Later this month, after scientists wrap up their field work and a skeleton crew prepares for a Greenland winter, a small staff of Polar Field Services workers will test a caravan of tractors and sleds as part of the Greenland Inland Traverse (GrIT). The traverse follows a route established in 2008 from Thule Air Base to Summit Station.
The crew will base from Thule and will make instrumental changes to sleds designed to be towed over the ice by large tractors in order to improve mobility and efficiency. A successful traverse was completed in 2008, but it was hampered by slow forward movement and unanticipated delays due to equipment sinking into the snow, said Jay Burnside, PFS construction manager.
“We think the problem lies in the thermal properties of the snow-sled interface,” said Burnside. “There is too much surface area, which prevents the formation of a thin layer of water between the sleds and the ice, which makes transportation easier. The strength of the snow in Greenland prevents us from developing enough heat to create that slippery layer. The snow is weaker in Greenland (compared to Antarctica, where there have been successful overland traverses), so you get more contact area, less ground pressure and no heat.”
At least that’s the theory. Burnside and his team will spend several weeks studying the temperature phenomenon and making other changes to the sleds to improve mobility. Specifically they will insulate the fuel bladders in the sleds to avoid “3,000, 000 gallons of cold fuel sucking up the heat.”
The team plans to launch a second traverse in summer 2010 (pending National Science Foundation funding) to deliver a Case tractor to Summit Station. Successfully establishing an overland traverse would create transportation alternatives for supply delivery to research stations in Greenland. Currently, all supplies, including fuel, materials, food, and personnel, arrive via airplanes; instituting a traverse could significantly reduce emissions, prove to be more cost-effective, and open up remote areas for more research.