A three-million-year-old landscape has been discovered, hiding 10,000 feet under the Greenland ice sheet. The ice sheet, covering 80 percent of the country, has been in place since before the first true humans walked the face of the Earth. 

Paul Bierman, a geologist at the University of Vermont, led a study of ancient soil, entombed in ice. Greenland's tundra areas are nearly perfectly preserved in the frozen landscape. 

Ice usually acts as an erosive agent, radically changing areas undergoing a deep freeze. In this instance, ice froze soil, keeping it in nearly the same shape as it was long ago. 

Researchers studied an ice core measuring 10,000 feet long to identify climatic conditions millions of years in the past. Of special interest to the team was the bottom 42 feet of the sample. It was around three million years ago when ice began to cover most of Greenland. Bierman and his team examined concentrations of carbon, nitrogen and beryllium-10, which provided the firmest evidence the area was once alive with life. 

Bierman and his team concluded the area around Summit, Greenland was once home to vast swaths of forests. Fossils found in northern areas of the country suggest Greenland was much warmer and greener than it is today. 

"The preservation of this soil implies that the ice has been non-erosive and frozen to the bed for much of that time, that there was no substantial exposure of central Greenland once the ice sheet became fully established, and that preglacial landscapes can remain preserved for long periods under continental ice sheets," researchers wrote in the article announcing their results. 

Greenland is a popular testing ground for researchers studying global climate change. The tremendous ice sheets there provide data on how similar features in Alaska and elsewhere may react to rising global temperatures. The extent of rising sea levels caused by melting glaciers is one of the biggest unknowns in models predicting the effects of climate change. Vast quantities of the world's water are caught in the ice sheets of Greenland and Antarctica. Melting glaciers and sheets of ice in Greenland could have a significant impact on rising sea levels. 

"[I]f we keep on our current trajectory, the ice sheet will not survive. And once you clear it off, it's really hard to put it back on," Bierman told the press. 
Discovery of the frozen landscape was funded by the National Science Foundation. 

Analysis of the frozen tundra regions of Greenland was detailed in the journal Science.