ROSS EDWARDS (Curtis University/University of Wisconsin)
Despite appearances, the relentless flow of the Greenland ice sheet is not uniform across its surface nor inside. It contains ice currents that flow at a much faster speed than the surrounding ice. Ultimately, we know these ice currents increase the stream’s flow of ice into the ocean and account for half of the ice mass loss of the Greenland ice sheet each year.
Understanding the processes that drive ice currents is crucial to comprehend the stability of the ice sheet in the near future and its contribution to rising sea levels.
Scientific research carried out on the 2017 Greenland WindSled crossing has included collecting samples from the top of that surface layer of the Northeast Greenland Ice Stream (NEGIS), around the EastGRIP ice core drill site (www.eastgrip.org).
This ice current begins in the central divide of Greenland ice and plunges eastward before dividing into three large streams in the area closest to the coast. The NEGIS ‘trigger’ is believed to be the strong melting that takes place at the bottom of the ice sheet, resulting in ice speeds of more than 100 meters (328 ft) per year and about 500 kilometers (311 mi) away from the coast.
Research during the expedition included drilling holes and collecting surface samples. As a scientist involved in the WindSled team, Ross Edwards collected many samples of surface snow and firn from about two meters (6 or 7 ft) in depth at the beginning of NEGIS and right up to the EastGRIP ice perforation site.
These samples will be used to study the surface processes, work developed with collaborators from the University of Copenhagen (such as associate professor Paul Vallelonga and Dr. Hans Christian Steen-Larsen) and the Geological Survey of Denmark and Greenland (with professor Jason Box).
Ross’s participation in the WindSled expedition was funded in part by crowdfunding organized through the Dark Snow Project (darksnow.org), which also contributed to other costs associated with the expedition. The expedition was also supported by EastGRIP.
