science Foundation, the $10 million WISSARD program aims to shed new light on ice sheet stability and subglacial life in West Antarctica.
‚ÄúIt is important to study what is actually happening beneath the ice because sub-ice water and sediment control how fast the ice flows into the ocean,‚ÄĚ Powell adds. ‚ÄúWe‚Äôre really interested in that because the ice that is melting from the Antarctic ice sheet has the potential of raising sea levels. That‚Äôs a huge concern to all of us.‚ÄĚ
Powell is among three chief scientists on the WISSARD program, along with UCSC‚Äôs Slawek Tulaczyk, an NIU alumnus, and MSU‚Äôs John Priscu, who will lead the initial field season. Its focus is the investigation of Subglacial Lake Whillans, which is of keen interest to NIU‚Äôs Scherer, who is among a dozen collaborating investigators on WISSARD.
‚ÄúA vast network of channels and ponded water underneath the ice sheet feeds out into the ocean, and in this network are communities of organisms that have never been studied before,‚ÄĚ says Scherer, who directs NIU‚Äôs Institute for the Study of the Environment, Sustainability and Energy (ESE Institute).
‚ÄúBefore going down the borehole, each instrument must be intensively cleaned to make sure that every microbe has been removed,‚ÄĚ he adds. ‚ÄúThese procedures ensure that we have not introduced any foreign organism to the pristine environment, and prevent contamination of the samples used for study.‚ÄĚ
Not long ago, most scientists believed it would take tens of thousands of years to melt polar ice sheets.
This view changed in the 1990s, partly because of research by Scherer, who was a key member of a team that confirmed the West Antarctic Ice Sheet has been unstable in the past and even collapsed, raising sea levels by as much as 18 feet.
‚ÄúThe stability of the West Antarctic Ice Sheet has been discussed for 30 years,‚ÄĚ Scherer says. ‚ÄúWe‚Äôre only now really getting to the point where scientists can measure what‚Äôs going on underneath the ice and assess the likelihood of retreat of the West Antarctic Ice Sheet during the relatively near future.‚ÄĚ
In addition to Powell and Scherer, others from NIU who will be participating in the Antarctic research include Ph.D. student Timothy Hodson in geology and computer science research associate John Winans. Powell also hopes to take along an undergraduate student in geology.