Greenland Ice Sheet Speeds Slide into the Ocean
The Greenland Ice Sheet is accelerating in its slide into the ocean, like snow sliding off a roof on a sunny day. According to the University of Colorado Boulder, massive releases of meltwater from surface lakes are speeding up sea level rise. During summer, meltwater pools into lakes on the ice sheet’s surface. When the water pressure gets high enough, the ice fractures beneath the lake, and a huge burst of water plummets through to the bed of the ice sheet.
Researchers used satellite images along with new feature-recognition software to monitor nearly 1,000 lakes over a 10-year period. They discovered that as the climate warms, catastrophic drainages are increasing in frequency, being 3.5 times more likely to occur during the warmest years than the coldest. During such drainages, about a million cubic meters of meltwater funnels to the ice sheet’s underside within a couple of days. Once there, it lubricates the ice sheet’s glide into the ocean.