At its peak, one meltwater lake drained the equivalent of an Olympic-size swimming pool every three seconds. From a report: A cerulean lake consisting of glacial meltwater on the surface of the Greenland ice sheet, located about 18 miles from where the Store Glacier meets the sea in west Greenland, briefly became one of the world’s tallest waterfalls during the course of five hours in July 2018. The waterfall, like many others on the ice sheet’s surface, was triggered by cracks in the ice sheet. In the case of this one meltwater lake that scientists closely observed in July 2018, the water cascaded more than 3,200 feet to the underbelly of the glacier, where the ice meets bedrock. There, the water can help lubricate the base of the ice sheet, helping the ice move faster toward the sea.
The observations of scientists, armed with aerial drones and other high-tech equipment, of the partial lake drainage that resulted could help researchers better understand how surface melting of the ice sheet could affect its melt rate, and improve global sea level rise projections. Scientists are keenly interested in how meltwater on the surface of the Greenland ice sheet — the largest contributor to global sea level rise — acts to speed up the movement of ice toward the sea by lubricating the underside of the ice surface. The new study, published Monday in Proceedings of the National Academy of Sciences, suggests that scientists are underestimating the number of melt ponds that partially, and rapidly, drain into the ice sheet each year. This means tweaks may be needed to the computer models used to predict sea level rise from Greenland.
of this story at Slashdot.
Source:: Slashdot