Scientists on December 2, 2019, said that they had used a drone to observe the rapid fracturing and draining of a lake on the ice sheets in Greenland. It is a phenomenon that may become more frequent as a result of climate change. Typically, the ice sheet is about a kilometer thick (1090 yards). However, it is normal for some of the surfaces to melt and form thousands of lakes, during the summer.
Many a time the lakes create vast openings at the base of the ice, up to a kilometer deep by draining just in a few hours. For the rest of the melt season, the meltwater from surface streams continues to flow down, creating some of the world’s largest waterfalls.
Even though the process was difficult to observe, a group of glaciologists from the Scott Polar Institute at the University of Cambridge managed to arrive at the Store Glacier in northwest Greenland in July 2018. Over the course of five hours, a few days later, two-thirds of the lakes or roughly 5 million liters of water disappeared from the surface through a fracture.
The picture captured by a drone from before and after showed a dark blue oval shrink into a smaller, shallower and lighter blue circle.
Co-author of the study, Tom Chudley, appeared in the Proceedings of the National Academy of Sciences. He told AFP that the “thing that drones can do is allow us to take these kinds of high-quality measurements in regions that aren’t safe to access for scientists on the ground”.The team was able to geo-locate and stitch together thousands of photos by making use of on-board GPS. The photos were, in turn, used to create detailed 3D reconstructions of the ice sheet’s surface.
Rising Sea Levels
A glacier is a river of ice that moves slowly under its own weight toward the ocean. After it reaches the sea, it breaks off into icebergs, which represent about 40 percent of Greenland’s contribution to rising sea levels. The Store Glacier advances at a rate of 600 meters per year (660 yards).
Later, it was found by scientists from Aberystwyth and Lancaster Universities that the sudden drainage of the lake temporarily increased its speed from two to five meters per day.
“That’s a kilometer of ice lifted up half a meter, so you can imagine the kind of pressures that were involved,” said Chudley, a doctoral student at Cambridge.
“As we see climate change progressing in Greenland, we’re seeing more lakes, and we’re seeing them get larger, and we’re seeing them higher up into the colder section of the ice sheet, and we can see that some of these lakes are beginning to drain,” said Chudley.
“Potentially we’re increasing the number of lakes that are draining in new places that we haven’t previously identified,” he warned.