Scientists have found organic soil 10,000 feet beneath the ice sheet that stretches across 80 percent of Greenland. The discovery reveals that the central region of Greenland's tundra—once covered with forests—was locked away and preserved, as if in an icebox.
"The traditional knowledge about glaciers is that they are very powerful agents of erosion and can effectively strip a landscape clean," says Lee Corbett, a University of Vermont (UVM) graduate student who is a co-author of a study appearing in Science. "We demonstrate that the Greenland Ice Sheet is not acting as an agent of erosion; in fact, at its center, it has performed incredibly little erosion since its inception almost three million years ago."
"Rather than scraping and sculpting the landscape, the ice sheet has been frozen to the ground, like a giant freezer that's preserved an antique landscape," adds Paul Bierman, a UVM geologist, who is the lead author of the study.
Greenland is a place of great interest to scientists and policymakers studying global climate change, since its huge ice sheet can reveal how other ice sheets in Alaska and Antarctica will melt and grow in response to changes in global temperature. The magnitude and rate of sea level rise caused by the melting of ice remain uncertain factors in climate models.
The ice sheet covering Greenland's tundra has not disappeared during the span of time in which human beings emerged a species. "But if we keep on our current trajectory, the ice sheet will not survive," says Bierman. "And once you clear it off, it's really hard to put it back on."
Source: Paul Bierman, University of Vermont