Konrad Steffen: Greenland ice sheet and dynamic response to global warming

The ice loss in Greenland shows acceleration during the last
decade. WSL director Konrad Steffen explains how scientists gained
new insight using ground penetrating radar and a video system
during the melt peak in August 2007-2010. Water penetrates to great
depth through moulins and cracks, lubricating the bottom of the ice
sheet.