USA: Massive releases of melt-water from surface lakes may be causing Greenland to slide ever faster into the ocean, according to a new study by the University of Colorado Boulder-based Cooperative Institute for Research in Environmental Sciences (CIRES).
Using satellite images and new software used to recognise features in the ice, the CIRES team monitored almost 1,000 lakes on an ice sheet the size of Connecticut. For more than 10 years the team studied these lake and discovered “catastrophic” lake drainages as the weather becomes warmer. In fact, the drainages were 3.5 percent more likely to occur in the warmest months than when it was at its coldest.
The new software is capable of spotting supraglacial lakes in satellite images, determining their size and where they appear. “Previously, much of this had to be double-checked manually,” said William Colgan, who co-led the new study with Yu-Li Liang, a CU-Boulder computer science doctoral student. “Now we feed the images into the code, and the programme can recognise whether a feature is a lake or not, with high confidence and no manual intervention.”
The study, which was funded by the Arctic Sciences Program of the National Science Foundation is being published online Monday, April 16 in the journal Remote Sensing of the Environment.