Studying the Effects of Climate Change on the Greenland Ice SheetThu, 28/05/2009 - 19:01 — Petzl America -...
Daniel McGrath is member of a team of researchers at the Univeristy of Colorado that has been studying the effects of climate change on the Greenland Ice Sheet. They spend weeks at at time on the rapidly shrinking frozen island, descending deep in the ice shelf through holes formed by meltwater known as moulins. Petzl has been supporting their valuable research by providing them with crampons, ice axes, screws, ascenders, helmets, etc.
Also be sure to check out the great article in Rolling Stone about their work.
I just returned from a 5-week field season living and working on the Greenland Ice Sheet, studying the ice sheet’s response to the warming climate. The Greenland Ice Sheet is enormous, nearly 2600 km long and 1500 km wide, holding the frozen equivalent of ~7 meters of global sea level rise. It was once thought that ice sheets respond to climate forces over time scales of hundreds to thousands of years, but the last decade has revealed that this is startlingly incorrect. Outlet glaciers are accelerating and the surface mass balance is increasingly negative, resulting in the loss of ~250 km3 of ice per year. This loss, when combined with recent glacier changes in Antarctica, Alaska, the Canadian Arctic and Patagonia, significantly contributes to sea level rise, which is projected to rise by 1 meter by the end of the 21st century.
Our research focuses on a variety of different facets of the Greenland Ice Sheet. Key to our understanding is the Greenland Climate Network Automatic Weather Stations. This network, originally established in the early 1990’s, has expanded to over 20 stations across the entire Greenland Ice Sheet, providing critical in situ climatological measurements. Secondly, a network of high-resolution GPS stations has provided tremendous insight into flow velocities along the western margin of the ice sheet. An interesting result of this research has been the interplay between increased meltwater production and the local acceleration of the ice sheet. The hypothesis, which has been observed on alpine glaciers, is that meltwater reaches the bed surface, where it slightly raises the ice and reduces frictional forces.
Understanding this relationship is key to understanding the ice sheets response to a warming climate. For this reason, our work during the melt season focuses on moulins, large vertical conduits that drain surface meltwater, lakes and rivers. Once the water leaves the surface, little is known about the englacial hydrologic system. Our group has employed ground penetrating radar and a series of laser-camera systems designed by NASA’s Jet Propulsion Laboratory to map the interior of these channels and voids. Last summer, we released an instrument package containing an accelerometer, pressure transducer and GPS with satellite transmission into the moulin. Unfortunately, the instrument failed to make it through the englacial system, but we will be heading back up to the ice this summer with new ideas gleamed from these experiences.