Using radar data from NASA’s Operation IceBridge and other airborne campaigns, scientists led by a team from the University of Bristol found the canyon runs from near the center of the island northward to the fjord of the Petermann Glacier.
A large portion of the data was collected by IceBridge from 2009 through 2012. One of the mission’s scientific instruments, the Multichannel Coherent Radar Depth Sounder, operated by the Center for the Remote Sensing of Ice Sheets at the University of Kansas, can see through vast layers of ice to measure its thickness and the shape of bedrock below.
Starting with a view of the surface of Greenland, the animation (top) zooms closer to the surface as the ice sheet is stripped away to reveal the false-colour topography of the bedrock that lies beneath. Regions above sea level are shown in shades of green while areas below zero are coloured by shades of brown. Yellow indicates the area near sea level. The topography is exaggerated from 12 to 40 times in order to accentuate the topographic relief. Visible in the topography from about the midpoint of Greenland to its Northwest coast is the 750-km-long subglacial canyon described by the authors.