Tuesday, July 21, 2009

New research provides insight into ice sheet behavior

British Antarctic Survey: A new study published this week takes scientists a step further in their quest to understand how Antarctica’s vast glaciers will contribute to future sea-level rise. Reporting in the journal Nature Geoscience, scientists from British Antarctic Survey (BAS) and University of Durham describe how a new 3-D map created from radar measurements reveals features in the landscape beneath a vast river of ice, ten times wider than the Rhine*, in the West Antarctic Ice Sheet (WAIS).

During 2007, two researchers spent months living and working on the Rutford Ice Stream in temperatures that dropped as low as −30°C. The ice stream moves towards Antarctica’s coast by one metre every day. The science team towed radar equipment back and forth across the ice measuring its thickness, and building up a picture of the landscape beneath. A lubricating mixture of sediment and water beneath the ice assists as it flows towards the ocean, and is sculpted into a series of massive ridges the size of tower blocks and separated by deep furrows. These features ultimately control the flow of the ice stream.

Lead author British Antarctic Survey glaciologist Edward King says, “It was really exciting to see this beautiful image of the landscape two kilometres below our feet emerge from the data. We are now sure that these amazing sediment formations are created by fast-flowing ice and we are much better placed to understand how ice streams behave and how they might change in the future.”…

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