A team of glaciologists from NASA and the University of California, Irvine designed a novel ‘mass conservation algorithm’ that combined ice thickness measurements with data on the velocity and direction of its movement and estimates of snowfall and surface melt to reveal the hidden landforms. They found that Greenland’s coastal glaciers, which appeared to be quite shallow, are actually long, deep fingers that stretch more than 100 kilometres inland.
The canyons in which the glaciers sit are well below sea level, which means that as warmer marine currents migrate north, causing subtropical Atlantic waters to hit the fronts of the glaciers, they will erode much farther than had previously been assumed.
Earlier models had predicted that as the ice melt reached higher ground in a few years, ocean-induced melting would halt. ‘That turns out to be incorrect,’ said the study’s lead author, Mathieu Morlighem of UC Irvine. ‘The glaciers of Greenland are likely to retreat faster and farther inland than anticipated – and for much longer – according to this very different topography we’ve discovered beneath the ice. This has major implications, because the glacier melt will contribute much more to rising seas around the globe.’
This story was published in the July 2014 edition of Geographical Magazine