According to a new study the glaciers and ice caps on the Greenland coast are not likely to recover due to melting also some shall be permanently lost by 2100.
Researchers at Ohio State University in the US found that the melting of Greenlands coastal ice will raise global sea level by about 1.5 inches by 2100.The deep snow layer that normally captures coastal melt-water was filled to capacity in 1997.That layer of snow and melt-water has since frozen solid, so that all new melt-water flows over it and out to sea.
Were all of Greenlands coastal ice to melt away at once, global sea level would rise a few inches. For comparison, were the whole Greenland Ice Sheet to melt away at once, global sea level would rise 24 feet.The problem lies between fresh surface snow and the ice, in a layer of older snow called the firn.
Normally, melt-water drains through gaps in the firn down to the ice surface, where the bottom layer re-freezes.When the firn around Greenlands edges became fully saturated 20 years ago, it froze through from bottom to top.Since then, there have not been any gaps to capture melt-water, and the ice has not been able to grow.
At the time, researchers could not have known, because they lacked three things: a high-resolution topographic model of the glaciers, a detailed map of glacier boundaries, and a high resolution numerical model of drainage processes.Howat provided the first two with his Greenland Ice Mapping Project Digital Elevation Model, which offers 30-metre resolution over the entire Greenland surface.
The researchers have found that, for the last 20 years, mass loss has been exactly equal to the amount of melt-water runoff lost to sea. Simulations showed that a frozen firn was the most likely cause.The Greenland Ice Sheet is subject to the same danger, but to a much lesser degree than the isolated bits of ice on its edges.